Are carbon rims for mountain bikes worth the splurge?

Today’s quality carbon rims for mountain bikes will cost anything from R4 000 to R10 000 per rim. Yes, that’s without the hubs and spokes and wheel builder’s labour cost. Extrapolate this and typically you’ll easily pay R20 000 or more for a decent set of mountain bike wheels built up using carbon rims. Now compare that price to alloy rims. Good quality, light, strong, stylish metal rims from some of the world’s premium manufacturers hardly, if ever, exceed R2 000 per rim – and most will cost around R1500 or less.

So what’s the real difference between the carbon and the aluminium rims?

Weight. There’s about a 100g per rim difference. Assuming the same spokes and hubs are used in the building of said wheels, there will be a, a 200g difference in the wheelset. That’s like 4 sips from your bidon.

Strength: A bit trickier to quantify, but in a severe impact, both alloy and carbon rims will be damaged beyond repair. In normal use, a carbon rim has a higher limit of material elasticity, so it’ll probably not buckle like its metal counterpart. An alloy rim will also bend, but will probably stay that way.

Width: No difference. Alloy and carbon rims are now both freely available in the more popular wider sizes, from 24-32mm wide between the bead hooks.

Is there a logical argument in favour of carbon rims over alloy for us mere mortals?

The weight saving is small and by spending the premium on other areas of your bike you’re likely to cancel the difference. By buying alloy you can save at least R4 000 – and with that you can upgrade other components of your bike to make it lighter, or other things to make you faster.

A dropper post costs about the same as the money you’ll save by going with alloy rims. That’ll make you a lot faster in the technical stuff. What about a fancy new wide-ratio cassette – that may get you over mountains with less effort than riding carbon rims, and will also cost you R3-4 000. Lighter weight parts like carbon cranks can save up to 500g compared to a more stocky alloy chainset. Push me and I’ll list skills courses, aimed at improving your riding ability. What about a professional bike fit? It’s a long list.

Yes, cycling is our passion, hobby and lifestyle. Just like nobody needs to drive a BMW or Porsche, we like to have nice things and spoil ourselves. So if you want carbon. Just get em. I will still build them for you 😉