# Mavic Ksyrium SL vs. Reynolds Assault - which are better climbing wheels?



## s4gobabygo

i have 2 sets of wheels, silver ksyrium sl at 1550g and assault clinchers at 1487g. ive been using the reynolds wheels as climbing wheels, but sometimes i wonder if the ksyriums actually have less rotational inertia. the rims on the mavics must be lighter, though the spokes are clearly heavier, and the overall weight is also heavier.


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## CleavesF

Unless you have the same tube/tires on both wheels, you can't really say which is better at climbing. 

Also remember that overall wheel mass doesn't mean much as actual rim weight vs actual hub weight. Better to have weight inside than on the outside. 

So it's entirely possible that a "heavier" wheelset can be a better climber due to mass concentrated near the hub as opposed to the rim.


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## s4gobabygo

i do have the same tubes and tires on both wheelsets. ultremo r.1 with michelin airlite tubes. the longer valves on the tubes for the reynolds wheels amount to about 3-4g more per tube, but otherwise they're the same. cant find specs on weight of the rims though.


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## farva

Of those 2, I'd go with the K's. that weight difference is negligible . I rode reynolds carbon clinchers in the mountains for 2 seasons & I've pretty much decided they make no sense at all. They are no lighter, have sh*t braking compared to machined aluminum (especially if you get caught in a t-storm) and the deeper profile can be terrifying in crosswinds. All those drawbacks for the sake of looking cool? Until disc road brakes are mainstream machined aluminum rims are the money for general riding. If racing is your bag then get some light carbon tubulars for race day use. Then you'll only be giving up braking for real weight savings. Sorry rant over


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## woodys737

Weight: 63g isn't worth worrying about as you won't be able to notice a difference imho. Inertia: Once he wheel is spooled up to speed the inertial concerns fade to zero.

I'd roll with the Reynolds myself. Better hubs. Better spokes. I think they look better as well.  The Reynolds are more aero which will probably make more of a difference with the exception of the steepest grades. 

JMO YMMV


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## BlackIce619

I have the same wheel sets. Mavics came with Supersix and I purchased Assults for races. 

Mavics feel great, but my Assults are Tubulars and you can completely feel the difference. Yes, braking does suck compared to Mavics. Assults feel like maintaining higher speeds is easier. I dont know the weight difference on my wheels, but I do feel the difference when climbing. 

I have been using my Assults, because I get lazy to switch back to Mav's and change break pads


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## woodys737

BlackIce619 said:


> I have the same wheel sets. Mavics came with Supersix and I purchased Assults for races.
> 
> Mavics feel great, but my Assults are Tubulars and you can completely feel the difference. Yes, braking does suck compared to Mavics. Assults feel like maintaining higher speeds is easier. I dont know the weight difference on my wheels, but I do feel the difference when climbing.
> 
> I have been using my Assults, because I get lazy to switch back to Mav's and change break pads


Tires make the most difference in performance and most noticeably feel imho. Are you using the same tires (even though one is a sew up)?


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## BlackIce619

woodys737 said:


> Tires make the most difference in performance and most noticeably feel imho. Are you using the same tires (even though one is a sew up)?


Mavics have "stock" tires. I believe they are Schawlbe Durano. I have not changed them since I might as well use up what I have until I decide to get something a little better. 

Assults have Continental Sprinters Tubular. 

That could be a big part of the difference as well.


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## farva

BlackIce619 said:


> my Assults are Tubulars


Although the name is the same, the tubular version is 200g lighter & uses completely different tire type. Sorry but not a relevant comparison at all


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## badge118

Assaults. The weight difference is neglible yes. The Rim weight of the Assault however is only 489 grams. Open Pros, which I think are lighter than the K-SLs are 435 grams.

However except in the wet the braking is equal to any aluminum rim I have ridden...in the wet it's a little worse until the rim is squeegeed. Aero counts going up hill as well and what goes up must come down. So if I can have equal weight...equal dry braking and okay braking in the wet I'll take the advantage of Aero as well.


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## farva

Respectfully disagree. Yes carbon brake tracks & pad compounds have improved since introduction but they are still no match to the stopping power provided by a good machined aluminum brake track. Dry or wet


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## badge118

farva said:


> Respectfully disagree. Yes carbon brake tracks & pad compounds have improved since introduction but they are still no match to the stopping power provided by a good machined aluminum brake track. Dry or wet


Do you honestly think the dry braking is so much poorer that minimal weight and aero advantages are of no difference? I love my HED Ardennes but the only time they are on my bike is in bad weather. In good weather CF wheels are on balance better if you can afford them.


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## farva

OP asked which are better climbing wheels. The kysriums are lighter for the up & melt free for the down. There would be virtually zero aero advantage going uphill at amateur level with the assaults. K's just make more sense for the mountains. Justify $2k for carbon clinchers however you like, but on paper they perform no better than their less expensive aluminum counterparts. 

