Output flange rpm on gs1100g..???

[Mark Harrop]

You looking for 5000 flange rpm or 5000 engine rpm?

Looking back at my figures, the shaft (flange) will be doing about 2448 rpm at 60 mph. My wife's 850's engine is turning about 4300 rpm. This would mean a ratio of about 1.75 from engine to output. (I just looked farther in the spec pages and found that it's actually 1.811 for the 850.) Using that ratio and the projected shaft speed of 4080, the engine would be turning about 7150. An 1100 might have a different ratio, so the engine speed would be less. If you are trying to get engine speed down to 5000 at 100 mph, you need to drop the ratio about 30%. You could do that by using a wheel sprocket with 30% fewer teeth than stock. Any idea what a stock sprocket is? If it's a 41 tooth sprocket, use one that is about 29.



Owww, stop it, my head is hurting.

.

You think your head hurts?

OK, I just posted more data, so it looks like final drive ratio is .961 (whatever that means)

Is that .961 of engine rpm? and what is the 25/26?, is that 25/26ths?

[Steve]

This would mean a ratio of about 1.75 from engine to output.

Primary reduction:
1.775 (87/49)

Pretty darn close, wasn't I?

Now you just need to find the stock ratio of, say, an 1100, to see what the tooth counts were on the sprockets.

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[Mark Harrop]

Pretty darn close, wasn't I?

Now you just need to find the stock ratio of, say, an 1100, to see what the tooth counts were on the sprockets.

.

You'd already figured it out while I was posting...damn fine cyphering Steve, my hat is off to you.

[Mark Harrop]

Compression ratio..9.5:1
Transmission............5 speed constant mesh, 1-down 4-up
Primary reduction..1.775
Final reduction....2.800
Gear ratios, Low...2.500
Gear ratios, 2nd...1.777
Gear ratios, 3rd...1.380
Gear ratios, 4th...1.125
Gear ratios, Top...0.961

Thats from an 1100e, so it looks the same. Guess I just bolt up some sprockets that are geared a little higher and go for it.That wasn't as bad as I thought. Its almost like Suzuki knew I was going to bolt sprockets to the output shaft flange...and they made it easy for me.

Thanks again Steve for holding my hand through that brain teaser.

Now, about cooling issues...

Or anything else that might come up running that motor sideways...

[SqDancerLynn1]

I would suspect you may have a problem with the drive flange breaking off due to the side loading with jackshaft. Who knows ? definate cooling problems

[Baatfam]

But at the 90 degree angle, it's not going to sit like an inline, almost more like a V twin. Sorta. The weight will be front to back, assuming that is the forcing mechanism behind the desire to lean. If it's just torque madness, the lean would probably be based more on how well balanced the rider stays and that the pants-crapping doesn't make the rider slide to the right or left, causing radical leaning one way or the other I've always felt like torque wants to stand the bike straight up, but that's me and I don't spend any time at 100mph. I'm only half as crazy as Mark. Maybe not even Other than the rider, the weight is in the engine. An I-4 has it distributed more east west, while turning 90 degrees it brings it north-south in relation to the frame. Depending on what Mark does to avoid burned legs/reduced weight from exhaust, that is. My guess would be that it will make the bike feel lighter, and be more wheelie-inducing.

MissFab...open the hood of your car and have someone rev the engine.
Watch how the motor twists over one way against the mounts.
It twists over on the line of the crank shaft.
Now put a motor in a bike with the crank inline front to back, like your car and it will do the same thing...only not on rubber mounts, so it will push the whole bike over one way....

A V-twin still has the crank 90? out from the center line of the bike...

[Steve]

A V-twin still has the crank 90? out from the center line of the bike...

Well, ... most V-twins do. Think Honda CX500/650 and Moto Guzzi, they have their cylinders splayed to the sides, leaving the crank in-line. Yes, they had torque reaction issues, too. BMW riders have learned to lean a bit when they take off. I think Wing riders are the only ones basically unaffected because Honda turns all the other shafts in the opposite direction to counteract the torque effect.

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[Baatfam]

Well, ... most V-twins do. Think Honda CX500/650 and Moto Guzzi, they have their cylinders splayed to the sides, leaving the crank in-line. Yes, they had torque reaction issues, too. BMW riders have learned to lean a bit when they take off. I think Wing riders are the only ones basically unaffected because Honda turns all the other shafts in the opposite direction to counteract the torque effect.

.

Good point...forgot about the Guzzis. Thanks!

[drhach]

Why exactly do you want to use a GS engine? Does it have to be air cooled? It seems like you are really making this needlessly complicated. Take a four cylinder engine out of any car and you're good to go.

[Mark Harrop]

Why exactly do you want to use a GS engine? Does it have to be air cooled? It seems like you are really making this needlessly complicated. Take a four cylinder engine out of any car and you're good to go.

Yea...old and air cooled. Remember, I also plan on winning an "old-school" chopper show after the race. Sure, I could use a car enging, but then it wouldn't really be a motorcycle.
Since this is pretty much a "harley" dominated event, I want to beat them at their own game. Using a GS engine in an unconventional manner will assure me victory. Especially if it is reminiscent of those old Indian inline 4s. I gotta one-up the Kamikaze!

Plus the GS motor is a natural...good power and reliability....and I want to get some notoriety for the GSR community!

As far as the output flange, I was thinking of running a support bearing (like they use on dragbikes) to remove the load....good point.

[Mark Harrop]

As far as torque reaction, I know it will be an issue, but I won't be launching hard. I plan on getting up to speed smoothly...so I can deal with it.

This is a purpose built machine for winning a transcontinental race and a chopper show. Since everything will be rigidly mounted, I also wanted a smooth running motor. I've ridden bikes with torque-lean, so I know what to expect.

There is an old saying "nothing is new in chopperdom, its all been done before"

Well, if anyone has done this with a shafty four cylinder, I've never seen it, but that doesn't mean doodly-squat. Has anyone ever seen a contraption like I'm planning?

[hp1000s]

Torque reaction shouldn't be a big deal...rode one of those cursed Boss-Hoss' for a year w/SBC 355hp/300lb/ft tq. Going straight down the highway wasn't bad at all...just don't whack the throttle mid-way through a curve. Looks like a cool project! Hope you pull it off!

[drhach]

....Sure, I could use a car enging, but then it wouldn't really be a motorcycle.
...

From Webster's Dictionary...

Main Entry:
mo?tor?cy?cle
Pronunciation:
\ˈmō-tər-ˌsī-kəl\
Function:
noun
Etymology:
motor bicycle
Date:
1896

: a 2-wheeled automotive vehicle for one or two people

Best of luck.

[focus frenzy]

Mark Mark Mark, the only chance you have is if you fabricate a large ugly cooling shroud. without it the engine will over heat and seize up and likely burst into flames.

the old Henderson's and Indians and several other in-line 4's made back in the early days had at best 30hp, and even then they had problems with over heating the back cylinders. that is why they went the way of the hard tail, it don't work and is un-safe.

know how many people lived to tell their adventure of running 100mph on a motorcycle with no suspension? not very many.

please reconsider, we don't want you to go up in a ball of flames at 100mph.

[Baatfam]

please reconsider, we don't want you to go up in a ball of flames at 100mph.

Of course if he does...I expect video...