rear triangle spread
 

I tried the search and wasn't able to find a post....so please direct me there if this topic has been beaten to death....

I have a 1986 Trek 560 Pro Series with a 6 speed freewheel out back. I may have access to a 2000 ultegra kit (9 speed). I think the current rear spread is 126 mm.....how big of a deal is it to spread the triangle to 130 mm, or just shove a 9 speed wheel back there? Thanks, and sorry if I missed this topic.

It's no big deal at all. You can usually spread the stays by hand. Permanently bending them is a little more convenient. You might want to have a bike shop align the dropouts.

I spread our old POS gaspipe tandem frame out from ~120 to ~145 with a length of err, gaspipe. Its fine so far.

I believe the 560 was Reynolds 531, which is thick enough and sufficiently ductile that it can be cold set by home mechanic, as long as reasonably care is taken. Some of the thinner and higher strength steels leave little margin for error.

It's going to take a bit of trial and error. Just start out with low force and gradually increase the force, measuring for a permanent spacing increase after each try. The last thing you want to do is apply too much force on the first try and buckle the stays.

I rode a couple of bikes that I just spread the dropouts and installed the wheel. After a while I cold set them to 130 because it's just so much easier when you get a flat. I think if you search for "cold set" you will find a lot of threads.

Just some notes:
1. Gaspipe bends easier than Chrome Moly. My Varsity was easy, my Premis took an extra 10 minutes because it is more like a spring.
2. Use a 2x4 to lever against, not the seat tube.
3. Make a frame alignment gauge to measure how far to move each dropout so the hub remains centered on a line from the headset to the seat tube.
4. Realign the dropouts so your rear wheel tracks correctly.

I spread my Gianni Motta from 126mm to 130mm every time I install the rear wheel. I see no reason at all to permanently spread it. A quick bit of pressure and it slides right in. I'd try it for yourself before you take any further steps.

it's surprisingly easy (and takes less force than you'd think) following Sheldon's directions and using a big 2x4.

You shouldn't have to cold set if you don't want to. Some frames spring easier than others. I've used 126mm spacing with 130 hubs no problem. When you get a flat its a little more fuss but no big deal. Once you get the wheel in the drop outs it will sort of spring in.

Its almost worth it to coldset it yourself or by a professional.

2mm difference on each side is nothing. Takes about 1.215349 ft lbs of pressure to spread the stays enough.

#1 Google hit

http://www.sheldonbrown.com/frame-spacing.html

I just did that this weekend using Sheldon's instructions.

At first I was being too ginger, and making no progress. Then I gave a couple of really hard shoves and overshot...out to 140mm from 126mm! :eek:

Shoved that side back down (whew) and then took it a bit slower. Hopefully the "overshoot" didn't damage anything...it looks okay, and the frame is properly spaced and aligned now.

I have yet to ride it...

Sheldon's method is less expensive, and just as good.

I've never found that having a frame aligned properly is a bad thing, and well worth the $40 tool investment (can you have too many bike tools?). I like the idea of spreading by hand better than putting a 2X4 into my De Rosa and yanking.

You probably don't want to see how they do it in the factory then...

Kind of like making sausage, y'know...

I told one of the mechanics at the lbs the same thing, he didn't believe me, I didn't elaborate. Some of the newer tubing will not take the same treatment, at least not the main triangle. There are plenty of buckled frame pictures on the interwebs if you look in the right place. But I think the tubing that can't take it came along mostly after the switch to 130mm spacing.

I'm fairly confident that my De Rosa's and Mercks were properly aligned at the factory. If Ugo wants to bend it with a 2X4, I don't have a problem.

Me with a 2X4, not quite as confident.

Like OFG I'm a great fan of having correctly aligned frame, fork, and wheels. It costs from $25 to $100 (yes, I paid this once, and it transformed a Trek) to get a stripped frame completely checked out and put right, and around $40 to get one bike cold set by a shop, with alignment. If you're gonna do a lot of this, get the tool.

8, 9 and 10 speed are on a road bike all 130mm OLN
6 and 7 generally 126mm
5 and compact 6 are 120mm

i did the same thing when I first did it. Surprisingly easy to give yourself 15mm.

All the more reason to use the Park Tools method.

You guys are giving me hope for spreading my tandem rear end as far as I want to. It has extra tubes like a mixte though. I think I'll need more than the Park tool or a 2x4.

Add me to the list. I would rather my nice Italian frames be cold set on a frame alignment jig by someone that knows what they're doing, as opposed to me with a 2x4 and string.

$40 is not that big a deal to make sure it's done right, with no damage. YMMV.

I watched famous frame builder Chris Kvale spread my vintage Columbus Trek frame. He clamped the frame on a benchtop vise at the bottom bracket shell, ran a string from the head tube to the dropouts. He then proceeded pushing and pulling on the dropouts and measuring the string-to-seattube distance. It just took a few minutes, he then aligned the dropouts with a Park tool. He said this is the best way if you know what you're doing...

I've cold set frames with the Park frame alignment tools and home made tools. I've checked frames set by both methods using piano wire and rulers, Park tools and precision measuring equipment on granite surface plates. Guess what? They can all give the acceptable results, if you're careful.

Most custom builders operate on a tolerance of +/- 0.025" (about 0.5mm), which you can achieve with a home made prybar and measure with piano wire and rulers. Typically, I try to avoid string due to the fraying and fuzzy edge. Piano wire can be pulled taught like string and has a well defined edge to make measurements easier.

BTW, the best, economical alternative to a 2x4 prybar is the shaft from a broken (ice) hockey stick. It's sufficiently long and strong, but as not as cumbersome. Also, a section from a narrow inner tube can be stretched over the contact end to prevent marring of the paint.