Category Archives: Other stuff

On-trail issues: unexpected loose spokes

Issue: Half way round a ride a rattling sound draws attention to loose spokes.

Damage: Not much in some ways.  The wheels can easily buckle once spokes come loose, and there’s potential for more damage to the spokes themselves and the tyres if the issue isn’t remedied.

Remedial action: If you’re not carrying a useful multitool, not much, although you could try temporarily screwing the spokes back in by hand.  If you are carrying a tool, hopefully it has a spoke key on it, in which case you can screw them back in and tighten them up nicely.  Since spokes should not typically loosen themselves this much, it would definitely be worth investigating the rest of them as well, and making sure that you have an even tension round the whole of the wheel.

Ways to avoid: This is arguably one of the consequences of buying a bike from a bike outdoor chain, as opposed to a local bike shop.  Big chains will have a checklist to follow when building bikes for the their customers, but checking spoke tension is more than likely not on it.  It certainly isn’t for some.  Perhaps a particularly conscientious bike technician with a particularly low workload might think to check them, but this will be the exception rather than the rule.  So, if you buy a bike from a big chain and ask them to build it for you, check it thoroughly before you ride it.  At the very least, ride it first in relatively low-risk places so that any issues come to light before you’re relying on the bike.

Advertisements

Leave a comment

Filed under On-trail issues, Other stuff

On-trail issues: herniated tyre

Issue: Sidewall of the tyre tears, and inner tube bulges out of the hole.

Damage: Given that the inner tube then clips the forks on every rotation of the tyre, this issue soon results in an explosive puncture.

Remedial action: At the time, not much.  Unless you’re carrying a full spare tyre with you there’s not a lot you can do with a genuinely damaged tyre.  I wondered about maybe wrapping duct tape around it (although sadly I wasn’t carrying any) or even perhaps changing the inner tube when it blew and tying the defunct tube around the damaged bit of tyre.  I have no idea if this would have worked.  It doesn’t seem overly likely.  Equally there’s only so long you can ride direct on an inner tube before it wears through.  Practically speaking all I could do was ride gently until the tube went as well, and then spend the next hour walking back pushing the bike.

Ways to avoid: Preventive maintenance would have been key here.  The sidewall of the tyre looks scored and definitely weakened – I’m not completely sure how that might have happened, but checking the bike over thoroughly before riding should have brought the issue to light.  I suspect that not riding my bike for a long time probably didn’t help the issue.  Obviously, the next step is simply to change the tyre.

Leave a comment

Filed under On-trail issues, Other stuff

Winter Riding

So you’ve had your summer fun.  You’ve cruised over hard packed earth at high speed, you’ve gone riding with nothing but shorts, a teeshirt and a pair of sunglasses.

Then suddenly you look outside and Storm Barney is ripping signs off shopping centres, closing roads and blowing sheep sideways down the road.  Why should you go out in that?

Well, you probably shouldn’t.  But when the wind dies down to less suicidal levels, there is still riding to be had in the winter.  Incidentally in this post I am not discussing riding in snow, or any other genuinely extreme weather.  That requires skills and gear that would make you more of an expert mountain biker in any case.

Riding in less extreme winter weather, though, can be very fun and very rewarding, and there’s nothing like the sense of achievement and peace when you get back to a hot shower and a warm house soaked to the skin and exhilarated.  Don’t let the weather and the temperature put you off!

So what should you expect?

 

The Trails

You still have the same choice of natural and manmade trails to ride on.  However, this is the time of year to ride mainly manmade trails.  Firstly, they’ll be largely better and easier to ride.  The surface will stay good even in awful weather (although be aware some trails will still be muddy and wet – just not as muddy and wet as some natural trails), and navigation will be a great deal easier, which really makes a difference in adverse weather.  You may have reconciled yourself to getting soaked through in the name of adrenaline, but that soon starts to fade after the first few minutes of standing in a waterlogged field staring blankly at a waterlogged map and trying to match landmarks that you can’t even see through the drizzle.  The second reason to ride manmade trails in winter is that they’ll largely be through woodland and therefore a great deal more sheltered than natural bridleways across bleak mountains.  Finally, the socially responsible bad mountain biker should be aware that the soft surfaces of natural trails can take some serious damage from bike tyres in wet weather – and so sticking to purpose built trails means less erosion and more rideable (walkable, horseable…) trails in the summer.

