Lesson On Brakes

[luccosleeps]

Hey kids,

Just thought i'd post up a how to for setting up v type brakes. Hope it helps a few people that still use them like me.

enjoy

The standard for mountain bike brakes is: your brakes should be able to stop your bike within 15 feet while a 150-pound rider is going 15 mph. (And they shouldn't screech or wobble.)

Optimum brake performance also depends on undamaged rims and a true tire alignment (perfectly round rim with no lateral warpage) -- you may need to replace or true your rims to get your brakes working right. This section describes a basic tuneup and cleaning. Please see other sections for brake pad replacement or truing of rims.

If your brake cables have dirt in the housing, the brakes may be hard to pull, or the calipers may not rebound away from the tire when you let off the brakes.

Clean all visible brake parts with a brush. Soapy water works fine. If there's substantial oil or grease buildup, use a degreasing solution.

Release the brake cable by detaching the retaining clip from the cable housing.

**Detaching the brake cable from a V-brake system**

Coil-spring brakes may be more susceptible to gumming than those with an external spring. To remove the caliper for cleaning, first release the spring tension by backing out the tensioning screws on each side.

Loosen the tensioning screw to relax the spring before removing the calipers.

Now unscrew the mounting bolt to remove the caliper. Clean the spring and bushing thoroughly. Relube and remount the calipers. Don't get grease on the rim or tire!

Removing the caliper to clean the swivel and spring.

Check the brake pad for wear. A ridge of unworn pad on top or bottom means your brake isn't hitting the rim squarely. Replace worn-down or unevenly worn pads.

Inspecting the brake pad.

Check the rim for damage. If you do much mud-riding, the rim may wear thin. As the brakes push in, the metal curves inward. Cracked or buckled rims need replacement.

If there are local rock-bites on the rim, smooth the ridges off with ultra-fine sandpaper. If the rim is widely rough, clean and smooth the rim with steel wool.

Now reattach the brake cable to begin aligning the brake pads.

**Reattaching the brake cable**

Go to the brake lever. Turn the adjusting knob back, leaving only about 1/8" of space between the knob and the lever housing.

Backing off the cable length adjuster.

Loosen the cable retaining screw on the caliper. Take up extra cable until each brake pad is about 1/8" from the rim, then tighten the retaining screw.

Loosen the stem of the brake pad. On V-brakes, this is done with the nut at the end of the stem.

**Adjusting the cable length**

Slide the stem of the brake pad up or down within the slot in the caliper, until it's exactly perpendicular to the plane of the rim as the pad touches. Turn the pad so it's aligned along the center of the rim along its entire length. Tighten very slightly.

Toe the brake in slightly at the front end. This means the FRONT end of the brake pad will be a trace closer to the rim than the back end. (Screeching brakes are fixed by toeing the brake pad.) Put a couple of business cards under the back end of the pad, then grip the brake lever to tighten the pad down against the rim. Now tighten the stem fully.

**Positioning the stem (push-arm) and brake pad**

Using the tensioning screw, add rebound to the calipers until they spring away from the rim strongly. Rotate the tire, while watching the position of the pads in relation to the rim. If the rim is not true, both brake pads may hit the rim at different times as the tire rotates. If so, you need to true the rim before proceeding.

**Checking clearance. Checking stem and brake pad alignment**

Grasp the brake lever and stop the rotating tire several times. Check the position of the pads relative to the rim. If one is closer (or rubbing), tighten its tensioning screw (turn the screw IN) so the caliper rebounds further away from the rim. Repeat adjustments of 1/4 turn until the pads remain equally spaced.

Adjusting the spring tension.

Tighten the brake cable with the adjusting nut at the brake lever. Goals: (1) The pads shouldn't hit the rim. (2) As you pull the lever, the brakes should engage at a point that's comfortable for your hand. (3) You should have around 1-1/2 inches of daylight between the lever and the handlebar when you're pulling hard on the brake. Some riders like a closer grip, leaving only about 1/2," but this puts you at risk of "bottoming out" the lever with the brake only partly engaged.

**Fine adjustment of cable length**

If you ride in mud, you may need extra room between the pads and the rim. Loosen the cable slightly. Be sure you still have plenty of space left between the lever and handlebar, so you'll retain braking power as the pads wear down.

**Checking brake lever position**

If your fingers are short, or you like the levers a bit closer to your hand, you can adjust the lever's starting position. The adjustment screw opposite the lever can be used to swing the lever back towards the handlebar. (This gives you less total brake-lever motion, so the tuning of the brakes needs to be more exact.)

And there you go, hope you have enjoyed this and most importantly i hope it taught you one or two things too.

cheers,

jake

[Trials Boy]

Nice one Jake Very well done and easy to understand!

You should get validated now!

