Bandit Coil Spring Conversion

Words & pics: Lee Workman

Bandit clutch conversionBandit Clutch

The clutch assembly fitted to all Bandit 1157 motors is, frankly, shite.

Based on the same principle as the GSX-R Slingshot unit, it’s diaphragm-sprung with ten driven plates and ten drive plates of 225mm diameter (the GSX-R’s are 230mm diameter which doesn’t sound much, but offers a huge increase in surface area for friction) and has a cheap cast alloy basket with a steel reinforcement strap fitted in an effort to stop it flying apart (as opposed to the large all-steel basket used in the GSX-R).

Under normal circumstances this unit is fine but, as soon as you start giving it a reasonable amount of abuse or tune the engine, it will struggle to cope with the extra demand and eventually slip. Heavy-duty diaphragm springs are available and will slightly improve matters at the cost of a heavy clutch lever, but the whole unit is better off in the bin. Trust me …

To convert your Bandit 12 clutch you’ll need the following parts from Suzuki,

No. Description Suzuki Part Number

Qty

Price � (ea.) Source Model

1

Clutch inner hub

21410-06B02

1

49.46 GSXR1100 G,H & J

2

Pressure disc

21462-06B00

1

23.49 GSXR1100 G,H & J

3

Coil springs

09440-20013

4

1.31 GSXR1100 G,H & J

4

Spring spacers

09180-06174

4

1.72 GSXR1100 G,H & J

5

Washers

09160-06020

4

0.53 GSXR1100 G,H & J

6

Bolts

01107-06307

4

0.71 GSXR1100 G,H & J

7

Drive plate (Fibre)

21441-48B00

11

9.53 All GSXR 1100’s

8

Driven plate (Steel)

21451-48B00

10

5.47 All GSXR 1100’s

9

Clutch Basket

21200-40814

1

176.53 GSXR1100 K,L,M & N

 

Yep, you’ll need to replace that crappy clutch basket, they are expensive new, but you could get one from B12 Clutch 1a breaker, you can use one out of any Slingshot model. Beware – they look identical to the earlier Slabside one, but the 1052cc motor has different gearing on the crank. The primary driven gear at the back of the clutch basket of Slabside engine has 73 teeth. The bandit primary driven gear (being essentially a 1mm over bored 1127 motor) has 72 teeth – the same as a slingshot one.
Follow the previous instructions for the GSXR’s then, once the inner hub is completely off, remove the outer basket also.
Pull the basket partially out, then push it back in again, this will expose the needle roller bearing and the spacer, remove these from the shaft then remove the clutch basket and alternator/oil pump drive gears careful remove alternator oil pump gear from the b12 basket and fit it into the slingshot basket
If its still stuck to your clutch basket, you will need to (carefully) remove this bandit drive gear, and fit it to the GSXR basket.
They are totally different; the alternator/oil pump drive gear off a GSXR has different pitch teeth and will foul your bandit alternator driven gear and your oil pump driven gear.

Once you’ve done this you can fit the new GSXR Basket using the original thrust washers in their original places.
Ensure the alternator an oil pump drive gears are engaged with the driven gear behind the basket
When positioning the basket on the counter shaft and sliding it ‘home’ – take extreme care to line up the alternator/oil pump drive gears with the alternator and oil pump driven gears, if they are not fully engaged, and you tighten the hub nut, it WILL snap, and they cost around £80!

Fit the new coil spring hub assy just like the GSXR procedure with one exception, –
The counter shaft of the bandit engine is again longer than the Slabside one, but it’s different to the Slingshot counter shaft, the dimensions for the bandit spacer are 35mm O.D, 25.5mm I.D and 6mm thick. Also as the original bandit hub has a different thickness base to either of the gixxers, it still works out that you need a 10mm ball bearing to take up the slack between your original bandit pushrod, and your push piece.
Again secure the hub using your original nut & washer on the new spacer fit the new GSXR clutch plates and pressure disc assy as above.
And you too have a GSXR spec, coil spring clutch!, Again you can go and fit a lock up straight on if you wished!, Or leave it as it is and go and do stoopid stuff, safe in the knowledge that you’re clutch can take it!
Now, extra hints and tips.
Tip 1: When you do the job, put the bike on its side stand and carefully lift the front wheel and chock it on a brick – this will stop you losing any oil when you remove the clutch cover.
Tip 2: When buying new clutch plates, use only genuine Suzuki parts – I know they’re more expensive, but it’s false economy to put cheapo plates in. I know, I’ve tried ALL the super-trick/heavy-duty ‘performance’ clutch plates and they just don’t compare with the genuine stuff. You have been warned!
Tip 3: With this particular conversion you fine-tune the biting point by changing the ball bearing – if it drags too much (assuming you’re using the correct grade oil and the steels aren’t warped), then you need more travel so try fitting an 11.5mm one instead. If it slips (assuming the fibre plates and/or the springs aren’t worn), you need less travel so pop in a 9mm one. It really does make a difference!

