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CX rim / wheel help or advice needed...(10 posts)

CX rim / wheel help or advice needed...memphistrials
Dec 1, 2002 4:54 PM
As many of you may remember, I've got a Surly Cross Check, which comes with these Alex rims.
Today I totally tweaked the rear rim in a race. It's got what seems to be an uncorrectable bend. So, I'm in the market for a new rim.

What do you guys think of this Alex rim for CX use? I'll be riding a lot of road, and some non-rocky and non-technical trail riding on the bike.

I wouldn't mind getting the same rim as I'm running now, but I cannot find it for sale anywhere. Bike Nashbar has the R390 for just $20 each. I figure I could get two and have both front and rear rims replaced, 'cause I'm anal about having matching rims. =)

My second question is this: given that the new rim is a tad bit taller than the old, and that the spokes on the bike are not quite 3 months old, could I have the wheel rebuilt w/ the old spokes?
I'm really going to have to do this economically as possible, so I'm trying to save $$$ where I can.

Any help / suggestions / advice would be appreciated!

Thank you!

- Chip
Webcyclery
Peddler Bike Shop - Memphis, TN
Everthing you wanted to know and more (IMHO)TWD
Dec 2, 2002 10:54 AM
OK here goes (this may take a while),

I just built up an extra set of CX wheels using the ALEX R390S. They are a nice looking rim, have double eylets, and the weight is OK (at least for a $20 rim).

I did notice a few things that I'm not crazy about with the R390s. First, when I built the wheel, I noticed that the sidewall had a bulge or thicker spot at one spot (not at the joint and only on one side).

Also, after I built the wheels and ran them for a while, I noticed that even though the sidewalls are machined, the wear pattern from the brake pads was really wavy (don't know how else to describe it). Also, the brakes don't have a very smooth even feel to them, you can feel some points where the brakes grab more than others.

As for re-using the spokes/nipples from your old wheel, it's not ideal because the wheel may not be as durable in the long run as a new wheel, but it can be done. It's definetely a lot easier to build with new stuff, so many (most?) builders will steer you away from re-using your stuff.

If you really do want to re-use your stuff, you want to stick with a very similar rim and exact lacing pattern for sure.

You will need to figure out the Effective Rim Diameter (ERD) of your old rim and the one that you are replacing it with to see if they are close. I couldn't find any specs on the Alex DV15, so you'll have to measure the spoke length directly. Remember that your drive and non-drive side spokes will be different legnth on the rear wheel. You'll have to remove a spoke from each side and your cassette to measure them.

Once you know your current spoke length, you'll have to determine what the spoke length needs to be for the new rim.
You'll need to use a spoke calculator for that. Go to www.sheldonbrown.com and take a look at his wheelbuilding page. He has links to several spoke length calculators (Daimon Rinards is my favorite). If you are looking for the ERD of the Alex Rims, go to www.bikeusa.com, they list the ERD for all the Alex rims they sell as well as alot of other brands. Otherwise the spokecalculator has a database of most common rims.

Make double sure you put all of the correct dimensions for the hubs and lacing pattern (follow the instructions on the spoke calculator)so that you come up with the correct spoke length. If the spoke length comes out to within a 1mm (maybe 2mm) of your current spoke length, it should be OK. If you're off much more than that your spokes will either run out of thread before you reach proper tension if they are too long, or the nipples won't have enough thread contact if they're too short. Both are bad.

My advice would be to try to find a cheap rim that is similar in looks and ERD to the one that you had, and rebuild the wheel yourself. It isn't that hard. Sheldon Brown's site is a good starting place for figuring it out, otherwise do some research over on the wheelbuilding forum at MTBR.com. There are alot of resources out there.

I'll warn you though, wheelbuilding is addicting, and it's almost as fun as riding. I started in the same spot as you about 3 years ago replacing one rim, and have since built abot two dozen wheels for myself and friends with excellent results. Every excuse that I can get, I'll build up a new wheelset.

Good luck,

TWD
Thanks TWD! Another quick question...memphistrials
Dec 2, 2002 11:43 AM
First off, thanks for your detailed reply!

I've decided to go the new spokes route in building up the new wheels. A friend is going to "show me the ropes" of wheel building. Perhaps I'll get hooked like you. ;)

I've also found a new rim I'm thinking about using. The WTB SpeedMaster. (It's the last one at the bottom of that page.)

