# single side drive.



## eischman (Apr 5, 2005)

Has anyone considered using a Hammerschmitt for the front crank and then using a 2 X 9 on the rear. The front shifting would be great under load. and the the rear would work like a 1X9. Or you could put an internal gear on the back as well. What are peoples thoughts?


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## PMK (Oct 12, 2004)

Thoughts, after a day of considering what you suggest, it sounds like a pretty dumb idea. Using the truvative cranks up front would mean you are turning one rpm while your stoker is turning a different rpm.

When the front cranks go to overdrive, the stokers pedals would be turning 1.16 times faster, basically the captain would be in the big ring and the stoker the middle ring for the timing chain. The final drive remains unchanged.

Why not just run a Rohloff rear and standard cranks with a chain guide of some type if even needed. Done, simple, proven and works. Just a little more expensive initially.

Curious also, your posts about the bike seem to have it heading in a retro mode being fully rigid. Why not just run the 1x9 as you just suggested and then standard cranks. Other than smoother sections, I can not imagine a rigid tandem needing a big ring. Anything above 20 mph would be brutal for the stoker and hard on the captain. 

Maybe I'm missing or overlooking something.

PK


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## eischman (Apr 5, 2005)

I am sorry PMK..you are the only one to come up with ideas : Just kidding you are very knowledgeable. I believe the hammerschmidt only has 1 chainring and gears. Perfect shifting underload. (I was actually thinking about a 2 X 1 for my single bike. (almost zero maintenance) Don't want a 1 X 9/10 on the tandem,,,not enough gears.

By going to a rigid fork you loose ~ 5-6 lbs, On a 100 mile race in the mnts 5-6 lbs is a good deal of weight. Don't knock it until you try it. I can't wait to try it on some technical stuff (may not like it) I do like my fully rigid bike.


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## PMK (Oct 12, 2004)

Let me rephrase, the cranks are a dumb idea on a tandem as you first posted to use them for captains cranks.

However, if the 2 speed cranks could be fit to the stoker position with the ability to run a timing chain that would be nice. 

The fork is just my opinion. The world needs to maintain equilibrium. You can push the envelope in a direction towards a rigid off-road tandem, this team works towards quality full suspension.

Walt will build you a great fork, it should easily exceed your expectations.

PK


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## eischman (Apr 5, 2005)

I guess I was thinking since it was 1 ring there would be no difference between the front and back. But looking at the exploded diagram I think you are right. The front might push a different revolution. I dont think they would work on the back since it is 1 ring


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## PMK (Oct 12, 2004)

If it matters, when I was building our 2x9 Fandango, I looked into using those cranks on the stoker position. I quickly could not see how to make it work. Maybe you can sort it out because that would be a great way to get around many things that limit a tandem in regards to driveline and suspension, plus tire clearance.

Best of luck with it.

PK


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