[Jez]

Forget the bit about toeing it in, just make sure the pads are hitting dead square on. You should be able to HEAR the pad 'clack' against the rim when you pull the lever while the bike is stationary. Toeing in gives you more modulation, which is usually not required for trials; you're usually out for power.

Edited March 9, 2006 by Jez

[Simpson]

great comment man! really needed this to set up my front brake, many instructions on how to set up maggies but none on vees i cant remember anyway well done man will take my laptop outside and give it a bash now cheers

[Walleee]

ctrl + C, ctrl + V?????

Good job anyway.....

[luccosleeps]

No not at all, im a fulltime Mechanic at halfords, been working there a while now and have learned quite abit there, got a sweet cycle staff in Folkestone. I just thought to myself that i've been on the NMc for abit too long now and know quite abit so i thought i'd post something up.

But yeah ignore the toeing in bit thats just for general mountain bikes and im use to doing that with the bikes i work on at work.

[luccosleeps]

sooo...... yeah if anyone has any trouble with their bikes and can't find out why, message me on msn or something.

[Walleee]

No not at all, im a fulltime Mechanic at halfords, been working there a while now and have learned quite abit there, got a sweet cycle staff in Folkestone. I just thought to myself that i've been on the NMc for abit too long now and know quite abit so i thought i'd post something up.

This section describes a basic tuneup and cleaning. Please see other sections for brake pad replacement or truing of rims.

What other sections?

ARGH, i just googled it and found it, did you have to lie?

http://www.utahmountainbiking.com/fix/braketun.htm

The only differance is, that one's better as it has pics.

Edited March 9, 2006 by jake1516

[Mr_Pitbull]

What other sections?

ARGH, i just googled it and found it, did you have to lie?

http://www.utahmountainbiking.com/fix/braketun.htm

The only differance is, that one's better as it has pics.

LMAO, for those who actually give a f**k, i spent nearly 1 whole hour doing this

http://www.trials-forum.co.uk/forum/index....topic=65888&hl=

Its complete bullshit to those who dont know about maguras and set ups...

Edited March 9, 2006 by Mr_Pitbull

[luccosleeps]

lol so yeah i did find it off a website but i mean, at least it was a useful post and i dont see many people posting about v brakes, but the fulltime mechanic thing is true, i just couldn't be arsed to write all that up. you can ask several people who live in folkestone that iam.

[Walleee]

I don't doubt that you are, but as an engineer in training, I wouldn't feel the need to plagarise other's work, at least give credit where credit is due eh?

[luccosleeps]

yeah suppose, just tried to help the old process of getting validated as i've sat in the noobie NMC for abit too long now

[Walleee]

Your name is jake, that's cool

[luccosleeps]

hehe yup damn straight it is

[flipkickbs]

LMFAO!! this topic is too funny.

and now.

How to set up a rear mech:

Rear mech set-up

By Mike Davis

The humble rear derailleur (or 'mech' to its friends) is a remarkable beast. When you think about what it's trying to do it's a wonder it works at all, let alone as well as it does. They don't like going without periodical TLC, though, so if your shifting's gone a bit awry here's how to sort it.

As with all maintenance jobs, this one's a lot easier if you clean your bike first. It was cold and nasty when we were doing this, though, so we didn't bother. Bad us.

It's a nice straightforward job tools-wise, this one. You'll need a 5mm Allen key, a cross-head screwdriver and a pair of pliers (unless you have fingers of steel).

First things first - get your bike in some sort of stand that lets you spin the pedals and back wheel. It makes things a lot easier. If you don't have a workstand you can try hanging the bike off a loop of rope, drafting in a willing volunteer or quickly growing a third arm.

The first thing to get right is the upper and lower limits. Left to its own devices the rear mech'll happily shift the chain beyond the top and bottom sprockets on the cassette. This is clearly a bad thing. Fortunately it comes equipped with two screws to limit the throw of the mech. The high limit is the easiest to set. Shift into the smallest sprocket (also known as 'top' or 'high') and twiddle the high limit screw (the one marked 'H' until the top jockey wheel is directly below the sprocket. Cable tension may prevent it moving out far enough, in which case you can undo the clamp bolt - we'll be setting that bit up in a minute anyway.

In theory you should do the low limit screw next, but we always find it easier to do that after the cable tension's sorted out. So that's the next job. Make sure the cable's clean and running smoothly. If it's sticky or gritty you'll never get it to work. Take a look back at our cable care article first. Once you've got free-running cables, make sure the barrel adjusters on the mech and shifter are wound nearly all the way in (one turn out gives a bit of useful scope for adjustment).

Then thread the cable through the barrel adjuster and cable clamp, pull it taut with pliers and do up the clamp bolt with a 5mm Allen key (or an 8mm spanner on some mechs). Don't pull the cable too tight, just take the slack out of it. And make sure that all the cable housing is properly seated in the cable stops.

