# Did I Just make a mistake? 50mm Wheels...



## canyonchaser (Jun 14, 2011)

So I found an amazing price on a set of 7850-50 Carbon Clinchers. Pulled the trigger and they are on the way! Then I read that 50mm wheels are miserable for climbing... But I live in Utah and thats about all we do because the only way to get away from traffic (or summer heat) is to head up into the canyons... An ordinary after-work ride I'll climb over 3,000 feet and last month alone I climbed over 40,000 feet. Climb, climb, climb, climb... 

I'm currently running a fairly tired set of 7800 Box section aluminium rims, but should I have gone with the 24mm or 35mm rims instead?

dp


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## Mike T. (Feb 3, 2004)

I would think that they're only "miserable for climbing" if they're boat-anchors compared to other wheels that allow for non-miserable climbing. Weight matters lots when climbing. Whether the relative weight is noticeable or measurable is very debatable.


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## Wookiebiker (Sep 5, 2005)

Unless they are very heavy wheels...then, no, you didn't make a mistake. 

In fact they will likely be a bit faster on shallow climbs say...5% and less average grades since aero trumps weight 95% of the time.

50mm is not that deep for a carbon rim, in fact it's around the norm. My climbing wheels are 58mm tubular wheels as they are nearly a pound lighter than my 32 spoke open pro "Box" rim wheels...and way more aero.


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## ukbloke (Sep 1, 2007)

Those wheels are relatively heavy - my recollection is something like 1700g. They are very well engineered, but they are get the aero benefits of a deep carbon wheel at the expense of weight. In particular, they have an alloy brake track with a bonded carbon "fairing". This means that you don't need to worry about special brake compounds, and they do not suffer from the delamination issues under excessive braking that plague many other carbon clinchers. The penalty of this method of construction is the weight. The other concern is whether you can handle the 50mm depth with gusty cross winds (if your rides are prone to them).

For your use case I suspect that the C24 carbon clinchers would be a better choice - they come in at about 1400g. The C50 are better for flats, rollers and time trials. I'd love a set of those C50 for those kinds of rides, but I wouldn't pick them for a ride with significant climbing (eg. 1000 feet per 10 miles of ride) or cross-wind.

How much did you pay?


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## canyonchaser (Jun 14, 2011)

According to weight weenies, the aluminum 7800 wheels weigh 1600 grams and the 7850-C50's weigh just over 1700 grams. So maybe a 120 gram difference. That seems pretty insignificant to me... 

Paid $750 for the set...

dp


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## LC (Jan 28, 2004)

Your only mistake may be that rides in cross winds are going to push you all over the road. Is it windy in Utah?


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## canyonchaser (Jun 14, 2011)

LC said:


> Your only mistake may be that rides in cross winds are going to push you all over the road. Is it windy in Utah?


Not especially. The mountains keep the wind from getting too out of hand, and wind blows up and down the canyons - almost never across.

dp


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## ukbloke (Sep 1, 2007)

canyonchaser said:


> According to weight weenies, the aluminum 7800 wheels weigh 1600 grams and the 7850-C50's weigh just over 1700 grams. So maybe a 120 gram difference. That seems pretty insignificant to me...
> 
> Paid $750 for the set...
> 
> dp


If you are comparing against your current wheels, sure. But your original post was also comparing the C50 wheels versus C35 and C24 alternatives. From weight weenies the C24 comes in at 1410g compared with 1749g for the C50. So that's 339g, or almost 25% heavier. You can decide whether that is significant to you. I know of quite a few riders with the C24s and they have only good things to say about them. The C50 carbon clinchers seem to be pretty rare.

As an aside, in watching the grand tours this year, I've noticed that on climbing stages the pro's are definitely not running anything like 50mm rims. Typically they have 24mm to 35-38mm rims. Some teams seem to even be using Al box section rims, presumably optimized to be exceedingly light weight.


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## takl23 (Jul 22, 2007)

Ride a couple times, if you don't like 'em sell 'em. Check out Boyd wheels they make a fairly light aluminum wheel for $400.


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## Salsa_Lover (Jul 6, 2008)

you did a mistake. you should have got Tubulars.


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## PoorCyclist (Oct 14, 2010)

I have set climbing PRs on Shimano C50s, mine are 1830g, climbs that take 30-40 minutes..
I don't let the gram counting get too much into my head, yes it is 1 lb more but doesn't seem to matter that much, maybe I'm just too slow. They feel stiffer than the C24.

On the internet there is a wheel aero test that says the C24 and C50 are almost as aero as each other in terms of watts, they were testing the C24 tubular, The Shimano C24 Tubular rim profile is looks to be much smoother compared to C24 clinchers, which is more boxy and have more bumps (somewhat similar the inter-spoke-milling on Mavic). So I wonder how much less aero it is than the Tubular version.

