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-   -   "We'll have to cut the frame down down". (http://www.bikeforums.net/classic-vintage/934415-well-have-cut-frame-down-down.html)

big chainring 02-16-14 08:47 AM

"We'll have to cut the frame down down".
 
Purchased a frame on ebay last week, arrived friday. All was good. Nicely packed. Really good condition for a 40 plus year old bike. I bought it with Nervar BB installed but no headset. French bike that needed a french headset. I popped a headset out of a Motobecane frame that I had laying around and discovered, after installing it in the new frame, that the steerer was quite short, no threads left for a locknut let alone a centerpull cable guide. The top of the steerer looked cut off/ angle cut. So what to do?

Took it to the local framebuilder and explained the situation.....and he said, "French steerer, not going to find one of those". "But we can cut down the frame". I laughed, "Yeah right, we can cut down the frame". So I said maybe find a replacement fork somewhere then? Then he said he was serious, he could cut down the headlugs, top and bottom, to gain perhaps 3/8". Quoted me a very reasonable price too. I was like wow, never thought about that. There IS extra material there.

Went home and emailed the seller. He insisted that he removed the old headset himself and it was in poor shape. So thats why he sold the frame without. He recommended a smaller stack height headset. My thought, not a lot to choose from when you are looking for a vintage French headset. Down to the basement shop I went and I removed a headset from a Gitane, one of my current rides, and of the same vintage as this new frame. I installed this second headset and gained a small bit of threaded steerer. Enough for the locknut, a couple/ three threads at best. So now I am thinking, shave down those headlugs maybe 3/16" and I'll be good to go with enough room for the centerpull guide.

So I think I'll go with the cutting the lugs down. Anyone have this done before?
Pics to come.

T

repechage 02-16-14 08:59 AM

Yes. A guy got a Wizard new and goofed on the stack height. A few mm off the top and a few mm off the bottom.
He could have gotten away with it had he not needed to use a Shimano first generation Dura-Ace headset.

auchencrow 02-16-14 09:02 AM

I have never encountered this.
- But it would be nice to be able to retain the original fork... In lieu of finding another longer fork &/grafting on the steerer from it, your frame builder's suggestion might well be a viable option. That is, I assume your frame builder knows what he's doing. If you do go that way, it would be best to measure twice to ensure you don't take too much off the top, and risk having the rear edge of the skirt from the threaded top race in contact with the TT.

aixaix 02-16-14 09:10 AM

If facing the head tube/lugs gives you enough thread to work with, that's your best approach. The steerer tube can be cut and lengthened by sleeving. If done carefully, this won't damage the finish on the crown. I've had this done on a fork that was way too short for the frame.

balindamood 02-16-14 09:15 AM

Could not the frame builder just un-brase a longer French steerer from another fork and use that one? If so, they are not that hard to find (I think I have at least two). How long do you need?

big chainring 02-16-14 09:38 AM

Quote:

Originally Posted by aixaix (Post 16500145)
If facing the head tube/lugs gives you enough thread to work with, that's your best approach. The steerer tube can be cut and lengthened by sleeving. If done carefully, this won't damage the finish on the crown. I've had this done on a fork that was way too short for the frame.

The sleeving idea was my first thought as well. But framebuilder didn't like that idea. And since the steerer is just a bit short the lug shaving seems like a simpler and more economic way to go.

ultraman6970 02-16-14 09:50 AM

If the new headset works why try to fix it? 2 or 3 threads will do the job.

big chainring 02-16-14 10:09 AM

Quote:

Originally Posted by ultraman6970 (Post 16500229)
If the new headset works why try to fix it? 2 or 3 threads will do the job.

No room for a centerpull brake guide thingy. And being this is a vintage French bike, its gotta have one, and i have a particularly nice one that I want to use. Also the steerer is cut on an angle so maybe 2 threads on one side and a thread on the other. I also omitted the serrated lock washer do-dad that stronglight headsets use. I would feel a bit more comfortable with a few more threads available for good lockdown.

I'm totally fine with the lug cutting, and the price is right. You start brazing stuff and it gets complicated with, paint finishing, and it has a chrome fork crown.