Now it's time to see how close you are. Spin the cranks and try shifting from the smallest sprocket to the next smallest. If it goes straight in, shift back, wind the barrel adjuster in (clockwise) a quarter turn (the adjuster's usually indented so you can easily count turns) and try again. At some point it'll refuse to shift, so turn it out (anticlockwise) again. Similarly, if it won't shift on to the next sprocket straight away, turn the adjuster out until it does. If you have to turn it miles, wind it all the way back in and retension the cable at the clamp bolt.

After a bit of twiddling you should have a mech that happily shunts the chain up and down the cassette without hesitation either way. Now it's time to sort that lower limit screw out. Carefully shift into the biggest sprocket. Go one click at a time, if the limit screw's way out you could easily shift over the end into the wheel. Once the chain's on the big sprocket, turn the lower limit screw clockwise until the mech just starts to move outwards, then turn it back a whisker.

All we're left with now is the mysterious B-tension screw. This controls the angle of the mech body itself and thus the vertical gap between the top jockey wheel and the sprockets. You should get the best shifting with the smallest gap you can manage without the jockey wheel actually touching the sprockets. Turning the B-tension screw anticlockwise allows the mech to swing further forwards, closing the gap. If the jockey wheel gets too close, turn it clockwise until it clears. And that should be it...

LMAO!!!!

Ian

[luccosleeps]

LMFAO!! this topic is too funny.

and now.

How to set up a rear mech:

Rear mech set-up

By Mike Davis

The humble rear derailleur (or 'mech' to its friends) is a remarkable beast. When you think about what it's trying to do it's a wonder it works at all, let alone as well as it does. They don't like going without periodical TLC, though, so if your shifting's gone a bit awry here's how to sort it.

As with all maintenance jobs, this one's a lot easier if you clean your bike first. It was cold and nasty when we were doing this, though, so we didn't bother. Bad us.

It's a nice straightforward job tools-wise, this one. You'll need a 5mm Allen key, a cross-head screwdriver and a pair of pliers (unless you have fingers of steel).

First things first - get your bike in some sort of stand that lets you spin the pedals and back wheel. It makes things a lot easier. If you don't have a workstand you can try hanging the bike off a loop of rope, drafting in a willing volunteer or quickly growing a third arm.

The first thing to get right is the upper and lower limits. Left to its own devices the rear mech'll happily shift the chain beyond the top and bottom sprockets on the cassette. This is clearly a bad thing. Fortunately it comes equipped with two screws to limit the throw of the mech. The high limit is the easiest to set. Shift into the smallest sprocket (also known as 'top' or 'high') and twiddle the high limit screw (the one marked 'H' until the top jockey wheel is directly below the sprocket. Cable tension may prevent it moving out far enough, in which case you can undo the clamp bolt - we'll be setting that bit up in a minute anyway.

In theory you should do the low limit screw next, but we always find it easier to do that after the cable tension's sorted out. So that's the next job. Make sure the cable's clean and running smoothly. If it's sticky or gritty you'll never get it to work. Take a look back at our cable care article first. Once you've got free-running cables, make sure the barrel adjusters on the mech and shifter are wound nearly all the way in (one turn out gives a bit of useful scope for adjustment).

Then thread the cable through the barrel adjuster and cable clamp, pull it taut with pliers and do up the clamp bolt with a 5mm Allen key (or an 8mm spanner on some mechs). Don't pull the cable too tight, just take the slack out of it. And make sure that all the cable housing is properly seated in the cable stops.

Now it's time to see how close you are. Spin the cranks and try shifting from the smallest sprocket to the next smallest. If it goes straight in, shift back, wind the barrel adjuster in (clockwise) a quarter turn (the adjuster's usually indented so you can easily count turns) and try again. At some point it'll refuse to shift, so turn it out (anticlockwise) again. Similarly, if it won't shift on to the next sprocket straight away, turn the adjuster out until it does. If you have to turn it miles, wind it all the way back in and retension the cable at the clamp bolt.

After a bit of twiddling you should have a mech that happily shunts the chain up and down the cassette without hesitation either way. Now it's time to sort that lower limit screw out. Carefully shift into the biggest sprocket. Go one click at a time, if the limit screw's way out you could easily shift over the end into the wheel. Once the chain's on the big sprocket, turn the lower limit screw clockwise until the mech just starts to move outwards, then turn it back a whisker.

All we're left with now is the mysterious B-tension screw. This controls the angle of the mech body itself and thus the vertical gap between the top jockey wheel and the sprockets. You should get the best shifting with the smallest gap you can manage without the jockey wheel actually touching the sprockets. Turning the B-tension screw anticlockwise allows the mech to swing further forwards, closing the gap. If the jockey wheel gets too close, turn it clockwise until it clears. And that should be it...

LMAO!!!!

Ian