 

The Gear

This varies according to the conditions, so check the weather forecast before you go and prepare accordingly.  It also varies according to you, so have some sense with your planning.  If you feel the cold a lot, bear that in mind.

At the very basic level, in good winter conditions, I’ll ride in exactly the same stuff I do in summer, but with a waterproof over the top.  The waterproof keeps you dry, keeps the wind off, and gives you an extra layer.

Having said that, worse conditions mean more gear.  The ideal here is to get hold of a complete set of winter gear – heavier gloves, base layers for you body and legs, waterproof socks, heavier shoes, trousers or more waterproof shorts, warm mid layers, waterproof jacket.  Personally, I can’t afford to buy a whole new set of gear and I don’t intend to let this lack put me off riding in the winter.  My light gloves tend to keep my hands warm enough, my shoes are fine with the possible addition of waterproof socks.  I still ride in shorts, and only add a base layer under them when the temperature really drops.  Again, I generally stick to a teeshirt and waterproof on my body, but there’s no doubt that on longer, colder and wilder rides, it’s worth having warm dry clothing with you (a lightweight fleece in a plastic bag, for example) in case something happens.  If you feel the cold more than I do it’s worth layering up a little more.  A helmet with a peak is handy in the rain, particularly if you wear glasses.

The essential point is to be aware of the conditions you ride in and how they will affect you and the bike, and plan accordingly.

If you were riding in the summer without taking a phone with you, then firstly stop it.  It’s stupid.  Secondly, definitely take one in winter, ideally in a waterproof container of some sort.  Remember books and maps get wet, so either invest in waterproof versions or keep them in something waterproof and use them sparingly.  On all but the shortest rides, take extra stuff.  More food, more water, more clothes, more tools.  Essentially you want to make sure that an accident is an annoyance rather than a genuine danger.

Have warm dry clothes in your car.  Driving for an hour in wet, cold, and muddy clothes is no fun.

 

 

The Bike

Largely, your bike should function fine in winter.  However, mud does a lot more damage to things than summer dust does.  Clean the bike after each ride and keep an eye on the moving parts.  Mud gets in and grinds.  Lube stuff up to keep it moving.  On long rides it might be worth adding a spare set of brake pads to your gear, since abrasive mud can wear them down to nothing in a couple of hours with heavy use.

Some suspension forks (by which I mean, my suspension forks, and no others that I’ve come across) seize pretty badly in low temperatures.  There are fixes for this, such as replacing the oil in the forks with a thinner one for the winter – but honestly that would either be difficult or expensive, and I haven’t done that.  Personally I have tried to rectify the issue by never locking my forks in winter.  Hopefully this means that rather than having a long climb in the rain to get cold and stop working, the forks will be kept moving enough to generate a little heat and keep them moving smoothly.  I think it works.  Sort of.

The point is, be prepared for there to be occasional things that stop working properly in inclement weather.  Speaking of which…

 

You

Things simply work differently when they’re cold.  Cold air into hot lungs will make them spasm and you’ll cough and gasp for breath – so try to warm up gently and give those alveoli time to adjust.

Personally, I find that my forearms, legs and feet get very cold.  Cold feet is uncomfortable but not too troublesome, but cold legs find the effort of cycling a little too much, and cold forearms can lock your hands up and make braking a bit of a trial.  Try to keep your muscles warm while you’re out, and take things a little more easily if you realise that the cold is making your hands a little slow to react.  Equally, everything that gets cold or uncomfortable distracts attention and resources away from riding.  You are likely to need more concentration in winter to deal with mud, slippery leaves, poor visibility and other adverse conditions, so its worth remaining aware of your body and trying to counter anything that gets too troublesome.

Remember that the conditions around you will have an impact on your energy and mood.  If you’re trying to ride through thick mud, you’ll use a great deal more energy to cover the same distance.  If it’s raining sideways, now is not the time to try to push your distance record.  Be prepared for the person you’re riding with to spend ten minutes standing under a tree and grumbling when it starts to rain.  Speaking of which, if you’re riding with other people, try to keep an eye on them as well.  A sudden drop in mood or energy can be a warning sign that someone is in need of some warmer clothing or food.

