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Discussion Starter · #1 ·
Does anyone know if Shimano is planning to upgrade the 7850 hubs on their Dura-Ace wheelsets (such as the WH-7850-SL tubeless, for example) with the new 7900 hubs that are due out in the fall? I like the idea of the allen key bearing adjustment method versus the standard cone wrench adjustment method. Seems easier for a newbie working on his own stuff.

Thank you.
 

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Don't know for sure, but my guess is that they'll release 7900 series wheels that are newer, fancier, and $$$$-er.

Personally, (if you're drinking the tubeless kool-aid) I'd pick up an 'old' pair of 7850 wheels, and use the $$ you saved by not going 7900 to buy a set of cone wrenches. But then again, I already know how to adjust wheel bearings - it's not too hard.
 

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I have been wondering about this myself. The wheel sets and pedals look to be the last components to get the 7900 label.
Interesting, too, is that the new rear wheel is all cross-spoke instead of the cross/radial arrangement of my 2 year old 7850-SL.
These are my favorite wheels yet, and I don't see the point in upgrading to the newer version right now. Considering that the Dura-Ace wheels were upgraded this past year, it may be another year before we see a 7900 series wheel-set. The Shimano web site for Dura Ace 7900 shows the current wheels with the 7850 label.
Just speculating, of course. Who knows?
 

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is that the new rear wheel is all cross-spoke instead of the cross/radial arrangement of my 2 year old 7850-SL.
??? The 7850-SL's wheels, as well as the 7850 hubs, have only been available for about six months. They're cross/cross in the rear. The 7801-SLs were cross/radial.

And considering that it's the end of June and the WH-7850 C24's still aren't readily available, I doubt we will see the 7900 wheel sets anytime soon.
 

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OK, thanks for the clarification. I have the WH-7801 (not the SL's), and ended up getting the WH-7850-SL's because I got tired of waiting for the C-24. IMO, the 7850 hubs are a significant improvement over the 7801's, and I'm really enjoying my 7850-SL's. A very nice wheel set.

As for 7900 wheels? Carbon/tubeless? :)
 

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Discussion Starter · #7 ·
Thanks everyone

Thanks everyone for your thoughts.

Sounds like the current 7850 version may be the way to go, if a 7900 version is a ways off. If that's the case, then I've got to decide whether to go tubeless (SL) or carbon-bonded (C24). That's a tough decision. Obviously the ligher weight of the C24 is really attractive, but I always worry about durability (though I've never had a problem with anything made by Shimano, and I've been racing and riding for nearly two decades). I'm just a bit troubled by the idea of the bonding. To me, that's "glue". It's not one solid substance, as the SL is. So I sort of worry that the C24 could be somehow weaker. And then I worry about the spokes/nipple/carbon interface and potential for cracking (though there are plenty of examples of all aluminum rims cracking at the eyelets). Maybe I'm mistaken about all this and just being unnecessarily concerned. Please set me straight if I'm wrong! I respect my equipment and take good care of it, but there are some stretches of road where I ride where it's simply impossible not to hit stress cracks in the pavements, little potholes, bumps, irregularities, etc. Those things are, unfortunately, unavoidable. I've heard rumors of the C24 merging with the SL into carbon tubeless sometime in the future. That's certainly tempting.... But you guys are probably right, and that could be a long way off (just like the hubs).

What are everyone's thoughts on the C24 vs. SL performance/durability issues? Basically I'm hoping to have high performance with high durability. I realize that everything's a compromise - you've got to give a little of something to get a little of something else - but I'm seeking to maximize both to the greatest extent possible.

Thanks again.
 

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I've never seen any C24 in the wild, and am not aware of anyone that posts here that owns them. They've been very slow coming to market. That said, they're Dura Ace, so you're going to get at least three years out of them - I wouldn't hesitate to buy them if I could and hadn't already purchased the 7850SL's. I've got a little over 3000 miles on them, and like all my Dura Ace wheel sets, haven't had any type of problem with them.
 