I noticed J.J. Cobo in the Vuelta was using some semi deep wheel (46? 50mm?) winning the climb to Angliru and took the leaders Jersey..


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## ericm979 (Jun 26, 2005)

canyonchaser said:


> So I found an amazing price on a set of 7850-50 Carbon Clinchers. Pulled the trigger and they are on the way! Then I read that 50mm wheels are miserable for climbing... But I live in Utah and thats about all we do because the only way to get away from traffic (or summer heat) is to head up into the canyons... An ordinary after-work ride I'll climb over 3,000 feet and last month alone I climbed over 40,000 feet. Climb, climb, climb, climb...
> 
> I'm currently running a fairly tired set of 7800 Box section aluminium rims, but should I have gone with the 24mm or 35mm rims instead?
> 
> dp


I use 45mm deep rims for climbing races. They're not miserable. They're carbon clinchers so they are not that light, and braking on steep technical descents can overheat the tube, but they work fine in races. The aero wheels give me a little more speed on the descents.

I often do 80,000 feet in a month. A couple years ago I did over 20k' every week for four months. The training is all on mid-profile aluminum rims because they're reliable. My usual set of training wheels are heavier than the wheels you just bought and I can't tell a difference in speed even when compared to my lightest wheels.

The only drawback to deep aero rims (besides weight) is riding no-hands in a cross wind, and on descents in stiff or variable cross winds. The wheels catch the wind more so you need to be on top of things to keep your line.


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## mimason (Oct 7, 2006)

The weight penalty of these wheels are primarily at the hubs. They will roll silky smooth and feel great but all in all are not the ideal climbing wheel which in my opinion is a shallow, light tubular. Did you make a mistake? Definitely not at that price. Ride them with pride or sell them.


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## ukbloke (Sep 1, 2007)

mimason said:


> The weight penalty of these wheels are primarily at the hubs. They will roll silky smooth and feel great but all in all are not the ideal climbing wheel which in my opinion is a shallow, light tubular. Did you make a mistake? Definitely not at that price. Ride them with pride or sell them.


Sure, the Dura Ace hubs are not the lightest. The Shimano C24 and C50 wheels use the same hubs so in that specific comparison the 339g weight difference is all in the deeper carbon rims.

I completely agree that the $750 price is a very good deal.


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## ronderman (May 17, 2010)

I wouldn't say you made a mistake, but I will tell you this - I have 3 sets of wheels - handbuilt clincher, bontrager aero xlite clincher and mavic cosmic ultimate tubular (these are 40mm).

The bontrager's are the worst, the handbuilts are the best-bang and the Ultimates are, well, ultimate - they also weigh just under 1100 grams - so they are a basically a pound lighter and I can feel it on the hills. If the gradient is over 6% I feel it - at 10% is very noticeable. 2 or 3% not so much. Basically all the teams sponsored by mavic: garmin, liquigas and Lotto ride these wheels all the time (sans roubaix where they rode the deep dish aluminum spoke). For good reason, light, stiff and aero. The zipp teams you see them on 303 or 202 on mountain stages to get the weight down - you see 404s but not a lot.

1700 grams is more than a regular handbuilt at 1500 grams. It will be faster on the decent and the flats, but on the steeper stuff, I think you will feel it.


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## Doug B (Sep 11, 2009)

You made a huge mistake. But, I'm willing to help you cut your losses. I'll do you a favor and offer you a quick $150 for those wheels.... you pay the shipping just to make sure you learn your lesson.

;-)


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## stevesbike (Jun 3, 2002)

from hed on their Jets

"we calculated two sets of numbers, one on 1320g wheelset with the drag characteristics of traditional low profile wheels, and a 300g heavier wheelset with the drag of Jet 6s. The lower drag of the Jets kept our model rider going faster until the grade reached 7.5%. Unless your race is all uphill in the mountains, Jets are going to get you to the finish faster".


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## Kerry Irons (Feb 25, 2002)

*300 gm*



ukbloke said:


> Those wheels are relatively heavy - my recollection is something like 1700g. They are very well engineered, but they are get the aero benefits of a deep carbon wheel at the expense of weight. In particular, they have an alloy brake track with a bonded carbon "fairing". This means that you don't need to worry about special brake compounds, and they do not suffer from the delamination issues under excessive braking that plague many other carbon clinchers. The penalty of this method of construction is the weight. The other concern is whether you can handle the 50mm depth with gusty cross winds (if your rides are prone to them).
> 
> For your use case I suspect that the C24 carbon clinchers would be a better choice - they come in at about 1400g. The C50 are better for flats, rollers and time trials. I'd love a set of those C50 for those kinds of rides, but I wouldn't pick them for a ride with significant climbing (eg. 1000 feet per 10 miles of ride) or cross-wind.


