kandnhome

I have a 90s Univega with an aluminum main triangle with cromo seatstays, chainstays, and fork. It is currently spaced for 126mm hubs, and has a 6 speed freewheel. I would really like to update the rear hub to a freehub design.

My question is, can a frame with cromo stays attached to an aluminum main triangle be safely cold-set to the new hub width? Or will it overstress/possibly break the attachment points? Has anyone else tried this?

Also, related Q. The front chainrings are Biopace 52/42 (in really excellent condition). Will these work with modern cassettes, or will I have chainline/chainsize/etc issues?

Basically, I want to upgrade my bike from 6 speed to 8/9 speed if possible. There is the alternative of Sheldon Brown's "8 of 9 on 7" but that would require me getting a custom built wheel (or finding one with a 7 speed, 126mm freehub for less than the price of a new car).

Sorry for rambling, any help, experience, advice (like, "Don't Do It!") etc, is greatly appeciated

Retro Grouch 

Not something that I've ever done, but I'd be willing to try it in a heartbeat. I mean, it's a 90's Univega with bio-pace chainrings. What do you have to lose? If you ruin your frame, you should be able to find a similar one in a thrift store or garage sale for about fifty bucks or so. That's peanuts compared to what your new shifters are going to cost you.

Complete a project ot two like this and you'll get so smart about working on bicycles that you'll be giving other people advice about how to do it.

sydney

Have you actually measured that 126 or just assuming? Chainrings don't care about the casette in back,but STI/ergo shifters may be less than thrilled with them,although they will work if adjusted right.

John E

Before doing anything, read Sheldon's advice on using a 9-speed freehub as an 8-speed, etc. Although I have spread plenty of steel frames, including the Capo, I would not attempt it with any other frame material.

gcasillo

I did a cold setting to a mid-80's Bianchi Nuova Alloro about two years ago in order to fit a new Record group (with 10-speed cassette) to it. It was 126mm like yours. Very easy to do following Sheldon Brown's advice.

As long as the stays are cro-mo, I don't see why there'd be a problem. In my case, it made a beautiful, aging steed an even better ride.

Then I sold it this year and finally upped to an EV3. Needless to say, the retro stuff can be great, but new bicycle gear is even better. Go for it. If you botch it, then you'll have extra motivation to save your $ and get a new bike.

kandnhome

I've actually measured, and the over locknut distance (or between drop-out distance) is definitely 126mm (maybe a shade closer to 127mm).

gcasillo, or anyone who's actually done this before: did you have to re-dish your wheel, or was it centered after spreading the rear stays? Sheldon's site seems to indicate re-dishing may be necessary.

The reason I asked about the chainrings is because I've heard/read that bikes designed for narrower rear hubs may have chainline issues once widened. Also, the narrower chain necessary for an 8 or 9 speed setup might cause issues with the chainrings being designed for a wider chain? Like the chain getting stuck between the front rings on downshift, etc? Not sure here.

Just a little nervous about screwing up the only decent road bike I've been able to find in my price range. All the old stuff around here is REALLY low end, or just poorly kept and rusted. And being a student, it would take me about 2 years to save up the cash for a decent road bike ($1000-$1200 min), so that's pretty much out of the question. Gimme two years to graduate and get a real job, and I'll have a madone or similar. I just want to get as much out of this bike as I can.

gcasillo

I didn't have to re-dish my rear wheel. Mavic Open Pro on Campy Record hub and skewer.

Retro Grouch 

Well, it sounds to me like you're being realistic about this. Now is the time to really think through the project because once you get started, it's sometimes hard to stop having to buy "one more thing" to get it all to work together.

My hesitation about spreading the frame has to do with the way it was built. Steel stays with an aluminum main frame means that it's glued together at the joint. I don't know where exactly, the stays are going to bend or what the extra strain is going to do to the bonded joint. If it was my bike, I'd try it and chalk it up to experience if something bad happens, but then I've got a different bike to ride if it breaks.

If you widen the stays out to 130mm evenly, a new 130mm wheel should fit without needing to be redished. If you're planning to rework your present wheel, you'll not only have to redish the wheel, but you'll also have to add some spacers and a longer axle. Redishing isn't that big of a deal anyway. I don't think that I'd worry too much about chainline. You're only extending the stays a couple of millimeters on the drive side. That's not enough to worry about.

Shifters are the biggie. Nine speed STI is going to cost more than the whole bike is worth. Bar ends will cut the cost down by a bunch. If you're willing to settle for non-indexed down tube shifters, that will be cheapest of all. You probably will be able to make it work with what you've got.

Economically, I don't think that this upgrade makes much sense. You can easily run up $500.00 in costs and all you'll have to show for it is an old bike with some upgrades. It's not going to look or ride as nice as a new bike. On the other hand, you'll learn a whole lot about bicycles in the process of doing it. How much do you have to spend for some group requirement college course to learn stuff that you'll rarely or never use once you graduate? Think of the $500.00 as tuition and the fact that you get to upgrade your bike is a bonus.

Indolent58

If you're already at 127mm it's just 3mm to 130. Not to worry. I'll wager that you could just pop a 130mm hub in by pulling the stays apart slightly as you mount the wheel. No elaborate cold setting required. I did this on an old Trek with aluminium stays with no ill effects.

It's not clear from you post what your real goals are wrt the upgrade. Presumably you don't want to spend gobs on the upgrade. If you just want 8/9 speeds you could probably get away with a new rear hub (or an inexpensive rear wheel if you are not handy at wheelbuilding), a new cassette and 9 speed chain. If you are satisfied with your current friction shifting you will probably be ok with your current derailleurs (after readjustment) , and your crank should be OK too. If you want modern indexed shifting and/or brifters you may end up in a parts replacement death spiral. E-bay is your friend in cost containment.