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Need Help with Fixing your bike, wondering how to change a tyre or adjust a gear cable? or just need a little advise on maintaining your bike between rides? Check out this section.

 

Contents:

  • Chain Cleaning/ Lubing

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General Maintenance

Chainset Cleaning

Looking after your chain and chainrings/ rear cassette, I always clean my chain and chainrings after a ride if they look dirty and have attracted debris and grit. the best thing to do is to buy a chain cleaning machine, Clean the chainset BEFORE cleaning the rest of your bike. the best way to clean the rear cassette is with the rear wheel removed (shift the gears to the smallest sprocket on the rear cassette to aid with refitting later, you will know which sproket to place the chain on!!), use a small sprocket specific brush and chain cleaning detergent to get between the sprokets and clean out all the dirt until spotless, unhook the chain from the front chainrings and drop carefully down on the bottom bracket or out of the way so the chain ring spins freely (use a rag to prevent scratching of your frame if you're that way inclined) then clean the chainrings as you did with the cassette. You will also need to clean the small jockey wheels of the rear mech as these clog up very badly and as they are usually only made from plastic they can wear down very quickly if left with grit on them!! refit the rear wheel and refit the chain to the chainring and cassette.Then to clean the chain, you simply insert the chain between the brushes of the chain machine and close the machines two halves together, add some cleaner fluid and spin the pedals backwards 40 or so turns, then I empty the machine and give it another go until the chain is clean (only necessary if still dirty).finally make sure the sprokets are clean again after fitting the dirty chain to clean it with the machine.

You can decide which order to clean in depending on which is dirtiest, the chain or sprockets or do a little of each then a final on each. its up to you.

Cleaning the Rear Cassette

Unhook chain, Clean Chainrings

Clean Jockey wheels

 

Lube

Once clean Allow to dry fully, THIS IS VERY IMPORTANT!! blow with an airline if you have one to get inside all the rollers of the chain (any cleaner left inside the chain rollers will prevent chain lube from sticking and doing its job, lube is no good just on the outside!) Once fully dry you need to apply a lube, its best to use a specific chain lube rather than something you have lying around the garage, they are fairly cheap and if applied correctly a bottle of lube will last a long time. I use a wet weather Wet lube in poor conditions and during the dryer summer months I use a Dry lube or try This one if you want to keep the same brand as the wet lube.

Pick a start point, either a split link or the main black chain pin (or use a dab of tipex to mark a link) then carefully add a drop of lube to each side of each link one by one until you have lubed the entire chain, mine is 108 links (sad eh?) then cycle the chain backwards to work the lube inside the rollers, also a squirt of lube inside the small jockey wheels of the rear mech where they run against their centre pin/ bearings. If you're using a wet lube remove the excess lube from the outside of the chain with a rag as this will only attract dirt, If you're using a dry lube shake up the bottle to mix the solution together before applying to the chain, but this time you dont need to wipe off the excess from the outside of the chain after lubing, it is actually better left on the chain to repel the dirt. Finally a small amount of lube on the pivot points of the rear mech and front mech (deraileurs).

Yes it is a pain to clean your drive train after each wet ride but the benefits far outweigh the time spent. Your drive train will last for a many years instead of maybe one year (it is expensive to replace a full drive train, which is what you will probably need) and also more importantly while out on the trail you will have smooth consistant shifting, which you cant put a price on!

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Bike Cleaning

You can Clean your however you like I just use a hose when I get back from riding and whatever has stuck to the bike usually just drops off, especially if its been raining (which lets face it, it usually has been) if its a little stuck on then I use a soft brush or sponge with a bucket and water with a little cleaner in it (I use Muc-Off or if I've ran out, fairy liquid, some people would advise you not to use fairy liquid as they say it damages stuff, personaly I haven't experienced this, But I always dry my bike after washing it) However its probably best to use a bike specific cleaner such as Muc-Off or other bike specific cleaners as they are designed with bike components in mind, one thing you must not do is POWERWASH around the components of the bike such as brakes/ brake levers, gear systems, hubs, cables, pivots, fork seals, bottom brackets, headsets etc as water in any of them will destroy them and end up costing you a fortune to replace them and it will mean lost trail time.Other than that it 'should' be ok to clean the other items on the bike with a jet wash and 'should' be ok to rinse the components mentioned above with a power wash if it is kept at a very far distance so as not to concentrate the waters jet at the components. Also if you have an Airline do not use it to dry around brakes, seals, bearings, fork seals etc as you will cause damage and even blow air into hydraulic systems, however it should be ok to blow dry at a distance (frame and components etc just do not force dry at close distances!)

