Carbon Wheel Question?

Quoted post said:

Originally Posted by danfoz
If going for an aero rim it's important to check the width. If you enjoy running 23 and/or 25mm tires, according to a white paper done by Specialized the aero benefit on a 19mm wide rim is almost completely negated due to the turbulence created by the lightbulb effect on a 25. If running a 19mm wide aero rim, to extract any benefit a narrower 21-22mm tire will be needed. If running a 23mm or wider tire on a 19mm wide rim it makes more sense to stick with a low profile rim, unless of course riding cyclocross where a deeper rim doesn't get bogged down in the mud as easily.

imo if investing the money why not just go to the newer paradigm of 23mm wide rims. Wider tires spread over a wider rim feel better, handle better, and supposedly roll faster. One doesn't have to go with one of the uber expensive all carbon models. Something like HED's Jet5 express offers almost all the benefits at a lower price - alloy breaking surface, 23mm wide rim, aero performance, a weight range that wont hold anyone back, and at a relatively competitive price (for the product received). There are others. After riding the last couple years on wider rims, I'll never go back to the old 19mm's.

Wow, great info, thanks for looking out.

The real question is...is a tire/rim that's TWO MM (that's a whopping .078" in Engrish) really better riding, have more grip, etc. than a 23 MM?

Or is it just marketing hype?

Would riding a 23 MM tire at 98 PSI ride/grip as well as a 25 MM tire at 106 PSI?

I have not spent enough time on 25 MM tires to discern any difference at the same brand/same pressure. So far. At least on our local craptastic roads.

Riding different widths of tire on a 19mm rim doesn't make a ton of difference - changing tire pressure makes more difference. Riding a wider rim makes a bigger difference - a 23mm tire on a 23mm rim is much nicer than a 25mm tire on a 19mm rim and is almost as comfy as a good tubular tire.

new_rider said:

Wow, great info, thanks for looking out.Â

The newer generation of HED rims are now 25mm wide - apparently the difference from 23 to 25mm is as big as 19 to 23mm. The kicker - the 25mm aero rims are more aero with a 22mm tire... ... And with such tires (22mm Conti Attack) the rims handle better is cross winds and have much better aerodynamics in cross winds. I need to measure my Ridleys forks and calipers to see if I can stuff a 25mm rim in there. Time to upgrade. HED Jet 6+ is looking good - stallion build because I'm such a stud. (Aka fat f**k) 😉 FLO cycling - no, not related to Aunt Flo, do some nice aero wheels at a great price point. I might go that route but have always likes HED products and the work that Steve has done.

Quoted post said:

Originally Posted by CAMPYBOB
The real question is...is a tire/rim that's TWO MM (that's a whopping .078" in Engrish) really better riding, have more grip, etc. than a 23 MM?

Or is it just marketing hype?

Would riding a 23 MM tire at 98 PSI ride/grip as well as a 25 MM tire at 106 PSI?

I have not spent enough time on 25 MM tires to discern any difference at the same brand/same pressure. So far. At least on our local craptastic roads.

I haven't tried it so don't really know. As the tire gets fatter, the psi should come down a bit - that's advice that comes directly from the tire manufacturers. As the rim gets wider the pressure should also come down a bit (because of the potential for spoke decompression due to the higher volume of air in the tire on the wider rim - advice directly from HED). Tires jacked up to their max psi typically don't grip all that well imo. I actually started on the 25's to dampen the ride on one of my old aluminum frames. I'm now surprised at how many riders (who race) seem mildly shocked at my choice of width... "You ride 25mm tires, aren't they slower!?" Like you said it's only 2mm. I'm also surprised at how many 150lb riders inflate their tires to max pressure (since tire pressure should be a function of body weight). Old habits die hard I guess.

Let's spread it out: 21 vs 19 (is a tire/rim that's TWO MM really better riding?), 23 vs 21 (is a tire/rim that's TWO MM really better riding?), 25 vs 23 (is a tire/rim that's TWO MM really better riding?). But I think we can all agree that a 25 rides/handles better than a 19. Somewhere along the way those millimeters caught up.

There's no holy grail for any aspect of a bikes performance. Phillipe Gilbert once said "Training, it's maybe 50%. The rest is 1% here, 1% there". Same for performance of the bike/equipment. The weight of the bike alone won't make a difference, the choice of tires/tubes alone won't make a difference, the pressure of the tires alone won't make a difference, the drivetrain friction alone won't make a difference, the aero profile of the wheel alone won't make a difference, the tightness of the riders clothing alone won't make a difference, the riders position - well that actually will make a tangible difference, but all together... VOILA! It's the same with saving for retirement, losing weight, etc. etc. Everyone wants the easy answer, but it's really lots of little things adding up to something big.

Swampy, I can corroborate that running a quality supple 23mm wide tire on a 23mm wide rim over latex inner tubes feels pretty darn close to riding on tubulars. I've got nothing but about 50k miles of subjective experience to back up that claim however.

Thanks, Dan. Good info.

I rode exclusively sew-ups for thirty-five years (give or take a season?) and the last eight on clinchers. As far as ultimate grip goes, the individual tire makes more of a difference than the construction. In other words, I've used sew-ups that felt like greased ice and those that you could howl around corners on. Those that gripped in the rain pretty well and some that rolled like they were glued to the road.

The modern 23 MM clinchers are damned good. And this is coming from a guy that laughed at them (and rightly so for many years) for almost an entire racing lifetime. I've only ridden three four brands of clinchers in those eight years, but I am impressed by all of them.

I know I can cram 25 MM tires onto the Wilier and 23 MM rims should be doable, but going only slightly out of true is going to wipe out some paint. Popping a spoke? I better get the Dura-Glass kit out to repair the carbon!