 

 

Thanks to Bad Mountain Biker’s resident Good Mountain Biker, for his sage advice on this post.

 

 

Leave a comment

Filed under Other stuff, Technique

On-trail issues: hedge clipping

Issue: Autumn in the UK means hedge clipping time – local councils and farmers clipping their hedges to keep them nice and tidy.

Damage: Rural roads and tracks strewn with thorns and jagged twigs.  Expect serious punctures, broken hangers, bent derailleurs, bent spokes and general problems with things catching in things and things.  At worst, being stranded in the middle of nowhere.

Remedial action: See specific pages for punctures, hangers and so on.  Punctures can be easily fixed at the roadside (although for giant thorns it can be best to leave them in until you’re past the clipped section if the tyre hasn’t already deflated).  Hangers can be replaced if you have a spare with you.  As for larger problems, I once freewheeled off a hill with my chain in my bag and my derailleur in my pocket, and on another occasion removed a section of chain to set my bike up as a sort of singlespeed, although the chain snapped again shortly afterwards.

Ways to avoid: There’s not a particularly good way to avoid the issue.  Manmade trails should be absolutely fine, but since Autumn is likely to be the last time to get in some natural riding before Winter it’s a shame to limit yourself at this point.  On roads you can sometimes do your best to weave between the worst bits of debris, but on tracks this is more difficult.  Punctures aren’t too much of an issue.  Broken hangers are a little more serious, and if you have the ill luck to hit something that breaks your hanger, snaps your chain, and bends your derailleur then you’re basically looking at a walk home.

Leave a comment

Filed under On-trail issues, Other stuff

Natural vs. Manmade

In mountain bike trails, like in breasts, there are distinct differences between the natural and the manmade.  Some people prefer natural.  Some people prefer manmade.  Some think that variety is a good thing and that their preference varies with mood, or with the time of year or the weather.

Frankly we’ve got to the point where it’s becoming difficult to maintain the boobs simile, so I’ll just talk about mountain biking from now on.

There are key differences between riding natural and riding manmade trails.  Here are a few of them:

 

The bike.

You can, to a certain extent, ride trail centre trails on something that is not technically a mountain bike.  You could ride them on something that looks like a mountain bike but cost you a hundred pounds at Argos, and therefore probably isn’t, and you might well be ok.  Many blue trails you could probably get away with riding on a reasonably rugged hybrid bike.  They might work.  Natural trails, however, might well demand a more hardy steed.  You need to have something that works well, that won’t unexpectedly break.  Ideally it should be well maintained and well set up.

Having said that, this is based on gross generalisations, but the truth is that trail centre riding will always come with a nice helpful sign telling you what to expect – and then everything that you ride will match it.  Out on natural trails you’ll face the infinite variety of bridleways and tracks that cover the country, and could find yourself riding on anything.  The bike should match this.

 

The gear.

As I mentioned in the ‘Essential Kit’ page, I normally consider it fine to ride manmade trails with the minimum of stuff.  So I’ll have the bike (it’s tough without it), shoes (for clipless pedals), gloves, helmet, drink, pump, inner tube, tyre levers, multitool and phone.  These means that basically anything minor that happens to the bike I should be able to sort out.  I know there’ll be escape routes back to the start.  I know that more than likely there will be other riders passing at fairly regular intervals.

Out on the hills, I’d always want to take more stuff.  Quite simply, there’s more that can happen when you’re in a less controlled environment.  You should always take more food, more drink, more inner tubes, more tools, more clothing – warm and waterproof, a good map, ideally a compass, and equally ideally a rudimentary first aid kit, emergency blanket, and whistle.  You never know quite what will happen when you’re riding and given the amount of ground you can cover on a bike, it’s quite possible that if you do seriously injure yourself, no-one would pass by and be able to help.  Take emergency stuff.

 

The terrain.

This to be fair, is sort of the whole point of manmade trails.  You know that what you’ll be riding will generally be a hard manmade surface that should shed water nicely and keep a very good riding surface all year round, in more or less all conditions.  Equally you know that everything that you’re going to ride should be rideable – even if it’s not completely rideable for you.  Hills will all be ultimately doable.  Descents will be attainable.  Features will be conquerable, given a sufficient degree of skill and gumption.

