embankmentlb

As a winter project I am looking into the idea of building a set of 700c carbon clincher wheels. I have build many sets of 28 & 32 spoke standard aluminum wheels but I am a total novice when it comes to carbon.

What I am contemplating is something like: Circus Monkey hubs, 20 & 24 spokes, carbon rim with aluminum brake track.

I have many questions...

What special techniques are there for doing this? I would think the spoke holes in a carbon rim would be somewhat fragile. Do you even use standard spokes & nipples?
Are there any special problems or concerns I should have lacing to a carbon rim?

mrrabbit 

Nothing fancy or special:

1. Most but not all use inverted nipples with NyLock...so you are basically going 8+ more millimeters on the ERD to engage the NyLock.
2. Most but not all are rated for 130kgf or more...
3. Get in the mental mindset that you are truing the hub in the wheel - as opposed to truing the rim in the wheel - most truing issues you run into become resolved.
4. Be prepared to settle for +/- .003-.004 tolerance as opposed to +/- .002 tolerance...

Watch out for very old Zipps with thevery low kgf rating - you will need to use a "nipple/thread glue" with those.

=8-)

embankmentlb

Thanks mrrabbit. It seems the more I look into this, carbon rims & certainly carbon / AL combo rims are heavier than plain old AL rims. Am i missing something? Do the rims need to be heavier to accommodate lower numbers of spokes? I may have just talked myself out of this project.

mrrabbit 

Typically profile for profile...the carbons will be lighter. In other words, make sure you are comparing 30mm deep aero alloy rims with 30mm deep aero carbon rims.

I.e., compare a Velocity B43 against a carbon rim of the same profile and depth...

=8-)

Kimmo

The B43 is not a typical rim; at 770g, it's irrelevant. The Deep V is more normal at 520g, which is a bit on the heavy side for a 30mm ally rim. The IRD Cadence Aero, also at 30mm, comes in at 465g.

mrrabbit 

???

=8-)

FastJake

Before you buy, definitely look at the specs and see how much everything will weigh. You juggle 3 things:

1. Low weight
2. Aero
3. Low cost

when building road wheels. Basically you can't have all three, you have to make a choice based on what matters most to you. If you live somewhere flat it may make sense to sacrifice weight to get the benefits of a really aero wheel at a lower cost. If you live somewhere really hilly you might as well stick with super lightweight box section rims with the least number of spokes you can get away with. If you have an unlimited budget, well, you know... get whatever you want.

For example, Kinlin XR-200 (20mm deep) weighs 390g. I used to have a Specialized tri-spoke front which was probably the fastest wheel I've ever used, but it was heavy. Another downside of going too deep is that you get blown around in crosswinds. That's why I got rid of the tri-spoke, and replaced it with a 30mm deep Al wheel with 18 bladed spokes. It's not as fast but much better overall.

embankmentlb

My rides are all about climbing walls. I place no value in aero. I was looking at options for light clincher wheels with al brake track.

I have about decided my Dura Ace / open pros cannot be easily topped.

FastJake

I would stick with them then. Open Pro weighs 425g IIRC, you will not find any clincher rim weighing much less than that. Plus, it's a durable solid wheelset that you don't have to worry about breaking.

You could, however, save a bit of weight if you switched to tubulars.

mrrabbit 

Open Pros are light weight racing clinchers for which durability is not a targetted characteristic. Mavic CXP-33 might have a little in that category, but then again it's a light weight racing aero clincher.

=8-)