Mountain Bike Reviews Forum banner
1 - 6 of 6 Posts

·
Registered
Joined
·
2 Posts
Discussion Starter · #1 ·
Hello folks!

I got my Covert in May 2010 and had a hell of a season! Love the bike and TBC.

My problem however, doesn't involve so much the frame itself, but the Hammerschmidt AM I'm running on it. To start off, let me say that the bike was built by my LBS.

Basically, the cranks are not centered in the BB shell. I just noticed this recently when the cranks were parallel to the ground.

When the drive side crank is parallel and next to the chain stay, there is only 3mm of space between it and the chain stay. And when the non-drive side crank is parallel and next to the chain stay, there is 11mm of space between it and the chain stay.

Does this mean my LBS faced off a little too much from the BB shell face? To confirm this suspicion, there is also an unusually large gap between the non-drive side crank and the BB spacer, such that you can see a washer/ring thingy that looks like it should be flush with the BB spaced.

Question: does a brand new Covert frame have offset between the BB shell and the ISCG mounts, or are they flush? Because the Hammerschmidt manual says that some bikes do, and for that reason special spacers are included.

There are no spacers on my setup. The Hammerschmidt sits tightly against the ISCG plate.

And finally, I can now recall something that the mechanic said when I was picking up my bike that I did not pay much attention to until now. He said it took him a long time to install the Hammerschmidt because he was having problems with spacers.

All this leads me to believe that my LBS faced my BB shell too much. I will talk to them about it of course, but they might deny it. So I want some objective opinions/advice first.

Thanks.
 

·
Sugary Exoskeleton
Joined
·
4,659 Posts
besoffen said:
All this leads me to believe that my LBS faced my BB shell too much. I will talk to them about it of course, but they might deny it. So I want some objective opinions/advice first.

Thanks.
over-facing even .5mm (which is a LOT of facing) wouldn't cause the large measurement discrepancy you are describing.

Far more likely is the possibility that your mechanic just used the wrong number/position/color/brand/smell of spacers. I don't know offhand the correct config for your setup, but follow the spacer trail and it should solve the mystery.
 

·
Registered
Joined
·
863 Posts
besoffen said:
Hello folks!

I got my Covert in May 2010 and had a hell of a season! Love the bike and TBC.

My problem however, doesn't involve so much the frame itself, but the Hammerschmidt AM I'm running on it. To start off, let me say that the bike was built by my LBS.

Basically, the cranks are not centered in the BB shell. I just noticed this recently when the cranks were parallel to the ground.

When the drive side crank is parallel and next to the chain stay, there is only 3mm of space between it and the chain stay. And when the non-drive side crank is parallel and next to the chain stay, there is 11mm of space between it and the chain stay.

Does this mean my LBS faced off a little too much from the BB shell face? To confirm this suspicion, there is also an unusually large gap between the non-drive side crank and the BB spacer, such that you can see a washer/ring thingy that looks like it should be flush with the BB spaced.

Question: does a brand new Covert frame have offset between the BB shell and the ISCG mounts, or are they flush? Because the Hammerschmidt manual says that some bikes do, and for that reason special spacers are included.

There are no spacers on my setup. The Hammerschmidt sits tightly against the ISCG plate.

And finally, I can now recall something that the mechanic said when I was picking up my bike that I did not pay much attention to until now. He said it took him a long time to install the Hammerschmidt because he was having problems with spacers.

All this leads me to believe that my LBS faced my BB shell too much. I will talk to them about it of course, but they might deny it. So I want some objective opinions/advice first.

Thanks.
I would call transition and run it by them,there c.s. is awesome,also pick up a mill. ruler and measure the bb shell
 

·
Registered
Joined
·
53 Posts
Photo with scale/ruler would help. After looking at mine I can see that the drive side crank is defiantly closer to the chain stay than the non drive side crank. Its a BR with HammerSchimdt not a Covert. I haven't noticed it while riding so am not too worried about it.
 

·
Registered
Joined
·
870 Posts
Your drive side is closer to give you the best possible chain line 50mm. It sounds correct, you can not space out the BB like a normal crankset with the Hammershmidt due to the mounting on the ISCG tabs...its a pretty fixed position. It sounds correct so go have fun, You can view the gap between the rotating mass and the fixed backing plate and the gap should be about 1mm all the way around.
 

·
Registered
Joined
·
2 Posts
Discussion Starter · #6 ·
Thanks for the comments.

I am glad to hear that this is normal. However, I do not see the necessity of offsetting the cranks. The crank arm on the drive side could simply be bent outwards, the same way the non-drive side crank arm is. This would not affect chainline either.

Seems strange that Hammerschmidt makes such a huge deal about precision in their manual, yet the crank isn't even centered in the BB.
 
1 - 6 of 6 Posts
Top