For anybody else who may have a Hunter frame and a Miyata seat (I got mine from Unicycle.com), I have a question for you.
How tight is your seat post in the frame?
When I ordered my Hunter last week, Unicycle.com was out of Miyata seats, so they sent me a temporary United one to get me by. The United seat I got is … uncomfortable. So, in preparation for my Muni weekend in Memphis, I decided to move the Miyata seat from my United Trainer over to my Hunter.
However, the Miyata seat post didn’t see to fit. I mean, I did manage to get it to go in a tiny bit, but it clearly didn’t fit, and my 2 friends who were with me agreed.
Does the seat post that comes with the Miyata fit at all? Or is a different seat post sent with the ones that are put in the Hunters? Or what?
I plan to call and ask Unicycle.com about it, but I’m looking to see what you guys say also.
Otherwise, the Hunter was sweet and I loved riding it (except for the temp United seat).
The Miyata seatpost is 22.2mm in diameter. The United seatpost (the more standard size) is 22.0mm in diameter. The Miyatas are 0.2mm or 0.008" larger. I find this annoying. VERY annoying. Try some grease. Then try polishing the post with 600 grit. Try to polish the inside of the seat tube on the frame.
I was lucky and was able to get the Miyata seatpost into any seat tube I tried. Others have not been so fortunate. I know you would hate to start altering your new frame. Search for threads relating to this problem because I remember seeing some solutions posted.
There is a difference between Japanese and Taiwanese seatposts. Taiwanese
ones are 22.0 and Miyata are 22.2
Although 0.2 does not seam much it is enough to make quite a difference when
fitting into your unicycle. Unicycles are always 22.2 (even the Taiwanese
ones!). When you first fit the 22.0 seatpost into the frame you will be
bending the frame in slightly, this is why it often takes a couple of goes
to get it tight on a new unicycle. When you then try to fit in a 22.2 seat
post you will find it does not fit, take the clamp off ease the new seatpost
in, if it is an uncut one it should have a little lead-in that will allow it
to go in. Loosen the clamp and refit the clamp and you will then find that
your miyata seatpost will fit.
>
> All,
>
> For anybody else who may have a Hunter frame and a Miyata seat (I got
> mine from Unicycle.com), I have a question for you.
>
> How tight is your seat post in the frame?
>
> When I ordered my Hunter last week, Unicycle.com was out of Miyata
> seats, so they sent me a temporary United one to get me by. The United
> seat I got is … uncomfortable. So, in preparation for my Muni weekend
> in Memphis, I decided to move the Miyata seat from my United Trainer
> over to my Hunter.
>
> However, the Miyata seat post didn’t see to fit. I mean, I did manage to
> get it to go in a tiny bit, but it clearly didn’t fit, and my 2 friends
> who were with me agreed.
>
> Does the seat post that comes with the Miyata fit at all? Or is a
> different seat post sent with the ones that are put in the Hunters? Or
> what?
>
> I plan to call and ask Unicycle.com about it, but I’m looking to see
> what you guys say also.
>
> Otherwise, the Hunter was sweet and I loved riding it (except for the
> temp United seat).
>
> Lewis
>
>
> –
> Animation - I unicycle in Mississippi too.
>
> Lewis W Beard
> lewis@lwb.org
>
> ------------------------------------------------------------------------
> Animation’s Profile: http://www.unicyclist.com/profile/615
> View this thread: http://www.unicyclist.com/thread/16733
>
>
I recently participated in an exercise of this sort with a noname unicycle that had a 22.0mm seat post that I replaced with a longer 22.2mm seat post. By hand, I could only get the 22.2mm seat post about 0.5 of an inch into the frame so I placed a scrap 2x4 on the seat post and proceeded to gently wack the 2x4 with a hammer. The seat post is now firmly seated in the frame with no visible damage. You may want to try things like sandpaper and grease mentioned earlier, and if that doesn’t work (or needs a little help), you may want to coax the seat post with a hammer.
Sanding and whacking seem like extravigant procedures for equiping an item that is sold as stock on this cycle. Is there more than one diameter Miyata seat tube? Do they usualy sand them to fit before shiping from Atlanta?
It’s tight, but manageable. I loosen the seat post clamp
completely, fit the first inch or so of the post into the
frame, and then twist the post back and forth while
pressing down hard on the seat. I don’t see any
evidence of sanding.
The unfortunate side effect of all of this is that now my Miyata seat doesn’t sit so well in its original United frame. Apparently the process of even briefly trying to insert it into the Hunter made it so that right now, I am almost unable to get it to stop twisting in my United frame. I really have to dig in on the quick release to make it stick in the United.
One problem with the Miyata post is that it is relatively soft. If you clamp down hard or force it in to a slightly undersized seat tube, you can compress the diameter of the post. If it gets compressed it is not going to fit snugly anymore.
The Miyata post is OK for starting muni. But once you start doing drops the seat posts’ days are going to be numbered. I destroyed two Miyata posts on my Pashley. They fail up at the base plate by the weld. The nose of the seat will collapse.
Use the Miyata till it bends, but then think about getting a bicycle seatpost and the Wilder rails attachment. It’s spendy, but it’s the strongest solution.
>You may want to try
>things like sandpaper and grease mentioned earlier, and if that doesn’t
>work (or needs a little help), you may want to coax the seat post with a
>hammer.
