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Technical & Reference Section => Tech and Restoration => Topic started by: motomagII on July 21, 2010, 09:14 PM

Title: craqnks can be pain sometimes
Post by: motomagII on July 21, 2010, 09:14 PM

right fitted set 3 piece cranks new school jobbies with unsealed bb set got em running smooth as butter .but the bolt that hold the chaintring in place is catching on the bb cup .so removed them and added another spacer to bring the chainring out bit hey presto no rubbing but the chain is out of line with the freewheel .????
does the chainring make type effect this or is it just leave the chainring bit further out so chain alignment isnt perfect .whichj then you can hear the noise it makes when pedalling as its rubbing on the freewheel sides and chainring sides of teeth not in middle

Title: Re: craqnks can be pain sometimes
Post by: meticulous on July 21, 2010, 09:47 PM

can you try another chain ring bolt or grind down the one you have a bit so it doesnt rub?

Title: Re: craqnks can be pain sometimes
Post by: bof on July 21, 2010, 10:19 PM

Just file the edge off the bolt . they are always real close on american BB's . the  bolt should be domed is  yours

Title: Re: craqnks can be pain sometimes
Post by: HEYWOOD BMX on July 21, 2010, 10:32 PM

 :) You can buy spacers to space out the freewheel,usually in 1mm increments for about 30p each.They are intended for Euro bbs but are exactly the same size as the threaded part of a freewheel.

Title: Re: craqnks can be pain sometimes
Post by: Jon The Bassist on July 21, 2010, 11:16 PM

The type of chainwheel shouldn't affect how much the bolt protrudes (much). As said before, the bolt should be very domed on the head. On my Felt Cruiser that bolt is barely 1mm from the BB, with a very good chainline. Shame the cranks are buggered where they fit the splines  :crazy2:

Title: Re: craqnks can be pain sometimes
Post by: crightonk on July 22, 2010, 01:11 PM

I machined the screw head on my kids GT to a dome shape, clears fine now ;)