Jarrett2

I'm on this quest to understand wheels better. I feel like I'm starting to get my head around alloy wheels a bit and now curious about carbon.

I'm trying to figure out what purpose they serve for the recreational rider, if any. And also the same question for a recreational Clyde. Are there compelling reasons to bypass alloy and go to carbon wheels for the recreational Clyde?

FBinNY 

IMO none. The plus side is they build lighter wheels, with deeper (more aero) rims than is possible with aluminum. The negative is that they cause brake track issues if you use rim brakes, and if you opt for discs, any weight savings is negated, and new issues are introduced.

There wan an old woman who swallowed a fly......

BTW- the best way to learn this stuff is to ride bikes, use various things until you see what work and what doesn't. You'll also see what you like in some applications, and what you like in others.

There aren't any answers, there's only considerations.

jimc101

Not really for any recreational rider, simply down to cost, even the cheapest carbon wheels are still significantly more than mid to high range Alu wheels.

Riders weight will have a bearing on if they can be used, but this will be the same as light weight Alu wheels which are spec'd with weight limits. Each wheel/wheelset would need to be looked at individually for the manufacturers recommendations/specs.

The only real reason for a recreational rider to go to carbon wheels is if they have loads of money to spend, functionally, they won't benefit from it.

Edit, the brake track issues that #FBinNY notes were an issue on early carbon rim brake wheels, but now brake tracks are normally coated with another material & propitiatory / specific pads are required by almost all manufacturers. Have a look at this article for more info, it's a few years old, but covers the basics Are carbon fiber clinchers safe? - BikeRadar

Kindaslow

They are lighter in the most important area, farthest rotating mass. Therefore less energy needed by you. Everyone will benefit, the question is whether or not the small benefit to a casual rider is worth it. And, they are cool....

Jarrett2

Thanks for the info.

mkadam68

Reason 1 for rec-riders to use carbon rims: perceived aesthetics. Granted, this seems a shallow justification, but as cycling is just a toy/hobby anyway, it is still valid.

While not strictly a rec-rider myself (my normal season consists of 50+ races from Jan--August), I do regularly ride with friends who are. I have some carbon tubulars wheels for my races and I do use carbon clincher wheels year-'round. At first just an experiment to see if they would hold up to my heft (260-lbs.), I currently ride carbon rims for my own reasons...

• Aesthetics (as mentioned above).
  I like the way the 55mm rims look.
• Less flats.
  The wider 23mm rim (coupled with a 700x23 tire) has drastically cut down on pinch flats to the point where I have not gotten a single one since using them, even though hitting the occasional small pot-hole/crack. (I still do get the occasional puncture, though.)
• Easier roll-up.
  The lower weight near the outside of the wheel (the rims) allows a quicker acceleration which allows for easier climbing as well.

Yes, braking can be an issue, but only on steeper, winding descents. With my mass generating momentum, I have to be careful not to over-heat the rims by braking too hard or too much. In all other areas? On straight descents, or rolling hills, or even the occasional emergency stop on level road? Absolutely no problems.

As with all internet things, YMMV.

10 Wheels

I

I tried some on with White Spokes for The Cool Look.

Jarrett2

Good stuff.

Kindaslow

wow!!!

10 Wheels

sstorkel

Doubt it. Most people buy carbon for their perceived aerodynamic benefits. That means that most carbon wheels have a relatively deep cross section and weigh as much or more than an alloy wheelset. It's possible to get low-profile, light carbon wheels (ex: Zipp 202) but most are only slightly (~100g) lighter than alloy wheels and they cost a lot more.

Back to the OP's question: there are a few reasons to consider buying carbon rims:

1) Because they look cool
2) Because they absorb "road noise" better than an alloy rim
3) Because they are aerodynamically more efficient

Of those, the only one that really matters is #3 . If you regularly ride quickly (18+mph) in events where seconds matter (think: time trials, races) then deep-section (50+mm) carbon wheels may be important to you. This doesn't apply to most recreational riders, however. Note that most carbon wheels are not especially light. Zip's 404 Firestrike carbon clinchers weigh (a claimed) 1620g. That's light for a wheel with a 58mm cross section, but you could easily build 1500g alloy wheelset for less than the cost of a single 404 wheel.

