1981 GSX1100 Katana Based Project

[Rijko]

Thank you Glen, that info saves me a lot of time

 

[Shin-Ken 1074]

Thank you Glen, that info saves me a lot of time

No worries Rijko, glad to have been of help.

Cheers.

 

[Suzukian]

The 17" Katana wheels on the older bikes seem to fit a lot of bikes. Usually bearings have to be changed, and dis rotors to match whatever calipers you are doing know. I am switching my '83 GS750ES to an GS1150 front end, using 3 spoke Katana 17" rims front and rear, as 16" tires aren't getting easier to find, and the 1150 front end will be better for my '83 GS750ES. I just have to change some bearings, I have the calipers, and make some bushings to make sure the wheels align. I also needed to get different discs for the front, but I was lucky, as this had been done before, I just had to read up on the modifications. A little harder when you're doing the exploration, but totally doable. You have a plan which is a lot of theprocess.

 

[Shin-Ken 1074]

Hi Rijko, here are the weights for OEM v DW180 front wheel:

1985 GSXR 18" front wheel after lathe work to fit Kat forks and fitted with a Bridgestone Radial T32 18 x 110 tyre, hollow axle/Ti nut, aluminium wheels spacers, aluminium bearing spacer, both brake rotors with Ti bolts and the speedo drive, total weight is:

12,770 grams

1981 GSX 1100S 19" front wheel fitted with 100/90/19 Pirelli Sport Demon tyre and inner tube, stock axle, wheel spacers, bearing spacer, stock rotors with bolts and lock tabs, speedo drive, total weight is:

15,055 grams

Shaving 2,285 grams from a front wheel helps to improve handling as well as contributing to the goal of shaving 50kg off the Kat project, every gram helps.

Cheers.

 

[Rijko]

Thank you Ken, that is indeed a good weight save and handling improvement ... didn't think it would add up so quickly.
TBH i thought 50KG would be much harder to achieve without drastic surgery, but you are at 45KG already ...
Learning something new here every time, thanks !

 

[Suzukian]

That's what great about this forum, the right people read your thread and you save a lot of time, and also get some really good deals on used parts.

 

[Shin-Ken 1074]

Thank you Ken, that is indeed a good weight save and handling improvement ... didn't think it would add up so quickly.
TBH i thought 50KG would be much harder to achieve without drastic surgery, but you are at 45KG already ...
Learning something new here every time, thanks !

Hi Rijko, the frame was spared drastic surgery however, some parts have been tampered with and in a way that some may find perhaps unappealing both from a visual and functional perspective.
The sump as an example now weighs 574 grams, much lighter than OEM. There may be an oil temp issue without fins on the sump but I will monitor engine oil temp under riding conditions and see how it goes. Can always install an OEM sump if needed. There are other parts that have been altered to reduce weight:

rear brake lever, electrics panel, rear brake res, sprocket case, oil filter cover, seat mounting bracket, front foot pegs, swingarm, fuel tank.

Some parts that will be deleted completely:

centrestand, helmet lock, lift handle, front wheeel dust cover, anti dive units, anti dive hoses and hose brackets, front brake line manifold, rubber speedo cable guide, seat strap, tool roll holder, number plate bracket, airbox and filter, rear foot pegs, rear guard sub-frame, front guard inner brace - (replacing it with an aluminium fork brace).

Cheers.

 

[Rob S.]

...rear guard sub-frame, front guard inner brace...

Please remind me what those parts are. I know what the rear sub frame is, but you seem to be talking about something else.

 

[Shin-Ken 1074]

Please remind me what those parts are. I know what the rear sub frame is, but you seem to be talking about something else.

Hi Rob,

the Kat front guard has a U shaped pressed steel brace that sits inside the front guard and bolted to each fork leg. Without the four bolts/washers it weighs 800 grams. The rear sub-frame I have removed is the steel frame that secures the inner rear guard to the main frame, without bolts/washers = 260 grams.

Cheers.

 

[Rob S.]

What is a "rear guard"?

What is a "front guard"?

Are you talking about fenders, or mud guards?

 

[Shin-Ken 1074]

What is a "rear guard"?

What is a "front guard"?

Are you talking about fenders, or mud guards?

In Oz they are guards, short for "mud guards".

 

[Rich82GS750TZ]

For those following along, 50 kg = 110.23 lb.
This got me to wondering:
Why is pounds abbreviated as lb? So I had to look it up.
“Pounds” derives from the name of an ancient Roman unit of measurement, Libra pondo. This Latin phrase translates to “a pound by weight.” Our word “pound” comes from pondo, and its seemingly unrelated abbreviation, “lb,” comes from the libra part.​

This all would be so much simpler if we had all gone all metric like our grade school teachers promised we would be by the time we reached adulthood. I wonder if teachers in the US are still telling that fib to the kids.

Sorry to derail this thread. Please carry on. Following with interest.

Ok, back to the program. And I will reiterate-

​

 

[Shin-Ken 1074]

Hi Folks, the DW 180 weight reduction today is 682 grams.

Remove set of steel exhaust flange clamps = 438 g. Replace with aluminium flange clamps = 161 g.

Remove OEM cam chain tension adjuster = 401 g. Replace with aftermarket aluminium manual cam chain tensioner = 86g.

Remove OEM fork spring pre-load adjusters = 216 g. Replace with aftermarket aluminium pre-load adjusters = 126 g.

Tomorrow I'll weigh the exhaust flange steel bolts and the replacement Titanium exhaust bolts as well as the OEM steel engine mounts and the replacement aluminium engine mounts.

Cheers.