Just for reference, 300 gm on a 6% grade means 0.1 mph difference. That means about 30 seconds per hour of climbing. Only the OP can determine if that is significant to him.


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## Kerry Irons (Feb 25, 2002)

*Cottonwood crosswinds*



canyonchaser said:


> Not especially. The mountains keep the wind from getting too out of hand, and wind blows up and down the canyons - almost never across.


It is pretty hard to imagine how you could get a crosswind in either of the Cottonwoods. Where would the wind come from and where would it go?


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## ronderman (May 17, 2010)

stevesbike said:


> from hed on their Jets
> 
> "we calculated two sets of numbers, one on 1320g wheelset with the drag characteristics of traditional low profile wheels, and a 300g heavier wheelset with the drag of Jet 6s. The lower drag of the Jets kept our model rider going faster until the grade reached 7.5%. Unless your race is all uphill in the mountains, Jets are going to get you to the finish faster".


Ah, I think that's consistent with what I said - however, races are never all uphill (except uphill TTs) however, most of the moves and race winning moments happen, guess where, on the hills.


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## ronderman (May 17, 2010)

Kerry Irons said:


> Just for reference, 300 gm on a 6% grade means 0.1 mph difference. That means about 30 seconds per hour of climbing. Only the OP can determine if that is significant to him.


I've heard from you before on this matter, and it was prior to the race season, I had my results this year - I stand by my points - in fact I double down on them - let's you and I agree to disagree, OK? :mad2:


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## carlislegeorge (Mar 28, 2004)

Have been riding the 7850-C50-CL for almost two years and thought they were great. Just bought 7900-C24-TL (tubeless) and had my first rides this past weekend. I know this isn't a tubeless versus clincher thread, but FWIW the overall weight reduction was just a little under 1/2 pound (bike total down to 15.75 lbs). I'm no racer or lightweight (200 lbs), but I had a couple of key observations. First, the 24s were much better in head and crosswinds - basically no effect where I noticed significant buffeting on the 50s. The 24s spun up fine and retained speed very nicely, didn't notice much degradation compared to the 50s. Hills were a little noticeably easier but (a) I didn't have any real serious climbs yet and (b) not a night and day difference. I'm keeping the 24s (tubeless in and of itself is an experiment worth continuing) but am not putting the 50s on ebay just yet.


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## Chris-X (Aug 4, 2011)

ronderman said:


> I've heard from you before on this matter, and it was prior to the race season, I had my results this year - I stand by my points - in fact I double down on them - let's you and I agree to disagree, OK? :mad2:


You agree to disagree, but you're doubling down on your points?

What are your points?

That 300 grams costs you more than a tenth of a mph on a 6% grade?


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## namaSSte (Jul 28, 2004)

> I'll let you know after tonight's ride since I just picked up some 50mm carbon tubulars, In my case, I am shaving 840g off my current wheels (old wheels were absolutely bulletproof Shimano 540's with Michelin Speediums 2 clinchers). Setting the math aside, I cannot imagine any circumstance where I'm not faster after shaving off 1.85lbs of rotational weight. Guess the proof will happen on the road but I am pretty optimistic. I say you ride them and let the results tell you the answer you to the question you asked.


_Well, I've gotten a week under my belt with the new wheels and I'd say my impression is positive overall. I have not felt fresh since I've had these wheels and have even been fighting a little cold so its probably worth mentioning. I'll also mention that its been fairly windy this last week so that also factors in. 

All that said, I've found that the wheels accelerate very well (much better than my aluminum clinchers) and also climb very well (I really notice the better performance on the climbs). What I don't know about is rolling resistance on the flats. My average speeds have been as good or better despite the wind and not feeling great but I don't feel like the wheels roll fast for some reason. Obviously, the numbers don't lie so its more of a feeling than reality. Truth be told, I am running Tufo S33s with glue tape (I know, there's plenty out there regarding this). I'm almost wondering if the feeling is all in my head since I've read too much about the Tufo's. Like I said, my speeds don't bear this out and I am definitely faster out of the saddle and when climbing._


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## kbwh (May 28, 2010)

PoorCyclist said:


> I noticed J.J. Cobo in the Vuelta was using some semi deep wheel (46? 50mm?) winning the climb to Angliru and took the leaders Jersey..


Those are Oval-branded DT Swiss wheels, I guess it's the 46mm RRC 445F/545R tubular combo which seems to be discontinued.


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