As others have mentioned, there are also some considerations to think about when buying carbon wheels:

- They frequently require special brake pads (ex: SwissStop "yellow")

- You can't use the same brake pads for your carbon and alloy wheels. Aluminum slivers picked up from the alloy brake tracks will eventually destroy the braking surface on the carbon wheels; when swapping wheels you must also swap brake pads

- Some carbon rim and brake pad combinations don't work well when wet. Some less expensive carbon rims have poor braking characteristics everywhere

- Almost all carbon rims have weight limits, usually due to low spoke count

- Rims with a deep cross-section can be difficult to handle when riding in cross-winds

If you're thinking about buying carbon wheels, I'll suggest that you don't want to go too cheap. If you do, you're likely to end up with a relatively heavy wheel that has poor braking characteristics. The "sweet spot" for carbon rims seems to be the 55-60mm depth. From what I've read, that's where you get decent aerodynamic gains, reasonably light weight, and handling doesn't become too scary if you're caught in a cross-wind.

FarHorizon

Were I a "regular" Clyde (from 200 to 250#), I'd be comfortable with carbon parts.


However, as an "Uber-Clyde," (250+), I won't risk them. I'm sure that some here will chime in that they've been riding the same carbon parts for decades without failure. And I believe them. But am I willing to risk my life on their experiences? No thanks. Unlike other materials that deform prior to catastrophic failure, carbon is prone to break suddenly with no deformation as a warning. That being the case, no carbon in my bikes, period.

FH

jsigone

Weekend warrior rec riders should be able to feel the difference if they ride fast enough or ride in groups.

Carbon clinchers weigh almost the same as alum clinchers, so weight saving isn't really there. The diff is in aero at speed and ride quality. I find this speed to be around 23+ mph and dramatically more at 30-5mph. And even better when in drafting. less energy to stay with the group. Since the group as a whole is more aero, and you are more aero in the group at their speeds. Takes much less energy to sustain their speed, giving you more energy to make up for the Yo Yo you get from not being in the front third.

Weight saving is done if you went tubular, better braking track for decending mountains. I went this route, lighter weight by almost 300 grams. Plus tubular tires ride so freaking good. I run Stans sealant in them so if I do hit a staple it will fix it self. I've yet to flat on tubs for over 2k miles and many centuries. Lighter rolling weight, faster to get to speed from a stop light and faster to slow down. I do run yellow Swiss stop pads for my carbons. I do carry a spare pre glued tub in my jersey pocket on centuries but have yet to ever use it. They have been reliable, stiff and aero. You can get some used Zipp 303/404 tubs on ebay for around 700 bucks. Maybe a bit cheaper next month when cross season wraps up, more wheels tend to pop up. They made changes per year so do you're homework.

To get the same ride quality like a carbon tubular would be to go tubeless setup. Stans Alpha 400s, Velocity A23, PACENTI PL23 would get my vote on what ever hubs you can afford. Yes tires are more expensive but you won't be spending $5-8 per flat you get running tubes, so in the long it, its about the same cost As @sstorkel mentioned, you can get a really kick ass set of custom blinged out clinchers for the price of one Zipp wheel, even just the front Zipp wheel is still $1100. You can get Chris King hubs or DT swiss hubs on any alloy hoop and still have $$ left over to buy a high end cassette.

achoo

Brake heat dissipation is still a problem for CF rims - and probably always will be as long as rim brakes are used.

While things are getting better, it's just a matter of degree - the resin will still soften/melt if it gets hot enough. Dump enough heat energy fast enough via braking, and a CF rim will fail. CF isn't as good at dissipating heat as AL, and it's pretty safe to claim CF will always have a lower failure temperature.

achoo

Except that the difference between "rotational" and "non-rotational" mass isn't that big of a deal when you look at it from energy/power costs. Mainly because the weight in question is well under a mere 1 kg and accelerations on a bike are really pretty pathetic.

