- 1 Ted’s Tips and Topics - Bike Maintenance
- 1.1 Bike Maintenance
- 1.2 The Puncture Saga
- 1.3 Tubeless Tyres
- 1.4 The Wheel Saga
- 1.4.1 Wheels – What Can Possibly Go Wrong ? – 1 Rims & Spokes
- 1.4.2 Wheels – What Can Possibly Go Wrong ? – 2 Spokes Again
- 1.4.3 Wheels – What Can Possibly Go Wrong ? – 3 Spokes Yet Again
- 1.4.4 Wheels – What Can Possibly Go Wrong ? - 4 Spokes Yet Again
- 1.4.5 Wheels – What Can Possibly Go Wrong ? – 5 Wheels Going Out-of-True
- 1.5 Check Your Rims
- 1.6 Brake Pads
- 1.7 Setting Fire To Your Bike !
- 1.8 Loss of Drive
- 1.9 The Chain Saga
- 1.10 Useful Links
Ted’s Tips and Topics - Bike Maintenance
As a basic guide, your bike should be serviced at least twice a year. If you're a keen rider, you'll know that your bike might need servicing more frequently than that - chains and tyres can wear out in 2000 miles and that's only 3 months for someone who's covering 8000 miles a year. But even if your bike slumbers most of the time, cables can seize up in 6 months if your bike lives in an unheated out-house, and frames can crack, so it's best never to assume your bike is fine - check it before you use it - it's your safety and comfort.
The next choice is where to get your bike serviced. If you have the knowledge, experience and the necessary specialist tools, you can do it yourself. To help you assess the level of your knowledge, I've put a basic 'cascade' together below. But be warned, although the basic mechanics of a bike are quite simple, setting-up modern gear systems is not always straightforward. Also I've found out yet again recently, that a hub has to be set with precision if its life is to be long and smooth, and you cannot assume that a new hub, from Shimano or anybody else, is set properly in the factory. If you are in doubt as to your knowledge and skills to carry out the work, then you are probably best to seek out a good bike mechanic to carry out the work for you. The best will use a Quality Assurance system to ensure the work is done properly and records for you exactly what has been done, and checked.
It helps to think about where you are in the cascade of knowledge, and where you want to be. Ideally regular cyclists need to be at level 3...
Level 1 (reactive): Can I fix common failures on the road (punctures, cable breakage, chain jams & breaks, fix loose items)?
Level 2 (proactive): Can I carry out a basic safety check of my bike ?
Level 3 (proactive): Can I recognise when my bike needs a service ?
Level 4 (proactive): Can I carry out a full service schedule for my bike including knowing basic wear limits for components ?
Level 5 (proactive): Can I take apart and repair specific items on my bike (hubs, bearings, gears, wheels etc) ?
Level 6 (proactive): Can I build a bike up from its component parts, run it, and maintain it ?
The Puncture Saga
Part 1 - Myth Busting
Let’s first bust open a few myths about punctures:
1) True ? - We can all mend punctures ? People often find punctures quite difficult to repair. Few of us have ever been taught how, or just don’t do it often enough to have learned from all the pitfalls. For most, it’s inconvenient discovery-learning ‘in the raw’.
2) True ? – Repaired tubes are weaker than new ones and more likely to fail on the road. Actually, in my experience, it’s wrong. A properly-carried-out (and that’s key) repair is a permanent solution. It means that I don’t have to dump tubes just because they have a couple of patches on them – usually I dump then when the valve blows out – a quite common occurrence these days with valves moulded into the tube. A lifted patch is simply telling you that you’ve done the repair wrong.
3) True ? – You can’t use a tyre lever to put the tyre back on. Actually it’s wrong, too. I’ve used levers many times to put back tyres, and for a very few tight rim/tyre combinations (not many) it’s the only way you’ll get the tyre back on. In any case, a VAR tyre lever is designed specifically to do this. The key to success is exactly how you use the lever and I’ve seen many new tubes ruined by incorrect use of tyre levers.
4) There is a myth that, for some reason, punctures rarely come singly. This one seems to be true. My tally for one grim 6 week period was no fewer than 13 (genuine & varied) punctures.
5) There is another myth that tyres deflate quicker when your bike is not used (as noted in Highwayman March 2017, p32). In Ireland and Norway it’s entirely due to the ‘Little People’ and the ‘Trolls’ who sneak in to the workshop and/or garage at night for a psssss. I’ve no explanation for us in UK unless to do with Brexit. But, there certainly seems some truth in this observed phenomenon.
Honestly, who would have thought punctures could be so interesting / involved / technical ? Here goes again….
Last time we looked at “Punctures – Myth-Busting”.. So before I start, here’s an alternative version of last time’s para 5 – the one which should have appeared is….. 5) There is another myth that tyres deflate quicker when your bike is not used (as noted in Highwayman March 2017, p32). In Ireland and Norway it’s entirely due to the ‘Little People’ and the ‘Trolls’ who sneak in to the workshop and/or garage at night to take the hsssss. In UK of course, it’s entirely the Government’s fault – anything unexplained is. It’s called ‘Air Tax’.
