This is a budget gravel set up I've just built. Having some issues with indexing and this chain line looks terrible. Is there anything I can do about it? Bare in mind this is a 1999 MTB frame so changing the cranks would be a hassle/expensive
by christiandoran
8 Comments
Yes. Don’t cross-chain. That combination of great is not natural. Neither is the opposite.
Ideally new cranks and shorter spindle. As a botch 3mm width of washers between crank arm and chainring – with (maybe) longer chainring bolts. That might but you 1.5 cassette sprockets. (Was this a 3x conversion to a 1x system?)
It is inherited in 1x. Saying that, from what I can see it is much worse line that it would be with smallest cog, and if you can find a way to move the chainring inward few mm, this combination will work better…
it looks like the bottom bearing cup is out two threads. Can you screw the cup on the non drive side two rotations outwards so you can get the drive side further inward?
It will still be bad, but a bit better wihtout purchasing smth
To me it looks like you have 4-5mm at most clearance between the chainring and chainstay, so you could try a narrower BB or offset chainring but it’s not going to help much.
There’s not much of a solution, you’re running a wide range cassette on a bike with rear spacing 12-18mm narrower than modern bikes designed for 1x
You could use longer bolts and washers to change the chain line, or get a 1x square taper crank. Shimano Cues is a cheap option. Not sure about the hassle/expensive part with respect to changing the cranks, it looks standard BSA, so there are plenty of options for any budget.
„budget“ with 300$ cranks /s
Something to consider:
Older bikes would have a lower number of gears at the back so using an eleven speed cassette would shift that chain line a lot.
Modern MTB bikes would have the necessary frame geometry because they were build for that many gears.
You may very well be trying to fight frame geometry to make these components fit.