Carbon forks? - maybe not then....

[Croydian]

I've recently been in a similar conundrum of whether to opt for carbon rigid forks as I have never got on with front suspension. In the end I've decided not to bother as I have felt very unsure of carbon seatposts and bars in the past. To the point I changed back to alloy. I'm picking up a pair of Cannondale Fatty R forks tonight basically because I like my Cannondale P-bones so much. After reading the reply about the Pace bonding/twisting issues I'm sticking with alu!! The fact that Cannondale fitted then to their MTB tandems is proof enough they'll be plenty strong enough.

 

[letmetalktomark]

I've also heard that weight limits (rider weight) should be considered when considering carbon forks.

I'll correct if wrong but dont RC31's have a 95kg rider weight limit? :?

At 15 stone ( rugby player ) I just could not have confidence in a carbon fork/bar for offroad use - and I'm a smooth rider :?

There are a whole selection of nice 26'' disc forks around that could run a 29'' wheel ( dependant upon a to c)

M

 

[steveslow]

The crash you describe is the sort of thing I'm sure we've all done dozens of times. I had a similar incident only last night! It's very worrying that an MTB product isn't capable of taking that sort of light punishment without breaking.

 

[Anthony]

Some of this may be unfair to carbon. It seems like a Pace issue rather than a carbon issue per se.

Messiah’s misfortune involved Pace bonding, and there’ve been problems with Pace bonding since the dawn of time and they’re just as likely to affect suspension forks as rigids. I thought Pace were generally pretty good about it, but maybe not so good now under their new owners.

As far as carbon in general is concerned, designers don’t specify a fork to be ‘silly light’, or to fail under an impact that a steel fork would survive, or anything like that. All parts are designed up to whatever strength factor is needed, and carbon forks are lighter than steel ones purely because, weight for weight, carbon is stronger than steel.

 

[Andy R]

Some of this may be unfair to carbon. It seems like a Pace issue rather than a carbon issue per se.

Messiah’s misfortune involved Pace bonding, and there’ve been problems with Pace bonding since the dawn of time and they’re just as likely to affect suspension forks as rigids.
All parts are designed up to whatever strength factor is needed, and carbon forks are lighter than steel ones purely because, weight for weight, carbon is stronger than steel.

I do agree with this - the bonding of the carbon legs to the aluminium crown and dropouts is potentially the weak part of the whole design, that and the fact that there is always potential for problems when joining two materials of differing flexibility characteristics.

Where carbon composites really come into their own is in monocoque construction where these things aren't an issue and best advantage can be taken of the material properties.
Tintin's Ritchey WCS forks ( well, the ones he mentioned, I mean !) are a good example of this of course, and I think it would be very reasonable for a user to have a lot more faith in these than in a typical carbon/alumium bonded fork.

Not something I'll have to deal with though as they are too short for me (410mm) and far too expensive (£315) too. As with anything, you get what you pay for of course, and for an uber light race machine I'm sure they'd be the business