Speedo gear 32 vs 31 tooth

According to Brewer's, I need a 31 tooth for 3.23s & 28" tire
According to the Interweb, a 32-tooth.

I have a mint 32, a mint 39, and a used 31 with a few teeth knocked off, of course

What's 1 tooth worth in MPH on this setup?
FWIW, I tend to drive by the tach on the highway, but around town I'd like to know my speed.

Check your email & you will be able to compare a 31 & a 32 against your GPS soon. ;-)

Thanks, Barry, you Da Man.

GPS ?!

I'd want the mint 32 toother in there just cuz how bad the 31 toother is but it'd show the MPH a hair low than actual MPH (might cost you a ticket, might not). The archives has a chart & someone posted a link for a comprehensive chart but I dont have that info. EDIT measure your actual tire dia to get it as dead on as possible (might change what tooth count you need). MORE EDIT the chart someone posted had a MPH/RPM chart that was very helpful & there was something about an Excel worksheet. EVEN MORE EDIT the Excel worksheet in the 2 links are right there on the same page, right in front of me, I missed it.

Yeah, I have the Brewer's chart.
Barry & I are trading my 39 for his spare 31.
Was just curious what the difference would be between 32 & 31...

About 1 mph at 31 - 32 mph

Thanks.

There is an XLS table on tech section here where makes the exact maths. You could get maybe a 31,45 result. So you decide which one is the best for you based on that ( rounding up or not )

I recently went from a 28 to a 29 and the speedo went from 4mph low to 3mph high. this was with a 2.76 and 26" tires and a 4 speed.

Maybe go up a tire size or 2 to get it dead nuts.

Kevin

I usually drive 5-7 over so the 3 hi gives me an extra cushion

IIRC, when I did the arithmetic years and years ago, each tooth was worth ~ 1.67%. Which meant you should be able to get it within 1% either way +/- if your speedo head is working correctly. FWIW, YMMV, ect. 2¢

Roibert