82 Kat resto-mod aka Project Bucket Case

[Guest]

Well, I finally can move on now. I found another machinist by chance. He bought a front wheel racing stand from me a while back and contacted me about a gsxr part that I had.

Have you mocked up the rear wheel/shocks/chain? Looks like you maaaay, be very close with chain/shock spring clearance. It is hard to tell, is the inside cutout for the shock mounts mounted to the swingarm radius'd or is it just a notch cut?

 

[ukilme]

Have you mocked up the rear wheel/shocks/chain? Looks like you maaaay, be very close with chain/shock spring clearance. It is hard to tell, is the inside cutout for the shock mounts mounted to the swingarm radius'd or is it just a notch cut?

I had mocked up the rear wheel-93 gsxr with a gsxr hub. And checked the clearance with a straight edge. It seemed fine. But I will be switching the hub to a GS1100 and most likely go with a 520 chain which should leave more room.

I will also be doing a 'dry' fit later this week when it warms up a little (-30c is to cold for me even with a heater). I will be mounting the GS motor etc and checking the clearances etc.

These are the mounts. I started with a c-channel, pulled out a miter saw and belt sander. I hope this is the answer you are looking for to your last question.

 

[Guest]

I had mocked up the rear wheel-93 gsxr with a gsxr hub. And checked the clearance with a straight edge. It seemed fine. But I will be switching the hub to a GS1100 and most likely go with a 520 chain which should leave more room.

I will also be doing a 'dry' fit later this week when it warms up a little (-30c is to cold for me even with a heater). I will be mounting the GS motor etc and checking the clearances etc.

These are the mounts. I started with a c-channel, pulled out a miter saw and belt sander. I hope this is the answer you are looking for to your last question.

The gixxr hub is not good, you are right to use the gs. Check the chain widths as you can get 520's almost as wide as 530's.

IN regards to the shock mount. I was wondering if the bottom of the slot is 90 degrees side/bottom/side or it is radius. 90 is mush less strength. Conscerned with your safety. Cheers.

 

[ukilme]

The gixxr hub is not good, you are right to use the gs. Check the chain widths as you can get 520's almost as wide as 530's.

IN regards to the shock mount. I was wondering if the bottom of the slot is 90 degrees side/bottom/side or it is radius. 90 is mush less strength. Conscerned with your safety. Cheers.

Okay, I get what you are saying. Is the inside of the mount 'curved' along the inside edges or is it 90 degrees. The 'curve' would give it more material for the corner and be stronger by acting like a brace. While the 90 degrees, may crack under stress. Hmm.. never though of that.

I got the basic design from the OSS board. My welder seemed to be okay with it and he does swing arms and frame work for local drag racers.

This is something to think about.

Thanks Rob.

 

[Guest]

The point right at the 90 is a fracture weak point. The radius helps to distribute the forces better. If one was to break it would be right at that 90.

Keep in mind that there shouldn't be a lot of lateral forces there but.. up to you. If you don't have the shock parallel that will increase the stresses both on the shock and the mount as the shocks compress.

 

[ukilme]

The point right at the 90 is a fracture weak point. The radius helps to distribute the forces better. If one was to break it would be right at that 90.

Keep in mind that there shouldn't be a lot of lateral forces there but.. up to you. If you don't have the shock parallel that will increase the stresses both on the shock and the mount as the shocks compress.

Thanks Rob. This is my first build and I want to learn. Therefore, I will take any info especially coming from experienced people like yourself and others.

If I have to redo the swing arm for any reason, I will do the raidus'd on the channel. Next time I might just stick with a shock made for the GS like YSS or Ohlins.

 

[Guest]

You may find my site helpful
http://www.suzuki-katana.com

 

[ukilme]

You may find my site helpful
http://www.suzuki-katana.com

Been there many times and was there just last night. I have also bought your B12 spacers, tint screen and have my eye on other things when the time comes.

 

[ukilme]

Got some more work done on the bike. I was able to modify some washers and got the shock to be perfectly square.

However while reviewing some of my photos, I noticed that something was a miss in the photo and decided to check the wheel alignment again.

As you can see, the left side string is farther out. It is by alot but that is because I had the wheel all the way to the front on the swing arm.