Natural trails are a different proposition.  No-one has looked at them and carefully designed them with you in mind.  That drop that looks unrideable?  Maybe it is.  That climb that looks just plain too steep and loose to get a bike up?  Perhaps it is.  If you’re following a route that’s described in a guide then chances are most of what you want to ride will be find, but it most certainly will not be kept neatly within the confines of a chosen trail grade.  An apparently blue route will suddenly have a bit that would probably be red or even black on its own.  A black route will have a long section that seems surprisingly blue.  The surface, needless to say, will also differ greatly.  A lot of places become a great deal faster and easier to ride in the summer.  Hard packed dirt and rocky descents are great fun.  Then winter rolls around and you try to ride the same places and realise that the hard packed dirt is now hub-deep mud.  It’s a challenge.  It’s a different ride.  The rocky descents are now streams and although still technically rideable are a great deal more slippery and unpredictable than they were a couple of months ago.  You should expect to get wetter and muddier than you would on a manmade trail.

A point that also should be emphasised is that in the autumn, farmers and local councils trim the hedges that border rural roads and bridleways.  This means that where you want to ride is often littered with sharp and thorny sticks that are perfect for ramming thorns straight through your tyres and/or jamming in your spokes and tearing your derailleur off your bike.

 

The time.

Natural trails take longer.  Firstly they are a great deal more unpredictable than manmade trails – so a ride that takes an hour in the summer might take two in winter, when everything’s muddier.  Secondly you have to factor in the navigation component, on trails where it no longer consists of glancing occasionally at a coloured arrow on a post but instead means finding a vantage point and staring at the surrounding landscape with a map in one hand, a guidebook in the other, and your Strava feed in your third hand.  No matter how well a route is described it will always take time to find it.  Equally given the changing nature of natural trails, they can be a great deal more exhausting than manmade trails, and so can involve a corresponding increase in you stops to eat and drink.

 

The expectations.

Quite simply, riding manmade trails and riding natural trails are completely different.  Manmade trails have miles of carefully sculpted singletrack – to the point where you’d feel cheated if at least half of a trail didn’t consist of this.  Natural trails are very different, since they often consist of a huge ride whose purpose is to get you to and from a particularly sweet section of natural singletrack in the middle of nowhere.  As a result you can ride five miles on roads and five on fire roads for two miles of awesome singletrack.  This can feel somewhat frustrating to the habitual trail centre rider.

However, for all the strength of the manmade trails is their careful consideration and planning, this is also their weakness.  As fun as it is, there’s something faintly sterile about trail centre riding.  It’s not a grand adventure.  But looking at a map or even at a guide and finding a trail that turns off a main road that you’ve driven along before and explores those mountains that you’ve always glanced at along the way is exciting in itself.  Reaching the far point on a ride and looking out across the wilderness that you’ve just explored – nay: claimed – on your bike is an intense satisfaction.  The five mile ride on the road and the five mile climb on fireroads suddenly seems a great deal less important when the trees clear and suddenly you see ahead of you the next five miles of beautiful, undulating singletrack, that has been there since people first moved into these hills and has been used by people and animals for centuries – and now you can ride it.

This is, in some inexplicable way, real mountain biking, in a way that trail centre riding – for all it’s merits – is not.

Leave a comment

Filed under Other stuff, Technique

(Very) Basic Navigation

Much as I’m a fan of trail centre riding, there’s something somewhat limited about it.  It’s like being a musician and only playing cover songs.  It’s fun, it’s a skill in itself, but somehow it’s ultimately a little unsatisfying.  Something about the idea of just getting on a bike and heading out into the middle of nowhere has an immense amount of appeal about it.  This is real mountain biking.  Bike vs. mountain.  The wilderness.  Finding an awesome trail to ride miles from anywhere.

However, riding in places that aren’t heavily signposted brings up the problem of navigation.  Many books and guides give excellent step by step instructions on how to complete a route, and yet it’s quite possible to accidentally wander from these, and it is essential to be able to find yourself again.  You need to know how to read a map, and to have one with you.

The map that you need to have with you is ideally the Ordnance Survey Explorer map (the one with the orange cover) for the area that you want to ride in.  These are at 1:25,000 scale and provide excellent detailed mapping that can help you to locate yourself nicely using landmarks.  Failing that, the Landranger maps (pink covers) will probably do, although these are 1:50,000 and can sometimes be a bit short on detail.