Compared to the entire weight of a rider and bike, wheel mass is pretty small. And the extra energy an ideal hoop requires to accelerate while rolling is only twice what the same mass requires to accelerate without rolling - and a real-world wheel of a certain mass will have a much lower moment of inertia than an ideal hoop of the same mass and radius would, because the real-world wheel has a lot of its mass closer to the axle. And rotational energy is conserved and helps you sustain your speed when you coast.

Lighter wheels do make your bike FEEL snappier, though, as the lower rotational energy can be felt in multiple ways - even though it won't make a significant difference in how fast you accelerate, it could be enough of a difference that you can feel it. The lower rotational energy will also make the bike change direction faster and lower the force required to turn the bars. You will feel that for sure.

Kindaslow

If I had said very small difference, instead of just small, would that have made folks happier? I am just teasing you because my half German wife has trained me better than that and I should have known better....

in the end, if someone is curious enough they need to own a set to figure out whether or not the pluses and minuses add up for them.

Daniel Jones

Another option are the rims from Flo Cycling. They are clinchers with a conventional aluminum rim and carbon fiber fairing and are considerably less expensive than full carbon rims at $424 front and $474 rear. The downside is they aren't quite as light as equivalent full carbon rims. The braking surface is aluminum so you use standard brake pads and they make a higher spoke count Clydesdale version that they rate to 242 lbs. Here's a picture of the 60mm front versions and the 90mm rear on my 2012 Specialized Roubaix Apex Comp:



Note that Flo doesn't recommend the 90mm on the front for most riders as they are sensitive to cross wind.

> Compared to the entire weight of a rider and bike, wheel mass is pretty small.

Has anyone run the numbers on the effect of lighter rims? I did the math when I switched from an iron to aluminum flywheel in one of my cars. The mass of a flywheel is small compared to the mass of a car but the effect of reducing flywheel inertia is surprisingly large in lower gears (and minor in top gear).

> And rotational energy is conserved and helps you sustain your speed when you coast.

Agreed. My Roubaix came with relatively heavy high spoke count rims (DT Axis 2.0) so I didn't notice them accelerating more slowly but they do coast better (due to less aero drag) and are faster overall. Flo did some simulation work where they compared the aerodynamic benefit of there rims to a lighter rim with worse aerodynamics. Their contention is that, even on relatively hilly circuits, better aerodynamics wins. Note that aerodynamic drag is proportional to the velocity squared and the power required to overcome drag is proportional to velocity cubed so the effect would be very dependent upon the speed at which you ride.

One thing to add, the Flo rims are wider and it is a tight fit on my Roubaix where the chain stays pinch in. I had a cadence sensor attached with a elastic band right at the narrowest point. Deflection in rim while riding rubbed on the elastic and until it snapped. I had to relocate the (replacement) sensor and attach with tiny zip ties for clearance

Dan Jones

FLO Cycling

We have studied the effect of lighter rims. You might find this article of interest.

Flo Cycling Blog: FLO Cycling - The Great Debate - Aero vs. Weight *Edited

Let me know if you have any questions.

Take care,

hammond9705

Nobody mentioned the other advantage. They make a neat whoosh sound as you ride

technobuyer

What? There's a whoosh sound? This changes everything.

Daniel Jones

> They make a neat whoosh sound as you ride

The rear ones are a bit of an echo chamber as well. The freehub that came with the wheel has a pronounced click-click-click when coasting (much louder than the freehubs on any of my other wheels) that the wheel amplifies. Also, sometimes when you ride over debris in the road (branches, acorns, etc.) it will ping like you've broken a spoke.

Dan Jones

Jarrett2

Thanks for the info, good stuff.

Does any of that translate to a 265lb club rider that regularly does 40-60 mile rides with 1500-2000 ft climbs?

sstorkel

If you have to ask, you probably don't need aerodynamic wheels

FLO Cycling

It all translates to a 265lb rider. Aerodynamic benefits are equally beneficial to riders of all weights.

sstorkel

That's true, but rather misleading. A 155lb rider and a 265lb rider may both save a few watts due to having aerodynamic wheels, but I'll bet that the 265lb rider won't notice the difference since their body mass (and possibly riding position) creates significantly more drag than a 155lb rider. Besides, if you're not competing who really cares if you make it home a couple of minutes faster?