Carbon fork on MTB.

[Brandane]

I have a 6 year old Trek 6500 which WAS fitted with Manitou Axel suspension forks. I found them to be heavy, and as I mostly use the MTB for forestry tracks rather than what it was really intended for, the suspension forks are also unnecessary (apart from the occasional visit to the 7Stanes centres, for which the forks will be swapped over again).

I decided to replace the standard fork with a carbon one, from carboncycles .
Having now fitted it, I am really pleased with the result. It looks smart, performs well and has shed about a kilo from the weight of the bike. Only thing I am concerned about is the flex when braking! The bike is fitted with Shimano Deore disc brakes with a 160mm rotor. The amount of flex in the fork when braking is quite alarming, and obviously means the front brake is not as efficient as it was before. That doesn't bother me too much, but I am slightly worried about how much flex the fork can take before it breaks. I am assuming that the manufacturers will know what they are doing, and it will have been tested to much higher limits than I am ever likely to put on it; or am I placing too much trust in them?

 

[lb81]

I have a 6 year old Trek 6500 which WAS fitted with Manitou Axel suspension forks. I found them to be heavy, and as I mostly use the MTB for forestry tracks rather than what it was really intended for, the suspension forks are also unnecessary (apart from the occasional visit to the 7Stanes centres, for which the forks will be swapped over again).

I decided to replace the standard fork with a carbon one, from carboncycles .
Having now fitted it, I am really pleased with the result. It looks smart, performs well and has shed about a kilo from the weight of the bike. Only thing I am concerned about is the flex when braking! The bike is fitted with Shimano Deore disc brakes with a 160mm rotor. The amount of flex in the fork when braking is quite alarming, and obviously means the front brake is not as efficient as it was before. That doesn't bother me too much, but I am slightly worried about how much flex the fork can take before it breaks. I am assuming that the manufacturers will know what they are doing, and it will have been tested to much higher limits than I am ever likely to put on it; or am I placing too much trust in them?

I very nearly bought some but ended up with some Aluminium Kenesis ones instead. I have carbon forks on my CX though and ride it down some pretty harsh trails without issue. My guess is they will deal with pretty much everything your likely to throw at them. A quick search on Google when i was considering them found a few reviews of them being ridden over pretty harsh terrain!

 

[02GF74]

i feel you dilema - have you contacted the manufacturer?

the flexing *may* be part of the design, as cannondale do this on the carbon chainstays of the Scalpel to give it rear suspension.

 

[Globalti]

Don't worry about it; I've got a Carboncycles eXotic carbon fork on my hardtail for the same reason as you - we managed for years without suspension and with stiff steel or aluminium forks and this is lighter and smoother riding than any of them. I only miss suspension (I sold my Rebas) on big hits like kerbs or steps. There is indeed a lot of flex, easily an inch or two if you rock the bike with the brake applied but you can also endo the bike - i.e. brake hard enough to stand it on its nose and the fork is more than strong enough. If there was no flex the fork would be rigid and would beat you up.

Most people have no idea just how strong carbon components really are!

My carbon Roubaix road bike has bendy rear stays and you can feel them flexing when you ride over a rough surface. With a deep profile tyre fitted the tyre has even contacted the unerneath of the brake stay as the stays flexed. The only problem with this much flex is that bike paint and lacquer is thick and brittle so you get witness cracks at stress points, which really alarm people!

 

[Brandane]

Don't worry about it; I've got a Carboncycles eXotic carbon fork on my hardtail for the same reason as you

That is what I was hoping to hear; thanks. I will be able to brake with a bit more confidence now!