 

[slayer61]

For those following along, 50 kg = 110.23 lb.
This got me to wondering:
Why is pounds abbreviated as lb? So I had to look it up.
“Pounds” derives from the name of an ancient Roman unit of measurement, Libra pondo. This Latin phrase translates to “a pound by weight.” Our word “pound” comes from pondo, and its seemingly unrelated abbreviation, “lb,” comes from the libra part.​

This all would be so much simpler if we had all gone all metric like our grade school teachers promised we would be by the time we reached adulthood. I wonder if teachers in the US are still telling that fib to the kids.

Sorry to derail this thread. Please carry on. Following with interest.

Ok, back to the program. And I will reiterate-

​

Ya. 3 pages so far and Ian is the only one to add a pic...

 

[Rijko]

Hi Folks, the DW 180 weight reduction today is 682 grams.

Remove set of steel exhaust flange clamps = 438 g. Replace with aluminium flange clamps = 161 g.

Remove OEM cam chain tension adjuster = 401 g. Replace with aftermarket aluminium manual cam chain tensioner = 86g.

Remove OEM fork spring pre-load adjusters = 216 g. Replace with aftermarket aluminium pre-load adjusters = 126 g.

Tomorrow I'll weight the exhaust flange steel bolts and the replacement Titanium exhaust bolts as well as the OEM steel engine mounts and the replacement aluminium engine mounts.

Cheers.

I LIKE you post the solutions and weight savings Ken, thank you.
Your last post makes it clear again that many smaller savings do add up.
For me, this thread is getting more interesting with every post you make, it's gonna be a favorite.

Thanks again !

 

[Suzukian]

This all would be so much simpler if we had all gone all metric like our grade school teachers promised we would be by the time we reached adulthood. I wonder if teachers in the US are still telling that fib to the kids.​

Having a young son who just went through the whole system, I can say for my town, they do not teach abut a "Metric Future", they teach you should know both systems.

All those little weight savings do add up, and inevitably make for a very interesting motorcycle.

 

[Shin-Ken 1074]

Hi Folks, today its the engine mount plates and header bolts.

OEM steel engine mount plate set, no bolts only plates = 837 grams

Complete set of OEM steel engine mounting bolts = 938 grams. Some of those will be swapped for titanium, not the long bolts - very expensive.

Eight steel header flange bolts = 200grams

Eight Ti tapered allen header flange bolts = 72 grams.

Using a mix of OEM steel and Ti bolts there are a few grams to be shaved here. Will know exactly once the engine is bolted into the frame in a couple of days time.

Have decided on a photo hosting service so in the next few days images will be posted, if all goes well? Painted frame, engine, side covers, cowl, seat, guard etc, look good in their new paint.

Cheers,
Glen.

 

[Shin-Ken 1074]

Hi Folks, weather has been damp and cold the last few days so painting the engine mounts has been delayed. Was hoping to have the engine in the frame this weekend and measure up for the aluminium rear axle spacers and off - set for the front sprocket if needed. Gives me time to order a few new parts from Suzuki so not a total loss.

Cheers.

 

[Shin-Ken 1074]

Hi Folks, having great difficulty trying to work out how to post images on the Forum from my phone using XnViewMP. So for today it is text update only.

1985 GSX1135 EF engine was installed into the 1981 Kat frame today, all good. Used a combination of OEM and titanium bolts along with OEM steel engine mounts. Did a bit of tweeking to the frame on Tuesday and it is now 17,984 grams bare but painted.

Engine went in missing a few parts to make it easier to fit: no oil,no oil filter cover, no tappet cover, no clutch cover, no sprocket case, no carbs, no starter motor, no sprocket.

It did have a set of Yoshi hollow cam shafts fitted, much easier to install when the engine is out of the frame.

1985 GSX1135 EF OEM cam shaft weight: Ex = 1,532g IN = 1,525g.

Yoshi Suzuki GSX 1100 hollow cam shaft weight: EX = 1314g IN = 1331g

OEM cams = 3,057g vs hollow cams at 2,645g.

So in its minimalist form the engine came in at 77,750 grams. Engine weight will increase as the parts that were removed to help with installing it in the frame are fitted. Several of these parts have been modified so there will be an OEM v DW180 parts weight comparison.

OEM steel engine mount plates with OEM and Titanium bolts total = 1,272g.

So at this stage the project with frame and most of the engine weighs 96,006 grams sitting on the bench. From today each post will end with the weight of the project for the day.

Cheers.

 

[Shin-Ken 1074]

Hi Folks,

Have spent the last few days planning the rear brakes before installing the swingarm. Going to use a 2005 GSXR 1000 caliper married to the stock 1982 Kat swingarm so a few mods are needed to make it work. Having an aluminium bush made to reduce the K5 caliper mount axle diameter down to 20mm to match the Katana axle size. Being an underslung caliper it will need a torque brace installed below the swinger so I'll make the brace from aluminium round tube with rose joints fitted at each end and a bracket welded to the swinger to house the forward rose joint.

The reason for going with the K5 caliper is weight, or to be accurate, less weight. The stock SZ Kat rear caliper is 1,415 grams compared to the K5 caliper at 814 grams, 601 grams off the caliper is heading in the right direction for the project. Ti bolts will also help.

Once the caliper mount has been sorted, the wheel can be installed and positioned for the chain alignment. With the wheel in place and measurements taken, next will be having the axle spacers made from alumimium.

I have adapted a set of Yamaha R1 aluminium axle holders and made a pair of aluminium chain adjuster blocks to suit. Total weight of the two chain adjusters is 184 grams less than the stock 1982 steel chain adjusters including Ti bolts of course.

With nothing added to the frame there is no change in project weight so it is still at 96,006 grams on the bench.

Cheers.