dwscrimshaw
Retro Guru
I wanted to recreate a bike I rode in the 70's for nostalgic reason and to have something to experiment with. The bike, late 50's Holdsworth Monsoon, came with 5sp Cyclo gears and at the time I rebuilt it as 10sp very much in a 70's style. For this bike I also wanted more than the std. 5 speeds.
Having looked at the Sheldon Brown web site it was clear that a modern cassette spacing could fit more gears into the reach of the Cyclo RD. I found some old 105 uni glide hubs that fit the rear spacing then swapped the free hub for a hyper glide one to fit a 10sp cassette. In theory the 24mm movement should cover 7 10sp cogs, in reality it does't quite so having to modify the barrel of the RD I took it to 8sp by drilling it out further to give 32mm moment. The narrow chain needed fits the jockey wheels ok, but tends to slip off the lower plane jockey wheel and jam on the cage. This was fixed by getting the chain line in the middle of the cassette and swapping the plain jockey wheel for a toothed one.
Once setup correctly a front rod derailleur was added to give 16 speeds. Once I got used to the friction shiftier again it changes really nicely, even with the closer gear spacing. I did try a trigger indexer, but the coil spring is too strong when fully compressed and a step too far. So a traditional Campag down tube level does the job very well. Done just over a couple of hundred miles on it now and so far all is going well.
May not be to everyone's liking, but it can be done.
Having looked at the Sheldon Brown web site it was clear that a modern cassette spacing could fit more gears into the reach of the Cyclo RD. I found some old 105 uni glide hubs that fit the rear spacing then swapped the free hub for a hyper glide one to fit a 10sp cassette. In theory the 24mm movement should cover 7 10sp cogs, in reality it does't quite so having to modify the barrel of the RD I took it to 8sp by drilling it out further to give 32mm moment. The narrow chain needed fits the jockey wheels ok, but tends to slip off the lower plane jockey wheel and jam on the cage. This was fixed by getting the chain line in the middle of the cassette and swapping the plain jockey wheel for a toothed one.
Once setup correctly a front rod derailleur was added to give 16 speeds. Once I got used to the friction shiftier again it changes really nicely, even with the closer gear spacing. I did try a trigger indexer, but the coil spring is too strong when fully compressed and a step too far. So a traditional Campag down tube level does the job very well. Done just over a couple of hundred miles on it now and so far all is going well.
May not be to everyone's liking, but it can be done.