Part 2 – Causes
Repairing a puncture is not a race (but 3 minutes is pretty good…..ha, ha). Your aim is to get yourself reliably back on the road, not to brag how quickly you did it – if you really do want fast then use a can of sealer and replace your inner tube when you get home. No, t’s about carrying out a reliable repair, first time, as quickly as you can. As with anything which fails, a reliable repair depends entirely on understanding why something has failed, so, why did your tyre go down ? (and the answer is not because the tube has at least two holes iit !!) Read on …. Here’s a list of reasons for punctures but you can probably think of a few more:
1) Valve problems - The tube peals away from the base of the valve or it blows out altogether. Sometimes this can be hard to see. There is no reasonable solution to this problem (although old-fashioned Woods valves often screwed into the tube, so if you have a screw-in valve you might be able to get yourself going again). Normally, you’ll need a new tube to repair this puncture. Sometimes, too, the little thumbscrew on a Presta valve can come off. If it does, there’s no solution to this either. There’s no need to inspect your outer tyre minutely
2) Poorly-aligned Brake Pads – You’re in deep with this one. What happens is that the brake pad catches the tyre-wall when the brake is applied and wears a hole in it, and the inner tube comes out to say ‘hello’ – and usually ‘goodbye’. You don’t need to search for foreign objects, but you’ll need some heavier weight material to repair both your outer tyre and inner tube if you need to use them to get home. This is a classic of poor maintenance, and very hazardous, too.
3) Failed Outer Tyre – Tyres can fail in a number of different ways, too, and although not commonplace, tyres can fail at the base of the side-wall above the tyre bead. As with poorly-aligned brake pads, what you see is a rip in the tyre just above and parallel to the rim. It’s here that the inner tube pokes out with a ‘pop’. Temporary get-you-home repair is often possible, but you need the right stuff in your toolkit. Most other forms of puncture, listed below, can usually be repaired on the road.
4) Glass – in my experience glass seldom stays in an outer tyre, although it can. Check the outer tyre carefully, though, and if using a finger just be careful, as a shard of glass can puncture you ! Ouch !
5) Nail or wire - Both often stay in the outer tyre and are easy to spot and remove, but you’ll usually need pliers.
6) Thorn - Blackthorn in Devon is a real hazard but stuff as soft as brambles can puncture tyres. If you have found the tiny circular hole that Blackthorn makes in your tube, you need to check your outer tyre very, very carefully. What happens is that the thorn goes in, makes the puncture incision, and then partially seals the hole it’s made. The tyre doesn’t deflate much at the time of the puncture and then with the rotation of the wheel the thorn goes further into the tyre and wears down to be at or even below the tyre surface making it, at times, very difficult to see. But find it and remove it, you must. Often the first you know is that you find a tyre flat when you want to use the bike in the morning. A lifted patch often has a similar symptom.
7) Flint - These can be horrors, too. Sharp small flints can actually work their way down under the rubber tread between the rubber and the canvas. There they can cause unbridled misery over weeks. Like thorns, they must be found and removed so you must check your tyre very carefully. Sometimes the only way to find them is in the workshop with the tyre as inside-out as it’s possible to get it. If you just put in a new tube you might get a mile down the road before you have to up-end the bike again, in puzzlement. And this can happen multiple times.
8) ‘Snake-bite’ - This is a classic two-hole puncture which means that you’ve grounded the rim on the road either from a very heavy impact such as crashing down a pot-hole, or because your tyre is under-inflated. The under-inflation can be caused simply by lack of maintenance. It can also be caused by a slow puncture such as a thorn, and if this happens, be aware that you’re actually looking for 3 punctures, and you won’t be the first, or last, to think you’ve mended your puncture only to find that there’s more, and you’ve to up-end the bike yet again !! If it’s due to a heavy impact, just check the bead of the rim and tyre for damage, and braking efficiency, but forget looking for objects in your tyre. You can also get ‘snake-bite’ punctures by inappropriate use of tyre-levers. Yes, I’ve seen grown people reduced to almost bald, pulling out hair after a new tube has deflated, one, two, three times.
9) Lifted patch - Most of us have had these but it’s telling you something. If this is your problem there’s not much point in inspecting your tyre closely. They are often caused by the French chalk used in manufacture to prevent the insides of the tube sticking together. What happens is that the chalk puffs through the puncture incision when you’re doing the repair, and prevents the patch from adhering. You usually won’t see this happening, which is why I stretch tubes to be repaired over a wooden block or similar, before cleaning them in readiness for the repair. That way they can’t move.
10) Spokes – Sometimes these caused punctures in the past, but with most deep-section rims it’s not usually a problem now.
11) Abrasion – I’ve seen tubes punctured by differential movement between tube and outer tyre. This can happen when a separate puncture strip is used inside an outer tyre, but this practise is now no longer common. Also, if a tube has been incorrectly installed with part of the tube caught under the tyre bead, this can puncture the tube, too.
Part 3 – Repairing the Puncture
When smugly I wrote the myth-busting section (part 1) of this saga, I didn’t reckon on life getting its own back on me. Barely 24 hours later I got a ‘lifted patch’ puncture on the road, nor could I seal it, and the final insult was that the tyre was tight on the rim and in using a tyre-lever, as you’ve guessed by now, I punctured the new tube! So much for celestial humour, but you’d better take my advice only for what it’s worth!
