Shift Limiter?

[Alaskavan]

I just thought I'd put this out here and see if anyone has any ideas.

I use pretty tall, and pretty small gears, on both ends of the pedal drive. On the wheel, my low gear is 34 tooth, and my high gear is 13 tooth. On the crank, my low gear is 34 tooth, and my high is 62 tooth. When I have the chain adjusted so it works well with the low gears, it will snap the chain if I accidentally hit the 34 tooth rear while I'm on the 62 tooth front.

So, here's the question: Can anybody think of a way I can idiot-proof the gears? Some way to absolutely prevent me from being able to shift onto that 34 while I'm on the 62?

[turkeyssr]

Off the top of my head, no, I can't think of a way. It's due to the waaay BIG 62 tooth sprocket up front. That's beyond anything I've read about on Sheldon's site, which I'm certain you're familiar with. I also assume, you've attempted to lengthen the chain by using Sheldon's method found here: http://www.sheldonbrown.com/derailer-adjustment.html

If his method doesn't work, my guess is you're simply outside the design limitations of the derailer.

--John

[srdavo]

Can anybody think of a way I can idiot-proof the gears? Some way to absolutely prevent me from being able to shift onto that 34 while I'm on the 62?

remember "Hee Haw"???

"hey doc...it hurts when I do this."
"well, don't do that!"

just use that danged front derailer some. I live in the flatlands, so I don't have much use for 'em.

[Alaskavan]

Thanks guys. I guess maybe the answer is for me to just be careful. Once I get the engine going on this thing maybe I won't be tempted to get anywhere near the low gear. Perhaps I could just adjust the rear derailleur so It won't hit the 34t. Then if the engine dies, I could adjust the derailleur so I could use low gear to limp home.