Isn’t sanding the seatpost threatening the chrome coating if there is
any? I sandpapered the seatpost of Jorga’s Showtime unicycle when she
just had it because the post went in and out with difficulty only. It
was in vain, turned out to be a “welding burr” (English?) in the seat
tube that a kind Semcycle engineer later removed with a reamer. But
now the seat post is rusty due to my sanding…
Klaas Bil
“To trigger/fool/saturate/overload Echelon, the following has been picked automagically from a database:”
“veggie, small pox, NAIA”
They fail up at the base plate by the weld. use the Miyata till it bends,
but then think about getting a bicycle seatpost and the Wilder rails
attachment. It’s spendy, but it’s the strongest solution. john_childs
My solution to the miyata seatpost breaking was to have an oddyssey 16"
(cut down) CrMo and welded to a miyata plate. the CrMo seatpost is stronger
than the lightweight steel post that comes on a miyata. works fine!
Go to a hardware store and find a 3/4" brush to put on you drill. Grind the inside of the tube, then had some
grease in… That works well and doesn’t alter the seatpost.
Christ.
Klaas Bil wrote:
> On Mon, 4 Mar 2002 17:46:03 -0600, bhuzyk
> <bhuzyk.10lty@timelimit.unicyclist.com> wrote:
>
> >You may want to try
> >things like sandpaper and grease mentioned earlier, and if that doesn’t
> >work (or needs a little help), you may want to coax the seat post with a
> >hammer.
>
> Isn’t sanding the seatpost threatening the chrome coating if there is
> any? I sandpapered the seatpost of Jorga’s Showtime unicycle when she
> just had it because the post went in and out with difficulty only. It
> was in vain, turned out to be a “welding burr” (English?) in the seat
> tube that a kind Semcycle engineer later removed with a reamer. But
> now the seat post is rusty due to my sanding…
>
> Klaas Bil
> –
> “To trigger/fool/saturate/overload Echelon, the following has been picked automagically from a database:”
> “veggie, small pox, NAIA”
This old thread is the closest thing I could find to my new problem. I have a new Hunter with Miyata saddle. The uni arrived with one of the adapter “shims” installed in the Hunter frame…seemingly for the purpose of making a seat post that is too thin fit into the Hunter frame. Problem is, doing ANY adjustments to the seat is next to impossible, and removing the seat…at least yesterday…WAS impossible until I enlisted a second set of arms and legs. The first couple times I removed the seat and post, it was difficult but achievable with lots of twisting back and forth. It became more difficult each time, until yesterday I couldn’t do it by myself.
If I read this thread correctly, the Miyata post actually is already properly sized for the Hunter frame…and hence may not need the adapter that was installed by Unicyle.com. Any experts agree or disagree? And any suggestions on how to make the seat easier to adjust?
The Hunter is desinged for a 26.8mm seatpost. That’s a standard and common size in the bicycle industry. Hunter is using bicycle tubing for the unicycle frames, hence the bicycle sized 26.8mm seatpost. You need the seatpost shim to be able to use a 22.2mm unicycle seatpost in the Hunter.
You may have gotten some corrosion either inside the seat tube, on the shim or on the Miyata seatpost. If there is any corrosion clean it off.
When you put it back together use grease. Make sure there is grease between the unicycle frame and the shim and between the shim and the Miyta seatpost. The grease is there to keep the metals from corroding and bonding themselves together. Two different metals in tight contact with each other will cause a chemical reaction and bond together (think back to college chemistry). This is one reason why seatposts get stuck. The grease forms a barrier and prevents the chemical reaction. For the ugly details of what can happen if you don’t use grease see Sheldon Browns 15 Ways to unstick a seatpost
I’m guessing that you’ve gotten some corrosion going on and that’s why the post keeps getting more difficult to remove each time. If the shim is made of aluminum you may have some aluminum oxide corrosion. You can use amonia to clean off aluminum oxide corrosion (see item XIII on Sheldon Brown’s 15 ways to unstick a seatpost).
I am a big proponent of greasing the seat post, especially after having to use a pipe wrench to get enough torque to break the rust bond on my road bike. Made real nice tracks on the aluminum seat post.
But I have found one exception for greasing the seat post. My Tandem takes a 29.8 post, when I got two suspension seat posts for my stokers both posts required shims. The instructions stated to not grease the contact between the shim and post as the grease could make the seat post slip.
If you do grease the inside of the shim let us know how it holds.
Thanks John and all: The grease sounds like a good idea. I’ve only had the ride a few weeks, so didn’t think corrossion worked that fast. I don’t pretend to understand corrosion…when I tried to think back to high school chemistry as you suggested, the only chemistry I could think of caused a flashback.
I’m assuming a plain 'ol grease of the K-mart auto aisle variety will do the trick?
Most any automobile, bicycle, or bearing grease will do the job.
Since everything is new it’s probably not corrosion. Another possibility is that the Miyata post is getting squished and is bulging out into a nice hourglass figure where it is clamped. The metal used in the Miyata post is not the strongest or the stiffest material and will compress when clamped tightly.
Ultimately the best solution is to get a good 26.8 bicycle seatpost and either a Kinport or Wilder rail adapter for your seat. Bicycle seatposts are much stronger than the Miyata post and a good bicycle seatpost won’t compress like the Miyata post when clamped tightly. A good bicycle seatpost is also less likely to twist and slip.
I went for Phil’s grease…it worked fine.
For those that inquired, I decided to grease both the shim/frame, and the post/shim contacts. Once I cranked down the ring, everything held together fine through a fairly tough ride. I’m going to wait a couple days, then try to remove the seat just to confirm the grease as solution works.
John: will likely follow your advice on the bike post soon…I also want to get a quick release ring…I’ve got quite a nasty palm bruise from cranking it down with the allen wrench.
As always, thanks for the great advice…
Tom