So, I reread some threads on wheel alignment and found that you should actually measure from the center of the pivot bolt to the center of the alxe on both sides to square up the rear wheel.

I then used a laser to check the wheel alignment. I found the string to be a pain in the @#!*% . The laser is easier to line up to the edges of the tire and then just use a measuring tape and break the laser's path to get the measurement.

Now, I checked and rechecked my measurement with the laser about a dozen times on each side and realigning it each time. I found that I was 6mm more of the left side of the bike which from what I understand is normal for stock bikes from the factory but I figured I might as well get it right. Therefore, I need to move it over 3mm to the right side.

So, I got a new alumimum spacer made and the brake hanger machine down 3mm on the outside.
The new spacer was in the middle. The outside spacer was a spare I had but it was not done on a milling machine and not completely flat. It would have distrody the wheel bearings.

My machinist got the order and parts Sunday evening and I had them Tuesday night.

Once, I got them on the bike. I rechecked the alignment again. I used the level to make sure the front wheel to make sure the front wheel was straight and true.

I used the laser again but this time I had hard time to get the measurements. It was not making any sense as now the rear wheel was to far over. I was @#!*% and started to put things away. I then noticed the stool being used was not flat and wobbled. I fixed that and realigned the laser. Took the measurements and was .5-1mm off depending on the time of the day, the air temp and wind blowing when the measurement was taken. I realigned the laser about 12 times again for each side and was always 1mm or less off.

Finally, I had to sit on the bike for the '1st' time. And found that the gsxr clip on were to low for myself. I have some CBR929 clip ons coming to raise it up a little.


I am hoping to the motor in the frame this weekend.

 

[Guest]

You have quite an angle on your swing arm M8. The shock mounts are too far forward. You are going to find that your chain will be sawing through your pivot. If you haven't already bought your offset sprocket I would suggestyou try a 19t front and a 51 tooth rear. Sounds big I know, but in actuality they are the same diameter as the stock 630 that came off it. Give or take a mm or two. Check it out and make sure your chain clears.

cheers,

 

[posplayr]

Have you mocked up the rear wheel/shocks/chain? Looks like you maaaay, be very close with chain/shock spring clearance. It is hard to tell, is the inside cutout for the shock mounts mounted to the swingarm radius'd or is it just a notch cut?

And I was wondering how you established the rear wheel on centerline of the bike. (Rob and I had fits with this on my bike )

Bandit swinger is offset by 3/16" I think but frame mounts are centered. .

So wheel should be offset With respect to the swinger by 1/2 of 3/16" closer to the right hand side.

 

[posplayr]

So, I reread some threads on wheel alignment and found that you should actually measure from the center of the pivot bolt to the center of the alxe on both sides to square up the rear wheel.

.

This is true (better than just sliding the axle all the way forward) but it does not center the rear wheel on the Rear axle.

 

[posplayr]

Okay, I get what you are saying. Is the inside of the mount 'curved' along the inside edges or is it 90 degrees. The 'curve' would give it more material for the corner and be stronger by acting like a brace. While the 90 degrees, may crack under stress. Hmm.. never though of that.

I got the basic design from the OSS board. My welder seemed to be okay with it and he does swing arms and frame work for local drag racers.

This is something to think about.

Thanks Rob.

Sharp edges are stress risers and will draw all the strain directly to that area causing an immediate break. It is like the weakest link in a chain. The strong links don't help a bit and all the load goes to the weakest link.

 

[Guest]

I run mine with a .650" sprocket side spacer with bandit arm. My laser lines up perfectly. Have not had any handling issues at speeds in access of 200kph. I do however use a custom sized front offset not a 5/8". With a stock arm a 5/8" is needed.

Jim has done extensive measuring in regards to this as well. I use a laser for alignment and it seems to be right on. We determined that a mm or two either way from center line of bike is not critical. Busa's with 300 tires run quite a bit of offset.

 

[posplayr]

I run mine with a .650" sprocket side spacer with bandit arm. My laser lines up perfectly. Have not had any handling issues at speeds in access of 200kph. I do however use a custom sized front offset not a 5/8". With a stock arm a 5/8" is needed.

Jim has done extensive measuring in regards to this as well. I use a laser for alignment and it seems to be right on. We determined that a mm or two either way from center line of bike is not critical. Busa's with 300 tires run quite a bit of offset.