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Dr. John,
I'm curious, other than the spoke lay-out, how different is the 7801 SL from the 7850 SL? I've been looking at the 7850s real close and have considered buying, but it looks as though the primary difference is spoke lay-out and titanium freehub on the rear wheel.
The other differences I've noticed are the powder coated spokes and slightly less aero profile of the 7850. Also, is there a difference in the hubs of the 7801 and 7801 SL? I know the spoke lay-out is different, as is the asymetric rear wheel spoke bed. I'm just trying to determine how much benefit I'd gain with the 7850 wheels over my 7801 SLs, and if I would notice the same improvements you have.
My 7801 SLs are the best wheels I've ridden. I actually like them better than my Ksyriums, which are terrific rolling wheels. Hub design? Angular contact bearings, perhaps?
I got a glimpse of the C24s while attending a crit. Anodized hubs, powder coated spokes, red spoke nipples and black rims. Very sweet looking wheels, and feather light. As much as I like the new look and tech, I wish they would have retained the rounded profile of the 7801 SLs. The new wheels have more of a Ksryium profile. They look terrific, but I'm wondering if maybe they lost some of the aero benefits of the 7801 SL?

IPA,
Like Dr. John has said I doubt you will have any durability issues. I read an article in a dealer magazine several months ago on Shimano's wheel manufacturing. In that article a Shimano rep stated that they will never sacrifice durabilty to obtain the lightest wheel. Durability always comes first. A good example of that is the new 50mm aero carbon clincher. Their goal was 1500 grams, but to achieve their durabilty goals, they had to allow that number to climb to near 1600 grams.
Besides, the difference between the C24 and SLs version is only 200 grams if I remember correctly. Not enough to make a difference IMHO, but the bling of CF is hard to ignore. But, if you want the security of an all alloy wheel, you could save $300 and buy the SLs.
 

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Discussion Starter · #10 · (Edited)
Durability

Thanks, Dr. John and Ronman. I think I read the same - or similar - article. I think the weight difference might be a little less than 200 grams, though, between the C24 and the 7850-SL (don't know about the 7801-SL). But I agree that the weight isn't the most crucial aspect (though it is nice when going up hill to be pushing less weight). If I leave aside the durability issue (I agree with you that Shimano wouldn't sacrifice durability for performance), what I'm curious about is how different of a "feel" would the C24 be compared to the SL. I've heard that carbon wheels damp the road vibration and make everything smoother (I've never ridden them). But the SL's are tubeless, which other folks on RBR report make for a very smooth ride (some say almost tubular-like). So, besides the weight difference between the two wheelsets, do you think there'd be a (noticeable) difference in ride quality? (Or maybe the key is to wait to see if a 7900 hub version is produced that is carbon tubeless: the best of both worlds!)
 

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Also, is there a difference in the hubs of the 7801 and 7801 SL?
Best I can tell, no. They share the same Shimano part numbers in the technical documents for all the parts and appear to be the same.

I'm just trying to determine how much benefit I'd gain with the 7850 wheels over my 7801 SLs, and if I would notice the same improvements you have.
Personally, I don't think it's worth changing from the 7801SL's to the 7850SL's. IMO, they took themajority of the 'annoyances with the 7801's and fixed them. You'd most likely notice the differences, but not necessarily as improvements, aside from less lateral flex with the 7850's. Just so it's clear, I use my WH-7801's on a Specialized Roubaix, which replaced a set of WH-600's that I cracked after 11,000 miles, and the WH-7850-SL's on a Tarmac. I didn't buy the 7850's to replace the 7801's.

For what it's worth, weight-wise, my 7850-SL set came in at 1536 g (claimed 1514 g).

I got a glimpse of the C24s while attending a crit.
:thumbsup: Were they the clinchers or tubulars? Glad to see they're trickling out.

So, besides the weight difference between the two wheelsets, do you think there'd be a (noticeable) difference in ride quality?
Good question. :) I would love to know too.
 

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I've had the 7850-C24 wheelset for the last two months and it's great. Nice and light coming from a set of Shimano R535s. I don't race so can't comment on how they hold up in those conditions but i ride as hard as i can and use them as my regular commuter wheels where they've held up perfectly so far. Definitely stiffer than what i've had before and they fell really nice.:thumbsup:
 

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Discussion Starter · #15 ·
Yup...

...I second that, though Dr. John speculated that maybe there'd be a carbon tubeless version offered in the future (maybe if there's a 7900 hub version of the wheels). That'd be the bee's knees. Tubeless or not, that gets me back to wondering whether or not Shimano will eventually produce a 7900 hub version of their Dura-Ace wheels. I've worked with cone wrenches before, but am always a little nervous about the adjustments, so the single allen key adjustment control is tempting. (Of course, if they do make a 7900 hub version, then presumably I could save some serious coin and get a 7850 version on clearance - which is also tempting!)
 
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