sprocket size help

This has probably been discussed here before but I am new to my VFR and new to this forum so please bear with me if you will. I do alot of long distance riding and would like to lower the cruising speed RPM of my VFR. has anyone had any experience or have any suggestions on sprocket changes i.e smaller rear, larger counter sprocket, number of teeth up or down, number of links to remove from the chain? Any help is appreciated. thanks mike

 

Sure its been covered you can do search did this one for ya

http://vfrworld.com/forums/mechanics-garage/959-drop-tooth-front-sprocket-questions.html

and there are others too

 

reg is correct, going down 1 on the front would increase the rpm at a given speed. Going up on the rear has the same effect. I am not sure wht the stock gearing is on your model nor what your cruising speed to rpm is ( i. e. 55mph @ 4000 RPM). As an example, I just changed my chain and sprockets. I ketp the stock size 16 tooth fron and went from a 43 tooth rear to a 45 tooth. I saw no significant change in rpm, tho I might not quite have been at 4K at 55 mph. As it is now, I am dead nuts on 4K @ 55 mph.

 

Because the speedo takes it measurement at the countershaft and not the front wheel, you can change the sprokets all you want and the RPM vs indicated speed will not change. You will have induced a speedo error.

Stock 16 front and 43 rear = 4k at 55mph

Mod 16 front and 45 rear = 4k at 55mph indicated but actual speed is probably near 50mph. (I'm too lazy to do the math)

You will have to find out the error in your speedometer reading to see the changes after re-gearing. Your ass dyno will feel like something is off right away.

Me personally, I hate not knowing exactly my rate of speed when highway cruising. On the track is another story, who cares.

Too bad we don't have an electronic speedo that we can adjust for the changes in gearing.

 

That's what I was thinking, that actually I did not feel I was going as fast as I really was. I need to ride by one of those roadside radar boxes. lol

 

Sorry for the mistake here is some valueable info on gearing maybe this could help someone. it helped my understanding alot

http://www.sportrider.com/tech/146_0008_gearing/

 

Hey. First post, long time lurker. Just brought home my first VFR (93) on the weekend. I have an excel spreadsheet that I used to use for regearing calculations when I did the same thing on my '89 FJ1200. I ended up going from17/41 to 18/38 which had the desired effect of lowering the cruise RPM but also had the unintended consequence of requiring more care and clutch slip getting the bike out of the hole and riding in traffic.

If someone wants to tell me how to post it up (is there a files section like the FJ site?) I'll put it up for people to use. I've already updated it for the gear ratios and final drive, but it could use rechecking by someone who knows both excel and VFR's....

Steve
Delta, BC
93 VFR

 

The speed calculator for gear and tyre changes

Anybody interested in a spreadsheet calculating the speed at different RPMs depending on selected rear tire and sizes of chain sprocket?
It shows the speed in KM/h and MPH for any RPM , tire size , different chain sprockets for all 6 gears and calculates the deviation from stock values.
It is originally written for 3 gen vfr RC 36 gear ratios but they may be changed to fit your model's actual ratios.
If there is an interest --- where shall i put it ????
Another issue. Anybody got pissed off by chain lube sitting in a rear rim after 20 min of ride? I have had it! So i designed a shield attached to OEM chain guard and the problem is gone. 500 km and no trace of lubricant. Total cost is less than 5$ in materials. Anybody interested drop me a line at my email asw@signalix.com