French Threaded Crank
#1
French Threaded Crank
A while ago I picked up a Stronglight 93. It's a beauty. Well, it was marked as english threaded. I recently put it on a bike.
It's french threaded.
hence my ISO posts for french threaded pedals.
So, I think I can have the threads retapped to english since Frenchy threads are smaller.
It would exponentially open up my pedal options. Not to mention if I use this bike for a brevet (which I most likely will), I'll probably throw spd's on it. I'd like to be able to do that without changing the beautiful crank out.
In fact I don't even have a puller for this crank yet.
So, any opinions on re-tapping? I'm not sure how I feel about modifying an original piece like this, even though it's most definitely the practical answer.
What would you folks do? It's only original once or just retap it and be done with it?
It's french threaded.
hence my ISO posts for french threaded pedals.
So, I think I can have the threads retapped to english since Frenchy threads are smaller.
It would exponentially open up my pedal options. Not to mention if I use this bike for a brevet (which I most likely will), I'll probably throw spd's on it. I'd like to be able to do that without changing the beautiful crank out.
In fact I don't even have a puller for this crank yet.
So, any opinions on re-tapping? I'm not sure how I feel about modifying an original piece like this, even though it's most definitely the practical answer.
What would you folks do? It's only original once or just retap it and be done with it?
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#2
Senior Member
Joined: Sep 2008
Posts: 1,350
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From: Collegeville, PA
Bikes: Ruckelshaus Randonneur, Specialized Allez (early 90's, steel), Ruckelshaus Path Bomber currently being built
Retap and be done with it. Even better, retap and helicoil, the threads will hold better.
#4
The crank was marked as English threaded or the auction was marked as such?
I ran into the same issue recently. I was going to tap my 93 but had the same reservations. I began looking for pedals and found a couple pairs of Lyotard rat traps. I really like them with clips and straps. Now I have two French threaded 93s and no real desire to tap them to 9/16" x 20.
The Stronglight 93 was not a rare crankset by any means so far as I know. If you're a dedicated SPD guy then I don't see an issue having them tapped or you could just continue to look for one that already has English threads.

I ran into the same issue recently. I was going to tap my 93 but had the same reservations. I began looking for pedals and found a couple pairs of Lyotard rat traps. I really like them with clips and straps. Now I have two French threaded 93s and no real desire to tap them to 9/16" x 20.
The Stronglight 93 was not a rare crankset by any means so far as I know. If you're a dedicated SPD guy then I don't see an issue having them tapped or you could just continue to look for one that already has English threads.

Last edited by ColonelJLloyd; 02-17-11 at 08:18 AM.
#5
i was actually hoping you'd chime in, and I was expecting you to yell at me for considering the retap 
the auction was marked as english thread. That, or even more likely I didnt read it entirely and just bid at the last minute...
I WAS a dedicated spd guy, but I've started riding platforms on some bikes and it's starting to grow on me. That said platforms are ok for a short ride, but I don't think I'll be switching over for longer stuff.
I guess I'll see about having Curtis at Via retap..it's the last thing keeping me from finishing this bike and I want to ride it!

The crank was marked as English threaded or the auction was marked as such?
I ran into the same issue recently. I was going to tap my 93 but had the same reservations. I began looking for pedals and found a couple pairs of Lyotard rat traps. I really like them with clips and straps. Now I have two French threaded 93s and no real desire to tap them to 9/16" x 20.
The Stronglight 93 was not a rare crankset by any means so far as I know. If you're a dedicated SPD guy then I don't see an issue having them tapped or you could just continue to look for one that already has English threads.
I ran into the same issue recently. I was going to tap my 93 but had the same reservations. I began looking for pedals and found a couple pairs of Lyotard rat traps. I really like them with clips and straps. Now I have two French threaded 93s and no real desire to tap them to 9/16" x 20.
The Stronglight 93 was not a rare crankset by any means so far as I know. If you're a dedicated SPD guy then I don't see an issue having them tapped or you could just continue to look for one that already has English threads.
I WAS a dedicated spd guy, but I've started riding platforms on some bikes and it's starting to grow on me. That said platforms are ok for a short ride, but I don't think I'll be switching over for longer stuff.
I guess I'll see about having Curtis at Via retap..it's the last thing keeping me from finishing this bike and I want to ride it!
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#6
#10
soon enough. two more minor details and the pics will be flowin'. I've been trying so hard for the past few months not to show anything until I'm done on the 3 builds I have going on.
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#11
https://www.treefortbikes.com/product...l-Tap-Set.html
maybe I should just get a set since I'll probably spend half of that having someone else do it.
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#12
multimodal commuter
Joined: Nov 2006
Posts: 19,811
Likes: 596
From: NJ, NYC, LI
Bikes: 1940s Fothergill, 1959 Allegro Special, 1963? Claud Butler Olympic Sprint, Lambert 'Clubman', 1974 Fuji "the Ace", 1976 Holdsworth 650b conversion rando bike, 1983 Trek 720 tourer, 1984 Counterpoint Opus II, 1993 Basso Gap, 2010 Downtube 8h, and...
You could just see if anyone has a set you can borrow. Come to think of it, I have a set you can borrow. Problem solved.
#13
Senior Member