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Bleeding Magura Disc Brakes

I have chosen Magura as an example of how to bleed disc brake systems as this is the brand that is fitted to my bike (specifically, Magura Louise) and I have therefore experience in doing so. (for other brands of braking system please refer to manufacturers specifications, there is a list of most of the main brake manufacturers on my links page)

I have taken this bleeding guide from Magura directly but have added in some extra points that I think are important and therefor are worth adding (I have high lighted them in RED text) I have also added some pictures to help with the process.

  1. For Marta SL, Marta and Gustav M - Fix the caliper in a postition so that the hose connection to the caliper is at the highest possible point. Hose must be positioned vertically. You may have to loosen or unscrew the caliper fitting bolts that connect the caliper to the frame or fork to get the caliper in this position. ....................................... For Louise FR, Louise, Julie - Fix the caliper in a position so that the bolts that hold the caliper together are horizontal. You may have to unscrew the lower caliper fitting bolt to get the caliper in this position. On my 2005 model Louise brake calipers there are no bolts holding the caliper together? I fixed the caliper with the fitting holes horizontal as per this picture below, there is a high point above the bleed screw but air is still bled out ok.
  2. Remove the Pads and push the pistons back into their cylinders completely with a Plastic tyre lever. It is important to remove the pads during the bleeding process to ensure they are not contaminated.To remove the pads simply straighten the split pin end and pull it out then unbolt the caliper and remove it from the frame (taking note of any spacer washers between the caliper and frame), remove the pads from the underside of the caliper one at a time, then fix the caliper in the position shown above in STEP 1.
  3. Assemble your Magura syringe, tube, and m6 threaded bleed fitting. Fill this completely ONLY with Magura Blood (see below) Make sure your bleeding syringe is totally full and air free. Point the thin outlet end/pipe and threaded bleed fitting upwards and gently push the syringe piston into the cylinder until a tiny amount of Magura blood comes out of the bleed fitting, check again that there are no air bubbles in the syringe.Unscrew the 3mm or 5mm bleed plug located on the caliper (see below) with a hex wrench and attach your bleeding syringe/ pipe/ threaded bleed fitting into this hole. Tighten fitting 1/8 turn with an 8mm open end wrench. Avoid mess by wrapping a piece of old rag around the caliper.
  4. Loosen the 5mm clamp bolt which clamps the master cylinder (Brake lever assembly) to the handlebars and level the reservoir so it is horizontal then slightly tighten up the clamp bolt again so that it does not move around. I also secure the bars with a bungie strap.
  5. Take the reservoir cap off with the T7 torx wrench (Mine came in the kit) and remove the rubber membrane.
  6. Start the bleeding process by pushing the fluid through the system from the bottom up using the bleeding syringe. Use the second syringe to take out the excess fluid from the reservoir before it over flows. Again a piece of old rag wrapped around the lever assembly will stop fluid dripping everywhere (make sure it is clean and free of dust/dirt though as you don't want this to enter the reservoir) Also it is important to lightly tap the caliper and brake line with the handle of a small screwdriver, etc while the fluid is being pushed through the system to help make the bubbles rise up to the reservoir. Push almost the entire amount of fluid through the system but leave a small amount in the syringe.
  7. Slowly start cycling the lever blade. This will push fluid through the system from the top and out the caliper and into the bleed syringe. Keep the reservoir full of Magura Blood with the second syringe which should be full from STEP 6 so that you do not introduce air into the system and have to start again. Cycle lever 20 times OR until air bubbles are no longer coming out of the bleed fitting and into the bleed pipe/ syringe. Your system should now be totally air free. When you slowly cycle the lever blade make sure that you really do cycle the lever SLOWLY, start by SLOWLY pulling the blade in completely, then as you SLOWLY release the blade back out, hold the piston of the syringe and the syringe body in a fixed position so the piston cannot move in the body, with your other hand to stop the fluid sucking the fluid back into the caliper again as the lever blade returns outwards. I found that if you cycle the blade at a normal speed like as if you were pulling the blade to test the brakes you dont have to hold the syringe and piston BUT lots of air is introduced into the system around the bleed fitting area and bleeding the system seems endless! The key to bleeding successfully is to do it slowly.
  8. Make sure that the reservoir is completely full and re-install the membrane and reservoir cap and secure the screws with the T7 torx. Wipe off any excess fluid from the lever assembly.
  9. Important step - Unbolt the caliper from the frame/ fork keeping the bleed syringe/ pipe/ fitting attached and make sure the caliper is clean and dry then place the pads back into the caliper, BUT do not secure them with the split pin. Now place the caliper with pads in and place the caliper over the disc rotor as though you are going to fit it BUT do not put the bolts back in, allow the caliper to be free on the rotor (see below). Now push fluid into the system with the bleed syringe at the caliper end until resistance can be felt. Check visually that the pads meet the rotor fairly equally and that one of the pistons is not stuck in, if one is stuck in, apply pressure to the caliper/ rotor to move it untill the pistons are roughly equally out of the caliper body, then repeat the pushing of the fluid with the syringe until the resistance is felt and the pads meet the rotor. This will set the pads on the rotor for the particular pad wear and ensure that the maximum amount of fluid is in the system.
  10. Take the caliper carefully off the rotor making sure that you don't spread the pads, then take the pads out of the caliper and place to the side out of the way of contamination and fluid spillages. Loosen and take the bleed syringe off the caliper and quickly re-install the original bleed plug back into the caliper and tighten.
  11. Clean off any fluid from the caliper/ rotor etc and re-install the pads back into the caliper, bolt the caliper back on along with any spacer washers that came off when removing it.

