So another hole in my knowledge of modern mtb stuff....
I'm going from 2 x 10 to 1 x 11 on my old Trance X 29er....
LBS have a Chainset in but it's a 52mm chainline. Bike is old 135 9mm QR.....what chainline do I want? I didn't even know that this was a thing if I'm honest?! The googling that I've done seems to suggest that I don't want a 52mm chainline though!
As always, any help is much appreciated.
I was looking into this recently building my gravel bike. This wolftooth guide was very helpful...
https://www.wolftoothcomponents.com/pages/boost-chainline-and-chainrings
Cheers for that, informative....but doesnt mention 135 qr.
I'm definitely thinking smaller than 52mm anyway!
135 and 142 are the same (the extra 3.5mm each side is just recessed into the frame where the end caps fit)
yer 52 is typically boost, so 3mm back on that ideally.. can you not change your chain rings? I've sued spacers and longer chainring bolts to tweak my chain line before. so you'd possibly use your outer ring position but space the ring inboard a little more
Ah right, cheers for that!!!
@alan1977 yeah I had considered that....whole drive train is fairly wrecked tbh anyway, so seems like a good time to pop a new chainset on.
TBH it doesn't really matter that much. I mean yes it's good to get it perfect but unless it's wildly far out it's still less than a single gear's difference. My fatbike's slightly misaligned and has been for 5 years, because I use a crank not exactly designed for the fitment, you wouldn't know if you rode it. And a lot of people space the ring over to get swingarm clearance (pretty common for older bikes to be designed for a 32T max middle ring)
TBF for 1x transmissions as long as the chainring clear the frame and the rear mech changes sweetly across the cassette I wouldn't worry. Chainline is more an issue for fixed gear / singlespeeds and 2x/3x transmissions where front mech offsets are more critical.
This may be a daft question, but in a 1 x setup, where will the chainring sit in relation to the existing (stock) 2 x setup. Inner? Outer? Neither?! Current chainrings are 26/38
When I went 1x11 on my BFe QR 135 I did not need to use spacers. It runs fine and I can't tell any difference from big to big and small to small on the 2 x 10 when at the extremes.
Edit - I used the 2x XT crank