Withdrawn ,Serotta 650c bike ,complete,57x57,singlespeed conversion,£400 ono

Serotta Columbus tubed frame and forks for 650c wheels,normal road geometry not a time trial or track frame ,wheels new Vision 30’s with Conti clinchers also new,1” Look carbon forks ,NOS Syncros 1” cattle head stem ,Tektro road levers ,SDG saddle on Cinelli seatpost ,Campag square taper cranks on NOS Campag bottom bracket,49t NOS Stronglight chainring ,Alfine chain tensioner ,VeloSolo cassette spacers and 14t cog ,Axis brakes ,Condor bars ,130mm rear dropout width ,not sure of exact Columbus tubing ,main tubes slightly conical and widen towards bottom bracket,cheers Stef

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Whats the standover on this rather cool thing...

Hmmmm is that a wise measure to go on? The wheels will make the fit deceptive if you base it on that.

Rad by the way - glws

How so? Standover height is an absolute measurement and therefor independent of wheel size. I wouldn't base my fit on it either, but that's just because it's an irrelevant measurement in my opinion.

Sorry ,bike in workshop on other side of town ,not down everyday might not be down to do extra measurements until Friday,I originally built her up as a conventional modern road build and I was able to transfer all measurements across from my 57/58 road bike with no bodging ,sorry for not being more helpful

Just a figure I like. It just helps me visualise it while compensating for 650c...

I may be wrong, but in this case it’s a 57 which would usually be too big for me. Given it’s a 650c the stand over height is lower so I may think, actually it’s alright. But as soon as I try and ride it, I’d realise the cranks are too far away from the saddle and the reach is too long.

Or am I being a moron?

I realise I’m probably being a moron.

Or am I?

I’am assuming frame builders have put bottom bracket in same place as a conventional 700c 57/58 as looking at main photo there isn’t much of a drop down in a line between hubs ,I remember in building her taking all my measurements off the bottom bracket,saddle and bar/stem position was same as my 700c Serotta

Ahh right I see. My bad.

Whatever was the point in 650c then other than for a better proportioned bike for smaller riders?

More Aero, was I think the marketing spiel that was around at the time. Most of the 650c Serottas are TT / Tri frames

The theory at the time was a combination of aerodynamics/lower wheel weight/lower rotating weight/faster acceleration ,Rominger ride a 650c carbon Colnago in some stages of a Giro I remember

That’s what I thought, but if you’re at the same height as being suggested above, how is it more aero??

Sorry if this is a thread derail. Consider it free bumps!

I think the aerodynamics was to do with having a smaller wheel [albeit one possibly rotating more often],I don’t necessarily advocate the views of the time though I do advocate Serottas

Edit ignore!

Good thread. This baby will sell, and I'm learning a lot!