Then, one member (name and address supplied) suggested that the solution to most punctures is not to have an inner tube at all. Now this might be lateral thinking, or just another saga of different problems, but it is true that racers use tubular tyres, and many mountain bikes now have tubeless tyres fitted. I don’t have experience of either, so…. Let’s assume that you’ve ‘punctured’ and that you’ve found the cause and removed any offending foreign body (no pun intended), having read last month’s part 2.
If your outer tyre is ripped, you can use ‘Duct Tape’ for an emergency get-you-home repair, and it might just avoid the need for that Brownie-point-consuming phone call to the husband, boyfriend, wife, girlfriend, partner….Just don’t use more pressure than you need in the repaired tyre and ride very carefully. I’ve tested this method and it does work provided you use at least 3 layers of Duct Tape crossing the casing one way, then the other, then at 45 degrees, lapping for good measure under the wire beading. I rode in excess of 200 miles like this as a test. It was a bit wobbly, though ! Make sure the cause of the rip, often misaligned brake shoes, is corrected before you set off again. If you know where the puncture is, you may not need to remove the wheel from the frame – this can help sometimes for solos, but specifically for the rear wheels of tandems or recumbents. Just lever off part of the tyre bead and pull out the deflated inner tube to repair it. However, if you replace the tube complete, then you do need to remove the wheel (only slight exception might be a mono-blade forks).
So, to repair the tube on the road, try and stretch the punctured area a little if you can over a frame-tube, seat, anything to immobilise the tube and provide a firm base to use the sandpaper or emery cloth to clean the area. It also allows you to place the puncture hole at the centre of the working area so that you then have the best chance of applying the patch to the right place (yes, I have!). In making patches stick, cleanliness, and dryness, is everything. It is quite important to immobilise the tube because some tubes have a lot of fine chalk inside them, and if this puffs through the puncture hole it will prevent the patch from adhering properly, and probably later cause the patch to lift. Select a patch of the right size – small postage size is usually big enough for most small punctures and remove the backing. Apply the rubber solution (just enough to dampen the area when spread) to the tube and work it out into an area greater than the patch will cover (I use a clean finger to work it into the punctured area). I apply solution to the patch, too. Wait until both are tacky dry – and that’s only a minute or so in warm weather, but much longer in the winter. Then carefully apply the patch to the tube over the area you’ve treated with solution, and press firmly from the centre outwards. Apply a little air to the tube to make sure you’ve sealed the hole – not too much as it’s not a good idea to blow off the new patch! Now you’re good to replace the tube and tyre. This set of instruction comes courtesy of Schwalbe’s excellent “Technical Info”, but modified by me and Tom Dunn:- • Observe any rotation direction markings on the tire sidewall. • Fit one side of the tire onto the rim. (If it’s a back wheel, make sure you put on the tyre’s right side bead first. That way you’ll have the drive cassette pointing away from you, not into your clothing). • Slightly inflate the tube until it is round (3 or 4 pumps) • Fit the valve through the valve hole in the rim. • Place the tube into the tire:
• Never use sharp fitting tools. • Starting opposite the valve, mount the other tire side onto the rim. (I don’t do this – I always start at the valve, making sure that the base of the valve is pushed up into the tyre so that the base doesn’t impede the tyre’s seating properly) Now here, Schwalbe have missed out the trickiest bit, which is to use the base of your thumbs to work the tyre over the rim. The last bit is usually difficult, but the trick here is when you’re left with just a bit of the tyre bead to pop on, go back and squeeze the tyre all the way round to make sure that the bead is in the bottom of the well in the rim. Keep doing this whilst putting on the last and tightest bit of the tyre bead. You’ll often be amazed that using this technique a tyre will be very easy to put back on, whereas otherwise, it’s just about impossible. • Ensure the tube is not pinched between the rim and the tire. • The valve must be in an upright position (fig. 5) before you put on the screw at the base. If it isn’t, deflate the tube and work the tyre with your hands until it is.
• Seat the tire properly before inflating it to the required pressure (by checking that the bead-line on the tyre is aligned with the rim edge). This can also be tricky with some tyres / rims, and sometimes it’s necessary to use detergent on the tyre bead and then over-pressure the tyre to seat it. A tyre which isn’t seated properly feels like you’re riding over regular bumps. Whilst this will get you home, in long-term use it will wear your tyre excessively and may damage your wheel if spokes break after losing tension. • Adjust the inflation pressure using a pressure gauge. The permitted inflation pressure range is marked on the tire sidewall. (I tend not to use the full inflation pressure with a newly-repaired tube, as the adhesive will still be ‘soft’).
Sorry about the length of this arrticle, but you need to know the pitfalls and the dodges.
Mark Pollard very kindly wrote this piece for you, as I’ve no experience yet of tubeless tyre systems… Mark says....
I have to declare an interest here. Ann and I have 8 bikes between us – road, hybrid and MTB - and not a single inner tube in any of them. We have been an ‘inner tube free zone’ for the last 3 years in our road and hybrid bikes and 10 years with the MTBs.
Tubeless tyres are simply normal looking tyres which fit onto the rim, and inflate without using an inner tube – just like your car or motorbike. They should not be confused with the tubular tyres used by road racing types which are self-contained units glued onto a different type of wheel rim.
