RichardB
Slightly retro
- Location
- West Wales
I'm currently building up an old frame to have as a fixed wheel/singlespeed. The frame has an OLD of 130mm, so I bought a 27" wheel with a threaded hub and 130mm OLD (capacity up to 7 speeds), assuming I could fit a fixed sprocket or single freewheel on the hub directly. Now I have read a bit and watched a few YouTube videos I realise that I may have a significant problem with the chainline. I'm still painting the frame and acquiring the components, so I haven't been able to measure anything in situ yet. However, measuring the parts 'unassembled' leads to me to think I will have a sprocket about 8-9 mm out of line with the chainring. I'm using 3/32 chain, which should tolerate a bit of misalignment, but I am wondering what to do if the chainline is not acceptable. As I see it, I have a couple of options:
1. Spacers on the hub to throw the sprocket outwards (limited by depth of hub thread)
2. New BB with shorter spindle to bring the chainring inwards (it will be fairly close to the chainstay as it is, I think, so not much room for manoeuvre here either)
3. Adjust cones and spacers on hub to bring thread into line with chainring, then re-dish wheel
4. Buy new wheel with flip-flop hub and keep the existing one for the next project.
I'm thinking that (1) and (2) will be of limited success unless the discrepancy is small. (3) seems to be the standard solution, but I am not keen to go down this road. I don't have a trueing jig and although I have successfully built motorcycle wheels to within 1mm of true, using a home-made jig, I doubt I would find a light bicycle wheel as easy. This option would also preclude the use of the wheel later on with a sprocket set and derailleur, which I would like to keep as an option as my locality is quite hilly and it's 40 years since I rode a fixed gear for a couple of seasons. Not sure how the knees/lungs/heart will cope: I intend to give it a try, but I won't feel any shame in going back to gears if I need to. I have got a few sprocket clusters and an old derailleur that I can throw on if needed.
I'm happy to buy a new wheel with the correct hub (4) - for the modest cost it would give me the best of all worlds, but so far I have not been able to track down a proper track hub with 130mm OLD and a 27" rim at reasonable cost.
Any thoughts from someone who had been through all of this before would be welcome! The whole point of the build is to keep it light and simple, so a straightforward solution would be ideal.
Just thought - perhaps option 3a would be an answer - move the cones and axle spacers, and pay an LBS to redish the wheel. I had hoped to do all of the work myself, but perhaps that might be a sensible way out. Thoughts?
1. Spacers on the hub to throw the sprocket outwards (limited by depth of hub thread)
2. New BB with shorter spindle to bring the chainring inwards (it will be fairly close to the chainstay as it is, I think, so not much room for manoeuvre here either)
3. Adjust cones and spacers on hub to bring thread into line with chainring, then re-dish wheel
4. Buy new wheel with flip-flop hub and keep the existing one for the next project.
I'm thinking that (1) and (2) will be of limited success unless the discrepancy is small. (3) seems to be the standard solution, but I am not keen to go down this road. I don't have a trueing jig and although I have successfully built motorcycle wheels to within 1mm of true, using a home-made jig, I doubt I would find a light bicycle wheel as easy. This option would also preclude the use of the wheel later on with a sprocket set and derailleur, which I would like to keep as an option as my locality is quite hilly and it's 40 years since I rode a fixed gear for a couple of seasons. Not sure how the knees/lungs/heart will cope: I intend to give it a try, but I won't feel any shame in going back to gears if I need to. I have got a few sprocket clusters and an old derailleur that I can throw on if needed.
I'm happy to buy a new wheel with the correct hub (4) - for the modest cost it would give me the best of all worlds, but so far I have not been able to track down a proper track hub with 130mm OLD and a 27" rim at reasonable cost.
Any thoughts from someone who had been through all of this before would be welcome! The whole point of the build is to keep it light and simple, so a straightforward solution would be ideal.
Just thought - perhaps option 3a would be an answer - move the cones and axle spacers, and pay an LBS to redish the wheel. I had hoped to do all of the work myself, but perhaps that might be a sensible way out. Thoughts?
