The seatpost on my beater roadbike is 25.8mm as is stamped on the seatpost. The angle of the seatpost is fixed in a grueling upwards tilt and is, um, painful.

I want to replace it with a micro adjust tilt post so that I can change the angle of the seat, but I can't seem to find anything in 25.8mm other than fixed posts. Anyone have any leads for something like this?

I can get normal adjustable posts, but nothing in Micro-adjust.

https://www.jbimporters.com/web/check...t_number=51001

Clarify 'normal adjustable'--can you adjust the tilt at all? The link doesn't look like it has any tilt control.

Why are seatposts of this diameter to hard to find? Am I better off getting something narrower and shimming?

Of course they're adjustable. I've never seen a saddle/seatpost that wasn't adjustable. Either the post is adjustable or the clamp is adjustable (for straight posts that use a separate clamp).

Single 6mm bolt on the bottom loosens the seatpost clamp/head so that saddle position (fore-aft and tilt) can be adjusted.

the linked post has an angle adjustment and should suit you fine. its not infinitely adjustable like a two bolt post, but it should do just fine for a "beater" bike.

are you sure yours is not adjustable?

Got a 25.8mm micro-adjust two-bolt seatpost right here on my desk. The lone decal reads "Instaloc", no other makers marks other than "25.8". The fancy clamp design inn black ano suggests high-end American-made after-market seatpost.

'Fraid I'm not willing to part with it.

As I recall it came off a Mongoose All Terrain Pro of 1980s vintage. Don't know if it was stock.

Okay, that helps, thanks. I'm apparently just an idiot. I loosened the bolt that controls the fore/aft of the saddle, and I was able to control the tilt. I guess I've never had a saddle that used that bolt to also adjust tilt before.

Thanks for the help!

dont worry about a thing. you have got to learn somehow.