Final drive Solution

[Dennyz]

I just picked one up off eBay $0.99 ($25 shipping).

[knewsom]

lucky dog!

I haven't found one for under 50 total

[xschop]

$50!

Man, robbery ebay style. But it'll pay for itself in the first few fill-ups of gas saved....JAT....chop

[pggg]

Stock XS11 gearing is perfect for the XS11 motor, the stock bike is geared for maximum performance, the 3600 revs @100k.p.h is still the gearing I prefer, the lower gearing is racier for sure, Chop if I put on a 13tooth sprocket with a 48 at the back, the gearing is gonna be lower, most I did was 141mph with tall gearing, the right gearing is taller than stock 4th gear but lower than stock 5th gear - in 4th gear. As for fastest XS11, the F1 XS1100 racebike article I saw had the bike officially clocked at Kyalami racetrack at 267k.p.h.

[xschop]

As stated

chop quoted... "whoever does this FD gear mod with the big bore kit will own top speed" I am sticking to this quote. PERIOD!

[mro]

165.91 MPH???

What kinda rpm's?
Where's them math dudes??? , too early to think.


mro

[xschop]

yes, math please

with stock xs11 gearing, what rpm's would it take to get the xs11 to hit 165mph?

[knewsom]

http://www.xs11.com/specifications/e-spec1.shtml

well, at 10K rpm, a 78 should be going 158. that's with the stock 3.3/1 ratio.

with the final drive off a 750, at 10k, you should be doing just under 180.

1/3.3 = .30303030303

1/2.9 = .34482759

.34482759 divided by .30303030303 = 1.379311

1.379311 * 158 = 179.79311 mph @10k RPM

Q.E.D.

However, with an 18" wheel, it's concievable that one could go faster.

[xschop]

woooooaaaahhhh!

I will just stick with my quote, it's pretty simple.I would buy the video of a 160+ xs11 run, but I will stick to 120 and below myself

[pggg]

Taller gearing alone WON'T increase top speed, there's more to it than that. Power and wind resistance is what it's all about. The article I'm talking about 267kph at Kyalami is in a English classic motorcycle magazine I have - www.classicmechanics.com is their website. That XS11 was a 1179 chaindrive tuned and tweaked, big carbs, ported ,cams etc.. Dunno if you guys get that mag in the States, but it's the best bike magazine around.

[knewsom]

sounds like a good mag!

I understand that top end speed is a function of more than just gearing, but the engine, just STOCK should have enough torque and HP to drive a bike to 150+, if provided the appropriate gearing.

You can have all the HP and torque and aerodynamics in the world, but if your bike won't go above 158 at 10K rpm, you're not going to set any speed records.

[pggg]

Put it this way - raise the gearing on a stock XS11, and the motor won't reach peak horsepower in the taller 5th gear. Beef up the power - then we're talking the stock gearing is perfect for the stock motor, bearing in mind this is all meaningless as 200 kph is soon real uncomfortable on a naked bike

[xschop]

Overdrive

the bike still launches quick and cruises like there has been a sixth gear installed.My motor is stock, dynatek coils, K&N filter, about 70 lbs lighter than factory though. So does anyone have a big bore motor they want to trade for that I can bolt on?

[knewsom]

Originally posted by pggg
Put it this way - raise the gearing on a stock XS11, and the motor won't reach peak horsepower in the taller 5th gear. Beef up the power - then we're talking the stock gearing is perfect for the stock motor, bearing in mind this is all meaningless as 200 kph is soon real uncomfortable on a naked bike

ya know.... there's really only one way to find out.

[50gary]

I read that magazine, it's pretty good but costly in the US. I also visit the UK Xs11 board they are a bit different than the US guys more performance oriented, less touring at least that's my view.
Cheers, 50gary