BB5 + 160mm Front Rotor = POOR!

Darkstalker420

Hi finally finished the new ride (great love the new Deore shifters with the 2 way action lol ). I fitted Avid BB5's (sintered pads) with avid speed dial 7's + Shimano RT52 160mm rotors. Right from the off the rear brake was great i could lock the wheel with ease BUT the front brake was nothing like its counterpart requiring a "reasonable" amount of force with two fingers before you come to an (eventual :shock:) halt even when really pulling anything like endos/stoppies ain't possible at all.

I have done my best to sort this out i have cleaned the rotors with iso and reset the calipers multiple times and nothing has helped. The kick in the teeth is that my girlfriends bike (before it was nicked! :evil: ) had a Tektro IO cable disk + Shimano v brake levers + 160mm rotor and i could endo with ease with a hard one finger pull!! I may just "sell out" and order a 180mm rotor for the front but just thought i would ask if there is a "knack" to it.

The pads were "bedded in" as best as i thought needed (got them warm by dragging then a series of HARD stops) which did help a little. Just a bit stuck now as what to try next (tempted to swap the pads and rotors around from back to front to be honest).

Thanks.

nicklouse

Darkstalker420 wrote:

(tempted to swap the pads and rotors around from back to front to be honest).

Thanks.

as it is cables i would swap the caliper and rotors around so that you dont possibly end up with two poor sets.

Darkstalker420

:roll: Now thats a better idea thanks Nick.

Thanks.

YeehaaMcgee

Just FYI, the rear brake is very easy to lock up, no matter how poor the brake is. That's because the rear naturally unweights when you decelerate, reducing the friction between the tyre and the floor. That means that you'll reach a point where the best the tyre can do is skid.
The front brake however, forces the front wheel into the ground hard, and the harder you brake, the better the tyre grips (up to a point, obviously).

So with poor brakes, it's very very common to be able to lock up the back , but have the front seem innefective.
As for bedding in - just ride it. It will bed in by itself soon enough.

rhext

You could try organic or kevlar pads too (the ones from Superstar components are cheap enough to have a play with). They're softer than sintered, which means they don't last as long, but they do sometimes grip better as a result.

leaflite

Are they set up correctly ie the pad that is fixed almost dragging on the rotor?

Setup guide here:
http://bikeshopgirl.com/2011/08/how-to-properly-setup-and-adjusting-avid-bb5-brakes/

Darkstalker420

Just swapped the calipers/rotors and WHOA! :shock: i was coasting along and grabbed the front quite hard (one finger though still!) and performed an impromptu sitting endo . It's like a different brake setup now the back is still ok to lock up (although i stopped skidding when i had to start paying for my own tyres! ). Stopping with one finger is easily possible so thats great.

Thanks for the guide leaflite i will bear it in mind when i need to "fiddle" but a secondary effect of swapping the calipers is that the annoying "ching ching" rub has now stopped so its all = WIN thanks for all the suggestions.

Thanks.