Advice needed - French thread bb.

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  • Hey,

    I'm currently building up an old french frame and looking to install a modern crankset. Is it worth getting the Velo Orange french thread bb or would servicing the old bb and installing a new axel to take the new cranks suffice?

    I guess the tradeoff is less maintenance and a longer lifespan vs having to always rely on someone making a new bb with french threading (and as far as I can tell VO is the only one?)

    VO also make a (seemingly) decent threadless option, but I might as well just get the correct threading a slightly cheaper price.

    Are there any other options i'm missing?

    Cheers!

    Rory

  • Which chainset are you thinking of using? Pics of the frame would be nice, simply because I like looking at old bikes :)

  • I was planning on using a Shimano double chainset I found in my parts bin - unsure of the model - but running it as a single for now.

    Here's a pic of the frame. Nothing to write home about but a fun project!

  • Ran a Zenith threadless BB for a while with no problems.

  • Ah nice to know - cheers. Did you have to file the frame at an angle to get it to fit properly?

  • No, fitted as tight as I physically could because I did read of people saying they slip. Mine didn't loosen, forgot it was in, just made sure to check it every so often.

  • The inside diameter and width of the shell are the same as english/bsa threading so you can have the drive side re-tapped to a left hand english/bsa thread.

    Some reports seem to suggest the bottom bracket will be a loose fit if you do this and you'll need to use loctite or teflon tape etc but I've actually ran taps the wrong way through a frame before (luckily my own and not a good frame, never put a bike upside down on the bars and saddle to chase bb threads!) and I didn't find the bb was a loose fit.

  • I had a VO french BB. Cost quite a bit and didn't make it through the winter - it was shit. That was some time ago so they could be better now.

    I'd prefer to stick with a french BB if you know the right length, Shimano still made french threaded BBs up to the early-mid 90s (7400/6400/105SC era, maybe some MTB too) so they're not impossible to find but limited selection of lengths.

    I've also had one french frame re-tapped on the drive-side with no resulting issues running a BSA BB.

  • Ah cheers that’s a massive help. I guess re-tapping isn’t as dodgy as I thought.

    Any recommendations for a trustworthy London bike shop that could do the retapping if I can’t find a suitable BB?

    Thanks again

  • Hello , I have the same problem as you - Bernard Carre frame - ... did you get any recommendations for someone who can do an English re-tap ... cheers - Dave.

  • Yeah I got it tapped at Hackney Peddler. Well fast with no problems.

  • .. tops ... cheers for the info ...

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Advice needed - French thread bb.

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