Do you need carbon wheels?

[adrian.gab]

A friend sent me this video from Dirt Magazine:

http://dirtmountainbike.com/features/carbon-mtb-wheels-do-you-need-them.html

I swapped from Aluminium to Carbon at the start of the year, these are my thoughts:

First, there is a massive difference between “do you need carbon rims” versus “do you want carbon rims”. Like most things in live there is often a big difference in what I need and what I want.

However, I’d agree with everything the guy in the video says. The differences I have found with carbon rims are:

Pros: lighter, snappier acceleration, the steering is very precise, they are super strong, they rarely if ever need truing (mine are as straight as day one after a few "Enduro" races and rough fast riding), they don’t ding like alu rims and last but not least, the cool factor.

Cons: I found ride comfort is noticeably reduced, I personally like the added gyroscopic stabilising effect that comes with heavier rims, I find the carbon rims are more nervous / twitchy whereas the alu are more stable. You certainly need more upper body strength to steer them.

 

[silentbutdeadly]

You forgot a con. Price.

 

[steve24]

Are you MAD? of course I NEED carbon everything.

Mods please delete this nonsense.......

 

[pistonbroke]

Carbon wheels and Enduro racing.
You're bang on trend there friend. But you failed to mention 27.5 or whip.

And just to answer your question, I'd hate to see a world without carbon wheels.

 

[crank1979]

Cons: I found ride comfort is noticeably reduced, I personally like the added gyroscopic stabilising effect that comes with heavier rims, I find the carbon rims are more nervous / twitchy whereas the alu are more stable. You certainly need more upper body strength to steer them.

I thought the weight difference is usually negligable?

 

[Hellyeah]

Do you need carbon wheels?

Just another trend in mountain biking a expensive trend

 

[hifiandmtb]

I like to tell myself:

"No I don't need carbon wheels".
"No I don't need carbon wheels".
"No I don't need carbon wheels".
"No I don't need carbon wheels".
"No I don't need carbon wheels".
"No I don't need carbon wheels".
"No I don't need carbon wheels".

But I do realise I'm wrong...

 

[Hellyeah]

To quote that vid

'For the general trail rider aluminium is a luxury'

 

[stirk]

I love my heavy alloy wheels because they carry more rotational momentum when I stop pedaling for a moment to catch my breath and apparently add to my suspension capabilities adding some millimeters to my travel making the ride more cumfartable, woot!

 

[adrian.gab]

@hellyeah Carbon is not a trend, it is here to stay.
@crank1979 That depends on your definition on negligible but the key thing is that they reduce weight where it counts most i.e. at the outer edge of a rotating mass. All things being equal, two wheels with identical weight, the one with more weight towards the centre will accelerate faster.

 

[jbg]

On a 27.5 dually I'm sold on carbon.
If I was on a 26 hardtail it would be alloy for the comfort but I think for 27.5 am and 29er carbon can have a more dramatic effect on the bike's handling and acceleration.
That vid confirms my thoughts on carbon being an option not a must have.
Alloy is definitely more forgiving and suited better to the recreational rider

The biggest point of difference with carbon is the width of the rim 30 - 40mm and I think that going wide is a greater trend than carbon vs alloy
Producing an alloy rim at those widths comes with a lot of extra weight.

 

[stirk]

On a 27.5 dually I'm sold on carbon.
If I was on a 26 hardtail it would be alloy for the comfort but I think for 27.5 am and 29er carbon can have a more dramatic effect on the bike's handling and acceleration.
That vid confirms my thoughts on carbon being an option not a must have.
Alloy is definitely more forgiving and suited better to the recreational rider

The biggest point of difference with carbon is the width of the rim 30 - 40mm and I think that going wide is a greater trend than carbon vs alloy
Producing an alloy rim at those widths comes with a lot of extra weight.

Really, that vid shows a guy who really can't explain anything in a way that makes any cents.

ah, ah, ah, yeah, it accelerates faster cause it's stiffer, my dick does the same thing!

I'm sold on having fun on my bike.

 

[Rider_of_Bikes]

The biggest point of difference with carbon is the width of the rim 30 - 40mm and I think that going wide is a greater trend than carbon vs alloy
Producing an alloy rim at those widths comes with a lot of extra weight.

Not exactly true my friend. Have you picked up a set of American Classic wide lightenings? Right around 1500g for a 27.5 wheelset with 15mm thru front and 142x12 rear. They are under $1g to boot.

 

[Rider_of_Bikes]

That depends on your definition on negligible but the key thing is that they reduce weight where it counts most i.e. at the outer edge of a rotating mass. All things being equal, two wheels with identical weight, the one with more weight towards the centre will accelerate faster.

On the contrary though; once up to speed the wheel with the external mass with hold its momentum through rougher terrain and over a longer distance.

 

[JTmofo]

Until you need to change direction in a hurry!

 

[Beej1]

Pros: ...snappier acceleration ...

This is one of those things I'm waiting for someone to actually prove under meaningful conditions - specifically when people refer to the difference in rotational mass between the two rim materials. To me it falls under the banner of "something which can be proved in physics, and regardless of the degree of actual noticeable difference by and benefits for a rider, we will add it as a marketing buzz-phrase for our product, or include it in our review to sound like we can distinguish such a thing."

About the only effect I can see is that a lighter rim contributes to a lighter overall bike. A lighter overall mass will obviously accelerate quicker under the exact same power supply (i.e. the human). But surely the weight difference between the two is about the same as taking a giant turd before going for a ride, or forgetting to punch it out and therefore carrying that mass around with you on the ride.

 

[mitchy_]

This is one of those things I'm waiting for someone to actually prove under meaningful conditions - specifically when people refer to the difference in rotational mass between the two rim materials. To me it falls under the banner of "something which can be proved in physics, and regardless of the degree of actual noticeable difference by and benefits for a rider, we will add it as a marketing buzz-phrase for our product, or include it in our review to sound like we can distinguish such a thing."

About the only effect I can see is that a lighter rim contributes to a lighter overall bike. A lighter overall mass will obviously accelerate quicker under the exact same power supply (i.e. the human). But surely the weight difference between the two is about the same as taking a giant turd before going for a ride, or forgetting to punch it out and therefore carrying that mass around with you on the ride.

if you had a 9kg bike with 1kg wheels, and a 1kg bike with 9kg wheels.. they would accelerate very differently, despite the same total weight.

 

[adrian.gab]

Hooray, someone making sense. I'd rather lose 300g off rims than 300g off the bike.

 

[teK--]

Regardless of the 100g or 300g, the reason why I went carbon is to have a wider rim for no weight increase (I haven't seen the American Classic alloy rims mentioned earlier). The bigger tyre volume makes the biggest difference in handling IMHO.

 

[pharmaboy]

if you had a 9kg bike with 1kg wheels, and a 1kg bike with 9kg wheels.. they would accelerate very differently, despite the same total weight.

Yes they would - but there ain't no free lunch, so you also lose momentum quicker - the gyroscopic effect means the heavier rim is harder to accelerate but easier to keep going up and over things.

Ultimately the advantage we would be hoping for out of a carbon rim, is longevity because it should flex less and be less prone to taco.

There isn't much weight loss, because nearly all carbon rims are around the same weight as crests anyway, so only helpful if you are coming from at least flows, and then the difference might be "felt" but it's extremely unlikely that it can be measured in time.

200g in rims is at best equivalent to 400g on bike which is not enough weight to make a real world time difference - they do look cool though ....