OK, I took on one of the new Miyata seat beasts tonight to perform the delicate air conversion surgery. Took pictures along the way and posted them along with some description in a gallery:
http://www.unicyclist.com/gallery/Miyata-seat-conversion
I’ve done several Miyata air seat conversions now but this was my first on the new style beast. Final product turned out very nice but I sure can’t say it was a breeze along the way.
Bruce
Cool, Bruce. Is it comfy? Were you able to take all of the bumper nuts off? I wasn’t so lucky. I was going to go the threaded rod route but I decided I didn’t want to heat it and bend it. It looks like you bent it cold without breaking it. I like your threaded rod u-bolt on the front through only one of the side bumper holes. That’s clever. I used bolt plates with square holes broached in them and carriage bolts all around.
Actually, I promised the air seat conversion to one of our club kids so I’m sure he’ll find it comfy. Evan just purchased his very first uni from Unicycle.com. He must be a good kid because his dad’s name is Bruce. Although, this Bruce is a dentist so I tease him sometimes about being a professional jerk.
I did bend the rod cold figuring there wasn’t going to be too much stress on the rod holding plastic bumpers in place. To finely adjust the angle of the rod, I installed a nut on the rod and tapped on the nut gently with a hammer. Worked well. The front bumper nuts were the ones I was able to reach and hold with a fingertip and then very gently coax the nut off the bolt in spite of the thread lock goop, or whatever it is. One detail I forgot to mention though is that, at the end when I tightened the nuts back in place, they seemed to submerge into the plastic more easily than the old style saddles. Seems I remember some talk about softer plastic somewhere along the way.
Bruce