Carbon clinchers = fashion
Aluminum clinchers = function


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## badge118

farva said:


> OP asked which are better climbing wheels. The kysriums are lighter for the up & melt free for the down. There would be virtually zero aero advantage going uphill at amateur level with the assaults. K's just make more sense for the mountains. Justify $2k for carbon clinchers however you like, but on paper they perform no better than their less expensive aluminum counterparts.
> 
> Carbon clinchers = fashion
> Aluminum clinchers = function


I don't think they are lighter on the way up though (from the numbers I have seen) and aero also counts going up hill. So based on that criteria Reynolds wins. That means the only possible reason not to use them is the braking so my question is "does only better braking make up for >/= weight and no aero." Sorry if I was not clear.


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## s4gobabygo

thanks for the thoughts, guys. to clarify and focus the conversation slightly, lets say for the purposes of this question, only my trip up the hill is relevant. lets disregard my ride to the hill and my way down the other side after i've finished. i'm simply wondering which wheel is likely to allow me to climb the fastest. 

i'm asking because i've been trying to beat a friend's time on a local climb, and would like to ensure i'm using the wheelset likely to provide the least resistance on the way up. if there's any climbing advantage between the two pairs of wheels, i'd like to be using the right pair.


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## badge118

s4gobabygo said:


> thanks for the thoughts, guys. to clarify and focus the conversation slightly, lets say for the purposes of this question, only my trip up the hill is relevant. lets disregard my ride to the hill and my way down the other side after i've finished. i'm simply wondering which wheel is likely to allow me to climb the fastest.
> 
> i'm asking because i've been trying to beat a friend's time on a local climb, and would like to ensure i'm using the wheelset likely to provide the least resistance on the way up. if there's any climbing advantage between the two pairs of wheels, i'd like to be using the right pair.


I would say the Reynolds then. I have not been able to find specific SL rim weights but looking at similar wheels IF the Reynolds are heavier you are talking only double digits. Aero works up hill not just on flats and the differences in stiffness won't be much either. 

You will see pros running shallower rims in races but typically they are riding tubulars and the same brand. You can find 100-200 gram differences in those circumstances but they don't seem to apply here. Even then you usually only see something shallower than 40+ mm depth when it is INSANE climbing.


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## farva

Depends how close you are to besting his time. If you are within a few secs then borrow some carbon tubs, ditch your water bottles, make sure you take a dump before riding etc... If you're 10 min or more slower then neither of these wheels will make much difference. You just gotta suck it up & ride more or accept reality - there will always be someone to chase. Just go out & ride your own race

On the other hand if he talks a lot of sh*t, then The fill his inner tubes with water. He'll never notice it stopped. It will just make his bike really sluggish when he gets going. If you do this you'll probably get payback tho - I ended up with a lead bar in my seat tube for that one


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## badge118

farva said:


> Depends how close you are to besting his time. If you are within a few secs then borrow some carbon tubs, ditch your water bottles, make sure you take a dump before riding etc... If you're 10 min or more slower then neither of these wheels will make much difference. You just gotta suck it up & ride more or accept reality - there will always be someone to chase. IMHO you are better off riding your own race. Turn off strava, disconnect all the performance measuring BS. Unless you are a pro, none of it really matters anyway
> 
> The other far more manly option is to slow him down. Fill his inner tubes with water. He'll never notice it stopped. It will just make his bike really sluggish when he gets going. Awesome for dudes with big egos who talk a lot of trash. You'll probably end up getting payback tho. I ended up with a lead bar in my seat tube for that one


This reminded me of a guy I saw at the Mt Washington hill climb. He removed his big chain ring and even removed his brakes. When be got to the top he was so fried he was yelling "no brakes HELP!!" when he was moving no faster than a walking pace. It was damn funny.

Another thing a buddy of mine did to someone who had hubs with an easy access preload on the hub was tighten the crap out of it. That was funny when he checked...spin the wheel and it had like 4 revolutions before it ground to a halt.


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## s4gobabygo

we're certainly no professionals. we ride together all the time, and are therefore very evenly matched. i beat him up the hill almost half of the time head-to-head, but he retains the bragging rights of having set the fastest time up. it's about an 8.5-minute effort, and the closest i've come was only 13 seconds off his best. obviously i just need to find a way to dig a little deeper, but i'd still like to prepare as well as i can, even if the only result is a "mind over matter" improvement. his record needs to fall!


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## farva

badge118 said:


> This reminded me of a guy I saw at the Mt Washington hill climb. He removed his big chain ring and even removed his brakes. When be got to the top he was so fried he was yelling "no brakes HELP!!" when he was moving no faster than a walking pace. It was damn funny.


yeah I've done that race. What a beast. Guys riding 8lb carbon single speeds all the way to retro grouches on 30 lb steel tanks. Good stuff. I do recall a guy passing me on old trek with downtube shifters & 32 spoke box rims. Goes to show it's still all about the rider in the end.


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## badge118

farva said:


> yeah I've done that race. What a beast. Guys riding 8lb carbon single speeds all the way to retro grouches on 30 lb steel tanks. Good stuff. I do recall a guy passing me on old trek with downtube shifters & 32 spoke box rims. Goes to show it's still all about the rider in the end.


A buddy of mine is a complete beast. First time he did it it was on a Cdale MTB/hybrid with head shock and disc brakes a few years ago before he finally got a dedicated road bike.


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