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carbon wheels on a hardtail

March 2, 2015, 11:30 a.m.
Posts: 486
Joined: April 11, 2011

I’m not evolved enough to be able to detect differences in vertical compliance. I’m usually hanging on for dear life or praying the landing goes as planned;-) Though, my intuitions about carbon rims correspond well with this article (warning: Math).

the tire deformation provides more than 100 TIMES the vertical compliance than that of the wheel, whether it is aluminum or carbon. It should be clear now that not only can no rider can discern the difference in vertical compliance between any two wheels, but rather these perceived differences must be coming from changes in tire volume, air pressure changes (even a few psi makes a big difference), tire casing, or even frame/fork/stem/handlebar flex. Keep in mind that wide rims increase the volume of the tire, so if you are coming from narrow aluminum rims to our wider carbon rims, not only should you not be worried about less vertical compliance, you should actually expect an increase in vertical compliance (comfort) due to higher tire volume!

I’ve got more than a year on a set of hookless 35mm on I9s from Nobl. I went the safe route with the 35mm because I live at about ~190 in the winter (and I’m a hack), but I’d be temped to go narrower next time. The rear has an HD layup and was built with competition spokes. Trevor built up the front with CX rays, with no HD layup. I never weighed them myself, but I think they were ~1650ish.

I’d have no problem moving these to my hardtail. I was coming off Flows (29) that needed frequent truing, and felt pretty loosey goosey, so I really like the continued stiffness in pretty much every situation. Moving them up hill feels money.

March 2, 2015, 12:15 p.m.
Posts: 3728
Joined: March 6, 2003

Just fit a BOOST 148mm Hub to your existing hoops.

You'll gain all the additional stiffness you need due to greater spoke triangulation. That's why they invented this new standard; to help those that don't want/need carbon but need the stiffness on 29" aluminum hoops :D

www.FVMBA.com 

"If everything seems in control, you're not going fast enough."
-Mario Andretti-

March 2, 2015, 12:18 p.m.
Posts: 5738
Joined: May 28, 2005

this article (warning: Math).

booya! somebody rep this guy

"Nobody really gives a shit that you don't like the thing that you have no firsthand experience with." Dave

March 2, 2015, 3:12 p.m.
Posts: 1006
Joined: Sept. 24, 2003

Boom, I'd hazard a guess that a wider rim would compensate for any loss in vertical compliance that a carbon rim would cause, plus as others have already listed the rest of the build could easily compensate. I think traditional j-bend double butted spokes would help bring the wheel back to where it should be in that respect.

Ever since I rode the Ibis wide rims I've wanted to try a pair on my Surface. I think the combination of the wide rim allowing the lower pressure would give a nice addition of some traction and compliance to the rear end. I haven't been able to try this yet though.

Jon-boy.

March 2, 2015, 7:42 p.m.
Posts: 2313
Joined: Sept. 18, 2008

i have a lot of miles now on the newest LB hookless wide 29er rims on my chromag rootdown, and they've been awesome. i came off of flow ex's (28 psi front, 35 rear), which would burp on occasion, required some truing on occasion, had a couple minor rear dents, but were pretty good. now i can run 25/28 psi, haven't burped once, and have smashed the rear rim many times with zero damage. the old LB rims exploded on my third ride, these have been awesome. hookless is the real deal. highly recommended.

March 2, 2015, 9:23 p.m.
Posts: 1172
Joined: Feb. 24, 2017

not quite 'exploded'. cracked maybe. with a few more cracks yet and still riding on a regular basis! hard to believe. the experiment continues. front is totally fine. when the rear finally goes, i'll replace with same.

March 2, 2015, 9:49 p.m.
Posts: 5731
Joined: June 24, 2003

booya! somebody rep this guy

Yes that was excellent. Zipp 303 tubular rims had designed in give when the first came out. The sides would bow out when you bottomed the rim on a cobble or root when riding cross. The thought was that this might prevent some pinch flats. Pretty much all pros use rims like this now for cobblestone races. I've bottomed lots of rims. The Enve 60-40 on my hard tail sure do thunk in a more abrupt fashion than any aluminum rim I've had. Maybe it's something besides being carbon and being stiff? Hookless bead?

Debate? Bikes are made for riding not pushing.

