Seat post non-awesomeness: Death to the reinforcement.

Last night I finally patched my trials uni’s tire and rode around on it for a while , because I wanted to see how high I could hop on a smaller lighter uni.

However, when trying a little rolling hop the seatpost simply bent backwards. Needless to say, it was a WEIRD feeling.

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Nekst:

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Ouch… Looks like your extention/stiffening bar has split open the seat post. Let me guess, you did it when pulling up on the seat handle going into a rolling hop? The force will have been transferred down the extension and the extra leverage (over the under-seat mounting point) caused this force to split the seat post… I’ve never seen anyone literally rip their saddle off their post just by pulling it! Nice job!

Next time, a stronger seat post might be preferable. Shame the stiffening plate is welded on though, it’ll be a pain to swap over or make a new one. Its always a bit disheartening when something goes bad…

Loose.

Do I see a resemblance?

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Couple of things you can do to sort this. You are obviously an animal in the way you ride and need the reinforcement… I mean this in a nice way. :slight_smile:
When welding your reinfocement on you need to put a lot less heat in to the tube, fully welding is of no use really, you need to stitch weld.
Go for one of the new Unicycle.com seatposts. I think you are on 22.0 seatpost so you should be able to get one of the extra thick version from Unicycle.com USA.
This should deal with it.

Have fun.

Roger

hehe the same thing happened to me at Toque, or atleast would have in the sense that I was testing out this metal handle that attaches to the seat-post but it turned out that the extra leverage just bent the seat-post. So… I no longuer use it as a handle… but it does make spiffy inexpensive seats with rake!

Lol, are you familiar with the term ‘stress concentration’ ? If you build another seat post with similar reinforcement then curving the edge of the reinforcement plate down so it runs more parallel to the post before ending should help spread that point load out to reduce failure.

Dave

Way to go!

Now we’re learning something. You don’t learn much if it doesn’t ever break. Maybe that’s a good way taking something away from this. :slight_smile:

Yeah, that’s what I figured happened. The post was also weakened by the welding, I think. I didnt’ actually weld it, I had a shop do it for me.

I’m not sure if I’m gonna build another. If I do, I’m gonna do it when I fix my trials. i’m currently in love with my MUni, so I’ll be fine as for unis to ride. I have a spare seatpost, too.

I really like my post on my KH MUni. It’s incredibly beefy, quite a bit thicker than this one, which is a unicycle.com knurled one I got last fall. It was new back then, I think.

EDIT: I think I’m just way too hard on equipment. This is just another on the wall of shame for me. I’ve got a rim, 3 or 4 sets of cranks, 2 other seatposts. It’s a nice little collection.

I think I may have seen in front of the seat handles which are attached to post bolted/clamped onto the round seat post. Anyone know if/where they are available?

Are they stronger than the plastic seats for hoping?

I could not find a source or a picture of those handles. Seems to me they would be a more universal, better, and simpler solution than re-in-forcing the seat. But then lots of things seem right from an armchair perspective.

You can use the aluminium seat post from Onza or KH with the brake extension on it and then use it to reinforce the seat by adding a tag to the rear 2 bolts on the KH saddle. You can see this mod done (not using the KH seatpost but it is similar).

Saves adding loads of weight in to the system when you can just use a bit of triangulation. This then reinforces the whole system.

Roger

This is what I’m going to do really soon to my KH MUni. I just took the cover off the seat to sew it up, and in the process noticed that the stiffener plate was broken. So, i’m just going to make some flanges of whatever you call 'em and attach them to the brake post. it looks like it should work perfectly.

I don’t know what I’m going to do with the trials. I think I might do a reinforcement version 2, but that is not in the near future.

Hello Roger, That looks great. Thanks for the help.