A bit of history:
Cars largely stopped using inner tubes in the 1960s and 70s, about the time radial-ply tyres replaced the old cross-plies. Motorbikes started to change in the 1980s and tubeless is now universal except for cheaper low capacity models.
The first bicycle tubeless system appeared in the late 1990s when French companies Michelin, Mavic and Hutchinson got together and introduced the Universal System Tubeless (UST) for mountain bike use. This needed wheel rims with no spoke holes on the inner edge and specially shaped and reinforced tyres. In essence, UST is a scaled-down version of what has been used on cars for decades.
Take-up by mountain bikers was reasonable despite the beefed up UST tyres and rims being slower than a traditional tyre/tube.
A couple of years later, American Stan Koziatek saw advantages in being able to use standard MTB tyres and rims without inner tubes, and developed a system using airtight rim tape and a liquid latex sealer to fill the rough edges in normal tyres. This allowed MTB riders to have lighter wheels and use lower tyre pressures for maximum grip without any chance of a pinch or ‘snakebite’ puncture. The latex liquid had the added bonus of sealing up most punctures caused by thorns and sharp stones without the rider even realising. Stan founded a company to supply the sealer and rim tapes and soon ‘Stans NoTubes’ had grown into a large concern supplying lightweight wheels, rims, hubs and the original sealer, for mountain-biking.
Today, 95% of MTB riders who compete in cross-country, enduro or downhill events, use the ‘NoTubes’ system, although a number of competing companies have jumped on the bandwagon.
Road bike tubeless took longer to get right. The higher pressures used in narrower road tyres meant that standard tyres couldn’t be used (they pop off the rim if used tubeless at anything over 50psi), so an ultra-strong Kevlar bead was developed by Hutchinson, IRC, Schwalbe and a couple of others. Although these tyres have been available since about 2008, acceptance by road cyclists has been slow.
However, 2017 seems to be the year when road tubeless becomes mainstream with the advantages being publicised by the magazines and forums, helped by a certain Fabien Cancellara winning some of the ‘spring classic’ road races with Schwalbe tubeless tyres.
What are the advantages of tubeless?
1. The ride is more comfortable. Tubeless tyres work best at lower inflation pressures and combined with the supple tyre sidewalls, this gives a better ride quality. 2. Fewer punctures. The latex liquid will self-seal punctures caused by thorns, glass and sharp gravel, often without the rider realising they have had a problem. 3. Pinch/’snakebite’ punctures are impossible – see Teds comments last time. 4. They are faster. Tubeless tyres have lower rolling resistance and so are faster. For a touring rider, this means that the same speed can be maintained for a bit less effort.
What are the problems or drawbacks?
1. You have to use tyres designed for tubeless (this doesn’t apply to MTBs or low pressure, <40psi, road tyres). Not every tyre manufacturer makes tubeless models. 2. The wheel rim has to be suitable, with a smooth inner surface. Rims with double eyelets like the Mavic Open Pro can’t be used as they are too rough inside. 3. The latex sealer loses effectiveness over time and needs to be replaced. Life is approx 5 months in summer and 7 months in winter. 4. The sealer can’t cope with a big puncture so it can be a bit messy to sort out.
What happens if you get a big puncture which the sealer can’t deal with?
You fit an inner tube in exactly the same way as in a conventional tyre. The remaining sealant is safe to pour away onto the verge/gutter as it is completely bio-degradable. It is extra important with tubeless to check the inside of the tyre for thorns and bits of sharp grit which have gone through the tyre without the rider noticing. When you get home, the tubeless tyre can be repaired with a patch on the inside of the casing in a similar way to patching an inner tube – see Ted’s last article.
All this applies to MTB and road bikes – how do touring bikes benefit?
If anything, the extra comfort and reduced punctures are more important to a tourer than a road-racer (and the extra speed wouldn’t go amiss either!). Things are changing though. Tyre manufacturer Schwalbe introduced a Marathon Supreme 35mm wide tubeless touring tyre last year. I have been using these on my hybrid for the last 12 months without any issues. The recent rise of multi-purpose gravel and cyclocross bikes has spurred tyre manufacturers into developing more choice in the 28-40mm wide bracket. Many of these tyres (and bikes) are tubeless-compatible and excellent for touring. Many new bikes are now supplied with TLR (tubeless-ready) wheels, usually fitted with cheaper non-tubeless tyres.
All your cars have tubeless tyres. Maybe it is time for cycling to join the 20th century and do likewise?
The Wheel Saga
Wheels – What Can Possibly Go Wrong ? – 1 Rims & Spokes
Leaving tyres aside for now, by far the most likely wheel failure is a split rim if your bike has rim brakes. This hazardous condition has dumped riders in all sorts of trouble in all sorts of places, so check rims regularly (minimum thickness of the braking surface is 0.5 – 0.7mm, 0.020 – 0.028 in – I’ve had a rim split at 0.023in) – they should never catch you by surprise if you love your bike properly. So, after a rim-split, the most likely wheel failure is a spoke-breakage. Don’t get too alarmed, as spoke breakage is not common with modern wheels and stainless-steel spokes.
So, what happens when a spoke breaks ? The first thing you might notice is a noise like a thunk and a feeling as though somebody has just aimed a side-kick at your wheel. It’s difficult to ignore. Your wheel will go out of alignment and be a bit wobbly. It may foul the mudguard, frame or brake. If this occurs, it's best to stop. What you do about it depends on lots of things..
