pgoat

I have read that, unlike rear frame stays which can and should be cold set to accept wider hubs, front forks can be simply 'sprung' apart to take a wider hub.

I have a typical 100mm front wheel I'd like to use on an old 1960s english frame - It may be 96mm, it may be less. I know when I've tried cramming the 100mm hub in it is not easy, even with some major elbow grease. In fact I've yet to get it in place!

Assuming I can gorilla it in place, am I asking for trouble? Is there a very good chance the forks could break from the stress of having a wide hub forced between them?

I should add I am a 200 pound rider who pounds potholed streets in Manhattan........

My apologies if the answer is bloody obvious (or has been addressed here before).

operator

Rear stays don't need to be coldset, depends on what you're going from.

amahana1

A lot of getting it to fit is what the fork is make of, steel, alu or carbon. going from a 96 to a 100 shouldnt be a problem. BUT, if your having to really put some major force to get it to fit, I would say dont do it, you are putting alot of stress on the fork. If it were me, I would hesitate doing that to a carbon or aluminum fork, especially if youre really having to fight it like that. Your best bet, just pick up a new fork.

pgoat

It's a steel fork. Good news is it's pretty tough - a top of the line Nottingham three speed, and in barely ridden condition. Bad news is it's a 1964, so even though it looks pretty dead mint outside, I imagine there's been enough aging to add a degree of weakness to the metal (thru inner corrosion, etc).

The frame says 20 40 hi-ten (as opposed to the typical 10-20). It feels and rides like your basic hi-ten stuff.

Trouble with buying a new fork is :
A) value of bike and ride quality don't warrant the expense and trouble (for me)
B) size interchangability problems anticipated with new forks? The stock one has a 1" threaded steerer, accepts your basic road quill stems no prob. The headset is a bit dicey, definitely wouldn't take a standard off the shelf replacement road fork to the best of my knowledge. Again, the cost of a new head set added to the price of a new fork is not an option for my use of this particular bike (a beater which is left locked on the streets).

Even given it's a steel fork, the amount of effort I've had to exert makes me nervous. Isn't it true you can go up/down one width size but not more without cold setting or a proper shop re-set? I know my hub is a 100mm (Campy record) but not sure if the fork span is 96mm or less. I'll check when I get home tonite.

peripatetic

I have a fork that's about 2/3mm too narrow for my hub, I can get it on with a small amount of effort--more awkward than difficult. I haven't had any problems, and when I took it in to Trackstar to have the guys look at it, they said that having to manually spread the arms wasn't a big deal. I would say that if you're putting in a LOT of effort, though, it might be a bad idea. I was told at Trackstar that Chelsea bicycles on 27th/28th and 6th/7th ave. will re-align my fork (it's a little bent) for 20 bucks. I bet they might charge something similar to spread yours a little further--still cheaper than a new fork. In Manhattan, I agree, why put the cash investment into an old beater for a new fork? Probably cost a large portion of the value of the bike in the first place.

amahana1

A steel fork can be reset, cold set, to a different width with no problem.

pgoat

Is this something I should just have a shop do? Or can I just pry them apart with a crow bar of some sort?

I paid New Gen on 9th ave aout $20 to straighten my forks after I lost a mini-war over a parking space with a small army of homeless people. They did a gr8 job and I wouldn't have tried that one myself cause the fork blades were pushed out of alignment. I'd be a bit worried about messing up the alignment on these as well.

operator

You coldset a bent fork?? Good luck.

pgoat

well, the shop did - it rode fine for a couple more years, not even a paint wrinkle - beefy hi-ten mtb!!

When I say 'out of alignment' (not sure if i was clear) I mean one fork blade was pushed fore and the other was bent aft, in addition to the blades being crushed slightly narrower (closer together).

I would be willing to try cold-setting/spreading my fork apart to accept the 100mm hub but I am worried that I might do the same thing (move them fore/aft) or not bend each blade out the same amount for an evenly centered wheel/brake.

anyone ever try this?

pgoat

Just to make sure we're on the same page - the forks I am thinkng of spreading wider are NOT the ame ones I had straightened at a shop - that was a different bike I no longer own.

The current forks I am contemplating spreading are fine; hi-ten 2040 steel, no crashes, hardly used in fact, just old (early 60s.) I am just worried that they are too narrow to be spread sufficicently for a modern hub.

