1970's Diamant

[Flandria]

If you mean by 'ruin the allen key hole', install the seatpost bolt then
drill out the bolt or something so the bolt can't be turned any more,
it sounds like a fairly terrible idea. What if you even need to remove the
post? (e.g. the frame is no good but you want to reuse the groupset).

A better idea might be to run a length of old bike chain through the saddle
rails then through the rear triangle. You could wrap the chain in
an old inner tube or some gaffer tape to protect the paintwork.

I think this is done in London by fixie riders/bike couriers.

Johnny

Yup, that's exactly what I mean by 'ruining the allen key hole' . Thought about buying another one and drilling it out once installed. A friend has a special kind of 'tap' to loosen worn allen keys, so removal wouldn't be a big problem. Aesthetically the best solution for some quids... The other ideas are nice too, but would affect the looks of the bike to much. But probably I wont need one of the solutions, once more I'm thinking of keeping a finished bicycle more in the shed than in the city .

IMO that saddle on that bike is like using a greyhound as a donkey.... not to suggest that I am entirely guiltless of using greyhounds as donkeys... metaphorically, you understand...

Good point! But since I'm not planning to use it as a greyhound, I think I'll keep the donkey look, just because I like it more . I've installed a brown suede Rolls: you can compare in the pictures below! The Rolls got a new suede cover, it was done by a friend and it looks very nice imo.


So, after all I've finished the bike today. Took it out for a small ride and it rolls nicely. Everything works well! I've added some Galli toeclips which I had on another bike. So now the group is almost complete Galli Sport : pedals, toeclips, derailleurs, cranks, hubs, brake levers, brake calipers and BB. I just miss some Galli shifters: these are Suntours...

Thanks for the useful comments, let me know what you think about it!