Dear hive mind: am currently toying with a purchase of a 650b boingy trail bike/E****o machine.

I like a bit of bling, and a chuckable light bike that can cover ground too – a carbon frame seems to add about a thousand quid in cost and save a pound or so in weight. (Fair?)

Opinions please: where’s best to spend money, on a carbon frame, or stick with ally and spend some extra on nice wheels and other performance parts?

Thx.

Usually a grand on kit will save way more than 1lb.

Weight is only one of the advantages of carbon, stiffness etc is worth a lot. Happy carbon owner here.

You can buy better kit later. Tricky to change the weight of a frame post purchase.

I agree, spend it on the frame, everything else can be upgrade when it breaks or deals are avaliable

I’m a tweaker so if I was sure I like the frame, I’d go carbon frame, then over time replace everything else. Then replace it all again probably, and again…

Weight is only one of the advantages of carbon, stiffness etc is worth a lot.

This ^
As a mech engineer working with carbon bits I would say that increased stiffness is worth a fair bit more than the weight saving. Think of the weight saving as an extra bonus.

How long do you tend to keep bikes for? I think I value carbon wheels over frame these days and make sure you are not scrimping on fork or shock. As for the rest of it stick deore or slx on if it means better suspension, frame and/or wheels.

Edit: but wheels are easily upgraded. So if you keep frames a while then carbon.

Depends if it’s good stiffness, though, not all bikes benefit from added Stiffs.

Depends if it’s good stiffness, though, not all bikes benefit from added Stiffs.

I think it’s safe to say increased frame stiffness is all good with a full susser. Obviously a bit different with a hardtail where you might want a degree of controlled flex in the frame at certain points.

With carbon it’s just easier for designers to make the optimum stiffness/weight trade-off. Carbon done badly is a disaster of course!

Nah, don’t agree. I used to have a 224 Evo, very unstiff as dh bikes go (my unscientific testing suggested it was more or less as laterally stiff as my titanium hardtail), it worked really well- bit of smear in the back seemed to add traction, especially when cornering, compared to my far stiffer Herb.

It’s more or less the same trip motorbikes did a few years ago- for ages, every motorbike wanted to be stiffer, til Honda put out the SP1 and suddenly people were removing chassis bolts and modifying the swingarm to soften it up. Now it’s all about stiff enough.

The trick is to effectively damp any “designer” flex you might decide to build in. I’ve been involved at a distance with Moto GP swingarms of varying torsional rigidity, but that’s a world away from removing chassis bolts!

Anyway back to reality, a lighter/stiffer carbon mtb frame would still be my choice over a relatively flexy alloy equivalent on a full suss trail bike. Is it worth £1K more? Probably not if you are on a tight budget and the rest of the bike spec (especially wheels) would have to be severely compromised to get there.

Thx all, good points.

How long do you tend to keep bikes for?

Anywhere between 15 years and 3 months, depends if I get on with them.

But any bike I buy I hope to be a keeper.