intermediate drive
10-28-09, 07:19 PM
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intermediate drive
To settle a debate using an intermediate drive. There are two ratios involved. One from the chainwheel to the intermediate sprocket. This would also be the jack shaft or intermediate shaft that now has another ratio( from another sprocket) to the cluster. What is correct? Multiply both ratio's for the final gear inches or add the two ratio's and then multply times the rear wheel dia?
10-28-09, 11:21 PM
#2
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I'm pretty sure the ratios get multiplied.
I saw on online gear-inch calculator somewhere that could deal with intermediate gears,
maybe someone else who's seen it can also remember where it was...
Edit: found it!
https://www.soulbikes.com/gears/
Plug in some numbers to figure if it's adding or multiplying.
I saw on online gear-inch calculator somewhere that could deal with intermediate gears,
maybe someone else who's seen it can also remember where it was...
Edit: found it!
https://www.soulbikes.com/gears/
Plug in some numbers to figure if it's adding or multiplying.
Last edited by mikewille; 10-28-09 at 11:25 PM.
10-29-09, 12:17 AM
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Multiply.
Very common with recumbents. For instance: 63T chain ring and 14T rear cog with a 28/21 mid-drive gives.... 63T -> 21T or 3X from ring to mid drive and 28T -> 14T or 2X from mid-drive to cog. Multiply to get 6X from the chain ring to the cog.
:)ensen.
Very common with recumbents. For instance: 63T chain ring and 14T rear cog with a 28/21 mid-drive gives.... 63T -> 21T or 3X from ring to mid drive and 28T -> 14T or 2X from mid-drive to cog. Multiply to get 6X from the chain ring to the cog.
:)ensen.
10-29-09, 05:48 AM
#4
Senior Member
Agreed. Multiply. I had a 63-speed recumbent. Take the chainring/cassette cog ratio of each chain, multiply them together, then multiply by wheel diameter in inches to get gear-inches.
