Putting a regular fork in a French frame?

davidd86 said:

I have an old cheapo French frame that I'm going to build into a commuter. The fork being bent, I need to source a new fork. I think life would be far easier if I just got a modern 1" threaded fork. My question: as you know, french forks have a different ID (22.0mm rather than the 22.2mm for modern 1" threaded forks). Additionally, they have different threading, so you need both a different headset and a different stem. Pain in the ass.

My question is, is the ID of the frame head tube the same as it is on modern bikes? I.e., will regular modern headset cups press into it correctly? If that can happen, I can just revert to a regular fork, which would be great. Or are the head tubes themselves different sizes?

I'd cut my losses and start over with a different cheapo frame.

The head tube is the same ID. A new headset plus fork plus labor for instalation is going to run you at least $100-150. Unless you have some deep sentimental attachment, get a new frame.

davidd86 said:

I have an old cheapo French frame that I'm going to build into a commuter. The fork being bent, I need to source a new fork. I think life would be far easier if I just got a modern 1" threaded fork. My question: as you know, french forks have a different ID (22.0mm rather than the 22.2mm for modern 1" threaded forks). Additionally, they have different threading, so you need both a different headset and a different stem. Pain in the ass.

My question is, is the ID of the frame head tube the same as it is on modern bikes? I.e., will regular modern headset cups press into it correctly? If that can happen, I can just revert to a regular fork, which would be great. Or are the head tubes themselves different sizes?

The OD of both French and ISO/British headset cups are the same, so nothing unusual there. Note that a JIS headset will not work well, as the OD of the cups is a bit too small for a proper press fit.

Take care to be sure that the "new" fork has the right steerer tube length, the same offset (aka, "rake"😉 and at least close to the same fork blade length as the original.

BTW, how badly bent is the old fork? Might it be repairable? If so, that might be the cheapest way out.

davidd86 said:

I have an old cheapo French frame that I'm going to build into a commuter. The fork being bent, I need to source a new fork. I think life would be far easier if I just got a modern 1" threaded fork. My question: as you know, french forks have a different ID (22.0mm rather than the 22.2mm for modern 1" threaded forks). Additionally, they have different threading, so you need both a different headset and a different stem. Pain in the ass.

My question is, is the ID of the frame head tube the same as it is on modern bikes? I.e., will regular modern headset cups press into it correctly? If that can happen, I can just revert to a regular fork, which would be great. Or are the head tubes themselves different sizes?

I asked a similar question recently relating to the diameter since I was considering installing a Ruby fork:

http://www.cyclingforums.com/t291188-.html

I haven't measured the head tube, but it visually looks smaller in diameter than my other road bikes.

meb said:

I asked a similar question recently relating to the diameter since I was considering installing a Ruby fork:

cyclingforums.comt291188 .htmlOpen ↗

I haven't measured the head tube, but it visually looks smaller in diameter than my other road bikes.

Your Peugeot came with a (nominal) 1" steerer tube fork. Any fork with a 1" steerer tube will fit with the appropriate headset (threaded/threadless). Be sure the fork is compatible in other ways (offset, etc.), or you may change the handling in some unforseen ways.