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Carbon vs alloy wheels. Worth it?

Posted: Fri Aug 02, 2019 7:14 pm
by fatbikerbill
So my fatty has carbon/tubeless wheels and I wouldn't have it any other way.

But I've been looking at 29er and 650b+ carbon wheels and I can not see the justification. The weight gains compared to something like the hunt wheels is rarely better than 250g total for both wheels making the £/g cost very high.

Or am I doing something wrong?

From what I've seen the better gains are in tyre choice.

Re: Carbon vs alloy wheels. Worth it?

Posted: Fri Aug 02, 2019 8:10 pm
by dlovett
Agreed, my fat rims are only about 50g heavier than a certain brand of carbon rims, but my tyres are 220g each lighter than the ones the carbon rims are shipped with. Also mine were about £400 cheaper and are far less fragile.

Re: Carbon vs alloy wheels. Worth it?

Posted: Fri Aug 02, 2019 10:47 pm
by fatbikephil
Must admit I've been idly eyeing up carbon 29+ rims, suckered in by the 400g weight saving but still not convinced how rock proof they are... (or, crucially, how idiot proof they are)

Re: Carbon vs alloy wheels. Worth it?

Posted: Fri Aug 02, 2019 11:10 pm
by Alpinum
I got my rims for 80 chf more than what I would've paid for alloy rims (Stans Flow/RaceFace Arc/Newmen etc). Yet with alloy I don't get a crash replacement and by the rate of rim destruction I get square money wise after three years. No winner. After three years the carbon rims start to get cheaper for me (well... my insurance) compared to alloy rims.
I damage carbon rims as much as I damaged alloy rims, yet the carbon rim I've sofar damaged could easily be repaired. Wouldn't have worked with alloy. Also I was able to ride on despite missing some spokes and having some badly bent. An equal built alloy wheel would've been unridable - I've been there with Flow and other, similar rims.

Less pinch flats. The LB/KHS rims I use are wide and hookless. The amount of less pinch flats is telling compared to DT, Syncros, Easton, Stans, Pacenti, Sun-Ringlé, Mavic (not sure I thought of all of them...).

Then there's the strength. The 420 g carbon rim is very noticeably stiffer, yet 110 g lighter per rim. Go with thinner/lighter spokes and 28 rather than 32 and the wheel is still a little stiffer, yet a bit more forgiving and comfy than a 'heavy carbon' build and stupid light. I went from 26" straight to 29" and my last two 26" bikes were a DH race bike and long travel trail bike. I wanted that same feel of the wheel stiffness and never got it with 29" until carbon rims... the 29" wheels of my long travel trail bike (420 g rim front, 460 g rim rear) which see lots and lots of abuse (hours in loose scree slopes and high paced descending) are a mere 1700 g and feel like a 1800 - 2000 g 26" wheel set.
I once test rode the same bike (long travel 29") except for fork, saddle, handlebars and wheels to what I ride now as my own and the difference the wheels made was staggering. More playful, more lively, faster in changing direction, accelerating and braking and far more direct/responsive.

I've never had to true a carbon rim build. With alloy it was very different. Wheels mostly build by the same professional.

The larger the wheel, the more sence carbon makes. I too started off with my fatbike and now all my trail bikes have carbon rims. I'm not sure I would've gone carbon with 26", but with 29" I'm glad I did a couple of years ago. My everyday bike (and penny farthing) are the only bikes on alloy rims.

Downsides surely are the harsh feel (for many riders) of many carbon rims builds. This is not just tiring, but depending on you riding, you'll not like the way the rims complies less to impacts. So make sure you get the right spokes and spoke count.

Larger gain with tyres is not an argument because you can still do that, no matter what material your rim is made of.

Re: Carbon vs alloy wheels. Worth it?

Posted: Fri Aug 02, 2019 11:14 pm
by Alpinum
htrider wrote: Fri Aug 02, 2019 10:47 pm Must admit I've been idly eyeing up carbon 29+ rims, suckered in by the 400g weight saving but still not convinced how rock proof they are... (or, crucially, how idiot proof they are)
In my experience more than alloy.

Re: Carbon vs alloy wheels. Worth it?

Posted: Fri Aug 02, 2019 11:38 pm
by BigdummySteve
I’ve WTB Ci 31 rims on my Fargo, don’t know the weight saving but they are one thing I never worry about, a lot of other things are going to fail before the rims, at which point I’ll most likely be in hospital :-bd

Re: Carbon vs alloy wheels. Worth it?

