Crang

An 82 Nishiki frame fell into my life I plan on building up. Before I get it powdercoated want to spread the dropouts to 130mm for a 9 speed conversion. Steel frame thats been chromed- watched some videos, made a drill rod spreader and went at it. Saw RJ the Bike guy on Youtube got his steel frame open to 160mm before it rebounded to 130mm. Working up 5mm at a time I went up to 175mm spread open and the frame rebounded back to the original 126mm. Can a chromed frame be spread open? Its starting to creak and groan opening up to 175mm so wanted to ask before I tried 180mm. Worst case I just leave it at 126mm and stick a 9 speed hub in there anyway. Thanks-

3alarmer

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...different frames and different steels all make for different experiences with opening up the rear dropout distance. I do not know what a drill rod spreader is, nor have I ever watched RJ the bike guy on Youtube. But I know of no early 80's Nishiki frames that cannot be cold set, using the right technique. IN this case, when I say "the right technique", I mean clamping the bare frame in a solidly mounted Bench vise, with aluminum angle soft jaws covering the surfaces, stringing it up to measure how far each side is moving off the centerline, and using some sort of hooked lever arm to bend out each side in its turn. If the right chainstay is dimpled, it will be more resistant to moving out, but it will still go.

Chrome should have nothing to do with this.

icemilkcoffee 

If all you want is 9 speed, the you can just do a '9 of 10 on 7' without altering your 126mm frame. In other words, leaving one cog out of a 10 speed cassette and putting it onto a 7 speed freehub body .

Crang

Interesting, that helps. The right chainstay is dimpled and its all Tange 2 I believe. In my other life its common to hard chrome metal parts to make them resistant to erosion from burning hot gases and to reduce wear. It certainly raises the surface hardness, so didnt know if it changes its bendability. The drill rod method is simply nuts and washers on a 3/8" drill rod placed inside the dropouts. The nuts are turned to force the washers apart thereby spreading the chainstays evenly by applying equal pressure to both. However after reading your post, if the dimpled side requires more force to bend, i may end up pushing the left side out further........

3alarmer

...spreading the rear distance by pushing or pulling on the dropouts is not a good practice. Eventually, you will encounter a frame where the brazing lets loose (where the dropout is inserted into the stays), and the frame will be damaged. It can still be repaired, but only at considerable cost and effort. Same thing with working on a fork. pull or push on the frame member, not stuff that is brazed onto it.

3alarmer

...yes, this almost always happens when the chainstay is dimpled for chainring clearance.

gugie 

Not quite sure what everyone's thinking here, but the thickness of chrome is insignificant to the thickness of the chainstays, there will be no measureable difference between the force required to cold set a painted vs a chromed frame.

The one issue might be that the chrome cracks. I've had that happen on poorly chromed forks while reraking. The chrome in tension is "stretched" and can crack, even pop off in small sections.

dddd

Allow me to extract the few bold-highlighted words from within your post! (and it's all-thread, not drill-rod).

In other words, definitely not a good idea to force the two sides apart and expect both sides to bend near-equally.
Usually, one side bends well (or entirely) before the other side does, and for reasons going beyond the crimping (as when there is no crimping).

RJ's videos contain useful information if applied only with real descretion to any bicycles of quality.
Certain of his video's contents nearly remind me of a freshly-stoked meth-head if applied to a quality bicycle.
BTW, many meth-heads definitely work on bicycles, seems one of their favorite pastimes (note that I don't think RJ is a meth-head, and that I perhaps jest with such extreme wording).

A chainstay with more crimping will be the first to bend, due roughly to the reduced moment of inertia of the crimped section.

So one may very well end up with the driveside dropout heavily offset, versus the non-driveside dropout.
This can be good if used with a dedicated custom wheel having a biased dish, both in terms of wheel strength and in terms of chainline (especially with triple cranks, even more so if combined with an oversized seat tube).

busdriver1959

If the dropout comes off with that little sideforce, it was going to break off anyway. Better to know now than after lot’s of time, effort and maybe dollars had been put into the project.

verktyg 

There are several different types of chrome plating that can be used on a bike frame:

Triple plating is superior in most applications. It's not 3 layers of chrome but an initial layer of copper which fills in surface imperfections and is then polished. The second layer is nickel plating which give a harder surface for the chrome plating to build up on. It's sometimes polished too. The final layer is a very thin coating of chrome from 0.0002 to 0.0006 in. (from 0.005 to 0.015 mm). The chrome itself is very hard and brittle, 70Rc to 78Rc.

