Chinertown
Chinese Carbon Road Bikes => Road Bike Frames, Wheels & Components => Topic started by: WWcyclist on March 17, 2025, 03:07:39 PM
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Hey everyone while I was perusing the AliExpress anniversary sale I found this seller (who appears to be a good one). This Wheelset seems like a great deal with "modern" wide rims.
For the 45/50 Wheelset, with Pillar Wing 20 spokes, it supposedly comes in 1280 grams +/- 30 grams.
What do y'all think?
Long shot but has anyone bought from RCRW?
I just found this on AliExpress:
912,39€ | 700C SL 36T Ratchet Wave carbon Wheelset 3540/4045/4550mm deep 31mm wide Rim center lock 24Hole Hub Flat Spokes Gravel wheelset
https://a.aliexpress.com/_mNrAAYJ (https://a.aliexpress.com/_mNrAAYJ)
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look good and at that price is mega tempting.
Apparently they are the manufacturer and do 25mm internal although a better rim profile would be more acceptable as it is V-Shaped!
No website and they only sell on Aliexpress
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look good and at that price is mega tempting.
Apparently they are the manufacturer and do 25mm internal although a better rim profile would be more acceptable as it is V-Shaped!
No website and they only sell on Aliexpress
Hookless, meh, no bueno for me.
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Hookless, meh, no bueno for me.
And hooked
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900 dollars for that? Speak with Peter from xiamen carbon speed, he's got better specs for less money. Also, his rims aren't V shaped, it's not 2002 anymore :)
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look good and at that price is mega tempting.
Apparently they are the manufacturer and do 25mm internal although a better rim profile would be more acceptable as it is V-Shaped!
No website and they only sell on Aliexpress
V-ish shaped rim profiles are actually back in vogue with tire widths over 28mm. Look at rim profiles for industry leaders like HED vanquish, Enve SES 4.5, Roval CLX, Zipp 303 and 404 (after MY2022). At least for rear wheels, all these rims have v-ish profiles. HED and Zipp use v-ish profiles front and rear. I think the idea is that with wider rims and hookless beads, recapturing air trailing off the tire is less of a concern because it stays attached across a wider range of conditions than before.
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Your won’t pay $900 if you speak to them.
More like. $500
Had a chat with them on Ali express and said they need to update there rim
Profiles to 23-26 and U not V said to have a look at this forum :-)
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V profiles are okay, but not like this, has to be curved
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V profiles are okay, but not like this, has to be curved
Isn't that what V shape means? V has no curve.
As opposed to U shaped rims. U is curved.
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V-ish shaped rim profiles are actually back in vogue with tire widths over 28mm. Look at rim profiles for industry leaders like HED vanquish, Enve SES 4.5, Roval CLX, Zipp 303 and 404 (after MY2022). At least for rear wheels, all these rims have v-ish profiles. HED and Zipp use v-ish profiles front and rear. I think the idea is that with wider rims and hookless beads, recapturing air trailing off the tire is less of a concern because it stays attached across a wider range of conditions than before.
Actual market leaders (i.e. CRW Works, Roval Rapide CLX II) don't use v-shape profiles. Zipps are trash tier wheels in general.
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Isn't that what V shape means? V has no curve.
As opposed to U shaped rims. U is curved.
Well yes, in truth a traditional V shape wouldn't be curved, but because most people are clueless, "curved V" is the easiest way to describe it. With the "V" signifying that the sides taper in mostly the whole way. What would actually be a better way to describe it is "partial ellipse" or "parabolic".
A U shape is just a U. Flat sides that don't really taper inwards until they reach the radius. A more "modern U", like CRW or LB WR65 still has flat sides for a bit, before transitioning into a parabola
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Isn't that what V shape means? V has not curve.
As opposed to U shaped rims. U is curved.
This is why I say these modern rim profiles are "v-ish".
"True" V-shape rims have flat walls that come to a point, like you saw on Lightweight Mielenstein or Mavic aero wheels from the mid-late 2000s. "Toroidal" and "U-shape" rims are characterized by a shape that bulges outwards, where the point of peak width and parallel walls is somewhere near the middle of the aerofoil chord (Toroidal) or closer to the spoke nipple bed than the rim bed (U-shape).
Unlike true V-profiles, "V-ish" profiles have a continuously bulging curve along the aerofoil profile to the spoke nipple bed. And, unlike U-shape/Toroidal rims, the point of peak width is no further from the rim bed than ~1/4 of the chord length.
