Comparing two wheels for climbing

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wingguy
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by wingguy

BugsBunny7788 wrote:Heres what I can gather on the weights for both wheels:

R-SYS (FR 555grams/RW740) = 1295 grams
Michelin Latex = 70grams.x2
Conti 25 GP4000 = 225gx2
Total weight 1885 grams.

Bora ONE 50 Tubs
Bora One 545/720 = 1265 grams
Conti Competitions 25mm = 270gramsx2
=1805 grams

So 80 grams lighter...

Dude you suck at maths. See corrections in bold above. Also Conti quote the Competition 25s at 280g, not 270g, and if you used Force/Attack instead of GP4000 you'd save another 80g per pair. In that setup (assuming the claimed weights are accurate and without taking into account tape/glue/skewers) the R-Sys would then come out 20g lighter as a system. Well within the margin of error and variance, so to know which pair really is lighter you'd just have to build and weigh them both.
Last edited by wingguy on Wed Jul 27, 2016 1:13 pm, edited 1 time in total.

wingguy
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by wingguy

BugsBunny7788 wrote:- Which will have the higher cadence for the same amount of effort/power? (I prefer high cadence, so a wheel that helps in this regard is preferable to me).

The cadence you ride for a given power depends entirely on the gear ratio you are in. The wheel will have no effect on that, apart from the small factor of how much overall weight they add that you're having to lug up the hill.

And anecdotally, all the guys here are raving on about the RSYS and prefering climbing wheels, which is screwing with my mind because I "SEEM" to think the Boras climb better.


Right, the R-Sys are a great set of climbing wheels... as far as aluminium clichers go. They're lighter than most comparable options, and a lot stiffer than most other alu clinchers that are any lighter. But you're comparing them to carbon tubulars which are a whole other ball game, and are inherently lighter for a given depth/stiffness and therefore are great for climbing.

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eric
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by eric

Rim weight has no more effect than hub, bike or body weight for steady speed climbing. Even when accellerating hard as in flat criterium finishing sprints the intertia effect of rim weight is small. This is why many pro road and track sprinters use aero wheels with heavy rims.

However light rims make the bike feel noticeably lighter, especially when out of the saddle. You may like that feel even if the real difference is too small to measure.

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Calnago
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by Calnago

A little off topic, but I'd like to add to what @eric just said but with respect to descending as opposed to ascending, since the two usually go together unless it's a one way ride. There is a very noticeable gyroscopic effect on wheels. And it's easy to feel. Here's what I show people to demonstrate... take a front wheel with a fairly weighty rim, hold it by the skewer in your hands and spin it as fast as you can. Now, while it's spinning move it around a bit as if your leaning, turning and twisting down your favorite descent. You can feel how it wants to right itself. Now, do the same thing with a wheel with a very light rim... compared to the weighty rim, this wheel is much less forceful in it's tendency to right itself.
Now, think about that when you're on the bike. It's just one more factor that contributes to downhill stability. And there's always tradeoffs. Probably my favorite wheels for descending would be my 32 spoke Nemesis tubulars. Low profile so they don't catch as much wind as a higher profile wheel, but also having the weight of the rim far away from the hub helps create that self stabilizing effect. Are they going to be as fast as a high profile carbon rim... no. But they inspire confidence and added safety which is something to consider as well. I love my carbon rims, but I'm generally a little more cautious on descents with them.

To the OP: you have sets of both of the wheels you're asking about. If you have to ask which ones are better, what does that tell you? Constructionwise, etc., maybe, but just stick with the ones you like the most and forget what other people say. Boras all the way :lol:
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BugsBunny7788
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by BugsBunny7788

Thanks guys for your thoughful responses. It's the type of replies that is helping me get to the bottom of it.

The R-SYS are clearly designed as climbing wheels, so they *logically* make sense to be the choice as a climbing wheel. The Boras on the other hand are often talked about on this forum in the context of their aero ability, how good the hubs are - but rarely does anyone comment on them in the context of a climbing wheel. And thats where I'm kind of looking for experience of other owners. Or owners of deepish carbon rims and how they perform on climbs - ie. why don't you use a wheel like RSYS/C24/Shamals for climbing instead of your carbon deep rims?