Wheels – What Can Possibly Go Wrong ? – 2 Spokes Again
So, what do you do if a spoke breaks ? First you need to stop to assess the problem. A spoke breaks for a reason, and the commonest is that the spokes in your wheel are not tight enough, or the wheel is over-loaded (too light for what you’re expecting of it), but there are others.
What you do depends on a few things: 1) Does the wheel still rotate without fouling mudguard or frame ? Yes ? You could probably ride gently for a few miles if other spokes are tight. 2) Where is the break - could I repair it on the road ? It is usually on the wheel's drive side and this is the hardest of all locations to deal with on the road. If the break is in the front wheel or the non-drive side of the rear wheel, then replacing a spoke on the road is quite easy if you have one. 3) Why has the spoke broken - how loose are the other spokes ? Don't try to ride a wheel in which other spokes are loose - it could collapse. 4) Do you have any spare spokes of the right length, a spoke key and the skills to repair your wheel on the road ? 5) How far are you from home or rescue, or are you on-tour and carrying heavy loads ? If you’re on tour, now’s probably a good time to start reflecting on your inadequate bike preparation.
First choice should always be to repair the wheel if you can. Even if the wheel fouls frame or mudguard, then it might be possible to true it up a bit by releasing some of the tension on the spokes either side of the broken one. If you do this, though, you will have lost much of the tension in 3 spokes – a significant segment of your wheel which will now be a lot more flexible and a bit wobbly. Consider this as an emergency get-you-by, only. Keep your speed well down, 12 mph maximum, and get your wheel repaired as a priority.
Wheels – What Can Possibly Go Wrong ? – 3 Spokes Yet Again
‘Sod’s Law of Maximum Cussedness’ requires that most broken spokes are on the drive side of the rear wheel ! This is simply because these spokes are normally under the highest tension and where replacing them is the most difficult, on the road. Usually you can’t replace them without removing the drive-cassette. Who carries a cassette remover tool, spanner and chain-whip, never mind on a day run, but even on a tour ? Not me. But if you do have access to these tools, then remove the cassette and replace the spoke. If the break is in the front wheel, or the non-drive side of the rear wheel and you have a replacement spoke of the right length, then you’re ok because you don’t need special tools - most good combination tools include a spoke-key. Once you’ve removed the tyre, tube and rim-tape first, actually replacing a broken spoke is quite easy. Read on....
You don’t need to be an ace mechanic to replace a broken spoke - it’s obvious from the gap in the hub, and rim, where the new one goes. Temporarily, it doesn’t even matter if you can't ‘weave’ the spoke properly, just bend and thread it in carefully from the hub end, exactly like the others and use the spoke key to tension it up to the same sort of tension as the other spokes on the same flange of the hub as the broken one (looking at the rim, every alternate spoke is threaded through the same hub flange although from the opposite side). Just check the wheel alignment by quickly slipping it back in the frame to make sure it clears mudguard, brake, and frame. If not just tighten (or loosen) the replacement spoke until the wheel is acceptably aligned. Put on the tape, tube, tyre and inflate, then ride home and get a wheel-builder to check over what’s been done. Do check that all the other spokes on each side of the wheel are reasonably tight and at the same sort of tension, because it’s common for a wheel which is working loose to break spokes. When plucked, they should ‘ring’ with a musical tone. If they just give a flabby ‘thunk’ you’d probably best walk or go very carefully to a bike shop. If you’re confident in your skills, tighten them all and align the wheel properly.
Just be canny in replacing a spoke. Some rims with single eyelets (inset in the inside face only, of the rim) can allow an errant spoke-nipple to drop inside the rim’s closed box section. This is irritating if you have only one spoke-nipple and you need it to get moving again. It can be doubly-irritating if you leave it there, too, as it’ll rattle and irritate the hell out of you.
Wheels – What Can Possibly Go Wrong ? - 4 Spokes Yet Again
– So Why do spokes break ? Spokes won’t break without a cause, and usually it's flexure in the wheel causing fatigue (Yep, it’s not just the rider !). In a wheel with loose spokes, a lot of flexure occurs. A wheel flexes on every single rotation (how many times does a wheel go round for every mile ? Answer at the bottom), so spokes are subjected to a lot of flexure, and like a tin lid that you waggle to break off the tin, so a spoke will break when it’s had enough waggling. It’s commonest for spokes to break where they pass through the hub flange but they can also break at the nipple. Just occasionally spokes can hide, broken, without being seen. This is just one of a whole lot of good reasons to get your bike properly serviced half-yearly. Some light-weight wheels use bladed spokes (like a blade, or aerofoil in cross section) and some have spokes grouped in threes. It is sometimes possible to repair these wheels, although they are usually regarded as disposable mainly because bladed spokes are not readily available. Good quality stainless steel spokes can be re-used four or five times if undamaged and you need to rebuild a wheel, for example, to replace a worn rim. So, if you have an identical new rim, you probably won’t need new spokes. Just check that they are not damaged by chain jams, crashes, wheel flexure causing ovalisation where the spokes cross, or damage at the hub.
