Riding impressions from Katana/radials swap?

[007jag]

Hello,

A bud & I were discussing the possibility of swapping the 88 - 97 Katana front end and rear wheel setup to an earlier GS. He wondered if the difference in rake/trail and switch to radials would cause any bad riding problems.

If you've done this could you share your riding impressions good or bad?

Thanks,
Jack

 

[posplayr]

Hello,

A bud & I were discussing the possibility of swapping the 88 - 97 Katana front end and rear wheel setup to an earlier GS. He wondered if the difference in rake/trail and switch to radials would cause any bad riding problems.

If you've done this could you share your riding impressions good or bad?

Thanks,
Jack

Rake will not change unless you cut-off and reweld your steering tube.

I did a 1st Gen to get RSU 41mm forks and 18" radials on an GS1100ED. I did more than that including bandit swing arm, cartridge emulators and extended length adjustable Ohlins, but I'll limit the comments to what appears to be the effect of tires.

The rear is an 170/60-18 and is a very round profile which tends to allow the bike to roll into turns very easily. In fact after getting the new suspension on it was much harder to follow a straight line without wondering when trying to hold a position on the freeway.

I have a small flat spot in the center now (about 2-3 inches) so it tends to allow the bike to stay more centered on the flat but still rolls easily into turns.

The stability markedly improved. Much less wander over grooves in the pavement than the old bias ply tires. After doing my 1166, the bike was feeling more squirrelly with the extra power. Now I can just gun it and there is no stability issues at anything near sane speeds (under 120mph ).

The wider lower profile front tire (110/80-18 v.s. 100/90-19) gives much larger contact patch and you feel much more secure. The old brakes really offer no comparison to the improved 4 pot GSXR brakes. The feel is improved and the stopping will have you crowding your gauges if you don’t squeeze your gas tank with your legs.

Depending upon your undertaking, if you are willing and do things correctly (i.e. chain and wheel alignments) then you will not be disappointed.

17" wheels with USD are a little more trouble. I guess Bandits have 17" with RSU so a easier conversion. The 18" wheels provide some more ground clearance.

 

[007jag]

posplayr,

Thanks for your time & input.

With respect to rake/trail difference, what I meant was that most newer Katana and for sure Gsxr fronts are usually at steeper steering angles. And the swap to an earlier GS would be extending them.

Anyone else?

Regards,
Jack

 

[Guest]

I will re-iterate what Jim said...there really isn't ANY comparison between radial and even the best bias ply tires (IMHO), but for me the greatest difference was the BRAKES. Even the early gsxr 4 pots are indescribably better than the stock GS brakes.

 

[Big T]

posplayr,

Thanks for your time & input.

With respect to rake/trail difference, what I meant was that most newer Katana and for sure Gsxr fronts are usually at steeper steering angles. And the swap to an earlier GS would be extending them.

Anyone else?

Regards,
Jack

The steering angle is a function of the frame, not the forks.

Lots of people have swapped fronts from GSX, GSXR, Bandit, Hayabusa

You'll need a wider swing arm unless you have an 1100 E or 1150

 

[Guest]

Rake will not change unless you cut-off and reweld your steering tube.

I did a 1st Gen to get RSU 41mm forks and 18" radials on an GS1100ED. I did more than that including bandit swing arm, cartridge emulators and extended length adjustable Ohlins, but I'll limit the comments to what appears to be the effect of tires.

The rear is an 170/60-18 and is a very round profile which tends to allow the bike to roll into turns very easily. In fact after getting the new suspension on it was much harder to follow a straight line without wondering when trying to hold a position on the freeway.

I have a small flat spot in the center now (about 2-3 inches) so it tends to allow the bike to stay more centered on the flat but still rolls easily into turns.

The stability markedly improved. Much less wander over grooves in the pavement than the old bias ply tires. After doing my 1166, the bike was feeling more squirrelly with the extra power. Now I can just gun it and there is no stability issues at anything near sane speeds (under 120mph ).

