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Cutting fork and seatpost(19 posts)

Cutting fork and seatpostbear
Nov 10, 2001 4:33 PM
I am going to be cutting a carbon seatpost and a alum fork . So what are some of the nots,,, and dont give be " go to the LBS" ok this bike is being build by me and no one else,,is my winter program and therapy.

pipe cutterdenti
Nov 10, 2001 5:13 PM
i have cut many alum. steer tubes with a cheap pipe cutter it also keeps it square, as for the carbon post the shop just cut mine with the park steer tube tool that keeps the hacksaw square when cutting,they did use a hacksaw, and i am more than happy. i am glad to see someone doing there own work i should have done the same have fun
NO, NO, NO!!!!!!peloton
Nov 10, 2001 9:04 PM
Do not use a pipe cutter on a carbon fiber seatpost or even an aluminum steerer. A pipe cutter exerts force on what it is cutting, and this can compromise the integrity of both a carbon seatpost and an aluminum steerer. Use a hacksaw, and you will be much better off. There is less fatgue on the material, and less chance of failure. Pipe cutters are great, but this is not the proper implementation of one. Use a hacksaw.
re: NO, NO, NO!!!!!!denti
Nov 11, 2001 10:40 AM
i did not mean use the pipr cutter on the carbon seatpost, but on the aluminum steerer if you are careful you will have great results and it is very square,i personally have done it this way many times and have yet to have a problem. you are right though, do not use a pipe cutter on carbon sorry for any confusion i my have caused
re: NO, NO, NO!!!!!!peloton
Nov 11, 2001 12:01 PM
If you ask a lot of experienced mechs they will also tell you to not use a pipe cutter on an alloy steerer as well. The force of the pipe cutter being tightened can create stress within the alloy and make it more predisposed to early failure. Alas, you will see some mechs that use the pipe cutter as it does cut very clean. It is better though to just use a hack saw and clean it up with a file if need be. You don't want to do anything to the steerer that could weaken it structurally and put yourself at danger. I used to use a pipe cutter myself, but some far more experienced mechs advised me against the practice for the above reason.
don't use a pipe cutterTheMaxx
Nov 12, 2001 9:15 AM
Pipe cutters don't work well for cutting steerers or seatposts. A pipe cutter pushes the metal apart and leaves a ledge at the end of the tube, so you will have trouble getting your stem on to the steerer. Even if you do this carefully, it will still leave the ledge.
For Carbon, I've used a hack saw with a composite cutting blade and it worked great. The blade is cylindrical, and you can get them at most hardware stores. The only problem is the blade is wider than normal so it won't fit in a Park steerer cutting jog.
re: Cutting fork and seatpostRui
Nov 11, 2001 12:13 PM
what about using a water jet?? not is has been employed in some industries to cut steel and some fibers.
simple and effective ?Cyclorocket
Nov 11, 2001 4:34 PM
I simply draw my line with a pencil on the steerer,
My father was holding the fork (at the botom of the steerer)
I took electrik saw...and cut slowly
Pretty simple
Very effective

If you got a water jet saw at home, well meaby you can try but has far has I'm concerned most people don't have these kind of machines !

Good luck (even there is luck involded in this situation!)
simple and effective ?Rui
Nov 15, 2001 2:33 PM
I am talking about a machine that works as a laser beam. it is employed to cut sheet metal and some fibers. maybe if you have some furniture industry near to you, they could help you. laser is also employed to cut metal. nowadays it is a common situation. it takes seconds to make a lot of cuts.
simple and effective ?grzy
Nov 15, 2001 2:54 PM
Gotta think about exactly how the laser cuts and what kind of a finish is achieved. Burning the CF/epoxy matrix isn't commonly done in industry. Resulting cut isn't that smooth. having the laser cut through one side of the tube and blow into the other may not be such a good idea. I'd say it would be best to verify the process results before you advocate a novel approach. Also, the local hardware store and bike shops are still waiting for their frirst shipments of affordable home owner industrial lasers.

Honestly - what's the point of trying to find some high tech shop to cut your steerer witha laser? Might as well buy a flame thrower to kill house flys (it's really effective, but a little tough on the carpet).
simple and effective ?Rui
Nov 16, 2001 4:55 PM
don't worry because it won't melt the fork. the process is so fast that that the temperature won't increase to scary values. it is a process that is not usuall to see, but it's faster than you could think. the finish is 10 times better than a hacksaw. when it is employed with sheet metal probably it won't be need not even a sand paper.
if you want the easy way talk to a plumber. not joking.they have a method that is fast, cheap and clean to cut the pipes.
re: Cutting fork and seatpostbrider
Nov 12, 2001 9:51 AM
Check out the Slowtwitch site for recommendations on cutting carbon. They talk of carbon steerer tubes, but I would imagine the same would apply to a seatpost.
Try using an axe!! (nm)Rusty McNasty
Nov 12, 2001 11:32 AM
Nah, Chop Saw!! (nm)grzy
Nov 12, 2001 12:21 PM
Nah, Chain Saw!! (nm)mnky
Nov 12, 2001 12:32 PM
Nov 12, 2001 9:33 PM
The Texas Seatpost Chainsaw Massacre

They lured bikers to stay in the Dew-Bike-Inn, but had no intention of ever letting them go with their bikes intact. It was a horrible sight when the bike police arrived. Bikes of all types slung around with their seat posts sawed off with the chain saw. Look's like a Poulan 24 inch bar 4CC chain saw, the one cop said. Yeah, sure weren't no Stihl said the second cop? Nope said the first. Well, how can you tell? There. Where?. There, under the hedge. Oh! Hay that's good detective work! What's that sack with the holes for the eye's and nose? Albertson's. Oh yeah, guess it is. Hey, whodunit? Don't know yet but first we'll check for the wankers. Yeh, good idea. Yeah. Yeah.

Nov 13, 2001 7:28 AM
Just cut the darn things with a fine tooth hacksaw. I've probably done this 20 times now with no problems.

It's not so much important HOW you cut, as WHERE you cut. Believe me.

hey dogpeloton
Nov 13, 2001 1:01 PM
I'm looking for a Colnago earth paint job fork with a really short steerer. You know where I might find one?
(In person, this would be said in a friendly, joking tone) ;)

It IS more important where you make the cut. Measure it, then measure it again. Then just do what dog says.
re:hey dogdenti
Nov 13, 2001 5:38 PM
even i agree with that