jonny7

This frame has been patiently waiting for a while now. During the pandemic I assembled the components I needed, basically a 10sp campy groupset and a basic Miche wheelset. The bike was stored the way it had been previously built, i.e. as a fixie with a formula hub in the rear. Somehow I assumed the rearspacing was either 126 or (if lucky) 130. I do not know the exact year of the frame. Well I should have measured it earlier. The digital caliper is firm: 120mm in the rear. I believe this actually matches the measure for track hubs, so in a way it sort of makes sense, but I'm still confused. Could this measure indicate that the frame has already been cold set to actually match the track hub? Or could it simply be that the nuts holding the previous hub in place applied pressure in such a way that it "naturally" cold set the frame over the course of time?




Here is a picture with the new wheels on, but I'm guessing that this amount of pressure on a modern hub is no good. Should I then cold set it, at least to 126? Advice is most welcome.

Oh and for those who worry, the frame is not actually clamped that way.

3alarmer 

...that's the most likely scenario. If the frame is old enough to go back to the days of 5 speed freewheels, it could have been 120mm spacing originally. But none of the frame details look that old (fork crown, bottle braze-ons, braze on for front derailleur, etc.)

...it doesn't work that way. You can keep a hub clamped in the rear forever, and it won't reset the spacing.

I wouldn't worry too much about the pressure on the hub from the dropouts. You get that much pressure or more from a skewer. But the misalignment of the dropout faces will make your rear axle more prone to bending or breakage. And it will often be less firmly fixed in the dropouts because of this misalignment. So yes, your preferred alternative is to measure the distance between the locknut faces, and cold set your frame to this new standard. You need to be careful to do it in such a way that each dropout ends up equidistant from the centerline plane of the frame.

The final step is to realign the dropouts so they are parallel at this new spacing. There are threads on here with advice on how to do this, and some of them have photos.

Fredo76

120 mm was standard 5-speed road spacing for a couple decades before 6-speeds and 126 mm came along. It was more likely built to 120 mm, I would think.

SurferRosa

An original '80s road bike with brazed fd and 120mm rear spacing seems crazae.

T-Mar

I agree with 3alarmer, this was almost certainly cold set to 120mm by the previous owner. The combination of frame features, such as short non-Portacatena dropouts. recessed brake mounting, front derailleur hanger, dual bottle bosses, pump peg and cable routing under the BB shell, suggests no early than mid-1980s, by which time 126mm would have been standard at this level. The only feature that I'm not seeing, are top tube tunnels or ports for the rear brake. I guess they could be hidden on the non-drive side but Bertrand typically mounted brake ports on the top side of the tube.

The other thing to consider is that Bertrand wasn't even building frames until the 1980s. I guess it could be a something other than a Bertrand, but with the exception of the previously mentioned brake routing, it looks legitimate to me.

I'd be cold setting and aligning to 130mm, for the proposed wheelset.

jonny7

Yes you're guessing right, the cable guides on the top tube are oddly placed on the side of the tube. This is the first time I see this on a Bertrand - nonetheless I see no reason to doubt the legitimacy of the bike, it has all the classic Bertrand features including the Cinelli BB shell. I will try to find someone in my area to carefully cold set it for me. I'd hate to ruin the rear triangle. Thanks everybody for the replies.

Doug Fattic 

I suggest you find a framebuilder 1st. This is a primary skill for them. There is a chance some bike store may have the knowledge and equipment but that is going to be a secondary skill they may have occasionally used sometime in the past.

CliffordK

You could try a straight edge along the seatstays. The bend should be pretty subtle, but should be noticeable at the brake bridge.

Shrevvy 

I had a 1984 Schwinn Peloton build by Panasonic. The specs are 120 mm rear, but it has all the more modern frame touches - recessed brakes, dual water bottle bosses, cables routed under bb. It did have a clamp on front derailleur. Schwinn went to 126 mm in 1985 for the Peloton.

SurferRosa

Yeah, that's very different than what most everybody else was doing with higher end road bikes that deep into the '80s. Schwinn catalog scans for that model show an Ultra-6 freewheel for '84 and Ultra-7 for '85.

jdawginsc 

Schwinn was always a bit slow to the table...

delbiker1 

I have a 1989 Fuji Ace, Ishiwata tubing, that was originally 120mm rear spacing. I cold set it to 130 just a couple of months ago.

SurferRosa

Originally, it should have been 126 with Suntour 6-speed Accushift (Blaze).

Fredo76

Why would somebody cold-set a road frame smaller to run a track hub? Maybe an early, proto-retro-grouch ordered his frame with new bits and old spacing, to run his old wheels, or...?

Olang

I have a Wilier from early 1980s which by all accounts should have been 126 mm, but came in at exactly 120 mm. So I chose to run it as a 120 mm/10 speed, as I had the spare wheelset and freewheels at home already.

But to answer your question. Someone has definitively cold set it to 120 mm/track hubs, and hopefully you can cold set it back to your liking instead.