Tandem + Truss Fork

Hi everyone,
I´ve been planning this build for quite some time and now I have time to start with it.
I don´t have experience with building a tandem or a truss fork. Tooling is there to make it happen though. Just need to build a couple of mittering jigs for the fork and handlebar.
Tubing for the frame is a mixture of reynolds and straight gauge 25crmo4, for the fork I´m planning to use 19x1mm 25crmo4 tubes. This looks like more than enough. The fork is built around [this steerer] (https://www.paragonmachineworks.com/tapered-steel-steerer-choose-size.html) and for the stem clamp I also have this part here.

Any advice on building a truss fork and tandem geo would be great. I think it´s dialed in but it can always be better :melting_face:

:wave:

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Super interesting project! Can you elaborate on the tubing? I just jumped on the tandem boat by modifying an old Bianchi tandem, but the frane is just soooo heavy I might need to make a better one myself.

The bianchi only had ~30mm rake on the fork. I feel it became more twitchy when I swapped it to a one with a larger rake.

The tubing is a mixture of Reynolds 631 and straight gauge 24crmo4.
DT, TTs and STs are 631, lateral tube is straight gauge 31,8x1 and boob is 44,5x1.

For the captain BB I’m using a T47 (instead of the normal tandem bb which is 60 something) and I’m planning to run a First Components eccentric bb. Hope it gives me enough adjustability.

Here is some progress on the frame, for the fork I still need to build the mittering jigs.

2 Likes

What a beauty! What’s the frame’s weight going to be like?

I had to go back and check what I said about the rake - I pulled the old fork out of the scrap bin and it is 50mm, not 30.

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Good question! I’ll let you know when it’s done. I’m planning to use a Yoke from Konga, but I still need to check the posibilities without it. It always deviates from the ideal CAD world in the end…

Got some progress over the weekend!

I‘ve changed my torch set up for this frame to the Uniweld 71 with TEN2 Tips because I read on the forum I was using the worng torch for my concentrator/propane set up, and I worked out really nice.
Hope to get some work done on the fork next weekend.

6 Likes