Right then. I’ve just got a replacement bolt for the front bolt of the
miyata bumper that I had to saw in half because it just turned instead of
coming off.
It’s not a coach bolt, but that wouldn’t matter anyway as the plastic hole
has worn circular. So… how do I make it stop turning while I fasten the
thing on? It’s got a groove for a (large) screwdriver on the top, but
that’ll be covered by the, umm, cover. So… short of training some small
rodent or other creature to hold the thing on from inside the cover, how do
I get the thing back on again?
Puzzling.
Phil, just me
“Cattle Prods solve most of life’s little problems.”
Phil Himsworth wrote:
>
> Right then. I’ve just got a replacement bolt for the front bolt of the
> miyata bumper that I had to saw in half because it just turned instead of
> coming off.
>
> It’s not a coach bolt, but that wouldn’t matter anyway as the plastic hole
> has worn circular. So… how do I make it stop turning while I fasten the
> thing on? It’s got a groove for a (large) screwdriver on the top, but
> that’ll be covered by the, umm, cover. So… short of training some small
> rodent or other creature to hold the thing on from inside the cover, how do
> I get the thing back on again?
>
> Puzzling.
>
Hmmm… Perhaps some two-part Epoxy? It would bond the bolt head to the
saddle and prevent it from rotating. Epoxy is quite strong and bonds to
most anything. Was the original bolt keyed in some fashion to prevent
it from rotating? I’ve never looked at my bolts.
Also, does anyone know what happened at unicyclist.com? They’ve been
down for quite sometime. Meltdown perhaps? If so, I hope they had
backups.
Phil, since the square hole is gone, short of replacing the seatframe with a carbon-fiber one, or using a metal stiffening plate, you could try using a fender washer (extra-large overall diameter with a small hole) with a star lock-washer (the type with a lot of little grippy points all around it) on both sides of the fender washer. The star lock-washer ought to bite into the plastic enough for you to tighten the bolt down.
My solution was to use a larger bolt of the same type. The square portion was able to bite into the plastic. Not the best solution I’m sure but the real fault lies in the design and fabrication stages. I had to cut the old handle to shreds and dismantle most of the seat to get the spinning bolt out. What a pain in the butt. Now for the same thing on the other unicycle…
Calvin at the end of this Thread http://www.unicyclist.com/forums/showthread.php?s=&threadid=19301
Has the right Ideal.
I had to use this method for my air-seat conversion.
Now I am in the Process of making a seat cover from scratch since the workmanship on my ROACH Tm cover was of less than loving quality. Also I nead the practice since I am seriously considering designing a seat to fit my bum.
Pull the front bolt and one of the bolts behind it out. Replace those two with a u-bolt made from bending a length of all-thread (threaded rod) to fit through those two holes. It can’t possibly rotate. Refer to Bruce Edwards’ air seat conversion post.
I got the thing back on again… the back two bolts are now slightly longer normal bolts with normal nuts and huge washers on them; the front bolt is another one of these bolts with an original acorn nut on it. The two back ones worked perfectly, the bolts didn’t turn at all; the front one did start turning but it let me get it tight enough to hold the thing on without too much wiggling. Which is good.
What’s bad is that this miyata bumper is starting to crack now too… I noticed a tiny hairline fracture in the same place as on the other one.
Now I’ve got a permanent way of keeping the thing on, is there a permanent way of keeping it in one piece? I don’t want to have to buy a new seat every month or two…
and :(…