Carbon Base and Thomson Seatpost

[ivan]

I just got a Thomson Seatpost in the mail and realised that it's for rail-type saddles(silly me ).

I'm getting this carbon base. Is there any way to make it fit the Thomson seatpost directly, without a rail adaptor?

[john_childs]

Originally Posted by ivan

Is there any way to make it fit the Thomson seatpost directly, without a rail adaptor?

Yes. Have you seen how Scott Wallis does the adapter for his CF seats? It's custom for the Thomson seat post.

Someone here (Gerblefranklin? Catboy?) has fabricated a similar adapter for their KH style CF base. It can be done but requires some custom work and custom thinking.

[The.Mars.Volta]

Silly Ivan. I can't help you. I barely even read your post.

[saam]

Originally Posted by john_childs

Yes. Have you seen how Scott Wallis does the adapter for his CF seats? It's custom for the Thomson seat post.

Someone here (Gerblefranklin? Catboy?) has fabricated a similar adapter for their KH style CF base. It can be done but requires some custom work and custom thinking.

Is it Kaycee you were thinking of?

[Unicorn]

Hi Ivan,

Very simple just get a rail adaptor. They sell them ant UDC and MDC.

Unicorn

[jamessd]

Just wondering, why are the thompson seatposts made like this?

[TrialsUni]

Originally Posted by jamessd

Just wondering, why are the thompson seatposts made like this?

what do you mean? thompson seat posts are Bicycle seat posts first and foremost. have you ever observed the way bike seats and seatposts attach? bike seat posts attach to the rails of a bike seat. this allows for more strength, and way more adjustability than to have a seatpost bolt to a seatbase like with a stock unicycle.

thompson and de-rail is the way to go!

[jamessd]

Originally Posted by TrialsUni

thompson seat posts are Bicycle seat posts first and foremost.

I assumed they were bespoke for unicycles.

[TrialsUni]

Originally Posted by jamessd

I assumed they were bespoke for unicycles.

nope. we've just adapted them to our sport. i notice that the freestyle end of the bmx crowd has too, in recent years. the reason is that the thompson happens to be one of the strongest, if not, the strongest post out there.

unicycling, in general, puts unique forces upon the seat/seat post area. and with trials/street/muni the forces a seat post has to take far exceed those of bicycling. not only does a seatpost have to take downward forces, but also upward and other weird-angled forces/stresses.

it's a lightweight, strong, and well designed product, albeit somewhat costly.

evan

[ivan]

Originally Posted by Unicorn

Hi Ivan,

Very simple just get a rail adaptor. They sell them ant UDC and MDC.

Unicorn

Not that simple, actually. It'll cost me 40 euros(because of the shipping) and will add 200 grams(assuming it's okay to saw the brake lever off the KH rail adapter) of weight to my uni. 200 grams of weight mean nothing at all, but I still don't want them.

And that Kaycee thread is interesting, but it seems he had a normal plastic KH base, not a cf one.

[ivan]

Maybe I could cash out for a Scott Wallis base(what with my new job and all...), but he says he won't take orders till next year. Does anyone have a used Scott Wallis base they'd like to sell?

[unisk8r]

Originally Posted by ivan

...Does anyone have a used Scott Wallis base they'd like to sell?

Sorry to be negative, but don't hold your breath on that one. Scott's saddles are the best, and precious few of them have been made.

[john_childs]

Originally Posted by ivan

And that Kaycee thread is interesting, but it seems he had a normal plastic KH base, not a cf one.

It's been done at least twice with a CF base. I just don't have pictures and can't find the threads where it has been mentioned. It can be done. But you'll need to use some engineering smarts to come up with a design that is strong and robust.

Also take a look at this thread for ideas. It includes good pictures of the Scott Wallis CF base.

You could also rig up something similar to the KH adapter pictured there. Weld or epoxy a half cylinder to a KH 4 bolt plate. Rig up some way of attach and adjust the two adjusting bolts on the seatpost. I'd follow that route. Something where you use the KH 4 bolt plate and the standard 4 bolt holes. That will be stronger and also allow you to switch over the KH rails adapter if necessary or other compatible seatpost mount options that may come in the future.

The bigger advantage of going rail-less is that you won't have to worry about your fingers getting caught under or between the rails. More friendly for trials and street style riding.

[unisk8r]

The concept JC describes is used on alot of BMX saddles, but with one bolt attachment into the center of the post, like the pic. You don't have to use a serrated semi-circle mount, Scott Wallis' is actually smooth and the 2 bolts provide enough clamping force.

[ivan]

Hmm, good idea. I've got a 4-bolt plate broken off my old seatpost. If I can attach to Thomson, it will make a very good seatpost.