Thru-Axle, road frame, derailer hanger fine-tuning
05-25-18, 07:23 PM
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Thru-Axle, road frame, derailer hanger fine-tuning
I have a new road frame (Hoy Alto Irpavi, sold by Evans Cycles, UK).
It features thru-axles and disc brakes (my first experience with either).
I'm preparing to bring it to the shop to be built up.
The rear thru-axle runs through a hole in the frame on the non-drive side, and screws into the derailer hanger on the drive side.
I noticed that the hanger doesn't perfectly, smoothly fit the thru-axle.
There is no doubt the proper thru-axle was purchased - length, thread pitch, etc. all check out.
I can get the smooth fit by loosening the derailer hanger from the frame first, then screwing in the axle. But because the angle is a wee bit off when the hanger is tight on the frame, the thru-axle screwing seems to require a little too much force. I'm worried about stripping the threads if I remove the axle / rear wheel a few times with this tight fit.
Ideas:
- It seems like I can put a micro-wedge in place to adjust the hanger angle which, through trial and error of the wedge size and placement, hopefully can allow both a tight fit of the hanger to the frame, and a normal (not too tight) screwing of the thru-axle. This seems like the best solution to me
- I could also leave the hanger a bit loose on the frame. I imagine this would negatively impact shifting, though.
- I could also stock up on spare derailer hangers and when / if one gets stripped, swap in a new one (it might even fit better). I think a hanger would go around $10-15, but the thru-axle itself would be more like $35-60. I'm not sure which would get stripped, maybe both. And due to cost and risk of availability issues, prefer not to risk it.
It should be easier to fix this before the derailer has been fitted, so I'm acting on this now before the build.
Anyone ever have this problem? Solutions? suggestions for material for a micro-wedge (duct tape?)
I will go over it with the local bike shop as well, but I suspect he won't have seen many thru-axles himself yet. And may not be as motivated to fine-tune the fit to the same degree.
FWIW, the front thru-axle fits nicely on the fork, without too much force. So I'm hoping to get the rear fit to about the same level.
It features thru-axles and disc brakes (my first experience with either).
I'm preparing to bring it to the shop to be built up.
The rear thru-axle runs through a hole in the frame on the non-drive side, and screws into the derailer hanger on the drive side.
I noticed that the hanger doesn't perfectly, smoothly fit the thru-axle.
There is no doubt the proper thru-axle was purchased - length, thread pitch, etc. all check out.
I can get the smooth fit by loosening the derailer hanger from the frame first, then screwing in the axle. But because the angle is a wee bit off when the hanger is tight on the frame, the thru-axle screwing seems to require a little too much force. I'm worried about stripping the threads if I remove the axle / rear wheel a few times with this tight fit.
Ideas:
- It seems like I can put a micro-wedge in place to adjust the hanger angle which, through trial and error of the wedge size and placement, hopefully can allow both a tight fit of the hanger to the frame, and a normal (not too tight) screwing of the thru-axle. This seems like the best solution to me
- I could also leave the hanger a bit loose on the frame. I imagine this would negatively impact shifting, though.
- I could also stock up on spare derailer hangers and when / if one gets stripped, swap in a new one (it might even fit better). I think a hanger would go around $10-15, but the thru-axle itself would be more like $35-60. I'm not sure which would get stripped, maybe both. And due to cost and risk of availability issues, prefer not to risk it.
It should be easier to fix this before the derailer has been fitted, so I'm acting on this now before the build.
Anyone ever have this problem? Solutions? suggestions for material for a micro-wedge (duct tape?)
I will go over it with the local bike shop as well, but I suspect he won't have seen many thru-axles himself yet. And may not be as motivated to fine-tune the fit to the same degree.
FWIW, the front thru-axle fits nicely on the fork, without too much force. So I'm hoping to get the rear fit to about the same level.
05-26-18, 05:41 PM
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An aluminum can ought to provide all the shim stock you will need. I am curious if you’ll need to align the hanger for the derailleur to index properly once shimmed for the axle thread.
05-27-18, 06:08 AM
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If it were my bike I would probably get a sparer hanger and file it, rather than shim, to fit. You will need to file the shim to a wedge shape anyway, if I understand your post correctly.
05-27-18, 06:01 PM
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Great thanks. I will play around with tape until I can determine the shape of the "shim" I need. Then, maybe I will try to apply it to an aluminum can. Although, there is a kind of aluminum tape which I think I would prefer to a can. For its adhesive property, as well as workability and probably its thinness.
