6-speed trans in 1st generation / slabside GSX-R 1100?

[manden]

On 2/18/2022 at 9:27 PM, no class said:

I knew 3 guys that did this 6 speed swap way back when it was cool…..and all of them had 2nd gear failures ….. fucking waste of time for the agrovation.

How did it work out for the third guy? Is it still running? What was his trick(s) for making it work?

Edited March 12, 2022 by manden

[Creg-ny-baa]

Gehr, regarding clutch six speed box, use the 1100 clutch as the alloy 750 one will break, if you use the original diapram spring you need to machine a little of the cutch centre out and then make a sleeved nut. or you can just use the centre from a 1200 bandit and run normal springs, from memory the bandit one just fits straight on using orignal nut. i will have a look tomorrow to see if i have a spare i can take a photo of.

[Gehr]

Cool

Edited March 30, 2022 by Gehr
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[Lachie04]

Why not just use the slabby clutch has more plates and contact surface than the 750 

http://oldskoolsuzuki.info/archives/tag/clutch

750 cases 1052 crank and clutch but in this case fitted to 91 GSXF1100 gearbox (my choice)

Btw you've sorted the clutch actuation out I guess ??

 

Edited March 15, 2022 by Lachie04

[Gehr]

F

 

Edited March 30, 2022 by Gehr
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[Lachie04]

Swap the input shaft for a 89+ GSXF 750 unit ???  Chamfer nut seen that on big stroke cranks??

 

[Gehr]

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Edited March 30, 2022 by Gehr
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[Lachie04]

My suggestion to use the 89 750 input shaft was so you can use the 1100 clutch basket instead of the oversize 750 unit. Also suggested by Creg-ny-baa, However as the 1100 clutch stack is taller you would probably need to use push rod clutch as doubt the 750 actuator could work or be modified (IDK never played with them you would have to play with that).

An alternative to drilling the shaft, as has been done (from the stories on here), the TEapot input shaft already has these.

Differences between teapot and R is first and Sixth gear ratios.

So if you're not comfy with possible contact between clutch outer basket and crank the only solution is to use later model transmission.

On my 1052 into 750 cases the No3 rod cap bolts hits the oil web I ended up shaving 2.2mm off the web  but this is only one reciprocating part not two as in yours.

BTW why I used the 5 speed from the GXSF was mainly that the gears would have needed to be replaced and I couldn't be shagged and its mainly a road bike.

Edited March 16, 2022 by Lachie04

[Gehr]

F

Edited March 30, 2022 by Gehr
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[Gixer1460]

I can't imagine a WERA machine is going to use a 'cobbled together' collection of parts, maybe ok for track duty but 12 or 24 hours reliability - nah! I reckon they would have had billet 6 speed gearboxes made to suit 1100 components in the clutch to avoid all the potential conflicts! Besides a £3-4000 gearbox is pennies in the grand scheme of racing teams! We used to spend that on GSX Auto boxes in Funny Bikes. 

In regard the clearance problem - thinking outside the box - how about losing a fibre and a steel and machining all components down by that depth, interference problem vanishes?

[Gehr]

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Edited March 30, 2022 by Gehr
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[Gixer1460]

I sort of can't work out why an engine that produces waaaay less torque, has a bigger clutch & more surface area compared to the 1100 torque monster! And as regards the rivet situation - are you nutz! You need 3 or 4 and you buy a 100 and then ship them around the world! Surely a local machine shop could make some up after hardness testing the OEM's and a 20 - 50 ton press would squish anything into place! APE still list rivets for GSX clutch backplates - they can't be that different and at $190 - cheapish, considering half the stuff you don't want LOL!

[no class]

1 hour ago, Gehr said:

Ahh, thought about that too Gixer1460 but I am pretty sure that it will work marginally at best but that will likely be my last resort!  I did the calculations on how much surface area each clutch plate has in each clutch pack using the formula A = (pie) x (radius) squared. That's the formula for calculating the area of a circle. Total surface /swept area of the GSX-R750 clutch pack is 33,515mm. But if you remove a steel plate & a friction plate that goes down to 28,727mm. The stock 86' GSX-R1100 clutch pack that is narrower than the 750's but has 3 more friction plates has a surface area of 42,810mm. I can machine down the tangs of the 750's outer clutch basket by 5mm & remove 1 steel & 1 friction plate from that 750 clutch pack & have enough clearance. But will that already marginal 750 clutch pack still be up to the task? Since riveting that 1100 primary gear to the 750 hub was a huge hassle I really don't want to do that until I have no other viable options. Try to find the correct sized rivets for that primary gear!  After months of looking I exhausted all leads in the USA & ended up buying some from Japan. But the seller would only sell them in bulk, minimum order was 100 rivets. That box of rivets weighed some 10 pounds so shipping from Japan was pricey. And the rivets' diameter were still were a little too large so I took them to a machine shop to be ground down. A ridiculous amount of time & money was spent on that "hybrid" clutch! Some steel plate clutch specs:

