replacing seat clamp on semXL

I have a semcycle XL unicycle, and I want to replace the standard issue clamp
that holds the seat post to the fork. However, unlike most bike clamps, this
clamp appears to have been welded or braised on to the fork. Does anyone have
any experience removing clamps in situaions like this?

I was considering trying the brute force method, and filing down whatever mess
remained on the fork. However, this is a new unicycle that I have quickly come
to love dearly, and I do not want to do any damange.

I would like to replace the clamp with the style commonly seen on new bikes
these days – rather than having a standard bolt, uses a hex screw. Assuming I
can get the old clamp off, any comments on the use of this style? I am most
interested because the hex screw will do less damage to my leg than a bolt, and
also will be easier to adjust, with only a single hex key needed, as compared to
the bolt where I’d need two wrenches.

jeff lutkus


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RE: replacing seat clamp on semXL

> clamp that holds the seat post to the fork. However, unlike most bike clamps,
> this clamp appears to have been welded or braised on to the fork.

This is common for unicycle frames. From my experience with old Miyatas, I don’t
know that you can remove the clamp without major work. The Miyatas were brazed
or welded on pretty good. My solution was to just cut the tubing below the
clamp. Then I extended the slot using a hack saw. The slot has to extend below
the clamp. Before you do this, make sure you have enough seat post.

> However, this is a new unicycle that I have quickly come to love dearly, and I
> do not want to do any damange.

Whether you file it down or cut it off completely, you will be compromising the
chrome plating, which you will have to live with. On my freestyle uni I have a
GT clamp, which extends over the top of the tubing. It has two screws. The
bottom half of the clamp tightens over the frame tube. The top half tightens on
the seat post. These work great if you can find them, plus they will cover up
the damaged chrome.

> I am most interested because the hex screw will do less damage to my leg
> than a bolt

The bargain basement solution is to cut off any excess bolt. You still have to
deal with the clamp, nut, and bolt head, but I’ve successfully hacksawed off
excess bolt. Just make sure you do it while the cycle is assembled. This way,
loosening the nut will restore the threading on the end of the bolt so it should
still work.

Enjoy, John Foss, the Uni-Cyclone http://www.unicycling.com

“Sometimes there just aren’t enough rocks.” – Forrest Gump

Re: replacing seat clamp on semXL

What about leaving the clamp there, but replacing the bolt with a nice
quick release?

Chris

Jeff Lutkus wrote:
>
> I have a semcycle XL unicycle, and I want to replace the standard issue clamp
> that holds the seat post to the fork. However, unlike most bike clamps, this
> clamp appears to have been welded or braised on to the fork. Does anyone have
> any experience removing clamps in situaions like this?
>
> I was considering trying the brute force method, and filing down whatever mess
> remained on the fork. However, this is a new unicycle that I have quickly come
> to love dearly, and I do not want to do any damange.
>
> I would like to replace the clamp with the style commonly seen on new bikes
> these days – rather than having a standard bolt, uses a hex screw. Assuming I
> can get the old clamp off, any comments on the use of this style? I am most
> interested because the hex screw will do less damage to my leg than a bolt,
> and also will be easier to adjust, with only a single hex key needed, as
> compared to the bolt where I’d need two wrenches.
>
> jeff lutkus
> _________________________________________________________________________
> Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com.
>
> Share information about yourself, create your own public profile at
> http://profiles.msn.com.

RE: replacing seat clamp on semXL

>
> > clamp that holds the seat post to the fork. However, unlike most bike
> > clamps, this clamp appears to have been welded or braised on to the fork.

The J C Penny 16" unicycle I recently bought for my great grand son came with
the clamp welded to the frame tube in 2 places. I managed to cut the welds with
a band saw, could have used a hack saw. I cut the frame tube down because it was
too tall for him even at it’s lowest setting, and I wanted to save the clamp.

> This is common for unicycle frames. From my experience with old Miyatas, I
> don’t know that you can remove the clamp without major work. The Miyatas were
> brazed or welded on pretty good. My solution was to just cut the tubing below
> the clamp. Then I extended the slot using a hack saw. The slot has to extend
> below the clamp. Before you do this, make sure you have enough seat post.

I tried a single saw cut for clamping on the seat post, but it was not enough, I
had to widen the slot with another cut.

> > However, this is a new unicycle that I have quickly come to love dearly, and
> > I do not want to do any damange.

Sometimes it is difficult to do things like that because you hate to make it
look like someone butchered it, but you do have to make it work like you
want it to.

> Whether you file it down or cut it off completely, you will be compromising
> the chrome plating, which you will have to live with. On my freestyle uni I
> have a GT clamp, which extends over the top of the tubing. It has two screws.
> The bottom half of the clamp tightens over the frame tube. The top half
> tightens on the seat post. These work great if you can find them, plus they
> will cover up the damaged chrome.
>
> > I am most interested because the hex screw will do less damage to my leg
> > than a bolt
>
> The bargain basement solution is to cut off any excess bolt. You still have to
> deal with the clamp, nut, and bolt head, but I’ve successfully hacksawed off
> excess bolt. Just make sure you do it while the cycle is assembled. This way,
> loosening the nut will restore the threading on the end of the bolt so it
> should still work.

That is one way to straighten the threads, but it’s best to grind a little angle
on the end of the bolt, about what the thread angle is, usually 30 degrees. It
doesn’t have to be a precision thing, just enough that you don’t snag on it. You
can also straighten the threads with a fine grade 3 cornered file, it has the
same angle as the threads.

One other tip, on my cheap Cycle Design uni I couldn’t get the bolt tight enough
to keep the seat post from slipping and letting the seat swivel. I kept
tightening it and finally the threads stripped. So I went to an automotive store
and bought a grade 8 bolt and nut. Look for 6 lines radiating from the center of
the head of the bolt. You won’t strip those bolts. It is nice and tight now.

> Enjoy, John Foss, the Uni-Cyclone http://www.unicycling.com
>
> “Sometimes there just aren’t enough rocks.” – Forrest Gump

     Lowell yoda@socket.net

Re: replacing seat clamp on semXL

Jeff Lutkus <lutkus@hotmail.com> wrote:
> I would like to replace the clamp with the style commonly seen on new bikes
> these days – rather than having a standard bolt, uses a hex screw. Assuming I
> can get the old clamp off, any comments on the use of this style? I am most
> interested because the hex screw will do less damage to my leg than a bolt,
> and also will be easier to adjust, with only a single hex key needed, as
> compared to the bolt where I’d need two wrenches.

I’ve had a hex screw type thing holding my Sem together for a while now with no
problems, they are neat, slim line and as you say easy. I definatly prefer it to
a quick relase as I don’t get so many bruises from
it. Just check you get one that fits, both long ways and fat ways.

sarah

Re: replacing seat clamp on semXL

That’s not going to help if he’s trying to avoid getting whacked with it. In
fact, most quick release units are bigger then the bolt.

I have a quick release on my Sem XL and I’d like to replace it with one of those
double hex head clamps instead. First off, the quick release doesn’t
consistantly stay tight. Second, it’s bulky and I have brusise on the inside of
my legs near the knees from getting hit by the thing. I don’t move my seat
height aroiund much, so something more secure would be nice.

Greg

On Tue, 07 Nov 2000, Chris R wrote:
>What about leaving the clamp there, but replacing the bolt with a nice
>quick release?
>
>Chris
>
>Jeff Lutkus wrote:
>>
>> I have a semcycle XL unicycle, and I want to replace the standard issue clamp
>> that holds the seat post to the fork.