If you fancy trying your hand at wheel-building, replacing a rim is a very good place to start. Just tape the new rim to the old one, making sure you have the valve holes exactly aligned with each other. Then work round the old wheel taking the tension off each spoke by undoing each say a couple of turns, until all the tension has gone from all of the spokes. Key tip – when working on wheels always start and finish at the valve hole as the point of reference and count your way round so you can pick up where you left off if you're interrupted. Then, in turn, undo each spoke and transfer it to the new rim, doing each nipple up by the same number of turns, two or three is fine. When all spokes are transferred, un-tape the old rim, and working round steadily around several times, doing up each nipple successively in turn by an equal number of turns to the point where you have some modest tension in some of the spokes. Then put the wheel in the frame and tension the spokes to get both the axial (side to side) and, arguably more importantly, the radial (up and down) alignments correct. Spoke tension is about right when you twang each spoke and you get close to middle ‘C’ on the piano. Drive-side spokes are usually quite a bit tighter – higher pitch, and non-drive side slacker – lower pitch. Front wheels are usually symmetrical. Aim to get the alignment as good as you can (+/- 0.5mm is good, 0.25mm about as good as it gets with normal used rims), and spokes evenly tensioned. Have a go – there is a lot of experience in doing it well and quickly, but it’s not as tricky as you might think, particularly if you don’t have to start from a pile of bits.
Older rustless spokes – you can tell which they are as they have a dull finish - were much more prone to breakage, and you’d be unwise to rebuild a wheel using these.
(Answer: about 750 revolutions per mile for 700c)
Wheels – What Can Possibly Go Wrong ? – 5 Wheels Going Out-of-True
Honest! This is the final part of the ‘Wheel Saga’ If a wheel goes out-of-true, as always there’s a reason which you need to understand. Commonest reasons are: 1) a rim is about to split. 2) spokes are losing tension 3) a spoke has broken
Rim splits and broken spokes I’ve already dealt with, so why do spokes lose tension? Well, no rim, or tyre can be made perfectly round. Alloy rims are made from flat sections, then bent and joined either by welding, or by steel dowel. It’s normal for the rim either side of the join to be not-quite-round, and so the join itself can be slightly high, or slightly low. Hand-built wheels can accommodate some of this in the building. As usual in life, you tend to get what you pay for, so better quality rims tend to be more perfectly round and so build a better wheel. Tyres likewise have imperfections in circularity, and it’s also sometimes not easy to mount a tyre such that its bead is exactly bedded on the rim’s tyre track. All of these imperfections can mean that your road wheel is not perfectly balanced or round on the road. This in turn creates a very slight bumping effect and together with the applied load, subjects a wheel to ‘periodic stress’ on each revolution. Bumps in the road add to the transient forces on your wheels. So it’s easy to see how individual spokes are subject to incessant and rapidly changing forces. At times, this can lead to spokes losing tension if the nipples start to turn in response. Some wheel-builders use ‘Loctite’ or similar to lock the nipples once the wheel is built, and particularly for highly-stressed wheels. Luckily a properly-built wheel acts far more like a single unit which shares the forces across the wheel. It is also immensely strong. Conversely, it’s why a poorly-built wheel with badly adjusted spokes or poor radial (up / down) alignment, is far more likely to go out-of-true, and, if left, collapse. And just bear in mind that I recently bought a bike costing £2k which was fitted with wheels which were so poorly built that I wouldn’t have ridden them ‘out of the box’. They’ve now been rebuilt. As a guide, I try to build all my wheels to a radial alignment of +/- 0.25mm where the rims (and necessary spoke tension) will allow. In my experience, even the best-built wheels need servicing, and occasionally may need just a tweak on the odd spoke to keep them perfectly true. And if you have V-brakes, then although these brakes are excellent and light in operation, very accurate wheel alignment is key to your safe happiness on the road - it might be worth trying your hand at aligning a wheel. In summary, then, always seek the reason for a wheel going out-of-true, then get it fixed before you get ‘landed’ in the ‘middle of nowhere’.
Check Your Rims
Devon is one of the most testing places in the UK for wheel rims. The steep hills, at times a very wet climate, mixed with gritty sandy roads, potholes and sea-salt can lead to alarmingly rapid wear of soft alloy rims. Under unfavourable conditions, lightweight rims can wear out in less than one winter season.
It's important to check regularly how much thickness of metal remains ...You'll hear all sorts of stories about how thin you can go, but a safe limit is 0.7mm or about 0.028" (28 thou in old money!) If the rim blows out, you WILL know about it, but only if you survive - see The Highwayman March 2015.
Check brakes routinely (every few weeks) and replace worn pads or blocks. It's too late when you are sailing down a hill and a horrible grinding noise tells you that you haven't got any rim pad left. Try shouting 'oh shit'; it helps, but not a lot.
Some rim pads, where the carrier is moulded into the rubber block, can be difficult to assess. Often they get a lip on them as they wear, and the drainage grooves disappear too. The lip is symptomatic of advanced wear of the block, and can itself cause wear of the face of the rim, not just the braking surface. Also, you need to check carefully on the block alignment as it is quite common for the alignment to change with wear and for the block to be happily wearing away your tyre-wall as a result. Be warned - this is not always easy to see until it is too late. It doesn't wear for long though as the tyre usually goes bang - I've seen it happen and, yes, I've got the T-shirt, too ! I generally take the lip off the block using a bench-grinder. Then with a small hacksaw, I put three drainage grooves across the surface of the block. This also acts as a check to see how deep the block rubber still is over the steel carrier. If the rubber is less than 2mm I discard the pad.
