Fitting new brake blocks on bicycle - which way round?

Chomeur

I've got some new brake blocks (http://www.aztecbrakes.co.uk/rim/v-brake/pba4002) to fit on my bicycle. They have grooves in to help water drain out. One end of the blocks has the word "Forward" written on it to help you fit them the right way round. That seems completely ambiguous to me. Does it mean:

1. That the end with "Forward" on should be to the front of the bike? or
2. That a point on the rim should pass the end with "Forward" on first, as the wheel goes round, as drossal says here http://yacf.co.uk/forum/index.php?topic=27222.0? This would be the opposite way round to the first one.

Anyone know?

sequence

It means the direction of travel. All the forward arrows should point the way you'd travel, towards the front of the bike. Unless you're a hipster fixie rider, who pedals backwards.

They're labelled so that the inserts don't get pulled out by the braking force, if the little locking bolt has fallen out.

Hope that made a bit of sense. Good brake blocks they are, too. I have them.

Chomeur

Thanks, actually to be fair to Aztec I notice there's an L and an R to show you which way round to put them, and that conforms with what you're saying

Chomeur

Strange thing is, the fitting for the brakes on one side is not parallel to the wheel so only the back of the break pad makes contact with the rim. This is the case at both the back and the front. It doesn't look very good really. I'm sure I can't have damaged my bike enough to have warped these fittings, they're pretty solid.

http://postimage.org/image/2t84luo84/

Strider590

They should not be parallel!!!

If they're parallel, they will "grab" and squeal like a b1tch...........

There should be around 2mm gap at the front of the pad when the rear is just touching the wheel. You normally have to rotate the spacers and shims (on either the pad or the brake arm itself) to achieve this.

This way when you apply the brakes they'll be more progressive and predictable, the harder you pull, the more brake pad with touch the rim.

sequence

As above! If you look closely, you'll see there's a little domed washers, this lets you alter the angle relative to the rim. They should be at a slight angle, as strider says.

SteveJW

To me your picture shows you have the spacers wrong

At the top of your picture you have a thin spacer/brake arm/thin spacer/thick spacer/thin spacer. At the bottom you have a thick spacer/brake arm

You need two spacers on the pad, one concave one convex
| ) )| brake arm | ) )| then the brake arm and then another two spacers again one concave one convex. These act as a cup and cone arrangement and allow sufficient movement to align the pads correctly

Sorry not explained very well, any problems drop me a PM and I will send a picture

Best way I have found is do not fully tighten up the brake pad securing nuts
Tear off a couple of pieces of card that the pads came mounted on, insert these from the front of the pads for about 10mm.

Get someone to gently apply the brake, jiggle / wiggle the pads about so they align with the rim

Tighten up, being carefull not to twist the pads out of line

Release brake, card falls out, gap at front of pad equal to thickness of the card.

Hammyman

I think I've just lost the will to live. If you can't work out which way brake pads go, especially when they have left, right and forward on them, there is no hope for you.

shandypants5

Strider590 wrote: »

They should not be parallel!!!

If they're parallel, they will "grab" and squeal like a b1tch...........

There should be around 2mm gap at the front of the pad when the rear is just touching the wheel. You normally have to rotate the spacers and shims (on either the pad or the brake arm itself) to achieve this.

This way when you apply the brakes they'll be more progressive and predictable, the harder you pull, the more brake pad with touch the rim.

Sorry but I think your wrong here.

The gap should be at the BACK so that they twist flat under braking pressure.

If you have the gap at the front you are seriously reducing the effectiveness of your brakes.



Vee brake Set up instructions linky

neilmcl

shandypants5 wrote: »

Sorry but I think your wrong here.

The gap should be at the BACK so that they twist flat under braking pressure.

If you have the gap at the front you are seriously reducing the effectiveness of your brakes.



Vee brake Set up instructions linky

This is the correct way.

Strider590

shandypants5 wrote: »

Sorry but I think your wrong here.

The gap should be at the BACK so that they twist flat under braking pressure.

If you have the gap at the front you are seriously reducing the effectiveness of your brakes.



Vee brake Set up instructions linky

You know what, it's been at least 7 years or more since I used V brakes and this may well be correct. I think a little experimentation is in order. All I do remember is they should never be parallel.


Hydraulic disc brakes, don't have to worry about this stuff