final drive ratio's and where to look

[Jon_P]

ok so the one guy at the show got me thinking, do i have the right final drive and is that why she likes to buzz and drink plenty.

so where do i look to see what ratio i have and what is stock, i cant find it in my books??

[Rob Valdez 79 R65]

It is stamped in the final drive.  Look near the fill hole for the driveshaft oil.  On my bike, I would have to wipe away a little dirt to read them easily.

[airhead]

For your model it's 9/31.

Bill................;-)

[Jon_P]

the only numbers i can find stamped on the final drive are stamped on the inside of the unit so ou have to look throught the tire. they are 8 and a 56 but are not stamped together or with a /, in fact the 8 is sideways.

[Jon_P]

boy oh boy my local dealer service manager is a 100% jerk! i have a feeling if he doesnt know the answer to the question this is how he acts. all he said was be happy that it goes down the road!

now i havent ridden it much with the gps to know how many miles i get from a tank of fuel but its not many, and i wonder if it is cuz this final drive? could that cause some of mine low mpg??? it has all kinds of low gearing grunt but when she gets in four and fifth there is not much there without a running start. or am i asking to much?

[Bob_Roller]

Without knowing the rear end ratio, it's hard to say. This is a crude method on determining the answer, but you could pull back the boot over the universal joint, and count the revolutions of the drive shaft to rear wheel revolutions to be absolute sure what you've got. But it sounds like you may have an other than standard rear end.

[NC Steve]

Okay, outside of going to an R80, what kind of final drive can I put on Blue to keep gears 1-3 close to the same, but let 'er run 4000 rpm at 75 mph?
Is this asking too much?

[Rob Valdez 79 R65]

Okay, outside of going to an R80, what kind of final drive can I put on Blue to keep gears 1-3 close to the same, but let 'er run 4000 rpm at 75 mph?
Is this asking too much?

Yes

At least, it it will not happen by swapping R.E. ratios.

[NC Steve]

Thanks Rob, that's kinda what I thought, unfortunately, but figured maybe I'd missed something somewhere.

Sounds like it's time to go back to the 2 Bike Theory...

[Rob Valdez 79 R65]

There is a place in Germany that has alternative 5th gears, to do what you may want.  I have never wanted for anything different than what I have.  
Sometimes I get on the I'state in a hurry and look for a 6th gear accidentally.  I guess that is what you might mean.  But when I am out for the weekend on the slab, 5th gear at 75mph is fine - as long as I can stand the wind!

I'm beginning to get a 2nd bike bug... thinkin' RS...

[NC Steve]

Sometimes I get on the I'state in a hurry and look for a 6th gear accidentally.  I guess that is what you might mean.  But when I am out for the weekend on the slab, 5th gear at 75mph is fine - as long as I can stand the wind!

I'm beginning to get a 2nd bike bug... thinkin' RS...

yeah [smiley=thumbsup.gif], thatswhati'mtalkinabout...

[MrRiden]

I would like some taller gearing for the wide open spaces myself. I came across an unofficial listing of ratios / models here: http://tinyurl.com/32vve5 Think I'll tuck it in my pocket for my next bone yard / swap meet visit. I have no Idea how interchangeable these rears are. Probably not at all is my guess. If your bike is really thirsty / buzzy I wonder if you have an r45 gear set. Grab the GPS and watch the speed/ RPM it would be interesting.
rich

[Ed Miller]

Geeze, how fast are you guys going?  90 in top gear feels nice, smooth, and easy on my R65.  I'm more worried about the aerodynamic effects from my saddle bags than anything else.  Well, tickets aka freedom tax.

[Jon_P]

well its not how fast i am going, more that how fast i would like to go

i will try this weekend to take a longer look at it, i will pull the boot and take a grease pen and make a mark on the drive shaft and tire and start counting, think that is about the only way i will know for sure. then i will know what i need to do or not do.

[Rob Valdez 79 R65]

[size=12]Anymore, interstate hwy speeds between cities are 70 mph _{[113 kmh]}, which equates to 75 _[121] cruise  

When I talk about how fast I am going, I am talking in GPS figures, not Motometer.

I used to think 85 mph _{[137 kmh]} (indicated) was a nice cruising speed, and I was impressed that the 'little' 650 could do that.
Then I got a GPS receiver and found out the truth!

I've never really written it down, but that 85 mph _{[137 kmh]} is really about 73 _[117]...

100 mph _{[161 kmh]} indicated is about 85 _[137], I think.


The only time I am going these speeds is when the bike is loaded with gear.  That is usually two saddlebags loaded to capacity, a sleeping bag on the rear rack, and a tent/pad/chair on the seat behind me.
That limits my top stable cruising speed to 80 mph _[129]  Anything above that, and the front end starts getting spooky.  I really need to rebuild the forks.

The good news is, I don't have to worry about getting busted on the interstate.
It is always those NON-interstate highways that LOOK like interstates (new bypasses around towns) but have lower speed limits, like 55? _[88?] where I get busted... [/size]