Miyata nuts slipping (easy solution)

Well, I didn’t want to mess with nuts and bolts using the Bruce Edwards fix, so I messed with nuts and bolts installing the Kinport Bumper onto my seat.

Wouldn’t ya know it, but 2 of the 3 bolts just spun (reading here, I knew it was because of the bolts spinning in the plastic)

All I did, was remove the back, peel off the cover up to the front (the front still on) and grab the heads of the bolts with a needle-nose vise grip. That worked perfectly.

I think I’m really gonna like this

Hey, that’s a great solution for people who can get one bumper off but not the other. Woe to the people who get spinning bolts at both ends… :angry:

Yes, woe to THEM :sunglasses:

As in, most of us… :frowning:

Phil, just me

As I have suggested before, try freezing (that’s leaving them in the freezer) the seats overnight before you try to get any bolts to move, then when it’s still cold you break the mystical loctite.

I’ll letcha know. It’s in the freezer. Airseat conversion and Roach cover sounds like a nice plan; if you can get the DAMNED bumpers off of the brand new seat. Spinning bolts at both ends. Looks like Dremel time. What moron designed this thing. Metal fasteners that lock into the plastic. or a metal plate with the bolts welded in place would have been much too easy. As with most things, if you want it right, you gotta modify it.

I thought you were supposed to apply heat to release the locktite, no?

From the loctite site, 242 (low strength) and 243 (medium strength) loctite lose most of their strength at 100deg C. The high strength stuff is a lot more heat resistant; you might melt the plastic in the saddle before the loctite let go.

http://www.loctite.com/datasheets/tds/Product_242.pdf http://www.loctite.com/datasheets/tds/Product_243.pdf http://www.loctite.com/datasheets/tds/Product_272.pdf

Anyway, if the freezer trick doesn’t work I’d try pouring a kettle of boiling water over the nuts and see if you can get them off then. Mind your fingers!


Miyata were forced to move their production to China because their Japanese-made stuff was too expensive and nobody was buying their unicycles anymore, even in Japan.

This does not excuse them for shipping us inferior, essentially defective new saddles as if nothing had changed. The Chinese versions are cheap copies of the Japanese ones, with corners cut and probably limited testing. And, there is probably some thinking at the factory that these seats are fine. If they weren’t, how could they have sold 1500+ of them?

Hopefully word is getting back to Miyata and the factory that these seats are not acceptable. Also, with the new Velo seats, for the first time ever, Miyata has competition in the seat market. Unfortunately, the one drawback of the Velo seats that I’m aware of at the moment is that they’re not easy to convert to air.

Back to the Miyatas, the older seats did have a small metal plate on top of the plastic, to prevent the carraige bolts from rotating. These held onto the seat post. The bumpers were held on with long U-shaped bolts that couldn’t rotate. Smart!

I thought the Velo was supposed to be better than air (the comfort of air with no air)- are people converting Velo’s as well?

Ooo, I cringed when I first read that… :astonished:


Yes, heat is theoretically the way to break loctite, but if the plastic is cold it is less likely to round out. I cant give you the physics of it though.

Re: Miyata nuts slipping (easy solution)

Here’s a couple solutions for the spinning bolt trick.



Re: Re: Miyata nuts slipping (easy solution)

i’ve added these to the maintainance faq.
i assume they are your galleries so i credited you with them, p.m. me if theyre not yours and i’ll fix the credits

Of course, you’re right, plastic is stiffer when cold. So maybe you could try to heat up just the nut, by putting a soldering iron on it or with of those little butane torches with the lighters inside.


Re: Re: Miyata nuts slipping (easy solution)

Well, the freezer bit didn’t work, dammit (short version of the actual string of terminology that was actually used at the time). After three days of relocation stress, I thought I might relax and spend a half-hour assembling a new toy (15 minutes, estimated by the assembly time of the Sem 26, and …….what could it take???..…15 more to put an air seat together??? Wrong!!!

And I apologize for the less than polite ranting that should not have been aired at the time of frustration.

By ‘dremel time’, what I meant was exactly what Yoopers has precisely described in the first link that I have quoted. The second link that Yoopers provided is exactly what I meant by ‘metal fasteners that will lock into the plastic’. Thanks Bruce, for providing an excellent explanation of some badly needed advice that EVERYONE will need if they wind up doing any work on the new style Miyata saddle. And the seat DOES melt quickly from the heat generated by the grinding. I did mine in the kitchen sink with the water running (my apologies to the wives who may suffer because of this statement). I thought that I had read that the GB stiffener plate provides a fix for this (with square holes and matching locking bolts). What I got was only a stiffener plate for the handle. Is there another plate that I missed (that covers the whole seat)?

Next problem;

  1. The Roach cover barely fits the Miyata saddle WITHOUT the air seat pouch.
  2. The pouch does not fit over the back of the seat, and is too long even if it did. The directions say to fold it in half. Then, it’s only long enough to cover a little over half of the seat.
  3. In either case, the Roach cover doesn’t even come close to fitting with the inner tube and pouch in place.
  4. And where is the best place to put the valve if I manage to get it together? Maybe drill a hole in the seat?

Did I waste my time tearing the Miyata apart?

Any help/instruction would be greatly appreciated when I get back to it.
My (apparently wrong) assumption was that everything would fit around the seat, and allow the bumpers to be re-installed for protection of the tube and the Roach cover.

Maybe that Viscount isn’t all that bad after all.

Oh yeah, the wheel also sits crooked in the Yuni frame; the second (of only two Yuni frames that I have seen) to have this problem. But it’s wide enough that the Gazz 3.0 still doesn’t rub the side. And with the 26” frame that was supplied, there is more than plenty of mud room on top for the 24” Gazz. Someone previously mentioned an aluminum can as good shim material for aligning the wheel; much easier than sending it back. And you’ll probably have plenty of shim material if you have to disassemble the Miyata.

Im sorry that didnt work for you, it worked the time we tried it. oh well.

It’s definitely worth a try before you break out the serious tools.