I think ukilme is doing a good job, but I just did not see where he established the (#1) first part of the alignment procedure which is to insure that the rear wheel is located properly on the rear axle.

The offset of the wheel to the forks needs to counter the offset between the center of forks and the frame pivots so the wheel is on the centerline. I think 3/16" is the offset. This is done with R axle spacers.

1-2mm accuracy is fine

Once this is done then (#2) the rear to front wheel alignment is done (adjusting axle adjusters)

finally the (#3) offset sprocket to get the chain in alignment.

 

[ukilme]

You have quite an angle on your swing arm M8. The shock mounts are too far forward. You are going to find that your chain will be sawing through your pivot. If you haven't already bought your offset sprocket I would suggestyou try a 19t front and a 51 tooth rear. Sounds big I know, but in actuality they are the same diameter as the stock 630 that came off it. Give or take a mm or two. Check it out and make sure your chain clears.

cheers,

Ya, I am a little worried about the chain rubbing agaisnt the swing arm. I figured I could use a larger front and rear but damn 19/51 is big. But if is the same diameter of the stock 630 sprockets then it won't be to bad.

I was trying to go for between 25-26 degree rake which it is but I wasn't think far enough ahead. And yes, I do plan on a damper. I have not decided how to go with it.

Now, with the engine in the frame, the shock will compress the shocks a bit. Would this help a little with the issue?

 

[ukilme]

This is true (better than just sliding the axle all the way forward) but it does not center the rear wheel on the Rear axle.

Agreed it does not center the wheel on the axle but it will help the z and y axis. If I got my terminology right.

 

[Guest]

With a .650 spacer the rear wheel is centered in the frame. This is how I have arrived at this conclusion.

have drill rod through my steering stem and swingarm pivot. I have measured both triangles which showed me that the neck is straight in relation to the pivot. Reason being the distances are exactly the same with each side of the triangles.
I then measured from the pivot rod to the center of the rear rim. With the numbers from each end of the drill rod through the pivot being equal to the mm, you have to use a .650" spacer on the sprocket side.

This aligns the front and rear wheels in my frame. It aligns the wheels with the center line of the bike and it requires the custom offset front sprocket to align the chain. All said and done, for the kat and bandit arm, everything is at least as straight as from the factory. I am most confident in these numbers.

 

[ukilme]

I think ukilme is doing a good job, but I just did not see where he established the (#1) first part of the alignment procedure which is to insure that the rear wheel is located properly on the rear axle.

The offset of the wheel to the forks needs to counter the offset between the center of forks and the frame pivots so the wheel is on the centerline. I think 3/16" is the offset. This is done with R axle spacers.

1-2mm accuracy is fine

Once this is done then (#2) the rear to front wheel alignment is done (adjusting axle adjusters)

finally the (#3) offset sprocket to get the chain in alignment.

Maybe this will help and you can let me know if I am doing it wrong which is what this thread is about.

I started with a straight frame. I checked it out when I bought it and my welder check it out when I got the bracing done.

Next, I got a complete 93 gsxr750 front end including the spacer, speedo, a 93 gsxr front wheel and even the brakes ect. Now, I did use a 02 CBR 954 tree but the spacing is the same. My thinking with this combo means that front wheel will be centered to the frame.

With the front wheel mounted, I made sure the forks were not out of line and the wheel was correct with the 3 axis-again, I hope my terminology is right.

This means my front wheel is a known at least to my thinking and the rear is the unknown

Now, the rear rim is a 93 gsxr750 rim as well. This meant that stock B12 spacers are the same (part number 64741-17e00/left side and 64751-46e00 the right side). With these spacers, I could mount the rear and make sure the front rim straight ahead. From here, I figured out the rear wheel spacer.

So, basically I work from my known (the front) to the unknown (the rear) which should take care of offsets. However, if I would have another unknown rims (R1, even B12) then I would have center the rear first.

Also, as I was using the laser to check the alingment. I was able to measure the laser along the frame especially at the cross member and the the distance was pretty much the same as the wheel alignment. About 1mm difference.

Let me know if I did this okay. You both, Katman and posplayr, know more about this then myself

And thanks for your advice and questions.

 

[Guest]

Yur doin it all right Bubba. Best to air it out now and correct than after it is built.