It’s a big colourful bit of paper.

Yes.  Yes it is.  If you look at it with the writing the right way up then North is up the page, South is down, East is right and West is left.

What you can see represented on the map are roads, rights of way, and physical features.

Roads?

They should be pretty clear, they’re the solid coloured things that look like roads.  Main roads pink or green, minor roads are yellow and orange, very minor roads will be white, and motorways are usually blue.  Don’t try and ride on blue roads.  Tracks will show up as parallel dotted lines.

Rights of way?

Legal rights of way (apart from roads) are represented in dark green on Explorer maps and pink on Landrangers.  Short dots are footpaths (don’t ride on them), long dots are bridleways (do ride on them), and widely spaced circular dots are restricted byways (ride on these too).  Be aware that for one reason or another, the legal rights of way do not necessarily match the actual paths.  They should, but they sometimes don’t.

Physical features?

The brown lines are contour lines, and represent areas of the same height.  So a bunch of concentric circles will most likely mean an unnaturally circular hill.  Woods are green.  Lakes and rivers are blue.

 

I’m lost!

Look around you.  What is there to see?  Is there a road that you can see?  Woodland?  A stream or a lake?  You should know the vague area that you should be in on the map, so have a glance at it and see if you can see features that match the terrain around you.  If you have a map of your intended route, see if you can work out where you left the route and how you can get back to it.  Look for junctions that should narrow things down.

Bear in mind that in the UK, the sun is broadly South from you in the middle of the day.  In the morning it’ll be vaguely South East, and in the afternoon it’ll be vaguely South West.  It’s a very broad thing to go with, but in all but the worst weather it can be enough to help you get your map the right way round.

You can also do this much more accurately using the stars, but if you’re navigating by starlight then something has already gone rather wrong – or you’re doing an epic night ride and probably know all this navigation stuff already.

If you are out in the worst weather, you should be prepared.  You should have, among your more comprehensive pack of stuff, a compass.  Use it to align your map and see if you can see the trails through the fog.

If all else fails give up on your trail and make sure you can get home.  In most of the UK you will never be very far from a road (bits of Scotland being the distinct exception to this).  Pick some kind of big feature that you can’t miss.  No idea where you are but there should be a road heading North-South somewhere West of you?  Head West in as straight a line as you can until you find it.  River just to the North that runs down to a road?  Find it and follow it.  Once you’ve got to this stage you’ve essentially given up on your ride anyway, and it will be tough getting back to civilisation, particularly if you’re pushing your bike.  Nevertheless, it’s better than being stuck in the middle of nowhere.

 

If absolutely all else fails ring mountain rescue on 999 or 112.  If you can see absolutely no way of getting off the hills before nightfall, and no way of getting home after dark, or if you’re seriously injured, give them a ring.  It’s what they’re for.  In the UK, if you find yourself in an emergency with no mobile signal at all, use 112.  It uses an emergency satellite network that will connect you regardless of whether your phone has signal.

Leave a comment

Filed under Other stuff, Technique

The Law

There are legal issues surrounding mountain biking in the UK.  I’m sure there are legal issues surrounding riding elsewhere too, but I’m a fair bit less familiar with them, so I’ll limit my discussion of them to saying: make sure you know what they are before you ride.

 

The bike, and you.

There are certain legal requirements that you and your bike should meet for riding on the road.  Your brakes need to work.  If you’re riding on the road at night, you need to have a white light in front, a red light to the rear, and a red reflector at the back.  Orange pedal reflectors are also a legal requirement, although the law is silent on how one attaches these to clipless pedals.  You can’t ride on pavements, you can’t run red lights, and you can’t ride in a manner that is unsafe – which includes under the influence of drink or other drugs.

There are also a whole pile of things that the Highway Code specifies that you should do (but aren’t actual legal requirements), including wearing a helmet, wearing reflective clothing, keeping your bike in good working order, and not carrying anything that would mess with your balance.

To be honest, before you ride on the road, it’s worth checking out what the Highway Code has to say.  Whether or not you stick to the letter of the law, at least then you’ll know what it is.

