Carbon Fiber Seat Conversion - notes only

Hi all,

Had to add that “notes only” comment before I got chastised about not posting pictures. My excuse is that I didn’t have the digicam on hand and needed to get the job done quickly.

Last week, I did a jump mount onto my uni, landed on the front part of my Miyata seat and folded the seat in half. It didn’t crack or break the plastic base but caved inward the side rails of the seat base just front of the seat post. When I disassembled the seat, I found that I had also bent down the curved plate on top of the seat post as well as broke the thin metal plate on top of the seat into three pieces. Enough of a manufacturer’s fetish with plastic, time for Carbon Fiber.

My CF base arrived this week and I went to work. The base comes with a computer-generated layout for hole drilling which I cut out and taped to the top of the base. Roger and John of fame are correct, the carbon fiber material IS very easy to work with. I wish the folks at my office were carbon fiber.

I have the old style Miyata seat with an old style Roach cover. Some of the Roach seams were coming loose so I had to do some sewing and used upholstery thread. Someday, I’ll make a great housewife.

I center punched all holes then drilled the seat post holes back a bit further than the layout called for (about 1/4") so the seat would sit forward a bit more. Once the seatpost and bumper holes were drilled, I drilled the hole for the inner tube valve stem taking care to temporarily install the rear bumper for proper valve stem hole placement. A bit of filing later and the edge of the hole was smooth and wouldn’t cut through the valve stem. Then with both bumpers temporarily in place, I ducky taped vinyl hose along the edges of the seat’s side rails to protect my dainty hands during side seat grabs.

After carefully bending seat post top plate back into shape, I thought it wise to use a bit of old inner tube rubber between the carbon fiber base and the seat post top plate. For some reason, I didn’t want to have metal to carbon fiber contact. Maybe the thin film of rubber will prevent a stress crack someday, maybe it’s of no use whatsoever but it made me feel better.

I’ve installed my Roach seat cover in the past on my old plastic Miyata seat without clamping the nose and rear of the cover into those little metal clamp thingys underneath and found that, over time, the front and rear of the Roach cover work their way out from under the bumpers and flap away in the breeze. Since the CF base doesn’t come with the clamp thingys, I drilled out a couple from my old plastic seat base and riveted (1/4" rivets) them onto the CF base. Worked well and will prevent unwarranted breeze flapping!

Someone mentioned using grommets and a lace to secure the Roach cover in place. Grommets seemed a bit big to me so I purchased an eyelet tool (Menards - $1.99) and used eyelets along the bottom sides of the cover. One shoestring later (I wonder why I have a shoestring left over), the cover and bumpers are in place and it’s looking good. Now all I need to do is come up with another seat post clamp to replace the one I just broke trying to put everything back together again.

One final note: I wonder if there is a better way to secure the Roach cover in place without the shoestring. Now on side seat grabs, my fingers and the shoestring try to occupy the same space and it’s a bit of a situation, but probably not enough to worry about.