I’ve just got my bike back from LBS after having a new Hope Bottom Bracket, Cranks, Cassette and Chain fitted to my Santa Cruz SL.
Now although it seems to be working fine (apart from an annoying creak) I noticed that the 2.5mm BB bracket spacers have been installed the wrong way ie 2 on non-drive side 1 on drive side. When I asked them about it they said that the chainline was off and the chain was slipping off middle chain ring onto granny ring, so they moved the spacer to rectify this.
Now my question is does this sound like a normal thing to do or not? Although it works fine I don’t want be do any unnecessary damage to the new components.
Thanks
As long as there's no issues with shifting onto the wee ring, chainrings rubbing stays, should be fine.
i would worry more about the remaining creak than the spacers not conforming to the 'manuals' idea of correct.
thanks that is what i thought, with regard to the creak i'm investigating the usual places.
The spacers should be arranged according to the bikes chain line measurement, hence you get three 2.5mm spacers not a 2.5 and a 5.
What has the chainline got to do with the chain dropping off the middle ring. Sounds like a lot of balls to me if they missed a creaking noise what else did they get wrong.
I fitted chainline spacers wrong once 2 on non drive side. The chain didnt drop off the middle ring I only noticed because my heel kept hitting the chain stay.
My chainline is WAY out, at least 5mm I'd say, but the chain doesn't drop off the middle ring when it's on the biggest cassette sprocket. Just as well really as I bought 4 identical BBs the same as the one I wore out so it's going to be years 🙂
Is chain line really that important on any bike other than a track bike? If it's out by 2mm what effect is it going to have?
Measure the from outer edge of each crank, to the centre of the frame. These 2 measurements should be as close to equal as possible with the available spacers. Then adjust your front mech to accommodate the chainrings.
Measure the from outer edge of each crank, to the centre of the frame.
this is called 'centring' and does not ensure correct chainline it itself unless the BB is the correct width.
So its agreed that so long as it all works it doesn't really matter how the spacers are arranged then.
The creak seems to be coming from the Bottom Bracket but i cant be sure, if it doesn't go away after i've checked everything else I'll take it back to my LBS i think.
Maybe a good time to start learning to do these things myself!!!
So its agreed that so long as it all works it doesn't really matter how the spacers are arranged then.
Yes. It's almost certainly bunkum that it makes any differece to chain drop. But it makes zero practical difference to the parts even though it's 'wrong'. My SS has 2 spacers on the non-drive side too and it works fine.
Creak is almost certainly BB.
As long as you chain is straight in your biggest and smallest gears and associated big and small rings, then its right. What happens ion the middle doesn't matter because we all ride cross geared anyway,
this is called 'centring' and does not ensure correct chainline it itself unless the BB is the correct width.
Maybe not, but if the cranks are off centre by more than 5mm then I'd expect the spacers to be not in their optimal positions.