Of course, some manufacturers get around the legal stuff about selling bikes (they must have reflectors everywhere and a bell) by attaching a conspicuous sticker to the bike before it’s sold that informs everyone that the bike is ‘for event use only’ and therefore not subject to the same restrictions.

 

Purpose-built trails.

Essentially, these will be more or less exempt from most of the legal issues around riding.  So long as you stick to the waymarked routes, you don’t need lights, you don’t need a bell, you don’t even need to worry about rights of way and with any luck you don’t even need to worry about pedestrians.  Good sense should still rule though, so wear a helmet and appropriate clothing, and keep your bike in good working order.

Equally, some trail centres are governed by bylaws or have their own rules.  Bike Park Wales in particular makes theirs very explicit – you must wear a helmet and so on.  In other places it’s less clear, and less obviously policed, but nonetheless be prepared to face some difficulties if you’re stupid enough to ride without a helmet, or with a knackered bike.

 

Natural trails.

Here, once again, you need to pay attention to the law.  I’m not saying for a second that everyone always sticks to the perfect letter of the law, but again it’s worth knowing.  Equally, in our efforts to make sure that cyclists and mountain bikers are respected as road and trail users, it’s worth being seen to ride considerately and legally.

In England and Wales (and I think also Northern Ireland, but I’d be inclined to check first…) it is not legal to ride on a footpath – these are for pedestrians only.  It is, however, legal to ride on bridleways, restricted byways, green lanes and roads.  These are what make up every natural route you’re likely to ever find directions for.  Bridleways seem to often be broad, stony, and relatively uninteresting tracks, and this is one of the reasons why using routes that other people have planned out is an excellent idea – they’ve done the work of exploring the area and weeding out the tedious or unrideable bridleways, and put together a route of more interesting and better trails.

Incidentally, the rights of way for cyclists don’t change on Access Land.  Stick to bridleways, and quietly envy the walkers who can head out into the trackless wilds.

In Scotland, however, the Right to Roam laws apply to cyclists as well, so it is permissable to ride on paths and tracks pretty much wherever.

Wherever you decide to ride, make sure you do it considerately and safely.  Give way to walkers and horses.  Close gates.  Don’t ride over planted crops or interfere with land management in any way.  Don’t try to ride through logging work.  Have some sense.

Leave a comment

Filed under Other stuff, Technique

Bleeding hydraulic brakes

So you’ve got some fine-ass hydraulic disc brakes on your mountain bike.  They’re great.  No cable stretch!  No messing around with tension!  Excellent!  They feel direct and firm and reliable.  And then, at some point, they stop feeling like that.  You can squeeze the lever right in after the pads have contacted the rotor.  Or, as happened with mine, once the brakes heat up from use they lock on to the rotor and you have to sit at the side of the trail and wait for them to cool down before carrying on.  There’s air in your tubes.  Your brakes need bleeding.  Simply, bleeding is the process of getting air bubbles out of a hydraulic system.

The process for bleeding brakes depends on the equipment you have and on your system.  Essentially you add new fluid to one end of the system and remove it from the other, hopefully flushing out any air bubbles in the process.  There are kits available which include a huge number of parts.  After a little research I decided on the basic equipment and procedure below, but I suggest looking into it a bit yourself.

Stuff you’ll need:

Well this will vary considerably depending on the brake system you have, and on precisely what manner of bleeding you feel like doing.  Here’s what I used.
Brake fluid.  Use what the manufacturer of your brake system recommends.  Shimano brakes use mineral oil, others use more traditional brake fluid.  You need to use the right one as the wrong one will degrade the seals and cause corrosion in your system.

Syringes.  Two of them.  I had one that I bought in a ‘bleed kit’ and one that I bought from a farming wholesalers.

Tubing.  It should fit tightly over the end of one syringe and over the bleed nipple on your brake calipers.

A spacer of some sort.  I used a stack of plectrums.  Other people have used credit cards, an appropriately sized hex key or a specific Shimano spacer block.

Torx drivers.  The top of my master piston is secured by two T10 Torx screws, and the bleed cover by a T8 one.

Hex keys.  You don’t have hex keys?  How on earth are you maintaining your bike?

