I am piecing together a bike to use to beat around the neighborhood with on bike rides with my daughter. The problem i am running into, i have 8-speed shimano STI and the only extra wheel i have, has an old 7-Speed hub. I have no desire to drop any money into this bike, will the 8-Speed shifters work with the 7-speed hub?
My thinking is that it should work, but i might experience the occasional skipping/jumping of gears. I can live with this since my daughter is only 7 and were not going to be time trialing through the neighborhood. If it gets to that point i will break out the tri bike.
It should work. I have a 7 speed freewheel on my disk that I use with my 8 speed indexed bar end shifters. Just be careful that you don’t shift ‘beyond’ your 12 tooth cog
FWIW I plan on making the move to the 21st century (Campy 10 speed) this winter
The spacing for 7 and 8 speed is the same. If you have the rear derailer set up correctly it will not overshift the cassette. Just set the limit screws apropriately. You will have 7 clicks up from and the 8th will be locked out. Good luck,
On Sheldon Brown’s cassette/freewheel page you can see that the cog spacing is different by 0.2mm. So I imagine you’ll have some noise, maybe a little bit of skippiness under hard acceleration. If your frame has adjustable cable barrels on the downtube, that may help during day-to-day riding.
Thankfully it should be pretty easy to keep the chain off the spokes and axle just with the limit screws on the derailleur.
I’m using a 7 speed wheel with an old sachs freewheel on a bike with Shimano Ultegra 8s STI right now. Works perfect. I use it for the same thing - an extra bike for easy rides or riding in the rain. Be careful of the rear drop out spacing. The 7s hub is about 4mm narrower than the 8s. You’ll either need to have the frame adjusted, get a new axel, use spacers or some combination of these. Any cheep old 8s chain should work fine.
I am piecing together a bike to use to beat around the neighborhood with on bike rides with my daughter. The problem i am running into, i have 8-speed shimano STI and the only extra wheel i have, has an old 7-Speed hub. I have no desire to drop any money into this bike, will the 8-Speed shifters work with the 7-speed hub?
My thinking is that it should work, but i might experience the occasional skipping/jumping of gears. I can live with this since my daughter is only 7 and were not going to be time trialing through the neighborhood. If it gets to that point i will break out the tri bike.
Thanks,
Mark
trimark0769,
A close friend of mine purchased a Softride at a special deal. The bike had sat in the shop for over a year. It was an 8 speed Shimano, supposedly.
He rode the bike for many years, but occasionally complained about minor shifting problems. He took the bike to more than one shop for tune-ups and shifting adjustments. Finally, after about 4 years and as many shops, he returned to pick up his bike one day when the shop mechanic pointed out that he was using a 7 spd derailleur with an 8 spd cassette!
It appeared that the shop that sold him the bike had probably “robbed” the derailleur once upon a time and then replaced it finally with a 7 spd derailleur instead of an 8 spd derailleur. I don’t think they knew they were making this error.
The point I am trying to illustrate is that the bike worked reasonably well and was ridden on many centuries over this time before this mistake was discovered. Changing the derailleur finally corrected the minor shifting problem that annoyed this rider. I’m quite confident that in your case, your set up will work more than adequately for your needs. Granted, it won’t be like riding your newest road bike, but then again your not expecting it to be.