It's a Campy Record qr going into a Rudge three speed fork. Not sure if I have to file the dropouts as mentioned on Sheldon Brown's site......

darkmother

Most steel fork blades have been bent cold anyway-that's how the rake is there. It is safe to cold set a steel fork, especially by only 2mm/side. Cold setting will be safer than riding around with the forks in a state of stress. Sheldon Brown's page has some info on cold setting forks. I'd feel confident doing it if it was my bike.

matheprat

Go for it.

rmfnla

Just to make sure we're on the same page - the forks I am thinkng of spreading wider are NOT the ame ones I had straightened at a shop - that was a different bike I no longer own.

The current forks I am contemplating spreading are fine; hi-ten 2040 steel, no crashes, hardly used in fact, just old (early 60s.) I am just worried that they are too narrow to be spread sufficicently for a modern hub.

It's a Campy Record qr going into a Rudge three speed fork. Not sure if I have to file the dropouts as mentioned on Sheldon Brown's site......


Remember that "hi-ten" is a marketing term for standard carbon or "mild" steel, NOT chrome moly. This is pretty soft stuff and will take a bit of bending. I am concerned that you are having so much trouble with a 4 mm difference; 4mm just ain't that much. I think you'd be better off getting a chro-mo replacement fork; you can find them pretty cheap if you shop a bit.

pgoat

20% carbon, if i am not mistaken......I think my trouble cramming it in there means the fork is narrower than 96mm.......plus the dropouts probably need to be filed out, but I'm not even getting close to that point - it's a real width mismatch........

ofofhy

1020 = 0.2% C in Fe, 20% would put you way off the steel charts. 2040 would be 0.4% C with some Ni.

pgoat

doh! That's what I meant.....20% would be one hard little mofo of a fork!!

pgoat

well, I finally figured out the problem - as usual, the most obvious one.....the wheel I want to use is the standard 100mm; the forks on my bike are 90mm!!! (actually 91 is a standard size according to Sheldon Brown, that's prolly it.)

No wonder I had so much trouble

Would y'all still try to spread the forks? we're talking 9 or 10mm now. I'd prolly have a shop do it unless someone has some idiot proof directions for me....

I'm not too concerned with wrecking the bike - it'd be worth trying as a learning experience if nothing else. But I kinda don't want the forks snapping while I'm coming down the mountain.

phidauex

I'd still do it..

Try this technique, if you don't want a shop to do it.

Install a hub (any hub) into one of the fork ends, and secure the steerer in a vice (be careful not to crush the steerer). That gives you a 'handle' to bend with. Note the position of the end of the fork, and use the handle to bend the fork out until you've moved it by about 4-5mm. You'll need to use some force, and move it a little beyond what you think you have to, then it will spring back most of the way, but end up with a little overall change. Make many small adjustments till you hit the right amount. Then move the hub to the other fork end, and move it by the same amount. Using the hub will help you keep the fork ends aligned, and will let you determine how much you've moved it. There are a lot of good solutions, but that is one that has worked for me. I've actually cold set rear triangles with the same technique.

Steel is real, and won't give you any trouble this way. You couldn't use this technique with any other frame material.

peace,
sam

pgoat

Thanks Sam.

to make sure we're on the same page - this is fork off the bike, and hub installed 'outside' the fork? ie, chainring side of hub bolted to outside of non-chainring side of fork?

phidauex

pgoat, you might find it helpful to install the hub several ways on each fork end as you go through the process. I'd start with the hub on the 'outside' of the fork (ie, the way you'd never ACTUALLY install a hub), and then finish up fine tuning by putting the hub into the fork 'normally', but only connecting the fork to one of the fork ends.

There is a park tool for helping with these sorts of realignments, and if you saw someone use it, it would help you understand. Basically the park tool is a big metal rod for a handle with a threaded collar on the end. Coming out of the collar is a piece of axle-like material, and then another collar, and an adjustable spacer. The idea is that you put this tool into the fork end, and you get a 'handle' on each side. The adjustable spacer lets you dial in how big of an adjustment you make, but fundementally, you are just grabbing the fork end and bending it around. Hubs do nicely as this handle as well, and are a lot cheaper.

peace,
sam

pgoat

cool - that makes more sense to me - thanks!!!

I'll check out their site to get a better visual idea but I think I got it now.