One thing that I can feel is an advantage of the Bora is that when seated in the RSYS climbing and putting out around 200W, the wheels feel okay. When I get out of the saddle and put out say 250W+, or when accelerating hard on the flats above 300W, and I'm swinging the bike with my upper body, the wheels flex laterally quite a bit. (My frame is Canyon Ultimate CF SLX 2015 version - so also rather stiff). This "softness" is something I don't like but then again it only has 16 spokes on the front and I'm thinking thats a compromixe I need to live with for a light climbing wheel?? The other thing I like is a wider base. The Boras at 24mm width just feel better than 15mm inner rim/20mm outer on the RSYS.

There is one more piece to my puzzle. That is the Bora 35.

As my intention is to go for a single wheel set - the BORA 35 seems to be a good compromize. Stiff enough, and wide platform and light. BUT - heres the catch, all the forums thread here tend to say that its "worth" the extra 60 grams for the Bora 50 over the Bora 35. So there is my other dilemma, should I flip the Bora 50 and go with Bora 35 - be it Ones or Ultras?

BugsBunny7788
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by BugsBunny7788

964Cup wrote:The Boras will have considerably lighter rims, so if you buy the rotational mass theory, they'll make better climbing wheels. Tubs are safer than clinchers for descending and give a better ride. Both wheels will brake well in the dry. The Boras will be a bit faster on descents as they are aero (but the drag effect is tiny in comparison to the impact of the rider).

The R-SYS might be easier to live with if you're not a routine user of tubulars. They'll stop much better in the wet. You risk blowing tubes if you're a very cautious descender (i.e. drag the brakes) but Exalith handles heat better than plain alloy. They'll have better cross-wind stability, which might be a factor for you on sketchy descents if it's windy.

I generally travel with two wheelsets - either Enve 45s (very similar to your Boras) or AX Lightness Ultra 24 (carbon tubs, much lighter than either of your sets) and R-SYS SLR tubs. I'll take the Enves if the terrain is mixed, the AX Lightness for big mountains and use the R-SYS if there's any chance of rain or bad weather. If I absolutely had to choose only one wheelset, it would be the R-SYS for wet weather braking capability...BUT all my sets are tubular, so it's not a straight comparison to your situation.


This is an interesting combination of wheelsets - and interesting how you split the three into different riding condidions. Just a question on your gearing setup. Do you run all three wheels with the same gearing setup - ie. same rear cassette size? or do you run say for example a 11-32 climbing cassette with your AXL and say an 11-25 for your Enves? And if you do, how do you make the swaps as easy as possible?

cmcdonnell
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by cmcdonnell

I have Bora 50C, Shamal and Neutrons and the Boras are just better on all accounts. Stiff, light and (theoretically) aero. I use them for climbing and they certainly feel quicker than the others overall, probably the same as the Shamals going up hill and definitely quicker when descending. They feel a fraction more sluggish to accelerate when standing but as Calnago eluded to this may be the gyroscopic effect rather than actually being slower. I see no argument for the Bora 35C at all. I nearly bought them initially because everyone said I was light (56 kg) and wold get blown about on the deeper rim but I've had no issues and live in a windy part of the world, now I wish Campagnolo did a Bora 65C!!
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eric
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by eric

I'd sell the R-sys while they are worth something. Narrow rims are unfashionable and those wheels are as un-aerodynamic as you can get. Also, they have a reputation for exploding carbon fiber spokes.

I'll note that in the Everest Challenge stage race which had 29,035' of climbing in two days, the top racers generally used aero wheels. I built a simple model and found that a small increase in descending speed more than made up for the added weight over wheels with low profile rims (assuming reasonably light aero wheels, not heavy ones for TTs).

Since then I have used super light non aero wheels for races that are uphill only, but if there's a significant descent I'm on aero wheels.
The one drawback is being affected more by side winds. Usually that is not too much of an issue for me unless it's unusually windy.

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