Tuesday, January 17, 2012

Making a quill style seatpost

Today we have a pretty simple project. The quill seatpost. Some may find these useful for their french constructeur bicycles, others to save a frame with a mangled or broken binder boss. I decided to build my touring frame for use with a Suntour quill seatpost. After about 4500 miles of touring (+ its life on a previous bike) the post developed a crack. I held it all together with an unsightly hose clamp until now.





Suntour quill post





I picked up a couple of old these old SR seatposts with the closed tops. They work well because the top provides a good bolt seat and after drilling it out to the correct size, the bolt fits snugly in place. A regular plain old seatpost could be used as well with washers or a little machined cap to hold the bolt in the center. Seatposts with a built in clamp will work but you must be choosy about finding one with enough area and material for an added bolt hole. I made a previous quill seatpost using this same Kalloy model pictures in this Yellow Jersey article on this same subject.

Yellow Jersey Quill Seatpost Article




SR closed top seatpost




I also picked up some old 1 1/8" stem quills. Their o.d. is larger than 27.2 so they were perfect for milling down to size.




Materials




To hold the wedge simple screw it onto the stem bolt and vice it up in the chuck. Adding a spacer provides some room for the cutter to pass.




Turning down the wedge




Then you'll need to cut the post at a 35° angle. Or whatever angle your wedge is. I cut mine at a 45° angle mistakenly and then cut it to 35°. That is why a little too much bolt is protruding. It will work but it is even shorter now. I recommend trying to find stem bolts that are 9 inches or longer, if such things exist.




Finished product




IMG_3813




A little more searching for longer stem bolts, and I will make some more.

Saturday, January 14, 2012

Long Awaited Update

Preface:

I've moved to Portland for a sort of frame builder residency or apprenticeship. I've been fortunate enough to land a position in the shared shop of Joseph Ahearne of Ahearne cycles and Mitch Pyror of MAP bicycles. Its a sort of mini dream come true. Although I'm not doing a lot of work with frames right now I'm happy to be building racks again, working on my brazing skills, and generally crafting things with my hands. I feel at home standing beside my new rolling cart bench.

This week Mitch asked me to help him construct a rack for a city bike he'd recently built. I was happy to accept the project. Mitch pretty much gave me authority over the design which was an honor, though I consulted him on my thoughts and ideas along the way. It was a collaboration right up until the end. We even solved some problems together that Mitch himself wasn't excited to solve on his own. The main problem being that the basket was just too big to make sense on the bike. The rack would have had to have been way out over the front wheel in a precarious and ridiculous fashion, or the handle bars would have to be jacked to the sky to clear it. The end result was something we both were proud to send out the door. Though it hasn't actually left the building yet.


 Rack Backstop




Wald Basket Rack top




Wald Basket Rack




Mitch Moding the Wald



Triming the wires














 Mitch brazing on the bungee loops




Internal wire routing by Mitch



Internal wire routing by Mitch




 Almost done