Posted: Sat Aug 03, 2019 12:08 am
by redefined_cycles
In reference what Alpinum said above regards 'ride on with damaged/missing spoke'.... i too noticed that aswell on my Dura Ace wheel. Broken spoke on a 20 hole count rim. Carbon with some alloy lining for the brake tracks. Amazing how the stiffness of the rim allowed me to just keep riding :-bd

Not saying the price is justified but for me it was as I always get 2nd hand and refurb.. In the case of these DA they just needed a little rebuilding (a real pain with DA spokes as the spoke keys are a bit special and tendency to round off at the gripping bit for the flat spokes) and I got 1k worth of wheels for less than £200...

So... maybe try and find some used fleabay deals? Definitely carbon rims are tough as owt (unless you start going down the ultralight routes at which point you might suffer rim-edge damage if putting a supertight tyre on whilst using levers!

Re: Carbon vs alloy wheels. Worth it?

Posted: Sat Aug 03, 2019 12:10 am
by redefined_cycles
Alpinum wrote: Fri Aug 02, 2019 11:14 pm
htrider wrote: Fri Aug 02, 2019 10:47 pm Must admit I've been idly eyeing up carbon 29+ rims, suckered in by the 400g weight saving but still not convinced how rock proof they are... (or, crucially, how idiot proof they are)
In my experience more than alloy.
See if you can find rhe Danny Mcckaskill vid where he tries to total some carbon rims sent him by Santa Cruz... Manages to total them but only after removing tyres and then jumping and riding down lots of steps over and over... (granted they were SC but still... mrb rims would be build pretty darn strong anyway I'd imagine)...

edit https://youtu.be/VfjjiHGuHoc

Re: Carbon vs alloy wheels. Worth it?

Posted: Sat Aug 03, 2019 8:03 am
by ScotRoutes
Not for me. I don't consider it an affordable upgrade.

Re: Carbon vs alloy wheels. Worth it?

Posted: Sat Aug 03, 2019 12:50 pm
by fatbikerbill
cheers all, especially alpinum, I'll keep looking & considering.

Re: Carbon vs alloy wheels. Worth it?

Posted: Sun Aug 04, 2019 11:31 pm
by Jurassic
I ran carbon rims on my fat bike and dinged the side of the rear one on a rock which led to it eventually delaminating catastrophically. I'll never run them again for offroad use tbh. I think that rims are just too exposed to impacts from the side and whilst I'd agree that they are super strong up to the point that they fail, the cost of replacements compared to alloy rims just makes them not worth the money for me.

Re: Carbon vs alloy wheels. Worth it?

Posted: Mon Aug 05, 2019 6:48 am
by Alpinum
Jurassic wrote: Sun Aug 04, 2019 11:31 pm I ran carbon rims on my fat bike and dinged the side of the rear one on a rock which led to it eventually delaminating catastrophically
Is it the gel coat or lay up that's delaminating?
What manufacturer?

Aren't there any possibilies to have it repaired professionally in your area?
Or even cheaper - DIY.

Re: Carbon vs alloy wheels. Worth it?

Posted: Mon Aug 05, 2019 11:40 am
by Jurassic
Alpinum wrote: Mon Aug 05, 2019 6:48 am
Jurassic wrote: Sun Aug 04, 2019 11:31 pm I ran carbon rims on my fat bike and dinged the side of the rear one on a rock which led to it eventually delaminating catastrophically
Is it the gel coat or lay up that's delaminating?
What manufacturer?

Aren't there any possibilies to have it repaired professionally in your area?
Or even cheaper - DIY.
Not now, it's in a skip! :lol: It delaminated and split through approximately 2/3 of the width of the rim, I didn't notice the damage initially then tried to bodge it myself but it was too late. Rim was a Nextie 80mm, cheap by carbon standards but not cheap by alloy rim standards. I have heard of delam issues with other Nexties as well (one being a 90mm rim belonging to a friend) so maybe they're best avoided?

Re: Carbon vs alloy wheels. Worth it?

Posted: Mon Aug 05, 2019 6:11 pm
by Alpinum
Ouch :sad:

I can ask a friend who helped design the Nextie Fatbike rim, perhaps he can share some insights.

After such an experience I'd be hard to convince other wise...

