To Cold Set or Not Cold Set My Frame...

[jberenyi]

...that is the question everyone.

Hey gents, I have a Burley tandem with a 140mm rear drop out. I want to upgrade my wheel set so I can go from 7-spd to 9-spd. Should I have the frame cold set for the newer 145mm standard? I only ask because from what I have read on this issue as written by Santana it is "dish" that gets the attention. Apparently too much dish causes issues with spoke integrity over time. In a perfect situation a "dishless" rear wheel would be the ultimate but I don't think this possible. So I have the option of either a 140mm hub dished properly for 9-spd or a 145mm hub with less dish being induced. I don't see why a 140mm wouldn't be sufficient...standard road bikes are 130mm with 10-spd cassettes.

Chime in everyone :)

[ColonelJLloyd]

So long as it's steel cold setting to 145mm will be a non issue. Just have the dropouts properly aligned after checking symmetry.

[cnighbor1]

I talked with Ed Litton ,frame builder and frame repairer, and he was against it. He has seen stays ripple, drop outs break even if aligned.
I would stay with seven cogs.

[Tandem Rider]

I coldset my old Santana from 140 to145, it will take some serious leverage and muscle. Just be sure to align the dropouts afterwards. This will let you use a modern hub/freehub/cassette. Heavy wall cromoly will take a lot of moving around, stays, fork blades etc all started out as straight pipes.

[oldpotatoe]

I talked with Ed Litton ,frame builder and frame repairer, and he was against it. He has seen stays ripple, drop outs break even if aligned.
I would stay with seven cogs.

Yep, it 'can' happen. Depends on a lot, including the skill of the wrench. I do 126 to 130 all the time..will not do 120 to 130 for the mentioned reasons. I have only 'hurt' one frame, a Merckx..popped the brake bridge off one side when cold setting..paid to have it fixed, and painted..costly for me, but I still cold set 126 to 130.

[TimD]

We are talking about 2.5mm deformation at the end of a 400+ mm arm. If I had another cup of coffee I'd do the trig, but I think we are talking about a small number of degrees. Not a lot of bend for mild steel.

Tim

[redir]

I've not done it on a tandem, my guess is it's pretty beefy back there. But I have done it on several bikes using the Sheldon Brown 2x4 method and it works. Some frames bend a lot easier then others so it's advisable to start off real slow and check and recheck constantly.

[JLP]

You know if it were some priceless heirloom or something, I might not do it, but I'd think the risk is very very small. YMMV.

[David Kirk]

Do we know what material the stays are made from and if they are round or oval in cross section?

dave

[ultraman6970]

Not a builder but from 140 to 145 in steel doubt will be like a big problem, 2.5 mm per side is just a super small amount, the only thing I would be sure of doing is to wrap the stays really well to get the bend in the right spot and not having problems with cracks in the bridges and stuff.

Never done such a thing in aluminum so cant tell for sure what will happen.

[toytech]

I would cold set on a tandem that 2.5mm per side, although it can be pretty damn hard to move a stiff tandem rear triangle though. You could likely re space a 145mm hub down or order a nice Phil in that width too. My Bilenky had a 145 wheel in 140 dropouts and was really freakin hard to put the wheel in the rear drops.
Those babies were STIFF!:eek:

[jberenyi]

Do we know what material the stays are made from and if they are round or oval in cross section?

dave

Chromoly and oval

[David Kirk]

Chromoly and oval


If the material isn't heat treated I think you would be fine.

dave