Any issues with Shimano 105 5800 1x conversion?
 

I have a new gravel bike that is already a 1x setup with sram rival RD. My old bike has Shimano 105 5800 crankset and has stages left side power meter which is why I want to transfer over to my new bike. it seems like all I need to do is change my bottom bracket and use the wolf tooth chainring. Any other issues I might be missing in making this change.

https://www.wolftoothcomponents.com/...shimano-cranks

You might need to tune the chainline, depending on whether you mount the chainring on the inside or outside of the bolt flange. You could use din 988 shims, 100pc for $3, for small adjustments, or chainring spacers for greater thicknesses. Shimano uses the same crank arms for single and double, but changes the shape of the chainring to shift the chainline.

The more important issue is that you select a bottom bracket that matches your crank spindle diameter and length. If you have a 68mm bb shell with BSA threads on a road bike, then use the standard Shimano BSA road bb. You can probably shim the drive side crank arm by 1mm if you want to push the chainline outward if you are mounting the chainring on the inside of the flange. Another thing you could do is use the mtb bb cups with a shaved road water sleeve, which will give you 2mm narrower overall bb width, then add 2mm shims under the drive side bb cup to move the chainline 1mm out while maintaining the same spindle length, or add 3mm shims to the drive side cup for an additional 1mm to the right and 1mm shorter spindle.

If the Shimano crank is still on the old bike, then you can remove the chainrings and measure the distance between the bolt flange and center of the frame, plus the flange thickness to estimate where your chainline will be if you mount the single chainring on either side of the flange. But it would depend also on the thickness of the wolf tooth chainring and whether the teeth are centered or offset to one side.

If you're able to achieve the desired chainline with the chainring on the inside of the flange, then you might consider adding a bashguard to the outside with longer chainring bolts. SRAM makes a truvativ bolt set with 14mm nut length including the head height, although it may be a little bit too long. You could probably use a nut with 9.5 to 11mm length.

Both bikes bottom brackets are English threaded so I had planned on transferring that part as well. The wolf tooth is offset inward. Thanks for the detailed reply.

If the single chainring is also radially symmetric, then you could flip it around to move the teeth to either side of the chainring. Oh, nevermind, i see that one of the bolt arms has a curved key shape, so it will only fit in one way. Actually, the key is a negative curvature, so if the FC-5800 doesn't have this key shape, then you could flip the chainring around. Flipping and mounting on the other side of the flange will probably move the chainline by around 6mm.

Wolftooth website says Chainline 47.5mm. So if you want 43.5mm, then you need to move the chainring 4mm inward.

If you flip the chainring and mount on the inner side of the flange to move 6mm inward, then you could probably use MTB BB cups with shaved road sleeve and add 3mm spacers to the drive side to get your 4mm chainline move. Or else use a MTB BB on non drive side, and road BB on the drive side with 2mm spacers, although MTB cups have longer threads, so maybe it's better to use all MTB cups. If you already have the road BBs, then you could try it out first and then measure your new chainline. Then afterward decide how to adjust it.

Otherwise, just using MTB BB cups without spacers and without moving your chainring will move your chainline 1mm inward to 46.5mm. Your spindle length will increase by 2mm, so have to check to make sure the splines on the NDS doesn't bottom out.

But actually maybe a chainline between 46-47mm might be good to prevent chain rub when on the outermost cogs. At 43.5mm or less, you might start to get chain rub on the inner cogs when on the outermost cogs. Road triple chainline is 45mm. The outer chainring on my double is somewhere around 47.5 to 48mm, and it works fine with all cogs, even when pedaling backwards, but very noisy on the inner 2 most big cogs. You'll have to just try and see.

Thanks for help. It's a lot for me to think about. I'm trying to decide between that using the shimano 105 and use that crankset but the problem is I want to still leave the old bike intact so I would need to buy a new shimano crankset, bottom bracket, wolftooth chainring (plus their bolts that they say are needed). So those expenses are adding up. Another option is to buy a quarq power meter crankset like below with a new chainring. More expensive but I could offset the cost by selling my old power meter. My bike has a gxp bottom bracket so I'm assuming that would be fine. Would I still potentially be working through similar chainline issues?

https://www.competitivecyclist.com/q...k-arms-gxp?s=a
https://www.competitivecyclist.com/s...chain-ring?s=a

I've used 3 different cranksets in roughly 20,000 miles of 1X use, and never adjusted or fiddled with chainline even once. Ever. Not one of those cranksets have been a dedicated "1X" crank.

You also don't need dedicated single-chainring bolts, though they are fairly cheap-- you absolutely do not need the $$$ Wolftooth bolts. My personal choice are Truvativ chainring bolts, because they're hex on bolt sides, and they're steel. I've snapped my fair share of aluminum bolts.

thanks. yeah. I'm not sure what's special about the wolftooth bolts.