6 Speed Gear Box Blandit 1200

[tyler]

Been searching through the forums trying to find a detail write up of someone using a 1988-89 GSXR 750 6 speed gear box in a Bandit 1200 engine. i know the shaft needs drilled to operate the clutch. But what about everything else? Bearing? Spacers? Machining? Can someone post a link to the correct forum and or maybe shed some insight on how to do this. i WANT 6 gears. a lower first and a taller high gear. i feel that with the mods i have and small carbs i should be able to get 40mpg or better. the way it is i can manage 30-35 but i have to run 4,200rpm to go 70 mph. i know a 100lbs of  torque will push the bike down the hwy @ 3,500 or less. thanks in advance guys

[dupersunc]

The swap is easy, it's in the archive section of the site.

Drill shaft for clutch. Swap output shaft bearings about, and I used a 1052 slabbie clutch inner hub and cover in a Bandit basket.  That's it. 

The spread of ratios in the 6speed box is no wider than the five speed box though. It's designed to keep the peaky 750 motor in the power. It's a great swap for track use and racing as the 5 speed box ratios are more for touring, the higher gear ratios are too widely spaced the lowers too close.

If you want to cruise at a lower rpm , fit a 43t rear sprocket or a 16t front. 

Much simpler and cheaper way of achieving your aims.

Edited May 28, 2019 by dupersunc

[vizman]

You could swop it all for a Prius.....I’ve heard red ones are shizzle 

just change the sprockets if mpg is what you’re craving.

[El_Retardo]

Ride more economically then. On a standard 12 I have seen over 50mpg doing distance half motorway 70-80 & the same on A roads with some very hard acceleration to overtake some long lines of traffic

[tyler]

i left out some vital details

 

Slingshot head

Sling shot cams

Mill cylinders to zero deck clearance

Slotted timing

Slotted Cam Sprockets

Full Yoshi

Still just CV carbs with over sized main and pilot

Still has Air box, w/ hole

 

the millage is shit due to the above mods and the fact i am running 4200 RPM!!!!! to cruise a 70 mph. i have lower geared sprockets to obtain the pep i want, and the fact it likes 10,000 rpm and not 8,500. you can gear it different sure, but then no more 3rd gear wheelies, its a dog, etc. Add one more gear with a much higher ratio than 5th in the B12 box. and your in like flin. 

 

 

i wore the shit out of first gear dogs. Literally will engage for a second pop engage pop. so that is why i am switching gear boxes, but i rather have 6 gears than 5. so swap a 6 speed box instead of a B12. no matter what i have to switch gear boxes.

im not looking for opinions on the matter, or sarcasm. just trying to find detail on what is needing worked on to fit these gears. Mileage is not a concern of mine, but it would be nice to have more. My concern is a ruined 1st gear. and how to fit a 6 speed box. 

as far as "ride easier" i have never, not even in stock form, got better than 45mpg. they are toys, i ride them as such. 

thanks dupersunc for the input

will search archive, if i cant find it could use some help...

 

[vizman]

If you don’t like sarcasm stay off the internet......

[Gixer1460]

I think the 750 / 1100 top gear ratio's are near enough the same so that won't change but if you are killing 1st gear (for whatever reason  ) then installing thinner width gears is not going to improve your reliability! Power helps - junk the CV's add 36mm Flatties job done - 3rd gear wheelies on the throttle and with stock gearing +152hp

[Lachie04]

 

2 hours ago, Gixer1460 said:

I think the 750 / 1100 top gear ratio's are near enough the same so that won't change but if you are killing 1st gear (for whatever reason  ) then installing thinner width gears is not going to improve your reliability! Power helps - junk the CV's add 36mm Flatties job done - 3rd gear wheelies on the throttle and with stock gearing +152hp

+1

4200 rpm at 70mph lucky! my teapot gearbox is doing 5500 engine rpm at that speed 

21-23 750

23-21 bandit

Looks like you'd be spinning faster

Edited May 29, 2019 by Lachie04

[banoffee]

http://oldskoolsuzuki.info/archives/404

[tyler]

thanks banoffee

With stock gears and a 190 tire i was doing 70mph @ 4000 give or take a couple. 4000 rpm now with one smaller front one bigger back only goes 65 or so. i have looked up the ratios, 6th gear is like a 1.03 or something and 5th in the bandit is .9 something. so there is 10% right there. More over, the first gear is crazy low, 2nd gear is like the bandits first gear. so everything about it sounds better to me except the fact it is going to be "weaker"

 

I bought this bike from my dad back in 2010/11, with 19,xxx it will cross 60,xxx on my way home from work today. Assuming that is why 1st gear has given up.