Also take the time to make the special tools, they’re a piece of piss to make, and really make life easier.

Special tool one: You’ll need two pieces of steel bar that are 200mm long, 25mm wide and 5mm thick (ish …), drill two 6mm holes in each bar with the centres 165mm apart then, at one end of each bar, fit a M6x30 bolt and secure it tightly with a nut on the underside. At the other end, open out the 6mm hole to 8mm and join the two bars together with a M8x70 bolt and loosely secure it with a nut on the underside. To use it, the M6 bolts will neatly fit into the slots on the diaphragm pressure disc and the M8 bolt will fit straight into the swingarm spindle – once the slack is taken up, you’ve got both hands free to undo/tighten the big 50mm holder nut!

Special tool two: First get one 400mm long piece of square section (20x20mm) bar and two old GSX-R clutch driven (steel) plates. Put the plates on top of one another and drill three holes equally around the diameter and secure them to the square bar using two M6x60 bolts and 20mm spacers and a couple of M6 nuts (this way, you can support the basket really well and reduce the chances off slipping, as the plates will be deep inside the unit). Finally put a small M6x10 bolt and nut through the remaining hole to secure the plates together. This is a wicked tool to have, when you’re trying to remove/secure the hub nut at 160Nm!

Anyway, in preparing this article I’ve been down to my local Suzuki dealer to get the correct part numbers for you to order and latest prices (all, are + v.a.t.,and correct at August 2002), and to ensure that those of you using second hand stuff from the breakers get the right bits off the right models. I’ve already checked to see which part numbers are superseded by later ones and that the information given is correct to the best of my knowledge and experience etc– aren’t I good to you lot, eh?

GSX-R Coil Spring Clutch Conversion

GSX-R COIL SPRING CLUTCH CONVERSIONS

Words & pics: Lee Workman

Before we start, I’m no journo, so you’ll have to forgive the lack of long and rambling intro and humorous asides throughout. I’m an engineer by trade and have been messing around with Suzuki’s big bore oil-cooled motors for ages and I’ve picked up a few tricks and developed a few of my own along the way.
I’ve done this coil-spring clutch conversion a few times on later GSX-R’s (and Bandit Twelve’s too). It’s cheap, very effective and it’s a piece of piss, so here are the facts.

There are the two types of clutch unit fitted to the GSX-R range and Suzuki’s first attempt, the coil spring type, is definitely the best. Fitted to all GSX-R Slabsides from 1986 through to 1988 (the 1052cc G/H/J models), it uses ten steel driven plates and eleven fibre drive plates and is clamped together with four coil springs acting on an alloy pressure disc.
With any clutch, the limiting factors are the unit’s overall strength, the surface area available and the clamp load on the drive and driven plates. The design of the Slabside coil-spring unit excels in all three areas – this unit can easily cope with even the most ham-fisted wheelie/burnout merchant and on the road it should handle over 160bhp as stock.

OLYMPUS DIGITAL CAMERA

For the heroes or for strip use, it can be still further improved with the use of heavy-duty coil springs, and for the serious drag racers out there, there are a couple of aftermarket ‘lock-up’ type conversions, which bolt straight in and replace the existing pressure disc. The lock-up is the ultimate in super-strong non-slip clutches.
Then there’s the diaphragm type. Fitted to all GSX-R Slingshots from 1989 through to 1991 (the 1127cc K/L/M/N models), it uses a similar clutch basket and the same driven and drive plates as the earlier Slabside clutch (with the exception that there are only ten drive plates in this unit), but the plates are clamped by two diaphragm springs acting on a different pressure disc design.
This unit is fairly robust and is less prone to ‘judder’ than the coil-spring type, but it starts to struggle with more than 140bhp and if you like your wheelies and burnouts or if you launch it hard on the strip, it’s not long before it gives up the ghost .

There is already a conversion kit on the market from APE, costing around £190, which converts a Slingshot diaphragm clutch to a coil-spring unit like that of the Slabbies and, therefore, allows the fitting of a ‘lock up ‘ kit at a latter date if necessary. But I’m going to tell you how to do it (using quality components) the cheap way. You can either get the stuff from breakers for around £30 or, using NEW genuine Suzuki parts for about £80 – about half the cost of the over-the-counter unit. And in a later article, I’m going to tell you how to fit one into your Bandit Twelve motor too, so keep any eye out for that, okay?