 

Step one: Prepare the bike.  Set the brake lever so that the reservoir on the top is horizontal.  You should also wind the reach of the lever out to its fullest extent, although I forgot to do this and it didn’t seem to affect things too much.  At the other end, remove the brake caliper from the bike.  This takes it nicely away from the rotor so you’re less likely to contaminate it with oil.  Remove the brake pads (see the brake pads post for how).  Push the pistons back into place and insert a spacer where the pads and rotor would normally be.

Useful things...

Useful things…

Step two: Open the top reservoir.  Take out the two screws holding the top down and the bleed cover and lift off the cover, and the rubber diaphragm beneath.

These two...

These two…

... and the diaphragm...

… and the diaphragm…

... leaving the oil exposed.

… leaving the oil exposed.

Step three: Attach the tubing to the syringe and draw up a syringe full of oil.  Uncover the bleed nipple on the brake caliper and attach the end of the tubing to it.  Ensure it’s a good fit, it’s annoying to have it slip off.  Once it’s secure, undo the screw to open the bleed nipple by about a quarter turn.  Sometimes this means undoing the bleed nipple itself (and so you’ll need to make sure you have a spanner on the nipple before you attach the tube), but in the case of my brakes it’s a hex bolt at right angles to the nipple itself.

Bleed screw arrowed, and the tube attached to the nipple itself.

Bleed screw arrowed (in front of the connector for the hydraulic line), and the tube attached to the nipple itself.

Step four: Clear the caliper.  Push a few cc’s of oil into the caliper with the syringe, give it a couple of taps and then draw the plunger back a bit on the syringe.  This should clear any air bubbles caught up in the caliper.  It certainly did with mine.

Step five: Bleed bleed bleed.  Now comes the bleeding itself.  Slowly press the syringe attached to the caliper and inject oil into the system.  At the same time, dip the other syringe into the reservoir on the handlebars and draw the plunger back, drawing old oil and air bubbles out of the system as you refresh it from the bottom.  Carry on doing this until the colour makes it clear that it’s new oil going into the syringe and there aren’t any bubbles coming out.

Step six: Close the bleed screw on the caliper (gently, overtightening can damage the seals), and pump the brake lever a couple of times.  It should feel firm even with the reservoir open.  Then open the bleed screw again and inject enough to bring the level right up to the top of the reservoir.

Step seven: Reseal.  Close the bleed screw again and detach your tubing.  Put the diaphragm and the cover back on to the reservoir at the top – it should overflow a little bit.  Screw it down nicely.

Step eight: Clean everything up.  All the oil that leaks out or gets everywhere needs to be sorted out at this point.  Particularly at the caliper end.  Use degreaser or isopropyl alcohol to clean stuff down.  The idea is that it shouldn’t have any chance to contaminate the brake pads once they’re back in.  Speaking of which…

Step nine: Put the brake pads back in.  See the post on changing brake pads.  It’s basically the reverse of taking them out.  Reattach the caliper to the frame, making sure the pads are properly set up round the rotor.  Put the brake lever back to the position you want it in.  Experiment with the brakes to make sure they still work.

 

A final note.  I ended up bleeding my brakes twice in fairly quick succession.  Anyone who read the previous version of this final note will recall that the first time it didn’t entirely fix the issue.  The second time it did.  Inevitably, the first time you attempt something like this you’ll make mistakes.  I think I didn’t have the bike upright enough the first time, and the tube coming loose from the nipple didn’t help.  It’s also possible that the seals on the brakes are a bit iffy, which means I should replace my brakes, but they seem to be working fine for the time being.

As always, if the first time seems to only be a partial success, try it again.

 

Hahaha, nipple.

Leave a comment

Filed under Maintenance, Other stuff

Disc brake pads

Like all mountain bike brakes, disc brakes rely on friction pads that gradually wear and need replacing.  At first glance it seems more awkward than the more obvious pads for V or cantilever brakes, but the truth is that it’s a simple procedure.  As always, the details I give here are for my brakes.  There are variations in exactly how it works, but the principles in each step are identical – it may just be a case of looking at your own brakes to work out what needs doing.