The wider lower profile front tire (110/80-18 v.s. 100/90-19) gives much larger contact patch and you feel much more secure. The old brakes really offer no comparison to the improved 4 pot GSXR brakes. The feel is improved and the stopping will have you crowding your gauges if you don’t squeeze your gas tank with your legs.

Depending upon your undertaking, if you are willing and do things correctly (i.e. chain and wheel alignments) then you will not be disappointed.

17" wheels with USD are a little more trouble. I guess Bandits have 17" with RSU so a easier conversion. The 18" wheels provide some more ground clearance.

I would agree wholeheartedly with you. I stayed at 17" in the rear (with a 160/60) and went bigger in front to a 110/70/17 from a 100/90/16. GSX600F front end and stock swingarm with a Hagon shock.

 

[77GS750inCincy]

sorry to resurect a old post. But to posplayer, rake can be changed by other ways besides cutting and rewelding the head tube. By simply raising the back of the bike you will alter rake, same as lowering it. As stated, rake is directly related to frame position. Thats why most sportbike riders run a rear spacer. This takes out more rake and allows quicker turn-in. This is something our GS's could benefit from. Also, to the OP, I am planning this swap in the not so distant future, along with some others. I am also concerned with the spring rates as these old GSs weigh a bit more than a Kat

 

[TheCafeKid]

Actually the older Kat( not the original) and Bandits aren't all that much lighter than the GS series. Maybe 80-ish lbs give or take ( I don't have the numbers in front of me) plus there are no problems getting springs to deal with the differences. Even using the ultra modern stuff off of bikes that weigh 3-400 lbs are still being used on our GSs. I'm personally considering going ahead and doing my 1100ES with first gen gixxer stuff using the stock ES swinger and the 18" wheels front and back. It's not as tremendous a difference but I will essentially be running the same set up as Pos. Minus the bandit arm and I'm using the 6spoke gixxer wheels that look the same as stock GS 83 1100 wheels. It will look stock but handle much better and it's all bolt on except I have to mod the spare 1100e swinger for the underslung brake stay.

 

[posplayr]

sorry to resurect a old post. But to posplayer, rake can be changed by other ways besides cutting and rewelding the head tube. By simply raising the back of the bike you will alter rake, same as lowering it. As stated, rake is directly related to frame position. Thats why most sportbike riders run a rear spacer. This takes out more rake and allows quicker turn-in. This is something our GS's could benefit from. Also, to the OP, I am planning this swap in the not so distant future, along with some others. I am also concerned with the spring rates as these old GSs weigh a bit more than a Kat

While I agree with you, it is not really clear what the OP was asking. I assumed head angle in the frame. Theoretcally the question is so wide open as to be difficult to answer because almost anything you do affects the "rack".

 

[posplayr]

Actually the older Kat( not the original) and Bandits aren't all that much lighter than the GS series. Maybe 80-ish lbs give or take ( I don't have the numbers in front of me) plus there are no problems getting springs to deal with the differences. Even using the ultra modern stuff off of bikes that weigh 3-400 lbs are still being used on our GSs. I'm personally considering going ahead and doing my 1100ES with first gen gixxer stuff using the stock ES swinger and the 18" wheels front and back. It's not as tremendous a difference but I will essentially be running the same set up as Pos. Minus the bandit arm and I'm using the 6spoke gixxer wheels that look the same as stock GS 83 1100 wheels. It will look stock but handle much better and it's all bolt on except I have to mod the spare 1100e swinger for the underslung brake stay.

Another minor diff is the rear rim on the 6 spoke is 18x4.0" v.s. the 18x4.5" rear on the 3 spoke. Dont try and go over 160/60-18 on yours. I'm running 170/60-18 on mine. The Dunlop Road Smart seems to have the best profile. That Michilin Pilot Road has that square profile even when new.

 

[Guest]

Hello,

A bud & I were discussing the possibility of swapping the 88 - 97 Katana front end and rear wheel setup to an earlier GS. He wondered if the difference in rake/trail and switch to radials would cause any bad riding problems.

If you've done this could you share your riding impressions good or bad?

