Canti post 700c to 650b conversion widget

[A. Nostuh]

https://www.treefortbikes.com/Promax-Brake-Post-Extender?utm_source=google&utm_medium=cpc&adpos=&scid=scplp333222398346&sc_intid=333222398346&gclid=EAIaIQobChMI08PA577U6AIVIv_jBx3Ifw11EAQYASABEgLk0_D_BwE

Any reason these could not be used upside down to convert to 650b?with v brakes

For a steel Rivendell bike...

Asking for a friend 

Al in Saratoga 

[Scott A]

Hi Al,

A friend of mine looked into these for much the same reason as your friend. He tells me that unfortunately they only work on frames that already have removable cantilever brake studs.

To the best of my friend's knowledge, Riv never made a frame such a frame...

Good luck with your 650b project!
Scott
Atlanta, GA

[Ian A]

The Promax converters work really well on a frame/fork with removable cantilever posts. The Promax widgets are for BMX frames, so they are not exactly the right height difference, but close enough to work without compromise.

Otherwise if the frame has brazed on posts the only options are
1) keep the frame/fork it 700c and enjoy it as designed
2) have cantilever posts replaced in the desired position (I've had this done a Rawland rSogn)
3) sell the bike and buy what your friend really wants
4) keep the bike AND buy the bike your friend really wants.
5) change to a 650b fork and run the rear wheel fixed.

I recommend option 4 (and possibly 5).

In my case (see option 2), I went from 650b to 26"/559 and am delighted with the outcome. Cost of moving canti posts was ~ $150 as the original posts were tigged and it took the builder a while to cut those off and braze new ones on. I rattle canned the repair, so minimal "repaint" cost. (The frame builder is a friend, so I may have got a better deal. The brazing work he did is superb too).

IanA Alberta Canada