Thanks to

Buck Mitchell

Magura USA

www.magurausa.com

 

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Replacing Chain/ Cassette/ Chainrings

Chains

After a while your Chain will begin to stretch and start to wear, the best thing to do is to buy a chain measuring device which will tell you if your Chain is past its sevicable life and is in need of replacement. If you choose to ignore this and carry on riding with a worn out chain then the Chain will begin to prematurely wear out the Cassette and Chainrings, The Chainrings and Cassette will eventually need replacing anyway as they are a wearing part and do need to be replaced every so often just like the chain. Things to look out for are teeth that look like sharks teeth/ saw edged or have large spaces in between the teeth and sharply pointed tips instead of a U shape between teeth and flat topped teeth! see below, new one is on the right!

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Changing a chain is a really simple task, if you have a split link then simply disconnect the link and remove the chain, if on the other hand there is no split link, which is probably the case if this is the frst time you have had to replace the chain on a bike which you have owned from new! then you will need a chain splitter, either buy a stand alone chain splitter designed premarliy for splitting chains or if you can? get a multi tool with a chain splitter included! Then once the chain is removed count the number of links the chain has and then count the number of links on the new chain and remove any that are not needed (If you order the new chain off the internet make sure that it is the correct size and length, chains are the same width for 7/8 speed rear casettes but thinner for 9 speed and thinner again for 10 speed rear cassettes) Sram make some brilliant split links to join your chain together that are as strong as a regular link in a chain, they are priced at around £1.99 and are really simple to use.

Chainrings

When replacing the Chainrings on your bike for the first time make sure that the new chainring/s you get (if ordering online) are the correct size! chainrings differ in width, be it 8/9 speed etc and the number of teeth but most importantly the BCD measurement! BCD (or Bolt Centre Diameter) refers to the diameter of an imaginary circle thats centre is the middle of the chain ring and runs through the centre of each of the bolt holes, On a 4 bolt Chainring this is easy to measure as it is the distance from one bolt hole centre across to the centre of the bolt hole directly opposite (see below for example) but on a 5 bolt Chainring the measurement is harder to take as non of the bolt holes are directly opposite each other. One way you could measure a 5 bolt Chainring is to measure from the very centre of the crank arm mount/ bottom bracket axle centre, outwards to the centre of one bolt holes and multiply by two, thus giving you the BCD (i.e if the distance was 55mm multiply by two gives you a BCD of 110mm)

