Cold Setting Type of question...
 

I have a Raliegh Technium Road bike. This is a PARTIALLY aluminum frame that is lugged and bonded together. According to my magnet, the only pieces that are aluminum on the frame are the Seat Tube, Top TUbe and Downtube. The rest is steel(CRMO I assume) It has a 126mm dropout spacing.

Can I safely move up to a 130mm rear hub? Can/should I stretch the spacing, or should I just wedge a wider hub/wheelset into the rear. What is generally recommended - especially on a bike that is bonded, rather than welded together.

Thanks in advance.
Greg

I owned an 88 Paramount once and tried to cold set it. Using all thread and nuts and washers . I stretched two inches + beyond the 130mm width and let it sit for days and it always relaxed back to 126mm.......i ended up just spreading the stays to get the rear wheel on and lived happily ever after.....

FWIW, it has nothing to do with how long you let it sit, you just have to spread it apart far enough to get it to bend. I know what you're saying in regard to the 2+ inches, etc., it does seem a little scary when you look at it. But apparently 2+ inches wasn't enough. But if you had spread it enough, it would have cold set (bent) instantly. The best way to do it is to use Sheldon's method, bending one side at a time to insure proper alignment, and to work incrementally if you can, stopping, checking the amount of change, and then working on it some more. The whole process can be done in a few minutes.


To the OP, I have no experience with bonded frames, but my thinking is that if you're going to use a hub with axle spacing wider than the dropouts on a frame like that, the best way would be to simply flex it apart by hand each time you install the wheel. And even that might be questionable, I don't know-

Shimano makes these axle-locknuts with beveled edges. It helps spread the dropouts 2mm per side when you insert the wheel. Really simple. Even without them, I just pull the dropouts apart by hand when inserting a 130mm wheel. :)

Seems to me that simply spreading it until is stays bent ensures that it bends at the weakest point.

Anyone tried a technique of stretching the dropouts as per above, then using a dead-blow hammer (over folded chamois or similar) to "encourage" the bend at a specific spot?

If the frame will easily stretch to 130mm to install the wheel (and it most likely will), then you are better off not cold setting it. With cold setting you risk over bending the frame and possibly causing cracking at best in the paint, at worst at a weld. A few extra seconds to install the wheel is no big deal. As has been pointed out, it may take bending the frame out over an inch (25mm) to cold set it, which makes bending it .080 (2mm) seem like nothing.

What everyone else said...about just jamming the wheel in there. It's 4mm or about 1/8". Plenty of flex in the frame.

To cold set or not to cold set will be dependent on what the bottom bracket shell and the lug the seat stays terminate in are made of. If they are both steel, you are probably ok to cold set it. If either is Al, don't do it.

I agree that putting a 130 mm hub into 126 mm dropouts by the brute force method does work. The difference isn't that much and the only problem is the fight you go through when you have a flat on a cold, rainy day when the wheel is wet and your fingers numb.

I'm sure all frames are not the same but on the two frames I've tried this on (one aluminum and one steel) they both spread very easily. The wheel almost guided itself in due to the locknut chamfers.

Agree. I would check on the Classic fourm or an LBS about this. The issues will be where the 2 metals are joined and how they are joined. Brute force works most of the time.

+1 pm on Danno's technique. I use it on all my steel bikes. It works great. I also have a Technium frame, it's a MTB. If the lugs that the seat and chainstays are glued into is AL, you're SOL. I wouldn't chance putting that much pressure on a glued joint or AL lug.

Remember what the only real flaw of those beautiful Specialized CF Allez's were? They used CF tubes glued into AL lugs. The CF never failed but the AL lugs cracked. In case you think I'm talking about the new Allez's I'm not. I am refering to those 1990's versions.

As for your problem. Use a magnet on the lugs. If it's steel, you probably can spread it. If the lug is AL, IMO spreading it is a bad idea.

Tim

As I said in my earlier post, I don't have any experience with bonded frames, but my guess is that it's a bad idea to cold set one. But in regard to cold setting a conventional steel frame, don't forget that the joints that take the most stress by far during cold setting, assuming the frame has seatstay and chainstay bridges, is where the stays are welded or brazed to the bridges, not where the stay is joined to the bb and seat lug. The stays bend just aft of the bridges because that's the first point of reinforcement coming forward from the dropouts. So those stay/bridge joints are the ones that are critical during cold setting. If you were to break a joint at the bb or seat lug, again assuming the frame has seatstay and chainstay bridges, it almost certainly means you've already broken the stay/bridge joint-

These chamferd locknuts were used on early 8-speed hubs so they would go into the (then) common 126 mm frames with minimal difficulty. By now manufacturers assume 130 mm hubs are going into 130 mm frames and the locknuts aren't chamfered.

They still have slight chamfers (like any nut) on them IIRC. Either way, getting the wider hub in place was very easy, although I didn't try it with numb fingers.