Primary Gearing

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Nov 24, 2015 | 05:21 PM

#11

grbrown

Club Member

Joined: Jun 2007

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From: Bedford UK

No Keith, my bike is old enough to have a speedo driven by cable from the front wheel. No electrons are employed or disorientated by my changes!

Nov 24, 2015 | 07:02 PM

#12

deadhawg

Stellar HDF Member

Joined: Apr 2010

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From: CA

Quote:

Originally Posted by grbrown

No Keith, my bike is old enough to have a speedo driven by cable from the front wheel. No electrons are employed or disorientated by my changes!

True, but on newer bikes, changing the trans sprocket or pulley will affect the speedo and odo, by the same percentage as the tooth change.

Nov 25, 2015 | 04:34 AM

#13

grbrown

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Joined: Jun 2007

Posts: 45,429

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From: Bedford UK

Quote:

Originally Posted by deadhawg

True, but on newer bikes, changing the trans sprocket or pulley will affect the speedo and odo, by the same percentage as the tooth change.

I realise that, but I have enough challenges with my build as it is, without being troubled by the speedo!

Nov 27, 2015 | 10:45 AM

#14

motosman1

Thread Starter

Intermediate

Joined: Feb 2009

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Quote:

Originally Posted by Keithhu

Curious, and sort of off topic - does any of this mess with your speedo/odo?

Exactly why I'm going with primary gearing change. Inner primary stays in place, no added cost of belt and frt. pulley, no added cost of "speedo recal unit" and no additional labor. Doing engine mods that require clutch upgrade so I'm already there. Customer is going with a Baker OD-6, so in this case the inner primary IS comimg off. Primary ratio ends up at 1.54:1, final drive becomes 3.37:1 and the .86 OD takes it to 2.90:1.

Nov 27, 2015 | 11:55 AM

#15

grbrown

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Joined: Jun 2007

Posts: 45,429

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From: Bedford UK

I recommend you do a cost comparison of changing the rear drive ratio, against the primary! The cost of that new clutch with different size sprocket ain't cheap. My shorter belt arrived today, so hopefully my build will continue tomorrow, with both modified primary and rear drive ratios.