……OCD are we ?  all that faffing about for what ….. lol

[Dezza]

2 hours ago, Gixer1460 said:

I sort of can't work out why an engine that produces waaaay less torque, has a bigger clutch & more surface area compared to the 1100 torque monster! And as regards the rivet situation - are you nutz! You need 3 or 4 and you buy a 100 and then ship them around the world! Surely a local machine shop could make some up after hardness testing the OEM's and a 20 - 50 ton press would squish anything into place! APE still list rivets for GSX clutch backplates - they can't be that different and at $190 - cheapish, considering half the stuff you don't want LOL!

It doesn't: the 750 clutch has a total surface area of 335 cm2, whereas that for the 1100 has a total surface area of 428 cm2. Each 750 plate has a larger surface area (47.9 cm2) than that of the 1100 (42.8 cm2) but the 1100 has 10 plates and the 750 only 7.  Deducting plates from the 1100 to gain more clearance trades-off to less surface area for the clutch in total but fewer than 10 plates will still mean a 'bigger' clutch than a 750. But increasing the power output of the 1100 engine and putting it all through an 1100 clutch of smaller than stock surface area just seems like asking for another problem down the line.

[Gixer1460]

3 hours ago, Dezza said:

It doesn't: the 750 clutch has a total surface area of 335 cm2, whereas that for the 1100 has a total surface area of 428 cm2. Each 750 plate has a larger surface area (47.9 cm2) than that of the 1100 (42.8 cm2) but the 1100 has 10 plates and the 750 only 7.  Deducting plates from the 1100 to gain more clearance trades-off to less surface area for the clutch in total but fewer than 10 plates will still mean a 'bigger' clutch than a 750. But increasing the power output of the 1100 engine and putting it all through an 1100 clutch of smaller than stock surface area just seems like asking for another problem down the line.

Sorry I read it arse about face ! If load increase is needed a simple lock up works good - certainly enough for over 300hp! So losing a plate ain't the biggest drama.

 

[Creg-ny-baa]

On 3/16/2022 at 7:10 AM, Gehr said:

Thanks for the information!  More research to do & thanks for giving me some options to consider. The biggest thing bothering me about this swap is I know the WERA endurance racing teams that were running the GSX-R1100's in 87' were using 6 speed transmissions. I am not sure if they ended up modifying the 5-speed transmissions or the clutches. I can't see the main body of the transmission shafts being machined to facilitate the extra gear but maybe they focused on the clutch side of that input shaft? 

The 6 speed gear box to use for this mod is 88 slingshot onwards, the best ones are L onwards as the output shaft is longer where the sprocket goes on, this makes chain alignment easier with 180 rear tyre, the 1100 clutch fits straght onto the shaft using a bandit centre, you will have to drill the clutch pushrod hole out. the bike below is fitted with standard 6 speed box, it has had six starts and six finishes in the Classic TT, And no breakdowns.

 

[Gehr]

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Edited March 30, 2022 by Gehr
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[dupersunc]

22 minutes ago, Gehr said:

So thanks for your input. Thanks for telling me I am an idiot for doing what I am trying to do without any background information. Nice. Great to see links to threads that have nothing to do with the bike I have from members who want to tell me what an idiot I am for not looking through this website's archives. Thanks to that Isle of Man person but no pictures of what you are claiming are truly worthless. I subbed to websites like these 20+ years ago to try to figure out issues with just released Suzuki's. But some things never change. Too many dim bulbs who do not want to work on their bikes but like to tell people what they should do.  So what do you endeavor to do? I like the banking at the Auto Club Speedway in Fontana. If you ride motorcycles on racetracks this is a great view of what the preferred line is going into the T1 / T2 chicane. My home track, done thousands of laps there. Thanks for the non help

 

No need to get the arse because you can't work out what others have managed to figure for themselves.

Forums are free info, treat them like you would anything else that is free.

They are also about give and take. If you give a little, you may get little more back.

[Gehr]

On 3/27/2022 at 4:24 AM, dupersunc said:

 

 

 

Edited March 30, 2022 by Gehr
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[dupersunc]

[clivegto]

Take a chill pill man then go figure it out your self with a bit of common sense then, instead of ranting