1981 GSX1100 Katana Based Project

[Shin-Ken 1074]

Thank you Diirk, glad to know you are enjoying the build. Like most projects there are days that are a struggle when Plan A falls over however, the Sun comes up the next day and back into it with the spanners.

Cheers.

[Shin-Ken 1074]

There are some parts that can be deleted as they are not needed due to a better engineering solution or no longer have a function to perform. There is a deleted parts list in a previous post however here are a couple of examples that highlight the extra weight being carried around that can be shaved off.

The tool roll bracket, number plate bracket and rear guard sub-frame along with the seat strap and Aux 12 volt switch block.

Combined, these five parts that have now been deleted save 674 grams in total and without work needed or money to spend to replace them with something lighter, win,win!


OEM rear guard 1 by Max Mutarn, on Flickr


OEM rear guard 2 by Max Mutarn, on Flickr


OEM rear guard 3 by Max Mutarn, on Flickr


OEM strap and Aux switch block by Max Mutarn, on Flickr

[Shin-Ken 1074]

Early stage of the build with a mock-up of the bodywork/tank/frame to figure out how to attach the seat unit to the frame. The seat unit was supplied without mounts, just a bare fibreglass shell.
Used a structural bonding agent to attach an aluminium flat bar to the underside of the seat that mimics the OEM seat bracket to secure the seat and used the OEM seat lock to secure the rear of the bodywork.

Mock-up 1 by Max Mutarn, on Flickr

[Shin-Ken 1074]

The seat unit on its own does not have enough strength to support a rider without sustaining some sort of damage so I adapted the seat support brackets donated from a GSX 1150 EF frame to the Kat frame where the rider sits.

Seat Support brackets by Max Mutarn, on Flickr

[Shin-Ken 1074]

Seat lock and forward bracket in place with bonding agent.

Seat forward lock tab by Max Mutarn, on Flickr

Seat lock retainer by Max Mutarn, on Flickr


seat lock 2 by Max Mutarn, on Flickr


Seat lock 1 by Max Mutarn, on Flickr

[Shin-Ken 1074]

Swing-arm and caliper bracket paint has cured and time to add some parts for the week. Front sprocket, 520 chain, swing-arm, rear brake and rear wheel. Combined all these parts came in at:

23,404 grams.

Running Tally = 124,389 grams.


GSXR 750 rear wheel installed.

DW rear wheel 1 by Max Mutarn, on Flickr


GSXR1000 rear caliper installed.

DW rear wheel 2 by Max Mutarn, on Flickr

520 chain and aluminium sprocket.

DW rear wheel 3 by Max Mutarn, on Flickr


DW rear caliper adjustment plate.

DW rear caliper adjuster by Max Mutarn, on Flickr

[Shin-Ken 1074]

Rear shocks should arrive in two weeks. Have ordered a set of Nitron R1 basic shocks for the build. Being much lighter than a stock Kat the spring rate and valving need to match the lower weight for the suspension to work effectively. Also as a bonus the R1 shocks are lighter than piggyback shocks, win,win.

[Shin-Ken 1074]

OEM SZ chain guard is a serious chunk of metal, 873 grams not including bolts.

SZ OEM chain guard by Max Mutarn, on Flickr



SZ OEM chainguard 2 by Max Mutarn, on Flickr

[Shin-Ken 1074]

Found a used carbon chain guard for the project, much lighter than the steel original, 118 grams without bolts. The lesson for me on this project was some carbon parts can be made at home and in some cases the end product can be presentable for a daily rider bike like this one. However, the fit and finish on the aftermarket chain guard compared to my effort on the parts I have made is night and day different. Thankfully the carbon chain guard is a used part so not expensive to buy, this time.

DW carbon chain guard 1 by Max Mutarn, on Flickr

DW carbon chain guard 2 by Max Mutarn, on Flickr

[Shin-Ken 1074]

The seat/bodywork shell was not supplied with a seat pad and although it would be very light without it I think my body would appreciate having something there to provide a level of comfort. Wanting to keep the weight down I glued some low density foam sheets together with a 6mm EVA foam on top and then shaped them to fit the seat shell. If it works that is all that matters, not concerned if it needs replacing every year or so, it is light weight and that gets the tick. Of course if it is to painful then something else will need to be done.

seat pad 1 by Max Mutarn, on Flickr


seat pad 2 by Max Mutarn, on Flickr


DW 180 seat bodywork by Max Mutarn, on Flickr

[Shin-Ken 1074]

Time to sort out the forks, these are a used set and I don't know their history so before installing them it is a good time to clean, inspect and replace the oil, seals, seal clips and dust covers. Will also be swapping the OEM pre-load adjusters for aftermarket all aluminium adjusters as well as swapping the OEM fork springs for new light weight TNK custom Katana fork springs.

DW forks 1 by Max Mutarn, on Flickr


DW fork parts by Max Mutarn, on Flickr


DW fork springs 1 by Max Mutarn, on Flickr

[Shin-Ken 1074]

85 ml of sludge from the right fork, less than half of what should be there and it should be fork oil not this goo!

right fork goo 1 by Max Mutarn, on Flickr


Right fork goo 2 by Max Mutarn, on Flickr

[Grimly]

85 ml of sludge from the right fork, less than half of what should be there and it should be fork oil not this goo!

Have a sniff of it. I wouldn't be at all surprised if it's the original fork oil from the factory, and they were fond of fish oil back then.
Stinks to high heaven after a few years.

[Shin-Ken 1074]

85 ml of sludge from the right fork, less than half of what should be there and it should be fork oil not this goo!

right fork goo 1 by Max Mutarn, on Flickr


Right fork goo 2 by Max Mutarn, on Flickr

[Shin-Ken 1074]

TNK fork spring set.

TNK springs 1 by Max Mutarn, on Flickr




OEM fork spring.
SZ OEM fork spring by Max Mutarn, on Flickr


TNK fork spring.
TNK springs 2 by Max Mutarn, on Flickr



OEM v TNK spring set.
OEM v TNK by Max Mutarn, on Flickr