I had just never thought something like this could be done. And i have one very experienced framebuilder to do the work within walking distance of my abode.

Barrettscv 02-16-14 10:13 AM

I would search for a correct headset for many months before altering the frame or fork. If it's impossible to source the correct or a workable headset, then you have no alternative.

miamijim 02-16-14 10:40 AM

I've cut down head tubes many, many times.

You could go the hybrid headset route. Procure a low stack height British headset and only use the lower half. Lower = British Upper = French

LeicaLad 02-16-14 10:58 AM

First, I seem to have missed the details: What IS the stack height? Which French headset came off?

The Stronglight P3 Stronglight is among the lower heights.

Hunt for measuring stack heights and find Vertkyg (Chas)'s entries here or on the GitaneUSA site.

MJ's hybrid idea would be next. Shaving frame would be down my personal list of frame alterations, but that's me.

dddd 02-16-14 11:30 AM

Quote:

Originally Posted by LeicaLad (Post 16500377)
First, I seem to have missed the details: What IS the stack height? Which French headset came off?

The Stronglight P3 Stronglight is among the lower heights.

Hunt for measuring stack heights and find Vertkyg (Chas)'s entries here or on the GitaneUSA site.

MJ's hybrid idea would be next. Shaving frame would be down my personal list of frame alterations, but that's me.


+1^^^^^

Daveyates 02-16-14 11:46 AM

Can you post a photo of your headset?
Maybe I have one that is smaller.
Also instead of using a cable hanger you could drill your stem instead.

4Rings6Stars 02-16-14 11:47 AM

My solution would be to use the headset that fits and get a dual pivot side pull brake caliper.

But I'm a weirdo and choose function over form on all of my bikes ;)



(Just messing with you. I don't have a single original bike and don't care to, but I understand some people like to keep things period correct)

Michael Angelo 02-16-14 12:26 PM

Have an English steertube brazed on. Problem solved.

big chainring 02-16-14 12:26 PM

This is what I have. Its the flattest headset I have. Stronglight early 70's. Note the angled cut on steerer. And plenty of material on lugs.
http://im1.shutterfly.com/media/47a4...D550/ry%3D400/

http://im1.shutterfly.com/media/47a4...D550/ry%3D400/

Preferred hanger
http://im1.shutterfly.com/media/47a4...D550/ry%3D400/

MAFAC hanger
http://im1.shutterfly.com/media/47a4...D550/ry%3D400/

http://im1.shutterfly.com/media/47a4...D550/ry%3D400/

Follis
http://im1.shutterfly.com/media/47a4...D720/ry%3D480/

miamijim 02-16-14 12:39 PM

That's so messed up....fist off you need the special serrated washer...then use a thin cable hanger.

big chainring 02-16-14 12:42 PM

Quote:

Originally Posted by miamijim (Post 16500534)
That's so messed up....fist off you need the special serrated washer...then use a thin cable hanger.

yeah I omitted the washer. Hoping it works without.

big chainring 02-16-14 12:46 PM

Thinking I will remove the material to about the top of the paint chips. Both top and bottom lugs. That should get me going. Thats about 3mm off the top and bottom. 6mm all together. In like Flynn.
http://im1.shutterfly.com/media/47a4...D720/ry%3D480/

Daveyates 02-16-14 01:22 PM

I'm sorry but i don't have a smaller headset than that.
But i do have a serrated washer that is a lot thinner than the normal Stronglight ones.
You could use that then drill a hole in your stem to use as a cable stop.

Like this

http://3.bp.blogspot.com/-Cq9lWNvbDd...0/IMG_3108.JPG

Savagewolf 02-16-14 01:31 PM

I don't like the idea of cutting the frame at all. To me, it seems a rather extreme procedure.

dddd 02-16-14 02:01 PM

Quote:

Originally Posted by Savagewolf (Post 16500627)
I don't like the idea of cutting the frame at all. To me, it seems a rather extreme procedure.

+110 ^^^^^


Not to sound like a broken record, but.....

Ok, thanks for the photos, big chainring!

This is too easy now.

