I just bought a Trek 7.3 FX trail bike and am looking to upgrade the front fork to carbon.
The trek website lists the steerer diameter as 1 1/8 diameter and length of 335 mm.
I see several forks advertised with the same diameter but slightly greater length. Will this still fit? I will let my LBS install it for me. What about offset? Is this the same as rake? I think probably not but the offset on the advertisements is often missing. Is this important?
Any information is appreciated.

The rake is pretty much determined by the headtube,not the fork. Well,unless you're going from a curved fork to a straight blade. The steerer tube length listed for the forks is uncut. They're always long so they can fit a variety of bikes. The shop will cut it down to the proper size.

What fork do you have in mind?
I have a 7.5 FX, and am thinking of the same upgrade.

I don't consider changing from cromoly to carbon an "upgrade." I've heard of and seen many shattered carbon forks. I've never heard of or seen a shattered cromoly fork.

A shattered fork can cause a fatal accident (there's at least one thread here in bikeforums about a fatal accident when the carbon forks shattered), and if it doesn't you're almost certainly going to do a face plant, with accompanying severe injuries. If it was me, I would keep the cromoly fork.

That's my opinion. Of course, other people may have their own opinions.

7.5 FX has a carbon fork already. At least the 2007 models, did older models not have a carbon fork?

That's scary. How common is this? And does the likelihood of it happening depend on what brand and/or build of carbon fork? I'm not too concerned about it happening unless I dump the bike in an accident and it develops an undetectable structural weakness as a result.

I don't know how often, but I do know it happens. I just heard about another one just this week.

And that thread about the cyclist who died is somewhere here in bikeforums. In his case, he had been in a minor crash the week before, and it created stress fractures in his forks. He didn't inspect his forks for stress fractures after the crash, which you should always do. He was on a steep, fast descent when his forks shattered, and he went over the bars and did a full face plant at speed. DOA.

I'm not sure.

That's when you need to have it thoroughly checked out.

I was thinking about a

Kinesis Crosslight EVO Carbon Cyclocross Fork
which has a 1 1/8 steerer tube, and is full carbon so it only weighs 485 gms. It also has the required brake mounts and since it is for a cyclocross bike must be hefty enough for road use. And it has the vibration dampening features of carbon.
What do you guys think? It my be overkill on this bike, since it costs almost as much as the bike did.

Definitely overkill.

Chromoly forks come in all types and Flexes. One of the Best steel forks around is the Kona- Project II. Not ultra expensive and This is one fork that comes in a variety of thicknesses for Flexability and Different brake mount systems for disc or V brakes. Pretty light too- but if you want real upgrade- Then hunt out a dealer for these and save LOT OF MONEY.


As to C.F, Forks breaking- This is rare and many of the Stock C.F. forks are overmade. They night aswell be solid C.F.- will not be light- Will not be Flexible and will not break. Might aswell stay with Steel.

Switching would NOT be an "upgrade". The fork that came with your bike was designed to provide optimal fit, handling, and ride qualities. If you bought the carbon fork that Trek uses for your same frame on different models, it would be a "side grade"...good handling, but less protection against damage.

Carbon forks originally became popular on racing bikes, because of a modest weight savings. Then, marketing "guru's" figured out that folks who will NEVER race assume that if something is on a racing bike, it is a "superior" product, and worth a higher price. So, they began putting carbon forks on bikes that are NOT race bikes, degrading the usefulness of the bike, but providing an excuse for raising the price.

Today, because carbon forks are on virtually all road bikes selling for more than $600 or so, cheapo carbon forks are made in "cookie cutter" fashion in Asian factories. At the wholesale level, many of them are really cheap ($20 or $30), a reflection of their "quality".

The best material for a bike fork is steel. Steel bends under mild stress, and then returns to its normal position. Under severe stress, steel will bend even more, but it can later be realigned. When a carbon fork is stressed beyond its limits, it does not bend...it simply snaps like a pretzel.

As others have said, save your money, a carbon fork is definitely not an upgrade.