Anyway, in preparing this article I’ve been down to my local Suzuki dealer to get the correct part numbers for you to order and latest prices (all are plus VAT and correct in August 2002). And to ensure that those of you using second-hand stuff from the breaker’s get the right bits off the right models, I’ve already checked to see which part numbers are superseded by later ones, and that the information given is correct to the best of my knowledge and experience etc. Aren’t I good to you lot, eh?

Firstly for those of you starting with a Slingshot GSX-R 1127 (a K, L, M or N model), you’ll need the following parts:

 

No. Description Suzuki Part Number

Qty

Price � (ea.) Source Model

1

Clutch inner hub

21410-06B02

1

49.46 GSXR1100 G,H & J

2

Pressure disc

21462-06B00

1

23.49 GSXR1100 G,H & J

3

Coil springs

09440-20013

4

1.31 GSXR1100 G,H & J

4

Spring spacers

09180-06174

4

1.72 GSXR1100 G,H & J

5

Washers

09160-06020

4

0.53 GSXR1100 G,H & J

6

Bolts

01107-06307

4

0.71 GSXR1100 G,H & J

7

Drive plate (Fibre)

21441-48B00

1

9.53 All GSXR 1100’s

The parts needed for the conversion. What You'll Need

Then you’ll need two extra components – a 10mm steel ball bearing from your local bearing factors, and a hub nut spacer too. You’ll need to get one of these knocked up by someone with access to a lathe or any local engineering firm should make you one for around a fiver. The dimensions are 35mm OD and 25.5mm ID and it needs to be 10mm thick.

Got all them? Good, so here’s how you actually do it. Firstly, shift the transmission into first gear and remove the nine screws from the clutch cover. Then take off the clutch cover and remove the large circlip in the centre of the hub before you take out the pressure disc lifter and the push piece and its bearings. Hold the pressure disc from moving using the special tool no.1 (see below), undo the big holder nut and remove the diaphragm springs and the spring seat and then the pressure disc.
Remove the drive and driven plates, followed by the wave washer and its seat, then hold the hub with special tool no.2 (see below an’ all) and undo the hub nut and remove the nut, washer and hub assembly. Important – ensure the long (steel tipped) alloy pushrod and the thrust washer between the basket and hub is still in place or you’ll be buggered. Now fit the new hub.
Problem number one – you’ll notice that the hub nut and washer will not now tighten down because there aren’t enough threads on the countershaft. This is because the Slabside hub has a thinner base and the Slabside countershaft is shorter, so this is where the spacer is needed on the driven shaft. Fit it over the shaft, then you can secure the new hub using your original nut and washer using special tool no.2 to hold the hub while you tighten the nut to the correct torque (140 to 160Nm or 102 to 115ft-lbs).
Now re-fit your original clutch plates (as long as they’re not fucked, check the fibre ones for the correct thickness – 2.52 to 2.68mm / 0.100” to 0.106”) and check the steels for warpage using a feeler gauge and a piece of plate glass (max limit 0.10mm / 0.004”), starting with a fibre one, then steel and so on (you should finish with steel, if you’re not a complete wazzock). Now fit the extra fibre one you’ve just bought.
Problem number two now rears its head – because of the differences in the length of the countershafts, your clutch push rod is now, effectively, too short. This is where you fit the ball bearing – it will take up the gap between the alloy pushrod and the push piece. Fit your push piece complete with its thrust bearing and washer and then fit the new pressure disc using the new spacers, springs, washers and bolts and secure the bolts in a criss-cross pattern to the correct torque setting (11 to 13Nm or 8.0 to 9.5 ft-lbs).
Re–fit the clutch cover, check the oil level and you’re away! You’re now the owner of a coil-spring clutch – told you it was easy!
Now, extra hints and tips.
Tip 1: When you do the job, put the bike on its sidestand and carefully lift the front wheel and chock it on a brick – this will stop you losing any oil when you remove the clutch cover.
Tip 2: When buying new clutch plates, use only genuine Suzuki parts – I know they’re more expensive, but it’s false economy to put cheapo plates in. I know, I’ve tried ALL the super-trick/heavy-duty ‘performance’ clutch plates and they just don’t compare with the genuine stuff. You have been warned!
Tip 3: With this particular conversion you fine-tune the biting point by changing the ball bearing – if it drags too much (assuming you’re using the correct grade oil and the steels aren’t warped), then you need more travel so try fitting an 11.5mm one instead. If it slips (assuming the fibre plates and/or the springs aren’t worn), you need less travel so pop in a 9mm one. It really does make a difference!
Also take the time to make the special tools, they’re a piece of piss to make, and really make life easier.

