Carbon Mountain Bikes

[Peter10]

Hello all,


I have ridden mountain bikes most of my life before converting over to road bikes earlier this year as I hardly (if ever) did any actual of road riding. I want to get back into it and have been doing a little bit of research into a new bike. I keep seeing people saying carbon mountain bikes are a big no-no and should be avoided. Is there any reason for this or is it preference? I know someone with a carbon MTB (Bianchi Pulse) and he loves it, but the guy in my LBS said they should be avoided.

I probably can't afford a carbon MTB anyway, but wanted to ask what is the issue with them?

Pet.

On a side note, rather than starting a new thread, who are the main players in MTB's (as in do a good range of entry to top end bikes?). Seems every man and his dog sells a MTB these days.

 

[Globalti]

I'm in the same position as you; I rode MTBs for 22 years but went over to road riding 18 months ago and haven't done more than two MTB rides since. Recently though, I tried somebody's Specialized carbon MTB around a car park and it felt absolutely sublime to ride.

The reason why carbon is mistrusted for MTBing is that it is extremely strong and light as a structural material but has very poor resistance to knocks, so if you fell off your carbon MTB (which you inevitably will) and clouted a tube on a rock it could break the resin that bonds the carbon weave, in which case it becomes something like wet cardboard, probably still very strong but a bit floppy.

 

[lukesdad]

Had my scott endorphin 10 years still going strong.

 

[Kestevan]

Some people have an inate distrust of carbon fibre.

They believe that one night they will come home and find that the carbon fibre has turned to cheese and their bike has melted.

 

[Tim Bennet.]

but has very poor resistance to knocks

Is that why they use it for the safety cell in racing cars and boats? Do the drivers walk out unscathed because the resin that holds the weave has broken away? What a load of cobblers!

A carbon fibre structure can be as strong as you like. If it weighs the same as aluminium or titanium then it will be many times stronger and stiffer. Any blow strong enough to break a carbon tube will be enough to totally bend or snap a tube in other materials.

However because carbon is so strong and stiff it allows designers to reduce (if they choose!) the wall thickness and make it as light as possible. A similar weight would be impossible with metal tubes as the wall thickness would be so thin it would fail strapping it to the bike rack on the way to a ride.

And don't get hung up on its mode of failure either. If you have two tubes of the same weight, the forces that will buckled and catastrophically destroy a steel tube will be shrugged off by a carbon tube because it will be massively over strength. If you make a steel tube the same weight as an adequately strong carbon tube, the steel tube will be so thin you could crush it in your hand. Lightweight carbon parts fail because they have been engineered to pander to weight weenies, but they're still way stronger than any other material of the same weight.

Carbon can deliver massive strength at reasonable weight (Car safety cells) and adequate strength at very light weight. By wisely to get what suits your needs and you'll be happy.

 

[Rammylad]

Don't know much about the science but love my Scott Scale which i use for events as its so much lighter and responsive than my full sus Trek.

 

[ColinJ]

I always felt a bit worried about CF mountain bikes. That's probably a bit illogical,given that I have been perfectly happy riding my Cannondale road bike which has CF forks. Having said that, I received a message on Thursday from someone who got pretty badly hurt recently when the front of his CF mountain bike suddenly snapped clean off - there's that catastrophic failure mode in operation!

 

[02GF74]

s. Having said that, I received a message on Thursday from someone who got pretty badly hurt recently when the front of his CF mountain bike suddenly snapped clean off - there's that catastrophic failure mode in operation!

isn't there a post on here, some forest trip - Dalby? where a steel frame bike snapped in two?

this catastrophic failure mode is not limited to just carbon fibre.

there is always restistance to change; back in the day when aluminium alloy frames first came out, everybody was up in arms much in the same way yet you'd be very hard pressed to buy a top end road or mountain bike made from steel.

(I am biased ofcourse having recently bought a CF mtb but have been riding on CF posts and forks for some time)

 

[02GF74]

here is the post I referred to;
https://www.cyclechat.net/

 

[addictfreak]

Don't know much about the science but love my Scott Scale which i use for events as its so much lighter and responsive than my full sus Trek.

Isnt the Scott Scale fanastic!

I have one, probably the best MTB i have ever owned. Its mega fast even with my fat ass on it.

 

[Cubist]

OP, you ask about main players in MTBs. You need to define your needs. If you're talking about CF I assume that you are into XC rather than freeride!

Having said that teh following mainstream makes cater for all disciplines: Cube, Specialized, Giant, Trek, Genesis,. Halfords' Boardman and Carrera MTBs are excellent spec. Pinnacle at Evans, Decathlon at Decathlon, Focus at Wiggle, some good 'uns to chose from. Many many more, but a lot of same old same old among the exotica.

Get a copy of What Mountainbike, as they do a guide to what sort of bike you want for what sort of riding, and then a guide to what's good and what isn't so good.

Think of a budget and then add half again. Not for extras, but because whatever you think you want, then the next price point will be better......

Be hnest with yourself. If you want to ride on towpaths, you don't need a 800 quid bike. If you want to ride trails you won't get away with a 300 entry level bike with c rap forks.

 

[Banjo]

Have a look at this video of a guy doing stunts on a carbon fiber road bike.

View: http://www.youtube.com/watch?v=5z1fSpZNXhU

 

[BigmechUK]

Carbon cannondales are amazing! Super light and yet super strong! Bit expensive but worth the money.

 

[jonny jeez]

Hello all,


I have ridden mountain bikes most of my life before converting over to road bikes earlier this year as I hardly (if ever) did any actual of road riding. I want to get back into it and have been doing a little bit of research into a new bike. I keep seeing people saying carbon mountain bikes are a big no-no and should be avoided. Is there any reason for this or is it preference? I know someone with a carbon MTB (Bianchi Pulse) and he loves it, but the guy in my LBS said they should be avoided.

I probably can't afford a carbon MTB anyway, but wanted to ask what is the issue with them?

Pet.

On a side note, rather than starting a new thread, who are the main players in MTB's (as in do a good range of entry to top end bikes?). Seems every man and his dog sells a MTB these days.

Peter, I think you and I may have been separated at birth!

I am in almost the exact same position. I ride frequently on the road and do want a good ali frame road bike (as mine is sadly showing signs of age now) but having recently re-found my love of off roading so also want a new cross country bike. (santa's going to be busy this year I think)

I am "attracted" to CF just because it smells like quality but I am also resistant as at the end of the day, I am not a serious off road rider (I'm not out every weekend plodding out mile after mile) and am not the smallest chap in the world so the weight gain would be less beneficial to me.

Tim, I'm interested in your reply as it makes perfect sense...but what is the conclusion...is carbon "worth" the extra cash or is it just a gimmick to someone like me who rides off road around once a month.

Sorry to hijack your thread Peter

 

[jonny jeez]

Having said that teh following mainstream makes cater for all disciplines: Cube,

no surprise to see them top of your list Cubist ...I have to say, they are very pretty bikes and weren't a manufacturer that I had heard of until recently.