Try using the wrong pads and things can get interesting. I was once going down a steep hill on a tandem which had alloy rims but brake pads for steel. I was watching with keen interest to see whether we would reach the bottom of the hill before the brake pads wore out, the desirable result, or whether the blocks would beat the hill, the undesirable result. As I’m still here and largely intact, you can draw your own conclusion, but it was close-run !
Setting Fire To Your Bike !
This is a tip I picked up from Yvonne Tomlinson. Apart from using 'Wettie Wipes' on her bike (how sweet !), she also likes to set her bike on fire. You see, she gets bothered by the little strands of fibre, which occasionally dangle from a tyre bead near the rim. She uses a flame from a lighter just to burn them off. I bet she doesn't have a fire extinguisher handy......
Loss of Drive
You get no noise, and you simply lose the drive. This uncommon failure is one of the most frustrating on the road. In my experience, you will have got, and ignored, the warning sign, as you’ll have found some time previously that after freewheeling, the drive ‘misses a beat or two’ before engaging properly. Ignoring the symptom simply gives you the excitement of being stranded somewhere arbitrary, with a bike that won’t work.
On the road, it’s unlikely that you can do much - few people will carry a replacement freehub body, the 10mm allen-key needed to remove and replace it, and the kit needed to take off the drive-cassette. However, it could be worth understanding what has gone wrong, because, usually, nothing breaks. A freewheel is a very simple mechanical device - a spring ratchet or three dragging over a set of teeth. In a freewheel the teeth are arranged in a circle and the ratchets – called pawls - (usually three or four) are quite tiny, each kept in contact with the teeth with a very small spring. The clicking noise you hear are the pawls dragging over the teeth, some freewheels being very noisy whilst others are quite quiet. The smallness is key.
So what happens when the drive fails ? When new, freewheel mechanisms are lubricated with a sparing quantity of oil or a very light grease. What happens in bikes that have done many miles or older, is that the lubricant dries to leave a thick residue just sticky enough to prevent the pawls from returning to engage with the drive teeth after freewheeling. By the time the drive fails it’s likely that only one of the pawls has been fully operational for some time, so although you won’t have known it, you were running on borrowed time. Sometimes you might be able to get drive back by giving your cassette a sharp tap, but bear in mind that any drive you achieve will be temporary as the next time you inadvertently use the freewheel, the problem will recur. If you can get to a garage, or you carry a tin of light oil, with the bike on its side, you could try soaking the centre of the cassette whilst turning the wheel to work the solvent into the mechanism. This might work, or rather it will work if you have enough time to ‘prat’ about with it. But be warned, you might be lucky or it could take an hour or two !
In the workshop, the solution is simple – take off the freehub body and immerse it in a solvent overnight. Dry it off and ‘Eureka’ it will work as new in the morning. Don’t forget to dry it and lubricate it with a very light oil – I would probably use 2-stroke petrol as the solvent, as this will leave a very light film of oil when you dry it off. And the beauty of this solution is you don’t need any spare parts. The solvent trick is a complete solution – I’ve never had a recurrence of the problem in any freehubs I’ve treated this way.
The Chain Saga
Chains Part 1 - Maintaining Chains
These unlovely bits of the mechanics are a truly wonderful invention. They are one of the keys to our fantastic way of life, along with high pressure tyres. So, treat your chain respectfully. Pay attention to its needs - a dry or worn-out chain wastes a huge amount of energy and will put you panting at the back of the Sunday ride group. Just one slightly tight link can cause your gears to slip. So how do I maintain the chain ? It’s quick and easy – I have a large rag, and a pair of riggers (gloves) to keep my hands clean. Before most rides I just rub the rag over and around the chain to clean off all the surface grit and dried oil residue. I then sparingly lubricate the chain with light oil in the summer, and something heavier and/or waxy in the winter to prevent the oil being washed off. I then clean off any excess. I never use a solvent on a chain because it removes lubricant from the pivot pins. However, those devices with rotating brushes in a solvent are very effective at cleaning a really dirty chain. If you use one of these, though, make sure that the chain is properly dried, preferably with some heat, then soaked in your lube of choice overnight, with any excess removed before your ride. As a cleaning solvent, I do sometimes use 2-stroke fuel - it leaves a film of oil when dry. Either way your chain will be properly lubed, and clean, too. Next time I’ll explain how to check when your chain should be replaced.
Chains Part 2 – Measuring Wear
How do I know when my chain is worn out ? Ha ! Good question. Well, a quick way is to put your bike into a middle front ring, then grasp one link between thumb and forefinger, and try to pull it upwards off the chainwheel. If the link moves little and feels tight, your chain is likely to be fine. If though the chain link moves a lot and you can see most of one complete tooth, then your chain could be heading for the scrap bin.
