Chopping off post below my nuts

General
1

I have just upgraded to an air seat + wilder bracket. I’m using a Pashley frame but the seat was previously as low as it could go (I’m short-OK!). Now I’m having to lower it by lopping off a bit of post. I think I’ll be able to do that with a pipe-cutter, but how do I cut that vertical slot at the top (for the seat clamp to tighten the frame)? Probably will be cutting it below the top two drink bottle bolts.

I personally think that the bottle cage bolts are wasted on a MUni. Does anyone actually use them? Would have thought that they would be jiggling around alot and getting in the way!

Did I say chop off my post? I meant seat-tube.

Ken

2

Gizmo –

I just did the exact same thing. We used a pipe cutter to lop off the frame and a metal cutting wheel to cut the slot. Drill a hole first so the slot has a rounded end.

You will probably also find, as I did, that the seat post supplied with the seat for the Pashley doesn’t let you adjust the seat’s position or angle properly. There is, after quite a bit of search, no 25.0mm seat post that has zero setback. So I am working on getting the seat tube reamed to 25.4mm so I can use a zero-setback Thompson seat post which should be sweet.

The lopped-off frame, though, has already helped a lot. I was able to ride some rooty downhills that I couldn’t before because I kept getting bounced off the pedals. With the seat lower I can pull up on the handle to keep my feet on the pedals.

I’ll post the reaming results as soon as things happen.

3

Gizmo-

Only use a tubing cutter if you are prepared to work out the pucker that will likely develope in the end of the tube. Use a hack saw; if possible, get a pipe to slide over the seat tube to use as a guide. For the slot, drill a hole first where the bottom of the slot will be, then cut down to it with the hack. Alternatively, you could drill a series of holes. Ummmmm- that serated look everyone’s after these days…

Good luck, and remember to de-grease and paint all that fresh metal.

Christopher

4

We used a rounded file to handle the slight pucker; not really a problem. You will probably find it difficult to hacksaw the slot because of the opposing wall – this is where the motorized cutting wheel really shone. We also had to do a significant amount of cleanup on the internal tube walls to get rid of burrs etc. but it was worth it.

5

RE: Chopping off post below my nuts

> Did I say chop off my post? I meant seat-tube.

Your subject like is open to some sick interpretation.

> tube. I think I’ll be able to do that with a pipe-cutter,
> but how do I cut that vertical slot at the top

I did this once upon a time, with a simple hacksaw and file. You would need
a pretty heavy duty pipe cutter to slice your frame I think, based on
breaking one or more cheap ones trying to cut Miyata seat posts. Regular
plumbing pipe is made of softer material.

If you work gently, you should be able to do fine with a good hacksaw.
Others who are more metal-working savvy can correct me.

After cutting to length, the same hacksaw can be used to make your slot.
First, drill a hole in the frame where you want the bottom of your slot to
be. Make this hole the width of your desired slot. You may end up drilling
it a little bigger later. Then make two vertical cuts to lead down to the
drilled hole. You do this by holding the saw on an angle. Put something on
the opposite side of the top of the tube to prevent you from cutting into
it.

The bottom of your slot may have some ugliness due to angled cuts from your
saw. If so, you might be able to tidy it up by drilling a larger hole there.

Then clean everything up with a file. After this, you’ll need to protect all
the bare metal you’ve just created. Paint it, nail-polish it, or if you have
my tastes, chrome the whole thing. Otherwise it will rust real fast. Make
sure you haven’t left any edges on the inside of the post to scratch up your
seat post.

> I personally think that the bottle cage bolts are wasted on a MUni.

They are if you don’t use a water bottle. When my DM ATU was new, I took off
the bottle cage. But I left the bolts there, to fill the holes. They don’t
rattle around or anything.

Stay on top,
John Foss, the Uni-Cyclone
jfoss@unicycling.com

“Vehicularly-Injured Sperm-Count seat: better known by it’s abbreviated
name, Viscount.” David Stone, on saddle preference

6

Thanks for the suggenstions everyone. I will attack my post tonight.

Ken Looi

7

Safty

Ah, I forgot to say: As always, remeber to wear eye and ear protection -and maybe even a full face shield- if using the cut off wheel. Your hands will love you if you use gloves- particularly when starting the hack saw cut on the slot.

Good luck,

Christopher