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I've been wanting to build a frame using a carbon ST and possibly HT as well. I've searched and the only source I've found is Rockwest Composites. I think I've heard that ENVE also has carbon tubing as well. Any other reliable sources I should look for?
Thanks.
Brandon
I know Nate Zukas does carbon seat tubes but I don't know how often he comes by here. You can get in touch with him via his website or IG.
Bikes and Planes go way back, the Wright Bros. shopped here.
https://www.aircraftspruce.com/categ...rbonfiber.html
There are plenty of companies that do roll wrapped uni tubing in a heap of different diameters and wall thicknesses/ layup schedules. The two you mentioned are probably the most popular. Google is a rabbit hole for suppliers.Quote:
Originally Posted by BigPoser
Rockwest and Enve are good places to start.
Why not make it yourself?
Roll wrapping a seat tube works well since there is no torsional stress on it.
A 27 mm aluminium round bar plus a layer of 0.5mm polypropylene makes an excellent mandrel for a 27.2 ID seat tube.
Carbon is hell on tools, I always have a base layer of something that is easy to work anywhere you are going to do so such as the top half of the seatpost and both ends of the headtube. I use the perfectly wonderful BioMid recrystallised cellulose for this but there are other materials available.
Easy composites in the UK have a good video on roll wrapping:
https://www.youtube.com/watch?v=vqlR74PlVgM
Headtubes are a little more difficult since they do have torsional stress on them, you could do a roll wrapped base tube then add some layers at 45 / 45. UPVC plumbing tubing (plus polypropylene layer) makes an OK mandrel for a head tube but it cannot be used at high temperature.
Lastly, make sure you use a good quality laminating epoxy, not a boat building epoxy (eg West System), the difference is night and day. I use Kinetix R246 but that's an Australian brand, find something local and look for a high glass transition temperature with elevated temperature post cure.
Assuming a controlled temperature curing oven is a bit of a stretch, you can achieve the post cure by leaving the tube in the car on a hot day.
Advanced version: if you re-arrange the layup at the top of the seat tube to minimise the carbon fibres in the hoop direction you can make it so it compresses under the seatpost clamp sufficiently to hold the post without being slotted. It took me a couple of goes to get this right but it is now my standard technique
Thanks everyone. I've been in touch with Rockwest as well as Origen who bought all of ENVE's tubing and tooling.
For those of you that have done this, what do you use for your water bottle bosses?
I use rivnuts with a carbon support. I hole saw a round offcut off a tube and bond to downtube and seat tube as the support then fix in rivnut. You can also just layup some extra carbon where you are going to place your bottle cages.Quote:
Originally Posted by BigPoser
Ah ok. I figured I could use stainless rivnuts but thought it might okay to use epoxy, then rivnut.Quote:
Originally Posted by progetto
Would that not be adequate?
Probably but I like the extra security of some beef in the tube in case of accident damage from a crash.Quote:
Originally Posted by BigPoser