Double chrome plating is more common and less expensive. The copper layer is skipped and it's just nickel and chrome. The nickel doesn't adhere as well as copper plating to the steel. Bending a plated surface causes the nickel to loose adhesion and eventually crack or peel off. The damage may not appear right away.

verktyg

gugie 

One can guess which type can withstand tubing bending better.

3alarmer

...this is simply untrue. Dropouts are inserted into the stays, and brazed in in such a way that the expected force on them will be primarily along the length of the stays, pushing inward, with the hub and wheel inserted. This is an entirely different situation than pushing or pulling sideways on one or both of them, without a stabilizing hub inserted. Sketch it out for yourself in a diagram, if you don't believe me. Regardless, it's simply poor practice overall.

3alarmer

...yes. He mentioned plans for powdercoating, so I didn't want to further confuse the issue.

busdriver1959

As a frame is ridden, dropped, cornered and sometimes crashed, the dropouts will be hit with forces from all directions. Since I’m getting ready to braze the dropouts on my 39th frame I don’t need to draw anything out. I’l stick with my original contention-if they break off that easily, they’re screwed up already and you’re doing yourself a favor by finding out now.

gugie 

Chrome can also be masked prior to powdercoat, so I was unsure whether it was an issue or not. Obviously a chromed frame can be cold set, so I answered the only two issues I could think of - does chrome make it harder to cold set (no), and added my experience in reraking chromed forks on 70's era Raleighs. I highly doubt cold setting chainstays would cause chrome flaking, as the localized deformation is small compared to my experience reraking forks.

3alarmer

...I had an Italian bike with chrome on it, that seemed like if you looked at it funny, some of the chrome would flake off.
You think I'm joking, probably, but that's honestly how it seemed to me after a while. I finally just sanded it and painted over it.

3alarmer

...sure. You go with what you know, and I'll go with my experience. If they're different, there's no sense getting in a kerfuffle over it.
If you really are brazing up all those frames, I'd be curious how you set them prior to use. 39 frames is probably not enough to buy a frame table.

You really just grabbing onto the dropouts and giving them a yank sideways ? I guess it cuts down on your tool investment. All you need is some Campy dropout adjusters and you're good to go.

krakhaus 

I don't know why anyone even bothers cold setting from 126 to 130. I've done it a few times, and it was never worth the effort. It's basically effortless to slide a 130 wheel into a 126 frame.

Crang

[QUOTE=krakhaus;22257200]I don't know why anyone even bothers cold setting from 126 to 130. I've done it a few times, and it was never worth the effort. It's basically effortless to slide a 130 wheel into a 126 frame.[/QUOTE

Im new to wrenching on bikes so wanted a project. Had done a couple old trucks but going through the learning curve here. Lots of specialty tools I dont have yet to be sure. Got a free beat to hell frame off Craigslist Free so seemed like a good place to start to get experience. It is my size and I think it has the potential to come out nice but at this point Ive got nothing in it so if I screw up, wont be crying.

busdriver1959

Yes I have built those frames with a few tube replacements along the way too. I use a Bringheli frame jig and a granite slab with a Bringheli BB post for an alignment table.

3alarmer

...you didn't really answer my question. So I'll repeat it. Are you really just grabbing the dropouts to do the final alignment, or are you pushing and pulling on the frame members when you're off in the final result ? Or are you never off in the final result ?

Believe it or not, there are lots of people in the world who can handle a brazing torch. I can eve braze in a forge hearth, but I don't do it any more. None of this changes how the steel frame is designed and constructed, or how the forces act on it.

gugie 

Except when you've ridden 80 miles on a loaded tour, tired, sun's going down, and, yeah, it's worth the effort.

ymmv

3alarmer

...you're on the right track. If you want a 130mm wheel in there, the time to do your cold setting is now, before you invest in paint or powdercoat. Some other things you might want to consider at this point is seatpost fit in the seat tube. (Sometimes, on an older frame that has been rode hard and put away wet, the seat lug is a little distorted, from someone fitting the wrong size post and tightening it down to make it work. The only really satisfactory solution is to ream it out round again,)

You can put off aligning the derailleur hanger for later, when you have a good rear wheel. It's not a big job. And you should check out the threading in the bottom bracket shell, to see that it's not boogered up. You can usually fix that, but it's PIA to have something all painted up, and then discover the only way you can make it work is with a threadless BB.

I used to build up project frames to rideable, before painting, just to see if there was anything I might discover in that process that needed fixed. This is also a good time to get someone to put in down tube bottle braze ons, if the frame is old enough that it doesn't have them.