Classic & Vintage - French Threaded Crank

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View Full Version : French Threaded Crank


-holiday76
02-17-11, 07:04 AM
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?


mudboy
02-17-11, 07:07 AM
Retap and be done with it. Even better, retap and helicoil, the threads will hold better.

Grand Bois
02-17-11, 07:10 AM
All of mine are retapped. Helicoil? Ridiculous!


ColonelJLloyd
02-17-11, 07:13 AM
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.

http://gallery.me.com/justinhughes/100201/IMG_3439/web.jpg?ver=12953985290001

http://gallery.me.com/justinhughes/100259/IMG_3381/web.jpg?ver=12937424710001

-holiday76
02-17-11, 07:20 AM
All of mine are retapped. Helicoil? Ridiculous!

i was actually hoping you'd chime in, and I was expecting you to yell at me for considering the retap :)


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.

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!

ColonelJLloyd
02-17-11, 07:22 AM
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 Carlton? The little 4M adjuster should be delilvered to you today.

-holiday76
02-17-11, 07:23 AM
The Carlton? The little 4M adjuster should be delilvered to you today.

i'm not telling.

nlerner
02-17-11, 07:24 AM
Tap 'em! I bought a set of the Park pedal taps a while back, and they've been invaluable.

Neal

ColonelJLloyd
02-17-11, 07:24 AM
i'm not telling.

I suppose that's better than telling and NOT showing.

-holiday76
02-17-11, 07:29 AM
I suppose that's better than telling and NOT showing.

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.

-holiday76
02-17-11, 07:30 AM
Tap 'em! I bought a set of the Park pedal taps a while back, and they've been invaluable.

Neal

that would be these right?

http://www.treefortbikes.com/product/333222335916/283/Park-TAP-6-Pedal-Tap-Set.html

maybe I should just get a set since I'll probably spend half of that having someone else do it.

rhm
02-17-11, 07:31 AM
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.

nlerner
02-17-11, 07:32 AM
that would be these right?

http://www.treefortbikes.com/product/333222335916/283/Park-TAP-6-Pedal-Tap-Set.html

maybe I should just get a set since I'll probably spend half of that having someone else do it.

Yup, those are they. You'll also make your money back with what you save buying eBay cranksets that *are* marked French threaded. They usually go for significantly less than English threaded.

Neal

ColonelJLloyd
02-17-11, 07:33 AM
Yup, those are they. You'll also make your money back with what you save buying eBay cranksets that *are* marked French threaded. They usually go for significantly less than English threaded.

Neal

Shhhh! Shush it!

nlerner
02-17-11, 07:34 AM
Shhhh! Shush it!

It did occur to me that I just gave away a C&V state secret. Well, not anymore.

Neal

-holiday76
02-17-11, 07:34 AM
Yup, those are they. You'll also make your money back with what you save buying eBay cranksets that *are* marked French threaded. They usually go for significantly less than English threaded.

Neal

that's probably why I scored the one I have so cheap, come to think of it...

Grand Bois
02-17-11, 07:55 AM
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.

Noah Scape
02-17-11, 08:08 AM
...you save buying eBay cranksets that *are* marked French threaded. They usually go for significantly less than English threaded.

Neal

Conversely, it seems to make French threaded pedals more valuable. I sold some Frenchy threaded Lyotard 45CAs on ebay last summer and got twice what I thought I'd get.

I've retapped a dozen or so Frenchy threaded cranks... I wouldn't hesitate in recommending it.

Zaphod Beeblebrox
02-17-11, 08:11 AM
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!

nlerner
02-17-11, 08:49 AM
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.

I also used to use a small crescent wrench to turn the tap, but then I got a real handle at a used tool/junk store. Very old school and cost $1.

Neal

randyjawa
02-17-11, 09:24 AM
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!

JohnDThompson
02-17-11, 10:08 AM
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!

Are the arms marked as English thread? Look on the back of the arms -- French thread will have "14 - 125" and English will have "9/16 - 20"

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.

-holiday76
02-20-11, 05:42 PM
thanks rhm for the taps. they worked great! I now can put my carbon fiber spd's on my '68 Carlton. Should look great.

DRietz
02-20-11, 05:47 PM
I'd like to see a picture of this...

:D

-holiday76
02-20-11, 06:25 PM
I'd like to see a picture of this...

:D

soon, very soon. :)

DRietz
02-20-11, 06:32 PM
Oh, and for the record, I tapped my own 93's out to English threading. No issue, no sweat. Very easy, actually.

Toytech knows - I sold them to him a year or so ago I think.

Rabid Koala
02-20-11, 07:42 PM
that would be these right?

http://www.treefortbikes.com/product/333222335916/283/Park-TAP-6-Pedal-Tap-Set.html

maybe I should just get a set since I'll probably spend half of that having someone else do it.

Thanks for the link, I just ordered a set. I have 2 French threaded cranks to retap and they would be very convenient for cleaning threads.

Charles Wahl
02-20-11, 09:47 PM
thanks rhm for the taps. they worked great! I now can put my carbon fiber spd's on my '68 Carlton. Should look great.

Why not spread the rear to 130 mm, go with a 10-speed cassette, and do it up with brifters, too? Maybe you can find some white hoods for them with the Carlton logo.
JK -- waiting to see this.

-holiday76
03-13-11, 10:08 AM
so I tapped the french threaded cranks as mentioned. No problems tapping, everything seemed great, until on the first ride this happened:

https://lh5.googleusercontent.com/_bYNfObzpWyA/TXzqaHsIjII/AAAAAAAACvM/0U5fN5xD1eM/s512/CIMG4827.JPG

completely stripped. No idea why. The other side seems fine.

Now I need a 170 non drive side stronglight 93 crank arm. Too bad I just sold my extra stronglight 93 YESTERDAY!
Also too bad I don't have a stronglight 93 crank puller.

juls
03-13-11, 10:44 AM
Bummer....helicoil?

fender1
03-13-11, 05:30 PM
I'd like to see a picture of this...

:D

Oh you'll see a picture for sure. Maybe a bit different than you might expect.............

Dawes-man
01-07-12, 07:46 PM
This thread (ho ho ho) came up on a search and I reckon it's as well to add to it for anyone searching in the future...

I think all the posts in this thread are about tapping out alloy cranks. I'm wondering about steel cranks. I have a few French chromed steel cottered cranks that I'd like to tap to take English pedals. As many have mentioned, it will drastically increase my choice of pedals.

I have the proper tap, and have used it, mostly successfully (one went in crooked), on 3 alloy cranksets so far. Will it work on steel? Or do I need a steel-specific tap?

prettyshady
01-08-12, 01:19 AM
french crank, french pedals

http://i.imgur.com/yyZMH.jpg

Dawes-man
01-08-12, 05:09 AM
french crank, french pedals

Oh dear, I think both La Liberté and Delacroix would be unamused at such a waste of time.