Another key characteristic of modern V-ish profiles is the trailing edges (at the spoke bed) have much larger radii compared to rim profiles of old. Those early V and Toroidal rims that had bad handling featured really sharp trailing edge profiles, with curve radii as small (if not smaller) than half the width of spoke nipples. In contrast, modern V-ish profiles have trailing edges with a radius of around 0.5cm or greater.
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Actual market leaders (i.e. CRW Works, Roval Rapide CLX II) don't use v-shape profiles. Zipps are trash tier wheels in general.
1) We don't have wind tunnel data on CRW so it's hard to say. Peak Torque attributes their good performance in his testing to the low spoke count.
2) While it's true the CLX front wheel has a more U-shape, it's hard to compare because the extremely wide shoulder rim bead is an aerodynamic feature that no other rim (besides the new Hunt rims) has.
3) HED Vanquish reliably comes out near the top of wind tunnel test leaderboards, and they use a V-ish profile. Cannondale even licensed the profile from HED for the wheels specced with the System Six. The only intelligent conclusion I can offer is that the difference between V-ish and the modern moderately Toroidal/U-shaped/Parabolic profiles like you see on the CRW is going to be really marginal, and which profile you believe is faster is not unlike affiliation to a religious faith.
My take here is you guys are shooting us all in the foot by telling this seller to change the rim profile, which in effect will limit our choices as consumers. Toroidal/parabolic rim profiles are abundant. These more V-ish profiles are rarer, and it's nice to have the option on the market.
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I did no say change just offer more choice especially in terms of current market trend for wider IW and more U-Shaped rims
Asked them to come and read the Forum and well they might learn something from reading the XM thread.
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900 dollars for that? Speak with Peter from xiamen carbon speed, he's got better specs for less money. Also, his rims aren't V shaped, it's not 2002 anymore :)
Did you look at the rim profile of the one I put in the original post? I don't think it looks like a V
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V profiles are okay, but not like this, has to be curved
The one that I linked in the original post doesn't seem like a V?
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Actual market leaders (i.e. CRW Works, Roval Rapide CLX II) don't use v-shape profiles. Zipps are trash tier wheels in general.
CRW were never a market leader in rim design. What they actually excel at, is hub design, and they were the first ones brave enough to actually make proper use of carbon spokes and significantly reduce spoke count. The hubs are where their weight gains came from and spoke count is where their aero came from. The profiles of their first 3 sets are all a very safe, slightly dated design, they won't give you amazing aero on their own, but they won't wreck it either.
Roval front is mostly an exercise in crosswind stability improvement. It's actually vaguely eliptical/toroidal but at that depth to width ratio, you kinda have to make it with a very wide radius nose. The rear is just a straight ellipse.
If you wanna talk other market leaders, scope are just straight up an ellipse, DT Swiss (designed by swiss side) also get more elliptical the deeper they go. Newmen are parabolical with large radii on the front. Bontrager aeolus are all parabolas with very sharp noses (and they're well regarded for their stability, interestingly enough), very similar to HED and Enve.
So there are many ways to design a rim and convergent evolution hasn't quite settled on a single approach just yet. I'm starting to think the industry moved away from the theoretical best - which is likely a toroid - because the need for a rim brake track kinda compromised its advantages and pushed design toward parabolas and U shapes that bulged out closer to the nose. Now that disc brakes got rid of that problem, it's moving back towards toroids.
Fully with you on the Zipp hate train though.
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So there are many ways to design a rim and convergent evolution hasn't quite settled on a single approach just yet. I'm starting to think the industry moved away from the theoretical best - which is likely a toroid - because the need for a rim brake track kinda compromised its advantages and pushed design toward parabolas and U shapes that bulged out closer to the nose. Now that disc brakes got rid of that problem, it's moving back towards toroids.
My guess is that a symmetrical toroidal shape is unlikely to be the best true shape because the leading half of the rim gets clean airflow while the trailing half of the rim gets more turbulent flow, on average. I remember Hunt's engineers saying as much regarding the rear wheel in an interview. The fact that many manufacturers' designs are converging on parabolic shapes (what I've been calling V-ish, I think your elipsoid/parabolic descriptions are more accurate than what I've been using) reinforces my suspicion that wheel designers are finding bigger gains from optimizing the profile of the leading half and throwing the trailing half to the wind, to some extent.