March 2, 2015, 10:10 p.m.
Posts: 0
Joined: Dec. 3, 2004

Just built these up for my Chromag. Velocity Blunt 35. Decided to try out after reading about DrewM's build on his bike. Haven't had a chance to ride them yet so I can't comment on the difference but they are replacing a tired set of Mavic 721 (5.5 years old) and I contemplated carbon but decided the cost wasn't worth it for me. I'm also running the virtually extinct 26" wheel size for what it's worth. Initial impressions (non-riding) is that it makes a 2.2 Maxxis Ardent Race look like a 2.5 Minion on a narrower rim. Hopefully this translates into a better cornering tire. Also used the gorilla tape (another DrewM recommendation) and the tires set up beautifully, nice and tight. Definitely cheaper than even the cheapest carbon option (LB rims I assume?), you can buy two of these rims for one carbon.

Comes in all wheels sizes. 27.5 link below.

http://www.velocityusa.com/product/rims/blunt-35-584

Shed head!

March 2, 2015, 10:24 p.m.
Posts: 2313
Joined: Sept. 18, 2008

not quite 'exploded'. cracked maybe. with a few more cracks yet and still riding on a regular basis! hard to believe. the experiment continues. front is totally fine. when the rear finally goes, i'll replace with same.

ha! exploded! that was a bit dramatic eh? i'm impressed they're still rolling.

March 2, 2015, 10:45 p.m.
Posts: 1172
Joined: Feb. 24, 2017

me too. seriously, it's an experiment. front is mint. i know the back one is fractured pretty good in about 6 places. and they are both holding tubeless without problems. liberal stans of course.

March 2, 2015, 11:38 p.m.
Posts: 1885
Joined: Oct. 16, 2005

Just fit a BOOST 148mm Hub to your existing hoops.

:D

That's one of them new fangled systems for full suspension bikes!

The way you increase the stiffness for the back wheel of your hardtail is to build up a singlespeed hub (~same flange width as a 150/157mm DH hub) and stand up more when you're riding uphills.

Just built these up for my Chromag. Velocity Blunt 35…

:)

Made In The USA as well for anyone who is into that kind of thing…

Mine have held up very well; hugely larger tire profile (same tire) vs. Stan's Flow on my other wheelset.

Mean People SUCK! Nice People SHOVEL!

Trails For All; Trails For Weather

March 3, 2015, 8:22 a.m.
Posts: 955
Joined: Oct. 23, 2006

I ran carbon rims on my hardtail last year. I like them, but they didn't last long (I was riding in the bike park a lot). I cracked the rear, and kept riding it. Then I cased a rock gap and it did actually literally explode. The tire blew off like a shotgun that left my ears ringing inside my fullface helmet. The rim was in 4 pieces, and my rotor was bent in half and my derailluer was smashed.

When I went back to alloy, I could really feel the flex in the corners. Kinda wallowed. I prefer the feel of carbon, but if you ride really hard in rough terrain you're not going to get a lot of mileage on a hardtail.

March 3, 2015, 10:38 a.m.
Posts: 5731
Joined: June 24, 2003

I recall guys exploding aluminum rims back in the 80's. Road rims. What they called hard anodized Mavic GP4 and Ambrosio Montreal tubular road rims. Aluminum rims we have today are light years ahead of 1980's rims that's for sure. To me carbon rims mean you can get a relatively light yet strong rim that is nice and stiff. And usually you can build to higher spoke tension than with a similar weight aluminum rim.

Debate? Bikes are made for riding not pushing.

March 3, 2015, 11:45 p.m.
Posts: 5738
Joined: May 28, 2005

i'm glad this turned into a discussion about the progress carbon wheels are making and vertical compliance

because for the record, i realized i don't care if my wheels are on the heavy side . i haven't touched them since i built them, and seem to be keeping up just fine

sticking with my wutubees :)

"Nobody really gives a shit that you don't like the thing that you have no firsthand experience with." Dave

March 4, 2015, 12:50 a.m.
Posts: 2313
Joined: Sept. 18, 2008

…if you ride really hard in rough terrain you're not going to get a lot of mileage on a hardtail.

what rims?
i said the same thing until these new ones. i'm hard on rims and these have been bomber. i'm 200 lbs and smashy.

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