Some of my rims come from the KHS factory and have the exact numbers like some Lightbicycle offerings and some were bought from LB.

Been great so far.

Re: Carbon vs alloy wheels. Worth it?

Posted: Mon Aug 05, 2019 6:22 pm
by Jurassic
Alpinum wrote: Mon Aug 05, 2019 6:11 pm Ouch :sad:

I can ask a friend who helped design the Nextie Fatbike rim, perhaps he can share some insights.

After such an experience I'd be hard to convince other wise...

Some of my rims come from the KHS factory and have the exact numbers like some Lightbicycle offerings and some were bought from LB.

Been great so far.
I don't think any amount of good design would mitigate against a big side impact from a rock, the same impact would almost certainly bend/dent an alloy rim. Kudos to the carbon rim appearing initially to be pretty much undamaged (I don't think an alloy rim would have remained round and true under the same circumstances). The problem arose from me thinking that the small mark on the rim was purely cosmetic and not getting it checked out properly straight away. I continued to ride the wheel and the crack and delam deteriorated to the point that the rim was scrap. I'd have carbon rims on a road bike but I'm going to stick with alloy for offroad from here on. You pays your money....................

Re: Carbon vs alloy wheels. Worth it?

Posted: Mon Aug 05, 2019 6:46 pm
by Alpinum
Ah, okay, that doesn't really sound like it was a manufacturing issue.

Did you feel a soft spot?

Usually, when I check my bike and see new damage, I check if there's a soft spot. If not, I don't do any thing about it.

Re: Carbon vs alloy wheels. Worth it?

Posted: Mon Aug 05, 2019 7:08 pm
by Jurassic
Alpinum wrote: Mon Aug 05, 2019 6:46 pm Ah, okay, that doesn't really sound like it was a manufacturing issue.

Did you feel a soft spot?

Usually, when I check my bike and see new damage, I check if there's a soft spot. If not, I don't do any thing about it.
No, it wasn't a manufacturing issue, the front wheel is still fine (relegated to a spare). There was no soft spot initially and by the time one developed it was too late. If I was in the same situation again I'd probably be able to save the wheel by realising what was going on earlier, hindsight and experience are wonderful things. Hopefully somebody else reading this might avoid making the same mistakes that I did and realise that even apparently cosmetic damage can actually become structural if it's not checked out immediately. :oops:

Re: Carbon vs alloy wheels. Worth it?

Posted: Mon Aug 05, 2019 7:50 pm
by Alpinum
Well, thanks a bunch for sharing.
Jurassic wrote: Mon Aug 05, 2019 7:08 pm Hopefully somebody else reading this might avoid making the same mistakes that I did and realise that even apparently cosmetic damage can actually become structural if it's not checked out immediately.
That's why I've been asking.
I'll surely draw from your experience :-bd

Re: Carbon vs alloy wheels. Worth it?

Posted: Mon Aug 05, 2019 9:41 pm
by Escape Goat
I use carbon wheels on 2 bikes. One road bike, one gravel bike. Weight isn't my thing, but, they are stiff! Really does transform the bike. :wink:

Re: Carbon vs alloy wheels. Worth it?

Posted: Wed Aug 07, 2019 10:36 pm
by Mbnut
It's rare I have a different stand point to Alpinum but in this I do.

Having cracked 3 carbon rims in one year I went back to alloy.

I found carbon rim damage meant I could not continue to ride whereas I have not experienced a catastrophic alloy rim failure some many years.

As with all things biking it depends on what you are riding and how.

On my rigid bike packing iron horse I currently have some old LB carbon rims, they are doing a Stirling job but I tend to nurse the bike on rough ground to protect the Thunder Burts. That said both rims and tyres have been terrific, hope I haven't just jinxed myself.

On the Enduro I run Flow Mk3s in 32 hole. I have a Vittoria Airliner in the rear and run a 2.35 SG Rock Razor. Up front a Huck Norris inside a 2.35 Magic Mary. Both have double the recommended amount of Stans Race Fluid in.

I expect to get a year out of each tyre, which is around 3000 miles worth of riding and around 400000ft of descent.

My current Flow Mk3 wheelset has done 2 years almost exactly with 3 new spokes due to breakages that made no difference to the wheel the odd tweak with the spoke key.

I cannot see me going back to carbon anytime soon.

Interesting to hear happy carbon rim stories though.