Joined: Dec 2005
Posts: 18,705
Likes: 11,283
that would be these right?
https://www.treefortbikes.com/product...l-Tap-Set.html
maybe I should just get a set since I'll probably spend half of that having someone else do it.
https://www.treefortbikes.com/product...l-Tap-Set.html
maybe I should just get a set since I'll probably spend half of that having someone else do it.
Neal
#14
#16
that's probably why I scored the one I have so cheap, come to think of it...
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#17
The T handle for the taps may cost you almost as much as the taps. I used an adjustable wrench to turn the taps until I broke down and bought one. Very little material is removed and the taps go through the aluminum like butter. It's not even necessary to remove the crank from the bike.
#18
I've retapped a dozen or so Frenchy threaded cranks... I wouldn't hesitate in recommending it.
Last edited by Noah Scape; 02-17-11 at 09:50 AM.
#19
PanGalacticGargleBlaster
Joined: Apr 2009
Posts: 7,531
Likes: 9
From: Smugglers Notch, Vermont
Bikes: Upright and Recumbent....too many to list, mostly Vintage.
LBS did my LA Cyclotouriste's for 10 bux.
after seeing how well it worked I bought a Tap and Die set from lowes that included a handle, the taps and the Dies to cut threads on a bolt. Just used em last night to thread a hole for a fender mount. Infinitely useful!
after seeing how well it worked I bought a Tap and Die set from lowes that included a handle, the taps and the Dies to cut threads on a bolt. Just used em last night to thread a hole for a fender mount. Infinitely useful!
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#20
Senior Member



Joined: Dec 2005
Posts: 18,705
Likes: 11,283
The T handle for the taps may cost you almost as much as the taps. I used an adjustable wrench to turn the taps until I broke down and bought one. Very little material is removed and the taps go through the aluminum like butter. It's not even necessary to remove the crank from the bike.
Neal
#21
Senior Member


Joined: Apr 2007
Posts: 12,552
Likes: 2,735
From: Thunder Bay, Ontario, Canada - burrrrr!
Bikes: 1958 Rabeneick 120D, 1968 Legnano Gran Premio, 196? Torpado Professional, 2000 Marinoni Piuma
Most bike shops will have a set of taps in the drawer, somewhere. Chances are they will be a great help if you approach them. And, for what it is worth, I too have purchased a set of taps, keeping in mind that you will need the proper taps, both right and left hand thread.
As for the helicoil idea - not!
As for the helicoil idea - not!
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#22
Old fart



Joined: Nov 2004
Posts: 26,257
Likes: 5,133
From: Appleton WI
Bikes: Several, mostly not name brands.
the auction was marked as english thread. That, or even more likely I didnt read it entirely and just bid at the last minute...
I WAS a dedicated spd guy, but I've started riding platforms on some bikes and it's starting to grow on me. That said platforms are ok for a short ride, but I don't think I'll be switching over for longer stuff.
I guess I'll see about having Curtis at Via retap..it's the last thing keeping me from finishing this bike and I want to ride it!
I WAS a dedicated spd guy, but I've started riding platforms on some bikes and it's starting to grow on me. That said platforms are ok for a short ride, but I don't think I'll be switching over for longer stuff.
I guess I'll see about having Curtis at Via retap..it's the last thing keeping me from finishing this bike and I want to ride it!
If they're marked English, chances are they just need to be chased out. If they're French, you may as well tap them anyway to allow a wider selection of pedals.




