Jump to content

Bb Problems?


monty221ti

Recommended Posts

Hi,

My try-all cranks is comming loose and i cant tighten the bolt more than it is? i tried to put a spacer between the crank and bb, it worked but when i turned the cranks backwards it was very tight. I also tried to put some monty 221 cranks on without a spacer and they are also pretty tight, what could be wrong?

Also, is it possible to change bearings on a fsa platinum pro bb?

cheers

Link to comment
Share on other sites

I understand where your coming from. The matter how hard you tighten the crank, it is still loose? How old are the cranks? Are they worn at all?

Could you take a picture of the crank/bb to give people a better idea of what is going wrong?

Link to comment
Share on other sites

There are two problems here:

1. Using spacers between the crank and the stopper on the BB axle means that you are effectively running your crank loose. ISIS has a 1 degree taper, the cranks need to be run either tight with a small gap, or (when they are old) butted right up against the spacer on the BB axle. It sounds like your crank may have stretched a bit :( It's not catastrophic though, it will still work fine for ages. Just making people aware that putting spacers on your axle is a sure fire way to reduce the life of your cranks!

2. If your BB is a 122.5mm model, I believe there may have been a batch which weren't 100% at some point in the past. The centre sleeve of the BB is a little too long, which means that when cranks are new the BB runs fine, but when your cranks bed in and butt up against the green spacer, it side loads the bearings and makes the BB feel awful/stiff. It's hard to spot since when you take the crank off and BB out, the side load from the bearings is removed and the BB spins fine again. The solution is to machine down the centre sleeve (around 0.6mm from memory) so the bearings aren't side loaded any more. If you got the BB from us then feel free to send it to us and we'll sort it for you free of charge.

Cheers!

Adam

Link to comment
Share on other sites

the bb was from you but i'm not the one who bought it:( i think it's the 127.5 version but not sure. Otherwise i could take the bb out and take the spacer of, and file it a bit?? but i dont know how.

Edited by monty221ti
Link to comment
Share on other sites

Hmm, I think it will be the 122.5mm version, as this never happened on the 127.5.

Anyway, if you take the BB out and take it apart, you will see two 'steps' on the axle. Measure this distance. Then, the black centre sleeve that has the Red Try-All sticker on it, measure the length of this. They should be the same to within about 0.1mm. If not, then you can use a file to reduce the length of the spacer. Not as neat but it will work!

Link to comment
Share on other sites

another problem:( the try-all crank on the nondriveside. when i put it on i can tighten the bolt until it meets the bb axle, so when i tighten the crank al the way in and the bolt is tight, the crank is lose ("nocking" a bit side to side) is my crank busted og can i fix this?

Link to comment
Share on other sites

tried that with a fsa platinum pro, didnt work, smashed the bearing to pieces:( but the fsa may not be one that you can service?

I smashed my FSA, or I should say destroyed mine by riding. It was replaced free with a Trial Tech. I still needed the BB tool to remove though.

post-29178-0-93280800-1303533528_thumb.j

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...