1981 GSX1100 Katana Based Project

[Shin-Ken 1074]

OEM SZ triple tree can be lightened and this is weight from a high point on a bike so reducing weight here helps with lowering C of G. I had the engineering company that made the ally axle spacers also make an aluminium steering stem for the DW. After reshaping the top plate with my set of files and using titanium bolts there has been a healthy reduction in weight for the complete triple tree.

The numbers:

SZ OEM triple tree complete including bearings = 2,473 g.

DW mod triple tree complete including bearings = 1,851 g.

Total weight reduction of triple tree = 622 grams


Running tally = 98,150 grams.

SZ OEM top plate by Max Mutarn, on Flickr

DW by Max Mutarn, on Flickr

DW triple tree by Max Mutarn, on Flickr


DW aluminium stem by Max Mutarn, on Flickr

[steve murdoch]

This is a great follow!
Thanks for sharing it with us.

[Shin-Ken 1074]

This is a great follow!
Thanks for sharing it with us.

Hi Steve, good to hear from you. If my bits of paper and whiteboard markings are close, once the Kat is at the roller stage there will be five areas of the build that combined I estimate will shave off 22.7 kg. Hope I pressed the correct keys on the calculator?

Cheers.

[Shin-Ken 1074]

Here is the top plate before being painted, gives a better idea on how the profile was changed. Filed off all the curves and went with flat surfaces and angled edges.

DW top plate a by Max Mutarn, on Flickr

[Shin-Ken 1074]

Rear master cylinder frame bracket. By trimming the edges of the bracket and drilling it removed 92 grams from the bracket.

This is the bracket before mod.

OEM mount by Max Mutarn, on Flickr

Bracket after mod.

OEM mount mod a by Max Mutarn, on Flickr


Some of the metal removed from the bracket, swarf from drilling and cutting not included.

OEM mount mod b by Max Mutarn, on Flickr

[GSX1100 dreamn]

Yeah nice one Drillit 2.0

[bull958]

Max, the pictures really add something to the rest of us mere mortals. Glad you got it figured out and great job so far, Im in awe. Steve

[Shin-Ken 1074]

Max, the pictures really add something to the rest of us mere mortals. Glad you got it figured out and great job so far, Im in awe. Steve

Hi Steve, thank you for your kind words, much appreciated. I had tried to post images with help from Suzukian and Rich. I am sure that most would have worked it out using either of the services Suzukian and Rich spoke of. However, for me the "How To" tutorial on loading images that Rich posted gave me a bouncing ball to follow, thanks again Rich.

Cheers.

[Shin-Ken 1074]

Lower steering stem bearing replacement, not difficult however, I wanted to make sure installing the new lower bearing went without a hitch. Holding a steering stem balanced and centered on an old bearing or piece of pipe with one hand while using a hammer in the other hand hitting the drift to drive the new bearing home is the usual back yard DIY way and has worked since day one but I wanted something that did the job without the chance of it going wrong. If you have access to a workshop or want to pay someone to do the job then all bets are off and this one operator DIY method doesn't apply.
Had some steel round stock, 20mm flat plate and a section of beam in the shed so decided to make a jig for one job - lower bearing installation.



Steering bearing jig 1 by Max Mutarn, on Flickr


steering bearing jig 2 by Max Mutarn, on Flickr


steering bearing jig 3 by Max Mutarn, on Flickr

[Shin-Ken 1074]

Like many others I prefer to cool down the steering stem prior to installing a new lower bearing. Heating the bearing as well as cooling the stem is another method however, I have found that just cooling the stem contracts the material a few microns and allows the bearing to be seated on the seal and shim without the need for heating the bearing.

I leave the stem in ice for an hour. Have the lower seal, shim, bearing, drift, hammer and spanner within arms reach of the jig.

Stem out of the ice, dry stem off and apply the same grease around the bearing area of the stem as the lube used in the bearing. Position the lower seal, shim and bearing on the stem, bolt the stem in position on the jig. I used an ally drift made from aluminium round tube and sized to match the bearing inner race, place drift on the bearing and three taps with the hammer and it was seated home on the seal and shim in a few seconds. Very happy with how it went.

lower bearing install 1 by Max Mutarn, on Flickr


lower bearing install 2 by Max Mutarn, on Flickr


lower bearing install 3 by Max Mutarn, on Flickr


lower bearing install 4 by Max Mutarn, on Flickr

[Shin-Ken 1074]

Next up is the swing-arm. Where the gusset joins each side there is a section of gusset that is not welded to the the arm, if it isn't welded then it is not needed so those two sections are coming off. The excess weld runs around the gusset can also have a tidy up. To fit the 2005 GSXR1000 K5 rear underslung brake caliper to a stock 1981 Kat swingarm I am going to have a tab welded to the underside of the swinger that will secure the caliper bracket to prevent the caliper from rotating and allow rear wheel movement when the chain is adjusted. Caliper position and chain alignment need to be done to work out the location for the caliper bracket tab. Before that, the K5 caliper mount needs to have a bush made to make it fit the 20mm Kat axle.

DW brake 3 by Max Mutarn, on Flickr

DW brake 2 by Max Mutarn, on Flickr


DW brake 5 by Max Mutarn, on Flickr

DW Chain wheel alignment by Max Mutarn, on Flickr

caliper position 1 by Max Mutarn, on Flickr

[Shin-Ken 1074]

Swing arm tidy up.

OEM swinger 1 by Max Mutarn, on Flickr


DW swinger 1 by Max Mutarn, on Flickr

[Shin-Ken 1074]

New swing arm bearings and bushes fitted as well as making an aluminium bearing spacer.

DW ally swing arm bearing spacer by Max Mutarn, on Flickr

[Shin-Ken 1074]

With the caliper location and chain alignment sorted the next step was having the axle spacers made in aluminium. These have been made and I polished them before sending off to be anodised gloss black. With a gloss black finish best results are when the parts are polished and is much cheaper if you do it yourself.

DW axle spacers 1 by Max Mutarn, on Flickr

[Shin-Ken 1074]

While waiting for the axle spacers to be made I made a set of adjuster blocks in ally to replace the OEM steel units. No milling machine at my place so its hacksaw and file time.

DW block 1 by Max Mutarn, on Flickr


DW block 2 by Max Mutarn, on Flickr


DW block 3 by Max Mutarn, on Flickr


DW block 4a by Max Mutarn, on Flickr


DW block 6 by Max Mutarn, on Flickr


DW bolock 1 by Max Mutarn, on Flickr