Hi all,
I am very new to bike fixing so I apologize if my terminologies are wrong.
First and second picture: the crank arm is on all the way where the splines are covered up my the spindle.
Third picture: when not on the bike, the crank arm goes on all the way covering up the spindles.
What could be the reason why this crank arm isn’t on all the way (I’m pretty sure it’s pushed it all the way – I even tapped it with a hammer a few times and there is no space left – maybe the bb is too long in length)?
For context frame: 2020 trek checkpoint alr3
Cranks: shimano SORA 175 (old) / 165 (new)
Bb: BB-RS500 BC1.37×24 ROAD
I thought this would be an easy swap because the cranks are the same just different lengths. I put the old one back on and the crank arm didn’t go on all the way again which makes me think it was that way when I bought it (used). So maybe the cranks not being on all the way isn’t that bad since it’s only a few mm off?
I did notice that the old cranks have RI while the new one have WB, see picture 5 and 6.
Thanks for all the help!!!
by Dry_Swimming8929
5 Comments
Most crankarms dont go all the way in the spindle when you put them in bottom bracket, and looking and the picture the space between the crank grooves and spindle is okay just put the preload and tighten it to specs.
as long as the pin drops into place then it will be fine
The original BB should be a BB73+. Which is a MTB bracket. You’re bracket, the RS 501 is a race bracket.
That’s normal, the extra depth is to allow the same crank to be used on a bike with a narrower bb
The really odd thing is that your crankarms are different lengths. The way they fit on the axle looks fine.