Dahon Seatpost Mod - I-beam to standard mount
 

I never really had any dislike for the SDG saddle on my 2005 Dahon Speed P8 - until I bought a Brooks B17 saddle for my non-folding tourer. After experiencing the benefits of a truly comfortable saddle, I knew I had to find a way of getting the Brooks (a tradional two-railed saddle) onto the Dahon. I also didn't want to buy a new oddly-sized seatpost. What I did was really quite simple and not at all clever; if it's been mentioned here before: I apologize.

I removed the SDG saddle and flipped the seatpost over so that the SDG mount is now down by the crank. This left the open end of the seatpost on top. Using a dremel (a hacksaw/sabresaw/etc., would work, too) I cut a 1/8th inch wide by 1 1/2 inch long notch, similar to what you see on some seattubes/frames. With a 34 mm seatpost clamp, the SDG post is now ready to accept the new standard XX.Xmm seatpost. (Sorry: I don't recall the exact diameter as I sit here at work but I think it's 27.2 mm) Now I have the option of using either my Brooks or the SDG.

Disclaimers: I haven't logged a tremendous number of miles but it appears to no less secure than a typical frame clamp setup and more secure than any telescopic post I've seen. Is the SDG seatpost warranted? I don't know but if it was, it's not anymore.

I'll track down the SDG seatpost's inner diameter measurement ASAP. Maybe some pix, too.

Toodman, great tip, thanks for posting it. I am interested in doing the same thing on my MU XL, I'd appreciate seeing some photos when you get the chance. Also, details of the dimensions of the clamp and seatpost you used to mount the Brooks.
Thanks, Fergus

A cheaper way is to buy off trade-in 2 railed seat post from those Dahon owners who are upgrading to Carbon post. These are folks who love upgrading their bikes (called zhnging here). I got one for about US$15. Your LBS may have some of these just sitting around...

And yes, I'm a B17 fan too. Love it on my Speed 8.

http://i98.photobucket.com/albums/l2...es/Speed8r.jpg