grasscutter

Ok. I've read the threads about putting 700c rims on an old 26" MTB. Fork clearance, brake reach and a few other odds ends are
things to consider.

But here's my question.

I build my own wheels and enjoy building my own bikes, with each having its own purpose and style.

So, when I shop around for parts to build my wheels...if I find a nice set of 700c that I like, they're good for either MTB or Road, right?

How about hubs? A dura ace front road hub, not good or good for a MTB application? And how about the other way...a shimano XT or XTR for a road or tour application?

It just seems to me, that parts are parts. If its a good hub, then its a good hub, no matter where you bolt it in.

Would appreciate some thoughts.

nahh

Troll? If you say you build your own wheels, you should know the answer to this.

grasscutter

Nope. I'm being serious. I've only built a couple sets. Completely new to building them. Just doing some research to get better @ it.

Jeff Wills

Hubs don't care much about what rim they're laced upon. "Road" hubs tend to be less bulky, weigh less, and be less well sealed than "mountain" hubs, but beyond that the sky's the limit. I've built several "road" rear wheels on "mountain" hubs because I like to have less dish, but "mountain" rims on a light set of "road" hubs might be the bee's knees for a fast set of commuter wheels.

I've been building wheels for 30 years- and I've gotten weird in my old age:
https://home.comcast.net/~jeff_wills/...es/bike042.htm
https://home.comcast.net/~jeff_wills/...es/bike004.htm
https://home.comcast.net/~jeff_wills/...es/bike034.htm

Retro Grouch 

The devil is in the details.

700c rims come in different widths. Hubs have different over locknut dimensions.

HillRider

+1.

Front hubs, both MTB and road, are almost universally 100 mm OLD (over locknut dimension) so they can be used interchangeably. Disc brake front hubs are usable with any rim but require a properly designed and mount-equipped fork for use with disc brakes.

Current rear road hubs are 130 mm OLD and current MTB's (and some touring, hybrid and cyclocross bikes) use 135 mm OLD hubs.

It is possible to convert a 135 OLD hub to 130mm OLD and vice-versa if you know what you are doing.

grasscutter

Jeff>

That's exactly what I was contemplating to try first. Dura ace road hub on a light mountain rim for a touring bike. Biggest concern I had was if the light Dura Ace hub shell was tough enough to handle rough roads, potholes, etc, that a tourer would encounter, or if the Dura Ace hub was built for lightness only, and no long term reliability. I rarely see that hub on touring bikes. Its usually a shimano xtr, PW or roloff, or similar.

Retro G & HillRider>

That's what I'm noticing. Looks like I'll have to start keeping track of those dimensions and do some experimenting.

Looks like fun!

davidad

The seals are just dust seals. They don't keep water out. My tourer has an Ultegra hub and has carried as much me at 185, the bike at 32 and 50 lbs. of gear.

HillRider

Dura Ace hubs can be pretty tough. I have a set of 7700 (9-speed era) DA hubs that are on their second set of rims and on their second bike. They have been is service for 55,000 miles and the original freehub body, cones and races are still in fine condition.

I would avoid the first 7800 series Dura Ace hubs with the aluminum freehub body as they accepted 10-speed cassettes only. Earlier and later DA hubs with the Ti freehub body will accept 8, 9 and 10-speed cassettes.

Jeff Wills

As others have said- front hubs are about as "universal" as you can find. For a touring bike, I wouldn't go below 32-spokes, but a Dura-Ace hub will work fine. The shell is plenty strong.

pat5319

besides what you've mentioned - when you change wheel diameters you change the geometry of the bike, this can sometimes make the bike dangerous, worst case or steer "weird"

Jeff Wills

Well... having made a very rideable ultra-mongrel around a 27" wheel frame, 24" road fork, 26" ATB wheels and narrow tires (cleared the fork crown by 1/8"), I have to say this might be overstating the case. Narrower 700C rims and tires are about the same outside diameter as very fat 26" ATB tires, in which case the geometry changes are minimal. Even with small changes in geometry, there's not much chance of "dangerous" effects.

tatfiend 

Depending on age rear hubs, and frame dropouts, can be as narrow as about 110mm to as wide as 135mm, or even wider for tandem rear wheels. The 110mm ones are older Sturmey Archer hubs as well as some old SS/FG hubs. 120mm was common for 5 speed and narrow 6 speed wheels as well as most current SS?FG hubs. 126mm was common for wide spaced 6 speed freewheels and narrow spaced 7 speed ones. 130mm is the standard for 8 through 11 speed road hubs and 135mm is the common MTB width that is also used on many hybrid, commuter and current IGH frames.

Most steel frames can be cold set to any needed width but this is not true of aluminum or CF frames. From what I have read not recommended for Titanium frames either.

The commonest wheel size change these days is from 27" to 700C. Most of the time brake pad position can be readjusted to handle the difference in rim radius, only 4mm. Greater changes in rim diameter from original can require major brake modifications or replacement unless the bike has disc or some form of dum brakes.