Adventure Cycling Association Forum

Bicycle Travel => Gear Talk => Topic started by: recumbentgerry on January 21, 2019, 08:48:55 pm

 
Title: Four chain ring set up
Post by: recumbentgerry on January 21, 2019, 08:48:55 pm
 I have a trike that I had thought about installing four chain rings for a wider range of gearing. The set up would be: 22-30-42-52, the spacing is right if the derailleur will shift that far. I also have spacer washer to go between the 22 and 30 chain rings.  Has anyone tried this set up and what was the out come ???
Title: Re: Four chain ring set up
Post by: John Nettles on January 21, 2019, 08:55:49 pm
You might have better luck over at BikeForums in the "Bicycle Mechanic" section. It is highly improbable that more than one or two, if that many, people have toured with such a setup.  You could also try over at BentRider, if you haven't already.

Out of curiosity, what would the range (low and high in inches) of gears be and if more than say 110, why would you need it? If you just want a bunch of tightly spaced gears if you have a high cadence, then maybe I can understand.
Tailwinds, John
Title: Re: Four chain ring set up
Post by: jcostanz on January 23, 2019, 01:29:42 pm
I have it setup via a mountain trainer on my green speed get trike.  I believe I switched out the bottom bracket to the widest I could get.  Sometimes I need to give the front detailer a little help with chain tube to shift to the granny.  I have had it installed for more than 10 years  and love it for loaded touring in steep climbs.  The only times I have had to push the trike is when the tire would spin on the ground instead of moving the trike.  I use bar end shifters and I dont think indexed shifters will work for the front.  I would not recommend on a smaller rear wheel then 20" as a long cage rear detailer would most likely drag on the ground.  As it is with my 20" rear wheel the last cog wheel on the detailer is a out level with the bottom of the rim in several gear combos.

I actually like this setup better than the dual drive setup previously on the trike.  (Had a rear rim fail on a tour and shipped a replacement without the dual drive and found I was faster on same section of road!)

You probably will get more replies on bentrider online fourms under trikes.
Title: Re: Four chain ring set up
Post by: recumbentgerry on January 23, 2019, 11:50:00 pm
 I thought this idea would fly. I have every thing I need to build it up, thanks for the replies.
Title: Re: Four chain ring set up
Post by: zerodish on January 28, 2019, 07:22:31 pm
What is going to happen with your setup is is the chain will shift from the 22 to the 42 and never hit the 30. Frank Berto discovered this problem in the 70's. Try and make the smallest cog and the second smallest cog as close as possible to each other. I use a 2mm spacer in my setups. Also if you place 2 chainrings on a single bold puts more stress on the bolt and it is possible to shear them. Here are a few I have tried. https://flic.kr/p/WxWrEf https://flic.kr/p/bCuNDq https://flic.kr/p/bCuDZh
Title: Re: Four chain ring set up
Post by: canalligators on February 09, 2019, 08:41:56 am
You should be able to get wide range and close enough jumps with a triple.