Thumper33
New Member
Incoming wall of text... :/
@DelPrete... that's great info, thanks so much for the reply!
It looks like you're using the sram XO crank, which as Rich-H says above means unless you shimmed it, your crank is now offset. I don't know where there is room for more shims to recenter the crank, but it sounds like Rich-H is saying it can be done, you just end up with a wider Q-factor. I'd be interested to know just how much wider the Q-factor becomes.
As for my personal preference if I couldn't get the chainline at an ideal 55mm, I think I would rather error on the side of too wide at the crank since I'm almost never in the bottom 7 or so gears. The biggest ring I can fit on mine with the stock spider is a 36t, and I'm dying to get a 38t to eek out a few more mph and actually use more than 5 gears.
Here are all the options (best I can tell)
1. - stock 52mm chainline - the downside being potential of not ideal shifting at the highest gears. For me this is where I need the best shifting. This also doesn't help me fit a bigger ring gear.
2. - 58mm chainline - keep the stock crank and spider and install the ring gear on the outside of the spider. I've seen someone else do this and I'm not sure how I feel about it since it's not machined flat where the bolts go. If I were to do this I would mill flat spots where the mounting bolts are. By my measurements it would leave about 3mm of thickness on the spider where it mounts, and therefore (factoring in the 3mm thick gear) the new chainline would be at 58mm. If you don't mill flat spots, then you'd be probably closer to 59 or 60mm. I've looked and couldn't find such a thing as a spider with more offset that would fit the brose motor.
3. - 57mm chainline + increased q-factor - As stated above, if you install SRAM's crank (or any other direct mount crank for that matter) you'll end up with a 57mm chain line and an offset crank. I believe the offset can be shimmed to recenter it, but that means a wider q-factor. How much wider I don't know exactly.
4. - shim the cassette out - I don't know if this is even possible, but if so, you could potentially put a shim between the cassette and the hub to get a mm back ( I wouldn't imagine more than that). Shimming the cassette out a mm would mean that the cassette's chainline would now be a 56mm center and now closer to centered with option 2 or 3 above.
5. - shim the direct mount ring gear - I also don't know if this is possible, but if so, you could potentially shim the direct mount ring gear inward by putting shims between the new direct mount crank and the ring gear. If you could get any amount of shims in there it would get you closer to optimal.
6. - ring gear with an offset - I looked around to see if I could find any ring gears with an offset that would help out. I couldn't find a +3 offset 104BCD to fit the stock spider, nor a -2 offset direct mount ring to fit the direct mount option.
7. - it seems possible that specialized has a new spider on the 2024 levo since there are models with transmission stock. Maybe this offers a bolt on solution, I just can't get an answer on that for sure.
Maybe @Rich-H could comment, but if you could do options 3, 4, and 5 above, it would all be perfectly aligned, but you'd just end up with a wider q-factor.
@DelPrete... that's great info, thanks so much for the reply!
It looks like you're using the sram XO crank, which as Rich-H says above means unless you shimmed it, your crank is now offset. I don't know where there is room for more shims to recenter the crank, but it sounds like Rich-H is saying it can be done, you just end up with a wider Q-factor. I'd be interested to know just how much wider the Q-factor becomes.
As for my personal preference if I couldn't get the chainline at an ideal 55mm, I think I would rather error on the side of too wide at the crank since I'm almost never in the bottom 7 or so gears. The biggest ring I can fit on mine with the stock spider is a 36t, and I'm dying to get a 38t to eek out a few more mph and actually use more than 5 gears.
Here are all the options (best I can tell)
1. - stock 52mm chainline - the downside being potential of not ideal shifting at the highest gears. For me this is where I need the best shifting. This also doesn't help me fit a bigger ring gear.
2. - 58mm chainline - keep the stock crank and spider and install the ring gear on the outside of the spider. I've seen someone else do this and I'm not sure how I feel about it since it's not machined flat where the bolts go. If I were to do this I would mill flat spots where the mounting bolts are. By my measurements it would leave about 3mm of thickness on the spider where it mounts, and therefore (factoring in the 3mm thick gear) the new chainline would be at 58mm. If you don't mill flat spots, then you'd be probably closer to 59 or 60mm. I've looked and couldn't find such a thing as a spider with more offset that would fit the brose motor.
3. - 57mm chainline + increased q-factor - As stated above, if you install SRAM's crank (or any other direct mount crank for that matter) you'll end up with a 57mm chain line and an offset crank. I believe the offset can be shimmed to recenter it, but that means a wider q-factor. How much wider I don't know exactly.
4. - shim the cassette out - I don't know if this is even possible, but if so, you could potentially put a shim between the cassette and the hub to get a mm back ( I wouldn't imagine more than that). Shimming the cassette out a mm would mean that the cassette's chainline would now be a 56mm center and now closer to centered with option 2 or 3 above.
5. - shim the direct mount ring gear - I also don't know if this is possible, but if so, you could potentially shim the direct mount ring gear inward by putting shims between the new direct mount crank and the ring gear. If you could get any amount of shims in there it would get you closer to optimal.
6. - ring gear with an offset - I looked around to see if I could find any ring gears with an offset that would help out. I couldn't find a +3 offset 104BCD to fit the stock spider, nor a -2 offset direct mount ring to fit the direct mount option.
7. - it seems possible that specialized has a new spider on the 2024 levo since there are models with transmission stock. Maybe this offers a bolt on solution, I just can't get an answer on that for sure.
Maybe @Rich-H could comment, but if you could do options 3, 4, and 5 above, it would all be perfectly aligned, but you'd just end up with a wider q-factor.