I picked up a new frame yesterday that came with a fork with a carbon steerer that I need to trim down. For those in the know - can I just slam on the crown race like I do with any other fork? And I'm assuming a hacksaw works best for cutting? I kinda doubt that my tubing cutter will work well. :lol:
Get a blade with a finer tooth then what usually is OEM on the saw. If you really want to be safe you can buy a blade designed for CF, I have used a Perma-Grit Tungsten blade and it works nicely. You should be able to pick up a "material specific" blades at the local hardware store. If you can't find one then your LBS can order a Park Took hacksaw with a fine blade for CF.
I've read it's advised to wrap the tube area where you will be cutting with tape. I don't think the type of tape is important; electrical maybe. This will help with splintering of the carbon when cutting through the other side.
You should do this with an abrasive style blade. Tooth profile stuff is not recomended at all.I have been building carbon and using it for years and sometime or another you will wish you did not use a standard hacksaw blade. Abrasive blades use diamond and cut so smooth , no splinters ever. Food for thought.Also make absolutely sure the compession wegde is used or cracks will develop.
I have the advantage of a carbon specific blade here on our band saw, but I have cut them with reg hack saw blades before, it just dulls the heck out of them quickly. Regarding star nut. I have never used one on a carbon steer before. I always use a carbon specific expander-type insert. I assume if you mar carbon with a star nut you weakening the structure. Not something I want to do to a carbon fork. Install the crown race like normal
I'm not a fan of carbon steer tubes. I'd rather have the reassurance of aluminum. If it were me, I'd pull your fork before cutting it, and put it on e-bay. Take the proceeds and buy one with an aluminum steer tube. Carbon has it's place but not for steer tubes IMHO...
Steerer tubes are a fine place for carbon. For one thing, only the OD is restricted, so they can make the layup as thick as they want. They're usually THICK. For another, carbon's weak point is impact resistance, and the steerer is well protected in that regard. Sure, if you plow your front wheel into something at speed, you'll be likely to break the steerer, but with an aluminum steerer you're just as likely to break something, it just may be a fork blade or the frame's head tube. An irresistable force meets an immovable object, something has to give.
what about the ID? isnt that where a star nut goes? forgive my ignorance if it is different than a mtb
Do not use a star-nut on a carbon steerer. You need a compression plug. Star nuts are designed for metal steerers and can damage/weaken a carbon steerer since you're "forcing" it down the steerer. Compression plugs expand out when you tighten the bolt/cap
that makes waaay more sense. cool. Thx for the info ID still has to be controlled for a "compression plug" then too. good stuff
As far as road bikes are concerned, pro teams use them on all the classics. We used carbon steer & drop outs on the Garmin/Slipstream Perris-Roubaix forks as well. Those cobbles are hell on a lightweight steer tube.
You're thinking about it wrong. The ID can be whatever they want it to be, they just then make an appropriate compression plug for it. 1.125 was a standard, so they stuck with that (until the advent of tapered anyway) but pre carbon steerers, there weren't carbon compression plugs. So they could do the layup however thick it was needed, and then make the compression plugs the right size to fit. Carbon steerers are a LOT thicker than Al or steel ones.
Some newer road forks such as Easton's EC90 series have a very stout steerer. It appears as though they internally sleeve the steerer with a threaded section to make tightening the top cap/steerer assembly easy and consistent. you have to use the included steerer plug but it works well. Most compression plugs have such a wide range that they can accomodate most steerers out on the market.
My Intense has a carbon steering tube with an aluminum crown. If it can put up with my fat ass on it, all y'all should be fine. (yes, I just ya'lled you and I'm English, got a problem with that? Incidentally I have a spare compression plug kicking around if anyone needs it.
You can debate it either way but one thing to consider is the junction between the carbon blades and aluminum steerer as apposed to a one piece carbon fork. Since the Aluminum has to be set in the carbon there is more chance of it seperating. A prime example was the fork used on Hincapie's bike a few years ago which the aluminum separated from the carbon. Granted an earlier crash was believed to cause the weak spot. :beer:
