Rory O’Brien - help please!

[Splatter Paint]

I’m considering an O’Brien.... I’d like to build a restomod around a frameset -

- can I fit 700c wheels?
- 135 mm spacing
- which model to go for?
- at 5’10” will a 56 cm be ok?
- what brake drop? Will modern calipers fit?

Cheers

SP (retro road bike novice)

 

[legrandefromage]

- can I fit 700c wheels? depends on original model
- 135 mm spacing dont overlook 130mm as they can be carefully spread or use 130mm wheels
- which model to go for? dunno
- at 5’10” will a 56 cm be ok? depends on inside leg measurement
- what brake drop? Will modern calipers fit? nutted are available and again drop will depend on original wheels fitted

 

[hamster]

I did some similar mods a couple of years ago to a 1979 Witcomb:
1 Careful re-spacing of the frame from 126mm to 130mm (allows all stock road bits to fit)
2 Swap to 700c wheels.

The frame was drilled for nutted callipers, originally built for 27" with mudguard clearance. Tektro R559 callipers fitted fine and work really well. I built the bike up initially with a bar-end shifter Shimano setup, swapping later to mid-90s Campag. It was all trouble-free. Respacing the frame took no time at all, using the Sheldon Brown method and taking it slowly and progressively. Care was taken also to re-align the long Campag horizontal rear dropouts to parallel.