Thanks,
Jack

a couple factors effect your rake/trail.
frame angle as mentioned. Changing heights of rear or front. MOst common is shorter forks which will quicken steering and in some cases make a dangerous situation at speed.
The other is offset of the forks. new forks tend to have much less offset which increases your trail. eg: my 83 kat has a 50mm offset on the stock forks. The gsxr forks have 30mm offset.

Tire profile will not change your geometry enough for you to notice. especially if your are changing both ends.

Also radials are dangerous and have a terrible ride quality, stick with the skinny wooden bias ply.

 

[Guest]

Actually the older Kat( not the original) and Bandits aren't all that much lighter than the GS series. Maybe 80-ish lbs give or take ( I don't have the numbers in front of me) plus there are no problems getting springs to deal with the differences. Even using the ultra modern stuff off of bikes that weigh 3-400 lbs are still being used on our GSs. I'm personally considering going ahead and doing my 1100ES with first gen gixxer stuff using the stock ES swinger and the 18" wheels front and back. It's not as tremendous a difference but I will essentially be running the same set up as Pos. Minus the bandit arm and I'm using the 6spoke gixxer wheels that look the same as stock GS 83 1100 wheels. It will look stock but handle much better and it's all bolt on except I have to mod the spare 1100e swinger for the underslung brake stay.

If you do it, You'll probably discover you can use your stock caliper with the gsxr mount.

 

[posplayr]

If you do it, You'll probably discover you can use your stock caliper with the gsxr mount.

We talking rear caliper here?

 

[Guest]

Yes. I'm using a gsx600 caliper (above the swingarm on my '83 750 like the stock one) on an '89 gsxr 1100 mount. Wheel and rotor is '89 1100 also.

 

[TheCafeKid]

Yes. I'm using a gsx600 caliper (above the swingarm on my '83 750 like the stock one) on an '89 gsxr 1100 mount. Wheel and rotor is '89 1100 also.

REally?? Just by looking Id figured the stock GS caliper to be way to large compared to the GSXR rotor (lil sucker) I might give it a shot tho. It would be dandy to not have to do any extra modifications... If i give it a shot I will report back and let you all know. It will be a month or so at least before i get around to this however...

 

[Guest]

The 600 Kat callper and the 1100 gsxr caliper look identical except for the stay arm mount being on opposite sides. When i first had the 600 kat rear wheel (before the 1100) i used the stock 750 caliper on it's own mount, only when i won a complete 600 caliper that looked like new for four bucks on ebay was that then i switched to that. Calipers are pretty much the same, it's the mounts that are different.

 

[TheCafeKid]

The 600 Kat callper and the 1100 gsxr caliper look identical except for the stay arm mount being on opposite sides. When i first had the 600 kat rear wheel (before the 1100) i used the stock 750 caliper on it's own mount, only when i won a complete 600 caliper that looked like new for four bucks on ebay was that then i switched to that. Calipers are pretty much the same, it's the mounts that are different.

Well the stock GS caliper won't work with the early gixxer 1100 hanger I have figured that much out. The bolt spacing on the caliper is just a hair to wide for the hanger. If I can find either a gixxer 600 caliper or another compatible hanger then this might work and make
this project go alot faster. Now that I have the parts
and can see exactly what's going on, aside from the wheel spacing and figuring out gauge mounts this looks pretty easy.

 

[salty_monk]

Take a look at this... custom CNC cut brake hanger in 10mm steel. (little heavier than stock but not too bad).

Doesn't work with the stock 83 caliper because of where the line bolts to it on the side (interferes with the swing arm)

but works fine with the GS550/750/850/1000 etc etc older version with the line on the back of the caliper.... No pics of it fitted but I can take some at some stage, I have it all fitted now.

I also have a custom Torque arm to clear the 170 tyre......

The best news for you... I got 2 of them made so we might be able to work something out as I have a spare.... (hanger & torque arm). I had to grind a little of the back of the caliper in a couple of areas to create clearance for the wheel but nothing serious.

I also have the first Gen front calipers you're after complete with lines & master cylinder.....

I have a set of 17" 3 spoke wheels too if you wanted to go that route... (4.5")

Dan