What do you think of this vs. the Alex R390 for cross / light trail riding? I can get the WTB for about $40, so that's what I'd pay for both Alex rims. But if they are that much better, I'll save up for the WTBs.

How tough do the R390s seem to be?

Thanks for your help!
don't mean to chime in butatpjunkie
Dec 2, 2002 11:51 AM
you can get good deals on velocity's as well. I'm a Clydesdale and my Aeroheads are doing great. I'm going to replace my rear Open Pro on bike 2 with a deep vee after the season
Not sure about WTB, but like VelocityTWD
Dec 2, 2002 3:43 PM
Can't say much about the R390s durability, since I built them up a month or so ago and don't have that many miles on them.

I don't have any experience with that WTB rim. I've used the WTB Lazerdisc rims on my MTB and they were OK, not great. It looks like an OK rim, but it's really hard to tell a good rim from a bad one by looking at a picture without any real world experience.

I think the build quality is just as important as the rim quality if not more so (not that you want a crappy rim). In general, I stay away from factory machine built wheelsets.

I'll second ATP's advice on the Velocity rims though. I use them whenever I can (road, mtb, and cross).

They are the most durable rims that I've used. The first set I ever used was set of Deep Vs laced to ultegra hubs. Bought them used from a guy back in '96 or '97 (he got them from Nashbar). I used them as my primary road wheelset through this season, as well as a backup set on my cross bike. Now my wife is using them on her cross bike. I'm sure I've got well over 10,000 miles on those things and never took a spoke wrench to them. I'm a clyde too, and ride pretty aggressively. Also built up a set of 48 hole Deep Vs for my road tandem.

I think the only way you could kill these rims it so run tire pressure too low and dent the sidewalls (problem with any clincher) or back over them with your car. They aren't the lightest rims though.

The Velocity aeroheads are a nice rim too. I just built up a new road wheelset with these, but haven't ridden them yet. Lighter and not as aero as the Deep Vs, but I think they will be great. Cane Creek uses the Aerohead for some of their wheelsets.

I am really anxious to try the Velocity Fusion rims (cross between the Aerohead and Deep V). These would be my first choice for cross.

The price on most of the Velocity Rims are pretty reasonable.

Hope that helps.
Aeroheadstihipscrew
Dec 2, 2002 7:14 PM
These are fairly nice. They are quite light (I weighed mine at 395g/401g). No eyelets tho. Therefore, do not use Rox rimstrips, as the sharp edges 'round the spoke holes cut the tape at higher pressures. A virtually instantaneous total flat results. That is not good. I must add that I had used the wheels for some days before this occurred, and had just inflated the tires to 115psi for a crit at the time of flats. Yes, both front and rear flatted at different times during warmup. I have never had this occur with an eyeletted Mavic rim. No probs with Velox tho.

As to the strength of the Velocities, I had someone put a skewer into my wheel in a cross race at speed, violently. This was a straight 14g DT spoke, and when I heard it whapping around I was afraid that it had been pulled through the rim. Nope, the spoke broke. The rim was unscathed. So despite the lack of eyelets, Aeroheads are pretty strong. I put a new spoke in, trued the wheel and- good as new.
Aeroheadsatpjunkie
Dec 2, 2002 9:52 PM
yes they take a bit of abuse
AeroheadsTWD
Dec 2, 2002 10:44 PM
Yeah, conventional wisdom seems to indicate that eyelets are better/stronger, but I've yet to have any problems on any of my velocity rims.

I've been using the Aeroheats on my MTB (kinda like their off road version of the aerohead) for a disc wheelset. Most people tend to recommend using eyelets especially on disc wheelsets (Velocity's VCX disc only rim uses eyelets) but I haven't had any trouble without them. Another friend of mine who is a mechanical engineer and framebuilder uses a set of Deep Vs on his mountain tandem disc wheelset without eyelets and hasn't had any problems either.

I never thought about the sharp edges causing flats though, but I usually run Velox anyway.
sharp edges no problemrichpierce
Dec 3, 2002 8:02 AM
When I build a wheel with velocity rims I rub each spoke hole on the inside of the rim with 180 grit emery cloth in a circular motion with my thumb a few times. Seems to round the sharp edge. Don't know if it helps but it eases my mind.
I like my Speedmasterstamjam
Dec 3, 2002 7:53 AM
They serve the purpose I wanted them for, which is a rim that can comfortably fit a size 44 tire and handle the beating I expect to give them riding my local fireroads. I don't race cross, so can't speak for how they would be on the course.