 

Already gone through a timing chain, exploded my oil pump once, had to find another slingshot head and cams. this time when i take the case apart im going to replace rod and crank bearings. they looked flawless last time (somehow with zero oil pressure for like 10 mins once, and 60,xxx)

 

 

[dupersunc]

Don't forget you have a different primary ratio on the 750 when working out your gearing.

[tyler]

Update.

 

I got the hole drilled in the input shaft for the clutch push rod. Pretty easy with a lathe

i swapped the 750 bearing for the 1200 bearing on the output shaft, the 750 was much smaller in width.

I noticed one small spot i will have to clean up with a die grinder to get a gear to "clear". it almost/kinds touches.

but my main issue is i can not get the key groove for the big bearing to line up in the case without forcing it so far that the first gear touches the case,

 

i have had the gears in and have found neutral, spun shafts etc. Gears are good, but it is like the only issue is the shaft is longer? and moving the bearing too far out?  i didnt measure when i had them naked, but i will try and see if maybe the 750 shaft is longer.

is there something i am missing? if i stuck with the 750 bearing it still would not line up in the correct spot. 

If anyone has some good ideas on this please let me know.

If not, i will end up making a key way, closing the motor up and trying it. thanks in advance

[tyler]

i have photos i will post in the morning. Also i just read that turning the bearing around, and making a new slot for the pin will get it to line up. So we will see i guess.

[dupersunc]

1 hour ago, tyler said:

i have photos i will post in the morning. Also i just read that turning the bearing around, and making a new slot for the pin will get it to line up. So we will see i guess.

That's the trick. 

It bolts in easy once you figure it out.  I did have a few how the fuck does the work moments when doing mine though.

[Duckndive]

If you use the right "750" clutch cover you don't need to drill the main-shaft......just need a cable and lever.. 

[tyler]

8 hours ago, dupersunc said:

That's the trick. 

It bolts in easy once you figure it out.  I did have a few how the fuck does the work moments when doing mine though.

So me pressing off the bearing and turning it around this morning was a good idea? i didnt measure i just hoped. Photos to come soon, so some other guy doesnt have same issues

[tyler]

as you can see the "grove" cut out in the bearing does not line up with the case. Gears mesh perfectly. Behind the gear closest to the counter sprocket "is" there is some grinding needed.

 

Will show what it looks like tonight after i put the shaft back in. 

[wraith]

Nice  keep the info coming  

Did the turning the bearing around work ok?

is it at the rear of the motor you need to grind off?

[tyler]

i have the bearing on the shaft turned around, just have to slide the gears back on it, and install. Another small bit of info is the bushing/spacer for the counter sprocket needs ground down 1/8th'', flat so the counter sprocket can fit on the splines 100% and be straight when the nut is tight against it. 

[tyler]

"Drill shaft for clutch. Swap output shaft bearings about, and I used a 1052 slabbie clutch inner hub and cover in a Bandit basket.  That's it. "

 

Am i about to have issues? i havent looked real close and when i return home i for sure will. But will i need clutch parts from other bikes to complete this now?

[tyler]

Looks like I need a different clutch assy. The input shaft needs to be a little longer so the nut can fully thread on. However flipping the bearing around solved that issue. I could gain a little room by machining down the two rather large washes in the clutch assy. One that backs to the bear on the shaft. The other separates the basket from the inner hub. 

 

Is there a list of years/models that have the correct clutch? What will I be switching to?

[wraith]

On 7/24/2019 at 8:49 PM, tyler said:

Is there a list of years/models that have the correct clutch? What will I be switching to?

As in the hole clutch of parts?

Also, to up grade the clutch of not ?

[tyler]

well im interested to know what clutch/clutch hub will i be wanting to use? it looks like the 1986 GSXR with the 1052 motor, but i am just unsure and do not want to order something and then feel like a fool. the issue is the hub is too "long" because the shaft is now shorter. 

[tyler]

I bought an entire clutch from a 1989 gsx1100f. With springs. See what it is like. Was only $40. So I figured I’d just try it. Next will be a “slingshot” gsxr. 1989. The slabslides have 73 teeth vs the 72. So I guess I will see 

[Duckndive]

23 hours ago, tyler said:

I bought an entire clutch from a 1989 gsx1100f. With springs. See what it is like. Was only $40. So I figured I’d just try it. Next will be a “slingshot” gsxr. 1989. The slabslides have 73 teeth vs the 72. So I guess I will see 

the slabbie 73T gear wont match the bandit crank gear ...and the rest "inner hub ,springs and plates are the same as the 1100F "powerscreem" one you already have

why don't you just machine the face the hub enough to get the nut on full thread