Which is needed? Or both?

[hitman46mod]

I want to hit 100 to 105 ish MPH with my GS 450 L. 16/43 now. I can get an 18 front sprocket. Will that do the trick? Or will I need a smaller rear? Not a speed freak just want to be able to do it.

[TheCafeKid]

Most every GS I've owned (and granted they've all been 750 or larger) ran out of HP well before it ran out of gearing in top gear...

[Steel Toed Tank]

I can do that speed in 4th with 15/41 on my 750. That's with a 630 chain.
I don't know if that relates to your set-up or if it helps, just sayin...

A good bit of info about sprocket math.

http://www.z1enterprises.com/reference/chainsprockets.aspx

Tank

[Steel Toed Tank]

my final drive ratio is 2.7333 and yours is 2.6875.
Not really far off at all.
I think TCK is right, it's more of a HP issue.
You could try shifting from 3rd up with your RPMs up high, if you don't already.
My peak HP is at 8,500.

Tank

[hitman46mod]

Running pods got the dynojet kit, it taps out at about 95.2 MPH GPS 95-96 next to another bike. (friend of mine). Just want to reach that 100 mark. Pulls good till then and just hits a wall. Don't think it's an HP issue. Besides, I mainly use the bike to commute and the lower revs in 6 at the "speed limit" wont hurt me either. Do these bikes having an electronic ignition, have a limiter?

This is my first Street bike. I already have plans to buy a 00' or newer GSXR 600 or better in the late winter feb of next year. If the world doesn't end on 12/12/12. LOL

But I'm going to keep this this cause its bada$$!

Redline on mine is 9500 rpm from what I have read about it. I'm at 7800 at current peak.

[Steel Toed Tank]

Check out that link about sprocket math. Tells you before you try what speed you can go at which rpms depending on your planned FDR. I was going to mess with my ratio to get a lower rpms on the highway but my first gear is already so tall that I can easily break the in-town speed limit of 50km/h (30mph) without much effort. Reducing my ratio would lengthen 1st even more. But she hums along just fine at 110km/h(70mph) around 5000rpm and easily gets to 170km/h(105mph) from there.


Tank

[tkent02]

I don't think it will go any faster with taller gears, unless it does it in a lower gear.
These puppies need to spin.

But 105 for a stock 1983 450 is a tall order.

Wait, you have an L?
Get rid of the doofy handlebars and it will go a lot faster.

[Baatfam]

I don't think it will go any faster with taller gears, unless it does it in a lower gear.
These puppies need to spin.

Correct! If you are not reaching redline in top gear, you should try shorter gears, not taller...
Make it easier for you engine to pull redline.

Still no promise you'll make it, though...

[hitman46mod]

Well, thanks for the input guys. I guess I will just have to be happy with what I got.

[koolaid_kid]

You need a really tall hill with a very long straightaway. Or an airplane with a cargo bay door.
Seriously, over 90 (indicated) is very good for such a small bike. Back when I was into it we would lay down on the tank to reduce drag as much as possible. Having a vehicle to draft behind helped us also.

[Nessism]

Would go faster with a bigger rear sprocket, not smaller.

Did you tuck in tight to get out of the wind during your top speed run?

Maybe try a 45 tooth rear sprocket? Or just be happy with what you got.

[tkent02]

Back when I was into it we would lay down on the tank to reduce drag as much as possible. Having a vehicle to draft behind helped us also.

I used to lay down on the tank, rest my helmet on the handle bars, feet on the rear pegs, pin the throttle and listen to the mechanical sound of the engine transmitted up through the helmet. With no wind noise it sounds beautiful. Wide open for miles and miles at a time sometimes. Drafting a blonde in a green Mercedes across Texas, got the 750 up to the highest speed I had done until then.

Couldn't catch the blonde.

[hitman46mod]

Ok, I ducked down behind my custom bikini fairing. 97.3 MPH @ 8k GPS. So yeah that is all she has.

[Nessism]

That fairing is most likely slowing you down. looks like a barn door. I believe a stock 450 should crest 100 mph if you tuck down low on the tank and have a long enough road. That fairing is pushing too much air and it doesn't look aero in the least.

[hitman46mod]

My original speed was 95.2! So 97.3 Is an improvement. The fairing makes a difference. And top speed on this model is 94.7. However I'm 6'3" 265lbs,almost 2/3 the bikes maximum load capacity. So I would have to say, I'm making progress. LOL
Side view. The fairing is low and small. Oh and the headlight visor is not on anymore.


I'm working on a cafe seat pan. And making the tank taller in the rear. To expand capacity.