When a chain wears, it lengthens. It’s called ‘stretch’, which seems to suggest it could come back to its former size. It doesn’t ! I replace a chain when wear has reached 0.5%. The beauty of this method is that you can usually get several changes of chain on the part-worn rear sprockets before having to replace them. You probably will get a small amount of gear slippage until the new chain ‘beds-in’, usually in 150 – 250 miles but it will stop slipping if you persevere. If your cassette has had a number of new chains, the gear slippage may become excessive with yet another new chain, and take hundreds of miles to bed in. That’s probably a good time to change to a new cassette too. Some cash-strapped cyclists keep part-worn chains to mesh with part-worn blocks to really eke out the wear. Sad, but true ! Front chain-rings seldom have to be replaced with the 0.5% method, either, and these are quite expensive bits, can be a bit fiddly to fit, when you get spacer washers in the wrong place and rings the wrong way round. Yup, I’ve done it !
How do I check accurately for wear ? The easiest and probably the best way is to measure your old chain against a new one. I have a nail in the door-frame of my workshop and I simply hang the chains up and compare them for length. Most chains have 112-116 links, so 0.5% is roughly half a link's extra length – easily seen. You can buy a chain wear gauge if your partner doesn't like oily chains hanging up on the lounge door-frame (can't understand why not), or you can make and calibrate one yourself from a piece of spoke wire carefully cut and bent to the length of a specific number of new links.
Manufacturers often recommend a change at 0.7% wear – or ¾ of a link's extra length on the full chain. I have found that this is just too much wear if you want your rear cassette to be re-useable. And if you wanted to ruin your cassette in this way, you'd probably ride the whole thing to destruction. What happens in the end is that the excess wear causes a gear, or some gears, to slip increasingly, or the chain breaks. Not surprisingly, I don’t like this approach because you have no control over when slippage starts to occur, a real problem if you are on tour. Your chain, rear cassette and most likely, too, some or all of the chainrings on your crankset will be scrap. If you can get the chainrings as spares, that’s maybe ok, but if you can’t, you’ll need a new crankset. (ouch!) This way, though, you will also have had to put up with rough-running, loss of lots of your precious energy, and a big hole in your wallet at the end - doesn't sound like a good method to me.
Chains Part 3 – How Long should they last ?
So, how long do chains last using the 0.5% wear limit ? This is a very difficult question to answer, because it depends on a whole list of things such as • How strong the rider is, so how much force the chain takes • How good the lubrication is • How clean the chain is kept • What weather and mud conditions the chain has been ridden through • How wide the chain is (7-8-9-10 or 11 speed) • What quality the chain is • Who manufactured it As a not-very-useful guide, chains can last anything from 800 or so miles (tandem rear chain) to 5000 miles or more for a light rider, and a good quality well-maintained chain ridden mostly in the dry. And if you read last month’s article, and you ride your gears to destruction rather than changing a chain at 0.5% wear, then you will get much longer than this, but have a much bigger bill at the end.
I now use chains from only one manufacturer – they make chains and only chains, so have to be the best or they go out of business. Their chains price-for-price last typically 50% longer than those made by the usual all-things-to-all-men manufacturers. Ask me if you can’t work this out – libel is not me !!
Chains Part 4 – Chain Problems
Finally, what other problems can chains suffer?
Well everybody, probably, has had a chain-jam at some time or other. These are usually caused by incorrectly set gears, or ‘chain-suck’ caused by burred or worn chainrings. Jams can be made inconsolably worse by just enough clearance to the frame for the jam to be 'solid', needing complete disassembly to disentangle them. These jams are not usually caused by problems with the chain.
The commonest chain problem is a breakage. Although not common they have become more frequent with the narrower chains for 9, 10 and 11-speed cassettes. What happens is that one of the side-plates slips off its pivot pin, and the first thing you might notice is a slipping gear – in all gears. If you look down, you’ll see a link has deformed. Sometimes you can hear it on every chain rotation. If you don’t, the next thing you know is you have no drive, and the chain is probably on the road, too.
So what do you do if this happens ?
Well besides using a mobile to call assistance, or a voice to call help, what you need depends on the bike you’re riding. If you have a 7 or 8 speed tourer, a decent chain tool will enable you to take out the deformed link and its partner, and re-join the chain successfully (but make sure the joined link isn't tight). Even so, you need to do this carefully and accurately. If you’re really lucky, you can get away with this technique for a 9 speed too, but you need to be really careful and practised in using the chain tool, and 'cranked' side-plates (typically Shimano) make the process much harder and fraught with difficulty. Better by far is to use a 'snap-link' for your 9, 10 or 11 speed chain, so make sure you carry one in your tool pouch. You need the chain tool, too, to remove the partner link to the broken one to enable you to re-join the chain. Be careful to have the right link for your chain as they are not interchangeable. Snap-links are fiddly to use, and it's useful to practise with them at home with a clean piece of chain before having to do this with a dirty slippery chain 'in the wild'. Be warned, I recently had a 7 speed chain that I failed to be able to join with the dedicated snaplink, which was tight. I tried two. There was no way to loosen them off when fitted, so I couldn't use them.
Chains sometimes develop tight links, particularly if you’ve ignored lubrication, or you’ve taken off and re-assembled your chain using a chain tool. It’s a bit complicated to explain here, exactly what you do, but in principle you use the chain tool to just ease apart the side-plates a teeny-tiny little. It's usually only a quarter-turn on a chain-tool. The aim is to free-off the link so that the chain will run easily over a finger.