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Discussion Starter · #1 ·
Has anyone put a 19T sprocket on a Bonnie with the newer speedometer? I'm pretty sure I read on here somewhere that the newer speedo (mid 2010 and newer models) was driven from the transmission instead of the front wheel. If this is true, wouldn't putting a 19T sprocket on help with the speedometer accuracy? We all know they read fast (as do most bikes), but with the bike now going faster than the transmission thinks it is going, will the speedo be more accurate?

Or am I thinking about it backwards? :)
 

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Makes sense to me if it's transmission driven. Guess the speedo cable will be different on a trans-driven speedo bike. No fat speedo cable arcing down to the front wheel. So, what speedo cable do the new ones have?
 

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I would think that electronic speedo is more accurate then the cable driven, that being said I would think the speedo will run slow in error with the 19 tooth. I'm sure somebody will figure out a way to re program that thing for different size sprockets. I know the HD guys have programs for such. I had an HD that was dead on with a GPS unit, so those electronic ones are darn accurate.
 

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my transmission driven speedos are mechanical devices just like any speedo driven off the front wheel.
 

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Mechanical or digital has no bearing on its accuracy with a 19T sprocket. If the pick up is transmission based on the new Bonnevilles then your speedo will be out. if its front tire based then no issue.
 

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Are you 100% sure its not taken off the front wheel? just because its electric dont mean its trans driven.I dont know what there useing.
 

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Somebody with a new 2011 with the new speedo, please tell us if there is a big old speedo cable going to the front hub or not.

If you're not sure, please pop your bike up on the centerstand, fire it up and rev it a bit. Then tell us if the speedo needle moves. If it does, then it's reading of the trans, either by cable and gear to the trans, or by electronic speed sensor (like the SpeedoHealer is meant to work with).
 

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Looking at the pics on the Triumph website, I only see a brake line going to the front wheel.
 

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Discussion Starter · #10 ·
Actually, I was at the Triumph dealer and can confirm that there was not a speedo cable coming from the front wheel on the Blue/White SE, but there was one on the Bonneville next to it (it would appear as if the speedo only Bonneville gets the older wheel driven instrument).

I was just musing that perhaps switching to a 19T front sprocket on an SE would not only lower the cruising RPM, but also make the speedo a bit less optimistic...
 

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My Sprint's speedo is electronic, but just as optimistic as my Bonnie was. The only difference is that the Sprint one is adjustable with Tune ECU unlike the mech one on my Bonnie...
 
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