by   February 4, 2013

Hello there folks,

I'm normally the one that's giving others advice, so if you all want to chip in, fire away.

So the trike came with a triple and its a 30/39/52 but I need some more range, its a 9/32 10 speed on the rear, but on the flat I'm spinning out the 52/9

So I'm looking at replacing a couple of the rings, maybe set it up as a 30/42/55 but having trouble finding the rings to go with my crankset.

Its a SRAM Truvativ Elita, here's the link to the "manual"

http://cdn.sram.com/cdn/farfuture/EHj107okLLfBSPXS9vasz1e3rQc-URzFQkv6s8...

So what am I going to do?

don't be mental if you have 20" wheels and can get to 110 rpm average you will be going 41.2 mph

posted by SammyG [286 posts]
4th February 2013 - 21:57

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Even with over 12 foot of chain?

Normal calculations do not work with recumbents

posted by Gkam84 [7538 posts]
4th February 2013 - 22:14

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Ah sorry 37.796 @ 110rpm on a recumbent

posted by SammyG [286 posts]
4th February 2013 - 22:21

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How are you getting that figure? I'm spinning through the 52/9 around 30mph if I'm lucky.

I'm used to a ratio around 125 inches.

I don't know if that figures into anything, but that's what I get from using online ratio calculators....

Putting all the figures into here http://sheldonbrown.com/gears/

My MPH is about right, 31.7 at 100rpm....

I don't know how this is all worked out. But I know I don't have enough gears

posted by Gkam84 [7538 posts]
4th February 2013 - 22:58

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http://www.recumbents.com/wisil/gearinches.asp if you have a wheel diameter of 20 inches, 52teeth front, 9 back you will have 115 gear inches.

60 - 21
70 - 24.2
80 - 27.3
90 - 31
100 - 34
110 - 37.7

posted by SammyG [286 posts]
5th February 2013 - 9:06

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still on the 3rd switch-back of Bwlch !

posted by therevokid [524 posts]
5th February 2013 - 9:46

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You will probably need a new front derailleur to cope with the bigger difference in teeth between the big and middle rings.

Ah! Condor

posted by Bedfordshire Clanger [296 posts]
5th February 2013 - 10:16

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I think those measurements are for a 451 20 inch wheel SammyG, Mine are 406

Thanks revo, they are 130's

Clanger, I wont need a new deraillieur, just move it slightly up the post, plenty of room to do it

posted by Gkam84 [7538 posts]
5th February 2013 - 11:56

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Does your front mech not have a limit to the difference in number of teeth that it can handle? You are proposing a change from 22 to 25.

Ah! Condor

posted by Bedfordshire Clanger [296 posts]
5th February 2013 - 21:31

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Not that I'm aware, when I had it in the LBS to have the shifter replaced, I spoke to them and they said I can just move it up the post slightly.

posted by Gkam84 [7538 posts]
5th February 2013 - 21:36

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