Sprocket sizing and speedo accuracy
 

Hey everybody.
I've been lurking on this site since it started and have finally posted :) I saw an auction on ebay for the 520 chain conversion and the seller had a statement on there regarding the accuracy of the speedometer and changing sprocket sizes. I was wondering if it was true or not.

Quote from auction:
"Furthermore the Honda Gauge cluster is about 8-10% high from the factory settings. One more benefit of the kit we sell is that it actually makes the speedometer only 2% high as opposed to 8-10% too high"

The kit is a 1 down 2 up sproket kit plus chain. Here is the link to the auction

520 Conversion Kit Auction

Does anyone know if this is accurate or not?

Probably about right. Hondas tend to be among the more optomistic of brands. However, every one is a little different and the variance grows with speed.

Re: Sprocket sizing and speedo accuracy
 

I guess I'll have to check my speedo to see how off it is and gauge from there. Thanks for the reply

Re: Sprocket sizing and speedo accuracy
 

OK, trying to "envision" this kind of stuff makes my head hurt so I'm usually wrong.

I've always heard that dropping down on the front throws off your readings in an upwards way; i.e., you'll be reading even higher than true roadspeed and you odo will read more miles. It seems doing that AND going up on the rear would make things even worse still.

IIRC, stock gearing error is about 6%. In my case, I have 15t and it reads approx 10% high compared to my sigma computer at highway speeds. I don't look at it much at lower in town speeds so I'm not sure what the error % is on the low end.

I tried 15/45 ( :shock: ) for a while and the Speedo error was worse than stock, in the same direction. The bike accelerated very quickly, but the error was just too much to live with. This kit would not be as bad as the ratio I tried, but it would be in the same direction.
The speedometer is picked off the transmission, so changing the final drive ratio will change the spedometer "calibration".
I wonder...has anyone tried a 16.5" inch wheel/tire setup on the Hawk...that would change the final drive ratio, right?

Re: Sprocket sizing and speedo accuracy
 

I went 1 tooth down in front (15t) Based on my calibrations and testing my bike was 7% off from factory. Going one tooth down in front is about 8% lower than stock. So when I installed my Yellow box I had to adjust 15% to get it dead nuts on with factory d204 tire in rear. I think that if you went 1 down in front and two up in rear it would be WAY to low geared. Even with a 15t front and stock rear I have to be carful not to pop the clutch too hard from a dead stop or she'll pull the front up very fast.

Re: Sprocket sizing and speedo accuracy
 

:shock: *immediately orders a 15t front sproket* :twisted:

Re: Sprocket sizing and speedo accuracy
 

[quote="RVO27";p="4286"]Hey everybody.
. I was wondering if it was true or not.

Quote from auction:
"Furthermore the Honda Gauge cluster is about 8-10% high from the factory settings. One more benefit of the kit we sell is that it actually makes the speedometer only 2% high as opposed to 8-10% too high"

The kit is a 1 down 2 up sproket kit plus chain. Here is the link to the auction

He has it bass ackwards. Be careful about this seller, since if he lies about this, he may lie about other things. It will make the speedo even more inaccurate.

By the way, a product I have used on my RC51 will also work on the VTR to correct speedo. It is cheaper than the yellow box, I believe, at $85. Here is the site for info http://www.jahlmandesign.com/

It doesn't list the VTR1000, but I emailed Jim recently and he said it is available for it.

Fred Z.

Re: Sprocket sizing and speedo accuracy
 

I thought the auction quote was a little fishy. I have a 15 tooth in the front right now and it's definatly high. I think I might get one of thos speedo calibrators to fix the gauge. Thanks for all the replies guys.