Special tool one: You’ll need two pieces of steel bar that are 200mm long, 25mm wide and 5mm thick (ish …), drill two 6mm holes in each bar with the centres 165mm apart then, at one end of each bar, fit a M6x30 bolt and secure it tightly with a nut on the underside. At the other end, open out the 6mm hole to 8mm and join the two bars together with a M8x70 bolt and loosely secure it with a nut on the underside.

To use it, the M6 bolts will neatly fit into the slots on the diaphragm pressure disc and the M8 bolt will fit straight into the swingarm spindle – once the slack is taken up, you’ve got both hands free to undo/tighten the big 50mm holder nut!

Special tool two: First get one 400mm long piece of square section (20x20mm) bar and two old GSX-R clutch driven (steel) plates. Put the plates on top of one another and drill three holes equally around the diameter and secure them to the square bar using two M6x60 bolts and 20mm spacers and a couple of M6 nuts (this way, you can support the basket really well and reduce the chances off slipping, as the plates will be deep inside the unit). Finally put a small M6x10 bolt and nut through the remaining hole to secure the plates together. This is a wicked tool to have, when you’re trying to remove/secure the hub nut at 160Nm!

Tuning your Kat – the basics

A standard Kat is nice as standard, and a valuable classic as is, but it’s very hard to resist the temptation of modifying it. You can hardly find one that hasn’t been tweaked to the max. In my point of view for a Kat to remain a Kat you have to retain the standard fairing, tank and frame. So here are some of the options…

Engine tuning

Well, what can we say about tuning GSX1100 engines other than the sky is the limit? Thanks to the immense popularity with drag-racers you can build an entire engine completely from aftermarket stuff.
It has to be said that the drag bike guys have been moving more and more towards the GSX-R/Bandit engines purely because the supply of fresh engines is becoming more scarce. The most popular tuning method for a GSX1100 engine is the big-bore kit in combination with a top-end overhaul including a headflow, hotter cams and maybe bigger valves. A good excuse for taking such action is when the engine starts burning oil after churning away lots of miles. Anyway, you could go on and on about the options and still only cover 50% so I won’t go with that.
Many people are opting to fit an 1127 (GSX-R) engine, which is a dead shame for people who love the old GSX1100 engine, but a very good alternative if you’re after a low-mileage and reliable power plant.

Chassis tuning

Front end

From Suzuki’s point of view a headstock is just two bearings holding a steering stem (won’t argue with that 😉 and so they felt little need to change it’s design and dimensions during the last few decades.

That means that about any Suzuki front-end will fit the Katana… you’re free to interchange the front-ends of Bandits, GSX-R’s, Katana’s and GSX’s from about every capacity class, and even a CBR600 front end mixes in. Just remember to swap the whole front end incl. yokes and it’ll be a very straightforward swap. Keep in mind you’ll possibly lose some ground clearance after fitting smaller 17″ wheels and somewhat shorter forks.

Rear end

The space between the frame rails is 240mm. You need 30mm for the (25mm) chain to run free between the frame and the tire and 30mm on the other side to keep the wheel centered. So your maximum tire width = 240 – 30 – 30 = 180mm
To get there you need to move the sprocket outwards using an offset sprocket and maybe a spacer or two.
People who want to go wider than 180, like dragracers, need to widen the frame at the swingarm pivot and fit an outrigger bearing to the driveshaft (to keep the bending forces in control).
The hub will probably also need modification to bring the chainwheel closer to the inside.

The first 7/11

The original 7/11 was built by Bradley O’ Connor and was featured in Performance Bikes Magazine Sept. ’92. He put a GSX1100F engine in a GSX-R750 chassis to create a bike that gave him the same surge of adrenaline as he got from riding a Kawasaki ZZR-1100 without spending a lot of money.bradley

Although built from standard parts and any further tuning it was measured to outperform the ZZR on every aspect. His bike became a inspiration to many and nowadays there must be hundreds of 7/11’s on the streets. Bradley later added nitrous and put the engine in a Harris Magnum 4 frame.

The combination of the monster torque of a GSX-R1100 and the light weight and short(er) wheelbase of a 750 chassis results in a bike which; “Has enough torque to pull a Brontosaurus out of quicksand” and “Leaps out of your hands coming out of corners without even being asked

brad711And that is exactly what we 7/11 owners want, a affordable bike witch will give you that same feeling of sheer power that you got when you got on a 1100 for the first time, even when you own it for years now, something you just won’t get used to.