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Cassettes

Cassettes will wear out just like the Chainrings at the front of your drive chain wear out, the teeth become 'Saw/ Shark toothed' and the U's become elongated with the tips of the teeth becoming sharp and pointed. To remove the Cassette you will need a special socket, these vary in type depending on the type of Cassette fitted, most mountain bikes have Shimano or Sram Cassettes fitted but I have heard of some XC whippets who fit 10 speed Campagnolo road cassettes which need a different socket. Shimano and Sram Cassettes for premium priced MTB's use the same type of socket which can be purchased fairly cheaply from most online bike stores or your Local Bike Shop (LBS), here is an example one that I purchased made by ICETOOLZ it says for Shimano BUT also fits Sram to! You will probably need a chain whip (see Chainwhip in box below Cassette tool) as well to hold the cassette while undoing the lockring for the Cassette they to are cheap to buy, I didn't buy one to remove my Cassette, instead I improvised by using the old Chain that was being replaced and therefor didn't matter if I damaged it. I wrapped the chain once around the Cassette and then used a nail (you could use a thinnish screw driver) which I slotted through the chain to hold it together and held the nail with a set of pliers, then undid the lockring! It is only secured to 40Nm and so wasn't tight to undo, when you come to torque up the lockring on the new Cassette you don't need to hold the cassette with a chain whip as the teeth are locked by the Freehub as though you are pedalling. Make sure that you adhere to the correct torque or you could strip out the lockring threads or worse the freehub threads as well! See below for use of tool with quick release skewer removed, the tool has a locating rod to stop the tool slipping out of the teeth (Please note, the spanner holding the tool is for illustration purposes only! a spanner or normal ratchet and socket should be used when undoing the old lock ring! to tighten up the new Cassettes lockring always use a torque wrench, NEVER use the torque wrench to undo as this will damage/ uncalibrate the torque wrench)

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Swopping out brake pads

Magura Louise FR, IS (International Standard) mount.

 

Firstly, while the Caliper is still bolted tight, squeeze the split pin ends to close up the pin for easy removal! then grip the ring end of the split pin and pull the pin out, then place it to one side ready for refitment later.

 

 

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Now that the split pin is removed you can go ahead and remove the caliper, make sure that the Allen key or socket is the correct size and is fully inserted into the allen headed bolt hole, if there is dirt inside the bolt hole use a small screw driver to scrape out the dirt (you could round out the bolt hole and/ or injure yourself if the key/socket is not fully inserted and slips out)

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When removing the pins that hold the caliper to the swing arm or fork, take note that there are loose washers/shims between the mount and the caliper which will fall and could be lost if you don't catch them! ( IS Type mount only ) also note how many washer/shims are at each bolt mounting and keep them with the respective bolt and mount (i.e the front bolt washers kept with the front bolt and refitted to the front mount for the caliper) this is because the shims are there to adjust the caliper in relation to the disc and may cause uneven wear, squealing, poor performance etc if fitted incorrectly.

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Once the caliper is removed gently ( slow/light action ) press the caliper pistons back into the caliper with a screw driver or other slim flat blade, do this while the old pads are still fitted that way you wont damage the pistons or new pads! ( it may be nessasary to slacken the lever/reservoir assembly and level the reservoir then remove the top cap and catch excess fluid as the pistons are pushed back in, try with first! see above guide to removing top cap and bleeding brakes when top cap removed)

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Remove the old pads and fit the new pads back in making sure that the friction braking surface is the correct way around, i.e the friction surface of the pad will contact the disc rotor and not the Metal back plate of the pad contacting the disc rotor! ( If when the first pad is inserted you find it difficult to slot the second pad into the caliper because the pads seem too thick, use a small screw driver or other blunt object to very gently push the already inserted pad and piston back into the caliper body while you insert the second pad, They will both fit in, trust me ) Now refit the caliper, making sure that the bolts and washers/shims go back where they came from. Screw one bolt and washers/shims in at a time by hand and leave slightly loose to help when fitting the second bolt and washers/shims.

 

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Secure the bolts taking care not to over tighten them and refit the split pin then bend the split pin ends back open to stop it coming back out. test the operation of the brake lever, if the lever has very litle movement or the brake drags without being pulled it may be nessasary to drain off and re-bleed the brakes as described above as there may be too much fluid in the system! Also if the lever pulls into the handlebar grip when pressed there may have been air introduced into the system while pushing the pistons back in and may also require bleeding (see above topic for bleeding brakes)

 

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Page last updated 26/06/2008

 

 

 

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