"Anglicising" a French chainset

[mikeymustard]

I bought this Stronglight TS crank a while back, I think it would look very nice on the "purpled" Raleigh frame I got for my partner, is there enough metal for me to tap the threads out to 9/16th?
Edit: also, any idea what size BB I might need?

 

[Yellow Saddle]

I assume you're talking pedal eye threads and want to go from 1/2 to 9/16th so you can use standard non-kiddies pedals.

I'm not sure but I can help a bit.

Firstly, threads are essentially as deep as they are wide (pitch). So a bit of calculation and measurement will tell you how much meat is in there.

If it is marginal, still try. If that fails, there's always the option of using a thread repair insert such as the excellent one from IGUS (SP?), the German bicycle tool manufacturer. I have repaired the most impossibly botched cross-thread and ride-it-till-the-pedal-falls-out jobs to arrive at a perfect crank.

 

[mikeymustard]

Yes thanks, pedal threads. I hear earlier stronglights had a funny crank removal tool thread but if I ever want to remove it I'll cross that bridge when I come to it!
Since I'd have to buy 9/16 tap I might just take it down to my lbs or forge to let them have a look.

 

[Yellow Saddle]

Yes thanks, pedal threads. I hear earlier stronglights had a funny crank removal tool thread but if I ever want to remove it I'll cross that bridge when I come to it!
Since I'd have to buy 9/16 tap I might just take it down to my lbs or forge to let them have a look.

You would have to buy two taps, left and right-hand. The one side has a "reverse" thread. Good bike shops should have the set.

 

[further]

Why not buy some french pedals ?

 

[midlife]

Why not buy some french pedals ?

They can be a nuisance to find, expensive and maybe not what you wanted. Easier to run an English Tap though them, preferably one with a gentle starting taper...

Shaun

 

[T4tomo]

BB looks to be a standard square taper, what length etc will depend on frame and chainline. Raleigh frame will be English thread. You can measure the BB to get the body length then you might be down to a bit of guess work or trial an error for the "sticky out bit" lengths - there must be a proper term for that. Spa cycles do a good range of square taper BBs

 

[Ian H]

A chainset of that age will almost certainly have a different internal thread for removal. I used to have the tool, and another for old TA. No idea whether I can find them now.

 

[midlife]

TA crank removers were 23mm while the rest were 22mm.

Length us a bit suck it and see.......I'd plump for un55 118mm at 15 quid, or try an SJS axle 116 mm using your own cups for about a fiver. a TA Axis BB Is over 100 quid lol

Shaun

 

[Sharky]

I used to ride with Stronglight 49d cranks with TA rings.
I still have the crank remover, gathering dust in my toolbox - might be the one you need. If you need it in the future, just let me know.

For crank repairs, Highpath Engineering are good. I've had two sets shortened and re-drilled.
http://highpath.co.uk/crank-repairs-and-modifications/

 

[stevevw]

The remover you will need for your Mid 70's Touring Sport chainset is a 23.35x1mm thread used on all Stronglight cranks pre 1982

Re-tapping the pedal thread to 9/16th will not be a problem. I recommend buying a pair of taps they are always useful to clear the threads in a chainset and not too expensive.

 

[mikeymustard]

Thanks for all the advice, I think I'm gonna take this to a "higher authority" (LBS) along with a regina freewheel I need to remove - I can't afford the cost of a bike on a couple of tools just at the moment! (edit: unless LBS wants silly money to do it of course!)
Cheers for the offer @Sharky I'll remember that when it comes to removal time

 

[Spokesmann]

I have my eye on a Stronglite triple for one of my bikes, are all the cranks using French threading?

 

[mikeymustard]

I think it depends what they came off, Mike.
They do make some very nice looking sets though

 

[Bobtoo]

I have my eye on a Stronglite triple for one of my bikes, are all the cranks using French threading?

My Super Galaxy has a Stronglight triple with standard threads on it.

20150705_140212 by RichardB5, on Flickr