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deep al. rim sh!t(8 posts)

deep al. rim sh!tWoof the dog
Jan 7, 2002 1:39 AM
seems like I have some decisions to make for my new front racing wheel. If I go clincher ~box section rim like aerohead, the wheel comes out to be ~920 grams (with tire+tube on, using am. classic hub).

I'll very likely go w/ a (tubular)campy Atlanta rim (seen on shamal wheels), microfront am.classic, 12 spokes(I weigh 130lbs). With the tire glued on, the wheel will weigh total of ~1000 grams.

A few questions:
would having such a deep rim in front "equalize" for the weight gain of 100 or more grams? I am not a math/computer person, how much speed gain at 25mph would it be?

Also, should I build the wheel spoke heads in or out(narrower) and more importantly what kind of spoke would you suggest for my light weight and this low spoke count(12)? radial lacing of course. Any advantage in oval spokes?

Thanx a great deal!

Woof the dog.
re: deep al. rim sh!tcyclequip
Jan 7, 2002 4:20 AM
All the anecdotal evidence suggests at higher speeds the aero benefits outweigh even radical weight differences. Kermesse racing might be different, but at 25mph the deeper the section, the better. If you want to run low spoke counts, use the deepest section you can find with the highest possible spoke tensioning. Radial will not give you any benefit except the minor weight gain of shorter spokes, but WILL seriously affect max spoke tension and wheel durability. With 12 spokes tho, you will radial spoke - then put the heads outside to create less angle on the elbow, tho evidence exists that spoke heads inside (ie wider) = stiffer laterally. Don't go too light on the spokes - unless you are using WIDE aero spokes (necessitating slotted hubs), don't bother. Normal DT/Sapim 2.0/1.8/2.0 will suffice - a racing wheel has 1 prerequisite - that it first and foremost FINISH the race. Durability is the primary concern, then aerodynamics, then weight.
re: deep al. rim sh!tmackgoo
Jan 7, 2002 4:42 AM
Check out www.sheldonbrown.com he has a pretty good article on wheel building. He mentions the oval spoke and spoke well of them, I forget why right now. It may have been with the oval spokes you don't have to slot the hubs. But I forget.
The advantage of oval spokes...Tig
Jan 7, 2002 10:34 AM
...is that they don't negatively affect bike handling as much as bladed spokes in strong cross winds.

Super deep aero rims and low spoke count wheels would be great for a TT, but for mass start races I'd stick with something more durable, yet lighter than the 1000 gram wheel you mentioned.
re: deep al. rim sh!tJimP
Jan 7, 2002 12:11 PM
I have been using a Nimble Crosswind (http://www.nimble.net/) carbon fibre tubular wheel that weighs 710 grams so with a Conti Comp Gp at 225 grams only weighs 935 grams and is very aerodynamic. I have ridden this wheel for 3 years and it seems to be bulletproof. The only downside is with gusty sidewinds where you have to keep it on a short leash.
Questiongrzy
Jan 7, 2002 2:54 PM
Why are you worried about deep dish clincher rims if you're going to be racing? You'll spend most of you time in the pack where the aerodynamics don't matter as much - unless you're off of one of the ends of said pack. The one thing you can be sure of about racing is that you will crash, and crash again. You should be thinking more towards economy, ease of maintenance/build and over all durabilty. Unless you're racing tri's or TT's then the aero stuff won't add up to a hill of beans and ultimately it's the motor, not the machine, that matters. Methinks you've been reading too many catalogs.
QuestionWoof the dog
Jan 7, 2002 8:00 PM
i'm not sure about the crashing part - its not like I crash every race.

I am usually upfront in road races anyway to control all the breakaways so that I could get in one too. Also there are things like time trials, and team time trials.

But maybe you are right. But I have no racing wheelset as of now, since I sold it. I am planning on sticking with my back wheel, as it is pretty light for a clincher and I can use my teammates' wheels to change in a race. However, it'd be nice to have at least a front wheel.

So the question now is: I can get that 12spoke shamal rim built up with microfront hub, or I can get a really light tubular rim and lace it with more spokes. I've decided to go tubular for the complete package so to speak, cause I just sold a light clincher with a microhub. It makes sense to get something deep dish now. So, what are other tubular rims that are at least moderately deep OR light?

Thanx a bunch.

woof.
QuestionJimP
Jan 8, 2002 2:04 PM
Sun Mistral rims are very light for a tubular rim. They are quite strong too and somewhat aero in cross section but not too deep.