I don't know what rim width Cadel Evans used today, but he's leading the Giro on skinny old 22 MM sew-ups.

Clinchers were damn good 25 years ago!

Remember the michelin hi lite comps? Pure bliss. Very quiet, very comfortable, excellent grip. Just an amazing tire. Their only flaw was cut resistance. Not very good in that area. But if you were careful, everything else was superior.

CAMPYBOB said:

Thanks, Dan. Good info. I rode exclusively sew-ups for thirty-five years (give or take a season?) and the last eight on clinchers. As far as ultimate grip goes, the individual tire makes more of a difference than the construction. In other words, I've used sew-ups that felt like greased ice and those that you could howl around corners on. Those that gripped in the rain pretty well and some that rolled like they were glued to the road. The modern 23 MM clinchers are damned good. And this is coming from a guy that laughed at them (and rightly so for many years) for almost an entire racing lifetime. I've only ridden three four brands of clinchers in those eight years, but I am impressed by all of them. I know I can cram 25 MM tires onto the Wilier and 23 MM rims should be doable, but going only slightly out of true is going to wipe out some paint. Popping a spoke? I better get the Dura-Glass kit out to repair the carbon! I don't know what rim width Cadel Evans used today, but he's leading the Giro on skinny old 22 MM sew-ups.

Some brands offer a few extra spokes on their "heavyweight" version. Tony Martin has used the "stallion" version of the HED Jet clinchers for TT wins - a few more spokes and a bit stiffer. Zipp used to offer several different spoke counts for each wheel but not sure if they still do.

I have a pair of Zipp 808 Max wheels and they are very durable. Zipp used their hybrid rim and added extra spokes. I am willing to give up some aspect of performance for more durability

As Zipp point out on some of their White Papers on spoke count - the "performance" you gave up is minimal.

The Max build is heavier than Zipps standard wheels. The reality for heavy riders is most carbon or areo wheels are not designed for them. Many manufacturers designs recommend around a 225lb. weight limit. I have been very happy with the Zipps. Especially when I happen to ride with people who don't point out road hazards. They don't have the snap of a lighter wheel, but you can cruise all day in the mid 20mph without really straining and fly up the shallow ascents. At 230lbs, I can bomb the descents on the 808.

Cruise all day in the mid 20's - you're talking mph, right? More spokes and heavier - really? Say it ain't so! :p

Zipp increases the spoke count by one, which in terms of weight, is not much, considering also how short the spokes are. The weight is in the hybrid rim. As far as I can tell, Zipp no longer makes Max wheels. I think they only have one hybrid wheelset in their catalog currently. I also have a set of 303's and while they have good snap, they are nowhere as stiff as my 808's

One spoke? How do you build a 17 spoke wheel? I thought the regular front 808s were 16 and the Max was 24... Still curious as to how you just cruise in the mid 20's mph range... I always used to find sitting on 25mph for a few hours a bit uncomfortable to say the least.

Shoot, I will have to count them when I get home. As far as rolling in the 20's, is more a matter of size than anything else. I pretty sure guys who can do 25 mph for several hours without strain are of a caliber beyond most of us. The manager of the LBS brother rides for Argo Shimano and he trains at that pace. I would do motor pace drills at the track where we would go 4 laps behind the motor and then sprint on the 5th lap to simulate a points race. The driver would go around 25 mph. Riding 808 has that same feel like you are behind the motor.

On the pre-Firecrest "toroidal" 303's, I believe it was 22 or 24 front for the XC version vs 20, the rear count may have been 24 across both versions. Don't quote me, that's coming from some distant memory. -/+ 4 spokes wont do didly for performance, they will however add a bunch more confidence riding off curbs, bombing some cobbles, or hitting a deep rut in the midst of the peleton during a curcuit race when such obstacles are often obscured. My old 101's with a 20/18 spoke count used to go out of true just by looking at them funny.

Here is a picture of my Zipps. I'm not much of a equipment-tech guy. I know the 303's have 24 rear. I didn't count the 808 rear. Well the picture didn't post.

Just read through this discussion and there's a lot of good experience being shared here. Coincidentally, I've been doing an extensive amount of research and testing on the subject of all-around wheelsets covering many of the issues you've been talking about on this forum. And yes after doing that, I too have found that wider rim, carbon or carbon/alloy, all-round wheelsets (25mm-50mm deep) with good braking tracks, at a good price for the reasonably fit cycling enthusiast who rides 4-6x/week in various formats from solo training to club racing do make a big difference. For what it's worth, here's the post I put together looking on these topics and reviews and my recommendations after looking at three dozen current wheelsets in this category. Please let me know what you think.

Specialized did wind tunnel testing to show that shaved legs can save you 70 seconds over 40km so I would advise leg shaving and a good light weight aluminum wheelset since you are new and you can race well on them and beat many with the carbon wheels with proper training but as you progress up the ranks they will make a difference and suggest saving up for a pair in the future I use the Profile design twenty-four series wheel set and love them.

quote by 3perez:
"Specialized did wind tunnel testing to show that shaved legs can save you 70 seconds over 40km"

If that figure were true I'ld shave my ballz and ride nekid to save another 10 seconds.

The actual figure is around 5 to 7 seconds, depending on which 'study' we put stock in.

"Aerodynamics
“A 1987 study conducted by Chester Kyle for Bicycling magazine concluded that the aerodynamic improvement is roughly 0.6 percent, which could result in a savings of around 5 seconds in a 40km time trial ridden at 37kph” For the metric challenged that’s 24.8 miles at 22.9 mph."

http://www.sheldonbrown.com/rinard/aero/aerodynamics.htm