So I had an idea and i was hoping to get some feedback on feasibility from y'all. I was wondering if it would be possible to add a second, larger diameter cog to the RadRunner1 for going uphill, I'm ok with getting off and manually moving the chain as well. Like old school tour de france before derailleurs were invented.
Possible, yes BUT:
Chainline would have to be considered when choosing a new right crank, and the whole bottom bracket might have to be replaced to get something appropriate, and then you would have to ensure nothing interfered with your PAS encoder wheel and sensor mounting.
The "capacity" of the chain tensioner on the RadRunner 1 is not spelled out in the general specifications so you would need to see if it could accommodate the difference, or get another one with a longer cage.
Have you considered something like an Efeno GTRO, Schlumpf, or Metropolis Paterson internally geared botton bracket? (all are relatively expensive and some more difficult to fit than others).
I've not considered those, as this is the first I've ever heard of such a thing, however, I don't think I can afford the $700. I'm wondering if I'd need to replace the crank at all with something like the white industries DOS ENO 2-speed.
I have some White components and they're bombproof, but the DOS ENO 2-speed freewheel is a new one on me, looks interesting.
Potential issues would be:
Will it thread onto the Rad hub?
Since it's made for fixies, which generally have horizontal dropouts without chain tensioners, would the close proximity of the tensioner on your Rad cause a chain alignment issue? Some derailleurs have sliding bogies on their cages to accommodate a bit of misalignment close to freewheels/cassettes, so maybe your tensioner either already does, or could be made to do so if nercessary.
A two tooth improvement does not a true climber make, but on a single speed bike, every little bit helps (been there, too old for it now).
Hi - would love to know if / what you end up deciding on. I kinda wish there were a couple more cogs on my RadRunner 1 for when cycling :-\