Optimum dropout for Belt Drive

[jaybeeboston]

Starting a belt drive touring bike project shortly. Steel, Rohloff Speedhub, disc brakes. Looking at Paragon Rockers and Polydrops. Any strong preferences or considerations? Other good options? If I go Rocker might machine my own seatstay separators just because it's a good machining sub-project.

Experience and advice gratefully received,

jay b

[Eric Estlund]

You need drop outs that support both the Rohloff shifting and the belt tension. If you go polydrops (or any other fixed vertical), you still need to figure out a tension method.

[jaybeeboston]

Thanks, Eric. I mistakenly thought that the PolyDrop allowed an insert with horizontal travel -- The Paragon description touts the ability to separate the CC and SS pieces "to allow for belt placement," but looking at the inserts, there's nothing that allows rocking or sliding to tension a belt.

[Rody]

Jay,

I've built a fair share of Rohloff builds through the years, many with belt drives.

I've used adjustable drops, EBB's, and splits of all kinds; couplers, gates, lap joints, split drops.

The most dependable, functional, performace combination I've found is machining your own EBB, fixed position dropouts made for an OEM Rohloff axle plate, and a gate passage for the belt located in the seat stay.

All the processes are found in the many years of blog posts if you care to look. Here are a few..

EBB - Groovy Cycleworks 33-988-537: Jay's Bigwheel begins to take shape

Gate passage - Groovy Cycleworks 33-988-537: Belt Drive gate...how I do it

cheers,

rody

[VertigoCycles]

2nd what Rody is saying. I've had no issues with en EBB, standard drops and a conical split in the seat stay. If you're going to install disc brakes, Cycle Monkey makes a nice ISO to Post Mount adapter that works very well with the OEM2 plate

[jaybeeboston]

Rody,

The EBB step-by-step is really great. I love the simplicity of it, and the ruggedness compared to dropout-based whizbangs. I've been spending a fair bit of time on the lathe lately for some other projects, so this fits right in nicely. Coincidentally I had taken a look at your SS splitter earlier and really liked it. Really appreciate your sharing.

j

[jaybeeboston]

Sean, thanks for the pointer to Cycle Monkey. I'll check it out and build it into the design -- I am going to go disc.

[jaybeeboston]

Rody, one quick question: the material for the threaded internal EBB shell -- is it also chromoly?

thanks

j

[Rody]

6061 Aluminum round.

Have fun and be sure to follow up with some process pics!