Stuff you’ll need:
Replacement brake pads.  These come in a number of shapes and sizes, although from what I’ve gathered, if it looks right it probably is.  Don’t try sticking circular pads into a rectangular slot, but if it looks the same then it’s probably the right one.  Take your old pads in and match them up would be my advice.  After that there’s a choice of sintered (metal) or organic pads.  Supposedly they act differently, but my experimentation hasn’t yielded an appreciable difference.
Pliers.  Ones with a thin nose.
Hex keys.  You don’t have hex keys?  How on earth are you maintaining your bike?

Step one: Get access to the pads.  You can’t change the pads with the rotor between them, so you need to either take the wheel off the bike (which means you don’t have to align the brakes afterwards as nothing has really changed), or take the caliper off the frame (which means you can wave it about and get at the pads easier).

Step two: Free the pads.  There will be some device that locks through the pads and prevents them from just dropping out.  In my case there’s a split pin that threads through a hole in the caliper, through the brake pads and leaf spring, and through another hole in the caliper.  Straighten the ends of the split pin and draw it out from the other end.  Other designs have a screw here that’s locked with a split pin, or something else.  Work out how it comes out and have it out.

Straighten and remove the split pin...

Straighten and remove the split pin…

Step three: Remove the pads.  On my brakes they’re removed from the other side of the caliper from the split pin.  Squeeze them together slightly and draw them out from the caliper.  Keep hold of them – you’ll have three things in your hands: two brake pads and a leaf spring between them.

Remove the pads...

Remove the pads…

Step four: Push the pistons back into place.  The pistons automatically adjust for wear in the pads, so you’ll never be able to jam the rotor back between your new pads if you skip this step.  Stick something between the pistons in the gap where the pads were, and push them back until they’re pretty well flush with the caliper itself.  Push on the edges of the pistons not the middle – there’s nothing much there to push on and you could easily rupture the diaphragm at the other end of the piston.

Push the pistons back...

Push the pistons back…

Step five: Insert new pads.  Open your new pad pack and make a sandwich of the two pads facing inwards with the leaf spring seated between.  It should be obvious how it goes, since it’s the same shape as the pads, and should fit nicely around the friction surface of the pads.  Pinch them together from the fat end and insert them into the caliper the same way the old ones came out.  They should seat nice and firmly in the caliper.

Step six: Lock them into place.  Reinsert the split pin you took out earlier, making sure it goes through the two holes in the caliper, both brake pads and the leaf spring as well, and then bend the end of one of its arms to hold it in place.

Step seven: Put stuff back where you found it.  Put the wheel back on, ensuring that the rotor sits neatly between the pads, or reattach the caliper and set it up carefully.  Job done!

Step eight: If your new pads are organic ones, you need to bed them in properly.  It’s recommended that you do twenty or so sharp stops at speed (read the sections on braking to make sure this doesn’t mean twenty graceful dives over the handlebars).  Otherwise you could end up peeling the braking compound away from the back plate.

Leave a comment

Filed under Maintenance, Other stuff

On-trail issues: hydraulic brakes locking

Issue: Brakes jam on after a short section of descent.

Damage: A distinct lack of fun.  Pedaling required even when going downhill.  The problem appears to be that as the brakes get hot, something expands and locks the brakes on, meaning that the issue will not solve itself even if I’m not actively braking – because the pads are still contacting the rotor.

Remedial action: At the time, the only remedial action that occurred to me was to break up the descent.  I’d ride for a bit, feel the brakes overheat and lock up, and then take a five minute brake until the rotor was cool enough not burn through my gloves, and then carry on.  This worked fine, but didn’t help the fluidity of the ride.

Ways to avoid: It’s highly unlikely that the rotor or the pads are expanding – they’re designed specifically not to.  This more or less leaves the brake fluid, which also shouldn’t expand much.  Air, however, does expand a lot when heated.  Therefore the solution is bleeding the brakes.  I’ve tried a quick fix for this before where you turn the master piston upright, open it up and jam the brakes on, and leave it for fifteen minutes or so.  This seemed to temporarily help.  However, now it seems like I’ll need to actually bleed my brakes.  See the ‘bleeding brakes’ post (when I write it).  As for the causes of this, I’d imagine that my bike is supplied with fairly cheap parts, which I’d imagine is part of the problem.  Similarly, being stored outside with fluctuations in temperature and sub-zero temperatures no doubt doesn’t help.

Leave a comment

Filed under On-trail issues, Other stuff