Mountain Biking - BB7 Problems

I know this is supposed to be in the mechanics section, but I've posted it there and didn't get a single view. Neither did my questions on rear shock mounting hardwar or a Z1 FR 3 ETA cartridge. Not a single view, and it's pissing me off. I think there's something wrong in them parts :P

Anyways, I got the front BB7 8" version installed and it appears to be properly alligned. Pads are parralell and it doesn't scrape the rotor when it spins.

However, sometimes when I turn it scrapes the rotor. As far as I've read in the manual and around the intarweb that means a misalligned rotor. Can't say it is, the pads are perfectly paralell to the rotor.

Also, if I put my weight forward and pedal in a somewhat high gear (more torque on the cranks) the rotor scrapes. I haven't been able to find anything on this topic.

Thanks in advance for any help.

if it doesnt rub when the wheel spins, then youre ok. probably just torsional forces

Undo the bolts that hold the bb7 onto the adapter, grab and hold the lever to that brake, and tighten the bolts up while you're holding the lever. That might make it go away.

Try moving the pads in or out too.

I may be out on a limb here...but is your QR as tight as it should be? maybe the wheel is shifting slightly under those conditions.

Undo the bolts that hold the bb7 onto the adapter, grab and hold the lever to that brake, and tighten the bolts up while you're holding the lever. That might make it go away.

Try moving the pads in or out too.

I'd actually suggest not doing this -- it implies a "death squeeze", and Avid's hate a death squeeze (you know, that's that overly-agressive squeeze some folks give their brake levers to "stretch the cable"... it's enough to wreck an Avid caliper).

Always stick with Avid's instructions for recentering -- they work, and there is no need to deviate.

I'm with concernicus and catatonic on this one: sounds like nothing to worry about if it's happening in turns, but double check your QR tension all the same. What fork you running? An 8" rotor is going to show any fork flex better than a smaller rotor.

I have the exact same front end as Defiance does, Speedhub.Nate, I've adjusted it hundreds of times. Do what I said and it should work fine.

a Z1 FR 3 ETA cartridge
I think you should call Marzocchi, or get your lbs to, they send your fork, Marzocchi puts in ETA, and they send it back to you. The manual says that ETA can be put in it, so that's probably the best way to get it done.

I adjusted mine with the Avid instuctions and I only have to adjust for wear....never any other problems.

I have the exact same front end as Defiance does, Speedhub.Nate, I've adjusted it hundreds of times. Do what I said and it should work fine.

I'm not getting into a pissing match with you, Jason, just stating facts.

Reefing on the levers too hard can break an Avid caliper. Period.

Secondly, performing youR technique (which works great for a two-piston hydro, by the way) either flexes the rotor, or more likely, "centers it" flush against the inboard pad. This procedure in no ways centers the rotor between the pads.

Not to mention it is completely unnecessary when you have independent inboard and outboard pad adjustments that will accomplish the same thing, without the stress on the caliper arm.

So again, stick with Avid's setup instructions.

I have the exact same front end as Defiance does, Speedhub.Nate, I've adjusted it hundreds of times. Do what I said and it should work fine.

If I ever had to do 200 brake readjustments, I would begin to suspect there was something wrong with my methods...and I surely wouldn't say they were working fine.

So again, stick with Avid's setup instructions.+1 Just read them myself last night so it's fresh in my mind. Caliper needs to be set 2/3 - 1/3 centering over rotor, then adjust inner and outer pads accordingly. If it's rubbing on side forces (turning, etc.) I'd suspect hub bearings and/or runout slop inside the hub. If it's a QR, try snugging up your cones (without overdoing it) slightly.

If I ever had to do 200 brake readjustments, I would begin to suspect there was something wrong with my methods...and I surely wouldn't say they were working fine.
Actually, my bolts come loose a lot. Not a huge amount, but enough to get the caliper out of alignment. The inside of my adapter is stripped a bit. Not to mention, I take my bike apart all the time to clean it up. Whenever I do it my way, It's PERFCETLY aligned.

Reefing on the levers too hard can break an Avid caliper. Period.

Any caliper will break if you pull the lever hard enough.

Don't worry about it, really, its normal and its fine, happens with my BB5s too, the little rubbing there is isn't creating any resistance so just chill up and ride :)

I'm sure that's true Chone, at this point it's more of an annoyance then anything.

Thanks for the help guys. Maybe this wasn't clear: What Jason was describing is how you use the "CPS" system on the BB7s. It's two sets of convex and convave washsers on each bolt that allow the caliper to rotate X number of degrees.

What he described (which is the same as what the manual describes) is what I did to align it and it does look perfectly aligned.

And it's not a QR, It's the "Fork of the unofficial Marzocchi Z1 FR 3 Club" (so far it's me and jason as members, who else wants to join!) and If I really need to say the name of the fork you've got to be getting me. To save the research time, It's a 20mm thru-axle, and It's about as tight as my hub will allow.

@Jason: If the adapter is stripped a bit it's probobly causing the bolts to come loose. Mine got stripped (completely stripped, I'm beginning to think the threads are really weak/thin) and I just called around bike repair shops 'till on the third try I found one with the proper part.

Also, since the failed thread on the topic [ETA Cart.] I've emailed Marzocchi and they've said I can send it into the factory and get it installed, but conviently left the price out.

It's fork/frame flex. There's nothing wrong with your bb7s.

What [Jason] described (which is the same as what the manual describes)...

??? Where?

http://www.booboodog.net/images/bb7-alignment.gif

Ahaha, nevermind. I feel stupid. I was reading the BB5 setup page :P That's this one.

http://img150.imageshack.us/img150/5564/scan00039bj.jpg

If you think about it, it would do the exact same thing. The pads are pushing against the rotor, the rotor is NOT being bent like in action because the bolts are undone. Tighten up, and then re-adjust the knobs a slight amount.

I just ordered the BB7's for my XC bike - how does everyone like them? So far I've been hearing only great things about them.

5/5

I just ordered the BB7's for my XC bike - how does everyone like them? So far I've been hearing only great things about them.

Pricepoint has them for $64 so I hope you got a good deal on them.

I recently upgraded my brakes to BB7's and it was WELL worth the money.

It's fork/frame flex. There's nothing wrong with your bb7s.

God its about time someone said this!!!!!

God its about time someone said this!!!!!

Yes, and I guess it's about time I announce my confusion to that proclimation.

If it's fork/frame flex, how come it never happened with my old tektros? Ironically, they're better in this sense. Could it be that the flex is more pronounced through the 8" adapter? The caliper sticks out farther, more distance caused by those damn "lever" thingamajiggers... :P

I would tend to suspect adapter/hardware flex before fork flex. Everything is bolted to the lowers; and the lowers are cast (magnesium or aluminum) and should be flex-free. If it's not coming from the hub, the mounting hardware is the next suspect. Frame, stanchion or bushing flex would have nothing to do with it.

This kinda thing really makes me wonder how long most people have actually been riding.