Replies to This Discussion

Permalink Reply by igz on September 29, 2009 at 8:42am

Thanks, Brian. The advice for the disc brake is appreciated, though i was already sold on em. My question still stands, however. Can what i want to do be done, or is there something im missing (other than a wheel buidling class, of course)?

Brian Benson said:

i'd opt for the front disc brake. if you've never ridden them before, you're in for a real treat (and possibly suprise).
couple imporant considerations:
-Hydraulics are better than mechanical for a number of reasons, but they do need to be 'bled' every so often just like car brakes (not too difficult...plus you only maybe need to do it every 2, 3 years depending on how much you ride). They are also better because with wet, mud, snow, etc. mechanical can slip and slide...never had a problem with riding soaking wet hydraulics
-Get used to them before you use them in a real life 'emergency'. If you get quality ones (personally i like Hayes or Avid (by SRAM)...the 'juicy' is a good model. A front one WILL STOP YOU ON A DIME if you really get into it so just be aware of their ability or you'll know what superman feels like...without the ability to continue flying ;)
-If you take the front wheel off a lot, pay attention to what the manufacturer suggests about the discs, they can't touch during travel or in theory they can meld together...i put a little sqaure of cardboard in between...

can't think of anything else, but I am a huge fan of disc brakes
hope this helps

• ▶ Reply

Permalink Reply by joe stein on September 29, 2009 at 9:40am

i'm a roadie, so maybe 29r rims are stronger, but i've always been told that it's more difficult to build with a used rim and that if you are going to spend the cash & love on a rebuild, pop for the new rear rim.

after 8 years, i just got my rear wheel done for about $175 with spokes, rim tape & nipples, and i expect to get 8-10k miles out of it.

hubs last ages, but rims take a beating.

• ▶ Reply

Permalink Reply by igz on September 30, 2009 at 3:23am

the only rebuild involved here is the wheels...so...all i need is a 29er rim and appropriate spokes. and i would be doing it myself, learning as i go.

what im still trying to figure out, before i take my wheels apart, can it be done?

joe stein said:

i'm a roadie, so maybe 29r rims are stronger, but i've always been told that it's more difficult to build with a used rim and that if you are going to spend the cash & love on a rebuild, pop for the new rear rim.

after 8 years, i just got my rear wheel done for about $175 with spokes, rim tape & nipples, and i expect to get 8-10k miles out of it.

hubs last ages, but rims take a beating.

• ▶ Reply

Permalink Reply by Gecko on September 30, 2009 at 5:17am

You can swap the rims/hubs without a problem, and you can even use a beefy double wall road rim if you want. I recently built a set of old Matrix Aurora road rims onto old GT mtb hubs for my Surly and they hold up just fine on and off road. The only thing I suggest doing lots of research on is spoke length. Different rims and hubs have different sizes and they make just about every spoke length in 1mm increments. If you're off 1-2mm either way it won't make a difference, but if the spokes are too short you won't have enough threads on the end to lace the rim solidly and if they're too long, they'll poke into the rim tape and could eventually punch through into your tube. I've also reused old spokes without a problem. As long as the threads are fine, they're relatively straight, and the nipples are good, you should be fine as long as they're the right length. Oh, and I'm assuming you checked already, but the wheels both have the same amount of spokes right?

• ▶ Reply

Permalink Reply by igz on September 30, 2009 at 7:12am

same spoke quantity, yes. and i agree with you on the research for spoke length. but how the ef do i figure that part out? and i assume that lacing patterns affect this also.

El Gecko said:

You can swap the rims/hubs without a problem, and you can even use a beefy double wall road rim if you want. I recently built a set of old Matrix Aurora road rims onto old GT mtb hubs for my Surly and they hold up just fine on and off road. The only thing I suggest doing lots of research on is spoke length. Different rims and hubs have different sizes and they make just about every spoke length in 1mm increments. If you're off 1-2mm either way it won't make a difference, but if the spokes are too short you won't have enough threads on the end to lace the rim solidly and if they're too long, they'll poke into the rim tape and could eventually punch through into your tube. I've also reused old spokes without a problem. As long as the threads are fine, they're relatively straight, and the nipples are good, you should be fine as long as they're the right length. Oh, and I'm assuming you checked already, but the wheels both have the same amount of spokes right?

• ▶ Reply

Permalink Reply by Gecko on September 30, 2009 at 9:44am

Well there are advantages and disadvantages to different spoke patterns, but 3-cross is the most common and the most versatile. Other types have different compromises between lateral stiffness and torsion. For example, you wouldn't lace a rear or disc wheel radially because although it's solid side to side, the torque from the drivetrain/discs will spin the hub right out of the spokes. Two cross is a step up from that, but I still wouldn't recommend it for disc brakes or rear wheels. 4 cross can get tricky because you usually need really big hub flanges so the spoke ends don't overlap. I run 3 cross on all my wheels and I've never had a problem. Mountain disc wheels, road wheels, everything.

If you're new to wheelbuilding in general, I'd recommend reading Sheldon Brown's Wheelbuilding Guide. It can be a little confusing at first, but the step by step nature of it puts it a little closer to someone actually showing you how. Wheelbuilding is like an art though, everyone does it a little differently, and I don't necessarily follow all of Sheldon's steps to a T when I'm building wheels.

On spoke length, different calculators measure different parts of the hub different ways. I'd look at the DT Swiss Spoke Calculator. This will give you a good idea of the measurements you need to know. Hopefully your hubs/rims are already in the list, which saves you from a lot of measuring and headache.

There are other spoke calculators out there, but I've found the DT Swiss one to be the most reliable and accurate. Also, if you're in doubt about any of your measurements, you can probably take the rims/hubs to your LBS and have someone measure them up for you. Once you know the spoke length, everything else is cake.

• ▶ Reply