airseat conversion problem

there is a very simple thing holding me back from having a very very comfy airseat. I cant get the back bumpers acorn nuts off. The bolt just turns when i twist it and nothing happens. ANyone have this happen to them before? How do i get it off???

I removed the front bumper, undid as many clips as I could, pulled the seat cover back and then pulled the foam out. I had success with a screwdriver and locking pliers to hold the bolt still while I removed the nut with a wrench. Ugly but it worked.
If you are just putting a tube inyou could peel everythin back, drill a hole for the valve and insert the tube without removing the rear bumper. If you do this make sure there is some kind of liner to protect the tube from the metal plate, bolt heads etc. in the seat. I punctured my tube halfway through a Muni ride and had a very uncomfortable ride home.

u could allways try phil’s cattle prod…


Hmmm… 'tis something I have not tried, because I have the same problem with my miyata with the cracking handle.

Although I’ve just got another miyata with my new muni… wonder if this one will last longer…

Phil, just me

Re: airseat conversion problem

There is a device known as a nut-splitter that is designed to remove stubborn nuts, rusted or otherwise unwilling, from the bolt threads. I’ve talked about the tool to others but haven’t tried it or even know if such a small tool exists for this particular size nut. I’ve seen larger versions for big nuts (like me). I plan on asking at the local hardware store next time I’m in but haven’t gotten to it yet. If someone were to beat me to it or have other information on the existance of this tool or know if it would even work for this application, I’m for input.

By the way Jesse, welcome to New Miyataville.


Here’s Sears’ version:

pic here (I hope): images/tools/large/00904772000-dlv.jpg

As long as there’s room around the nut for the frame of the nutcracker to fit, this tool will split it right off with a few turns of the spindle. It may damage the bolt, too, but you’re gonna replace that with a carriage bolt anyhow, right?

Dang! Let me try to post this picture link again…

one more question…Do I put that thick foam thing back in after im done if im not using a gel thing? the thing doesnt really say.

for some reason this post disapeared from Im just replying to make it pop up there again

One way to do it may be with a drill. A drill press being more desirable than a hand held.

Hold the nut with a wrench and drill into the exposed end of the bolt. As the drill bit removes metal in the bolt it will also relieve some of the radial pressure. At some point the drill bit will grab the bolt and screw it thru the nut.


Re: airseat conversion problem

Ok I did an airseat conversion yesterday and i managed to get one nut
off the front handle all the res spun.

As per the previous posting
All of the dome nuts (acorn) knock off the dome with a chisel and a
hammer and then centre punch and drill a small pilot hole 2 or 3 mm
diameter down thru the bolt (this will stop the larger drill
wandering) then drill a 6 or 6.5mm down through the bolt, holding the
nut with a spanner when it spins, until it falls off.

This will allow the front and back bumpers to come off.
(make sure your drill is sharp as if its blunt it will heat up and
start melting the bumpers)

Now you have the cover off and the foam out the plate bolts can be
punched and drilled fron the top thru the head of the bold first with
a pilot the with the larger drill bit

I used all u bolts on the front and back bumpers made from Studding
(all thread) and made a u bolt to fit in the front hole but drilled an
extra hole just infront of corner of the metal plate through the
plastic to take the other side of the uneven U (more like a J) Bolt
all with penny washers (the front washer cutaway)

And I used Standard nuts and bolts for the seatpost and plate.

One very comfy seat !

A 12" tube went in nicely and penny washers

ok i finished it and everything went well. the front has a big
bump but it is still about 10 x more comfy