tag:blogger.com,1999:blog-3981818070383270774.post7350302729339809400..comments2023-04-25T00:07:18.976-07:00Comments on Greens and Machines: Fabricating a Bike Seatpost -- Part 2Vinnyhttp://www.blogger.com/profile/00698488155519377079noreply@blogger.comBlogger1125tag:blogger.com,1999:blog-3981818070383270774.post-67330259338015115612014-07-15T15:10:53.658-07:002014-07-15T15:10:53.658-07:00I was given a bike with a seized seat post. After ...I was given a bike with a seized seat post. After removing the remnants of the post I wondered if I could make one. Looking through my salvage collection I found the down tube from an old Raleigh racer. This was 28.6mm but I needed 29mm. That might seem near enough but I was not prepared to distort the clamp (the bike was built from nice quality Columbus tubing). I found an old socket that when driven through opened it up to 29mm. This took a while and made quite a bit of noise.... This was pretty thin walled tubing of course (hi-tensile steel) and opened up with no cracks - in fact the white enamel on the tube didn't crack either. Next, I had to press fit an aluminium seat cradle into the post, and this is where it got tricky. <br /><br />After a couple of rides I felt a small amount of movement in this fit, so I decided to split the tube about 50mm and welded it up. This reduced the internal bore giving a much tighter press fit. I now had a unique seat post in white with the original Raleigh supplier's transfer facing to the rear - on a Peugeot MTB made 15 years later :)<br /><br />This bike's frame was also too small for me, so it looked pretty distinctive with so much post showing, and it actually worked very well due to its naturally springy steel properties absorbing buzz better than an aluminium post. Unfortunately, after a few weeks the cradle developed slight movement again - not dangerous but annoying so I decided to buy an aluminium post. There was about 50g difference in weight - not bad I thought considering my own post was longer. <br /><br />I would just add that when doing mods of this sort use the best steel you can get your hands on.ZeroGhttps://www.blogger.com/profile/11891098343878826344noreply@blogger.com