What is needed to finish what you started, is to ditch the idea of the fancy CLB hanger. It's not correct for a Mafac-equipped bike anyway, and it's not an original upgrade anyway, just a hipster bling bump if you will allow me to be so bold.


Take the threaded top race to someone with modest grinding skills and buzz off the jaggedies with a bench grinder, then follow up with some slow fine-tuning on a bench grinder. Yu'll get more threads than you need.

And, in cases where perhaps too few threads engage the locknut, use a drop of medium-grade Loctite on both the top cone-race or whatever and on the locknut. In this way, a much lower torque will need to be applied to said locknut, and the headset will never loosen.
I've even used Loctite on worst-case sort of headset threads, and never a problem even over years of hard use.

big chainring 02-16-14 02:19 PM

Quote:

Originally Posted by dddd (Post 16500678)
Quote:

Originally Posted by Savagewolf (Post 16500627)
I don't like the idea of cutting the frame at all. To me, it seems a rather extreme procedure.

+110 ^^^^^


Not to sound like a broken record, but.....

Ok, thanks for the photos, big chainring!

This is too easy now.

What is needed to finish what you started, is to ditch the idea of the fancy CLB hanger. It's not correct for a Mafac-equipped bike anyway, and it's not an original upgrade anyway, just a hipster bling bump if you will allow me to be so bold.


Take the threaded top race to someone with modest grinding skills and buzz off the jaggedies with a bench grinder, then follow up with some slow fine-tuning on a bench grinder. Yu'll get more threads than you need.

And, in cases where perhaps too few threads engage the locknut, use a drop of medium-grade Loctite on both the top cone-race or whatever and on the locknut. In this way, a much lower torque will need to be applied to said locknut, and the headset will never loosen.
I've even used Loctite on worst-case sort of headset threads, and never a problem even over years of hard use.

But i am in desperate need if hipster bling. Brakes are CLB. I actually bought the frame so I had something to put the bling brakes on. I could see skipping the hanger, or perhaps thin the CLB hanger.

Yeah grinding the teeth off the top cup would be a great idea. It threads on very tight anyway, threads are a bit bunged up.

I'm going to take the frame in to the LBS as it is now, hand it over to him and tell him to do what needs to be done. He's the expert.

lungimsam 02-16-14 02:48 PM

If you are not into preserving the original brakes you could switch to sidepulls maybe, if the frame will take them.

Or, doesn't someone like Paul make a cable hanger that mounts to the brake bolt? There must be a problem solver out there to address this

dddd 02-16-14 02:48 PM

Quote:

Originally Posted by big chainring (Post 16500713)
But i am in desperate need if hipster bling. Brakes are CLB. I actually bought the frame so I had something to put the bling brakes on. I could see skipping the hanger, or perhaps thin the CLB hanger.

Yeah grinding the teeth off the top cup would be a great idea. It threads on very tight anyway, threads are a bit bunged up.

I'm going to take the frame in to the LBS as it is now, hand it over to him and tell him to do what needs to be done. He's the expert.


If I was sure that the paint won't get all chipped up at both ends of the head tube, I'd give you 1mm off of each end.

No reason to leave the engagement splines on the top of the top race though. Did you know that CLB offered hangers with teeth to match the top race? Not sure how that would stack up.

Always keep in mind that bicycle shops put hourly work time at a premium when it comes to stuff that's hard to bill to the customer.
Never expect a shop mechanic to do your engineering decisions for you, it usually doesn't happen, and when it does, it is only sometimes done as the customer would have wanted.
This is too nice of a bike to sacrifice to such chances imo.
Does your shop even have a bench-grinder and belt-sander(?), (I would also check for parallelism as I proceeded, using a caliper).
Wishful thinking is bliss, sometimes. Trust, but verify, etc.

You do not need many threads to secure a headset locknut, and I've used as few as 2-1/2 full turns when I had to.
The Loctite gives you the assurance that you won't have to apply thread-threatening torque to a meager few threads, which appears to be of paramount concern with this build.

Also, noting that this is a good-sized frame, the stresses on the upper headset are thus relatively lower near the upper end of the longer steerer, so this also enables one of the steerer-splicing techniques to be considered as well.


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