Project Novice seeks Katana fork swap!

[BrianDamaged]

Can't think of a better place to ask this question...so here goes!

MY 1100 Kat has some fairly grotty fork tubes on it, and I was going to get them re-chromed, until I started thinking about alternatives. Scanning a few threads here revealed a whole lot of people have already done this, with varying degrees of success.

To be honest....I have got more confused reading the threads than when I started....

What is the SIMPLEST way of doing this?

I want to end up with:

1) Better brakes
2) Better suspension
3) No stock parts damaged so I can put her back to original easily
4) Keep the stock clocks/fairing undamaged
5) Have a matching front and rear wheel
6) Use only stock Suzuki parts without 'one off' parts being needed

I have heard you can use SV parts, but the forks need extending. Not for me. I don't know a good machine shop, and hate the idea of having a join in my forks....

I haven't got a huge pot of money to spend, so I want to avoid exotic bits.

What should I look for, what fits, what should I watch out for, and what parts would I need to source to complete the project.

All help gratefully received!

[rapidray]

Fork Fix

The easiest( & Cheapest!) way to achieve your goal is to contact Forks By Frank to get a set of replacement fork tubes that will use ALL of your stock internals & external parts. I have NEVER had a single problem with ANY forks they have made for me. Then again, if you are independently wealthy, you could just go down to your local Suzuki dealer & spend at least TWICE as much for stock parts. Or if you ARE wealthy just bring the bike to my shop & I will sell you all KINDS of go faster stuff! HAHA! Ray.

[BrianDamaged]

yeah, soon as that rich aunt dies, I am going to buy all those NOS parts, have the frame gold plated and a new screen carved out of solid diamond......

In the meantime, I am using her for an 18mile commute through the busiest parts of London, and the stock brakes scare me!

All the stock parts I take off will go in the loft, wrapped in plastivc and coated with corrosion inhibitor, so I can put the bike back to stock in an afternoon. Hence my desire to alter or modify none of the stock parts.

I do want fatter tyres for more grip, thicker stronger forks so they don't flex under braking on the way into slow corners, and better brakes so I have some more control over which side of the road I am on when I come OUT of those tighter corners! And no....I don't want to sell it and buy a GSXR....

[terry]

Brian, have you ridden a Kat with forks and brakes in good condition? Although fitting later forks, wheels and brakes is a popular fashion, I'm old enough to remember how the media raved about how well the stockers handled and braked back in the day.

The Katana frame was very similar to the earlier GS1000 item, described in the book "Best bike's of the 70's" as being the best handling Japanese bike ever built!

I've got a 1981 GS1000S, and even though I also have a much later BMW K1100LT with ABS, big fat forks, wider tyres etc etc, I don't have any problem with the stock forks and brakes on my Suzy, in fact I think the bike is quite capable.

I fitted new Koni 7610 shockers on the back in 1999, and rebuilt the forks with new seals and oil etc, replaced the tyres with Bridgestone BT45's, and fitted a fork brace, (because it looked nice) replaced the brake fluid and pads, bled them, and I reckon it handles and stops great. I've never felt the tyres letting go, get really good mileage out of them, and certainly have never felt the forks flexing.

I don't know that there is a "bolt on" arrangement to replace all the bits that you want to, but I applaud your decision not to hack your bike about in the process, there are too may guys who want to try to turn our classics into modern sports bikes, and end up destroying these icons in the process.

I recently saved a 1981 GS1000G from a wreckers yard after a young turkey decided to "Street-Fighter" it, luckily enough he only bodged the cosmetics, (aluminium checker plate sidecovers screwed directly into the frame, for example) but did no permanent damage to the mechanicals. As most of the saleable bits had already been destroyed, I got it cheap, the engine and gearbox is a gem, but now I've got to find new sidecovers, seat, gauges etc to bring it back from the precipice, thank God for Ebay! Cheers, Terry.

[RJ]

1989-1995 GSXR front ends will bolt up to your bike without any problems. You may get a mismatch on the steering stops and fork lock as you'll need a different ignition switch. To run a matching rear wheel you'll need to go with a GSXR rear brake arrangement that will necessitate moving the torque arm from the top of the swingarm to the underside. That requires welding which cost me all of $65 to have done. If you keep the original torque arm bracket in place you can always return to stock. The other issue is switching to a 530 chain with an offset front sprocket to line the chain up. This setup gives you the ability to run modern radial tires which, along with a modern front end and brakes, will give you a vastly superior handling machine than stock. The single most expensive part of this project for me was having the forks rebuilt at around $350. You can knock that price down if you do the rebuild yourself but it takes specialized tools to perform. Overall a worthwhile endeavor IMHO.

[BrianDamaged]

Terry, keeping the stock look is REALLY important to me. I bought the KAt because I love the shape, and have done since I was a spotty teenager who couldn't afford to buy one!

I have done a simialr project on a old X7 a few years back, but I had to have a custom set of yokes made up from a combination of X7 stem and GSX400F yokes to take the GSX front end. It had the same wheel pattern as the X7 and gave me twin discs and a front end that didn't flex like it was made of spaghetti!

The Kat is fairly firm up front, which may be down to tired springs sagging a little, and the braking rip from the skinny front tyre doesn't feel quite right to me. The mile-long wheelbase means she is stable, and a forkbrace might help some too. Tyres are Bridgestone...but compound choices are limited with a 19" front wheel. I run a Yam Supermoto when the weather is bad, and that runs Bridgestones ...but I use an 014 front with an 020 rear. I can't find anything suitably sticky to go on the front for the Kat.

Whether I end up just throwing the cash into new forks, springs and seals, plus some high quality rear shocks and sticky front tyre.... or I go for a front end swap, when I am finished, the Beast will still look like a 1982 Katana. I want nothing else

If I go for GSXR bits, I will need to source pre-USD forks, so I am going to be hunting for earlier bits...not later.

[Billy Ricks]

Terry, keeping the stock look is REALLY important to me. I bought the KAt because I love the shape, and have done since I was a spotty teenager who couldn't afford to buy one!

I have done a simialr project on a old X7 a few years back, but I had to have a custom set of yokes made up from a combination of X7 stem and GSX400F yokes to take the GSX front end. It had the same wheel pattern as the X7 and gave me twin discs and a front end that didn't flex like it was made of spaghetti!

The Kat is fairly firm up front, which may be down to tired springs sagging a little, and the braking rip from the skinny front tyre doesn't feel quite right to me. The mile-long wheelbase means she is stable, and a forkbrace might help some too. Tyres are Bridgestone...but compound choices are limited with a 19" front wheel. I run a Yam Supermoto when the weather is bad, and that runs Bridgestones ...but I use an 014 front with an 020 rear. I can't find anything suitably sticky to go on the front for the Kat.

Whether I end up just throwing the cash into new forks, springs and seals, plus some high quality rear shocks and sticky front tyre.... or I go for a front end swap, when I am finished, the Beast will still look like a 1982 Katana. I want nothing else

If I go for GSXR bits, I will need to source pre-USD forks, so I am going to be hunting for earlier bits...not later.

'90 and earlier forks were conventional. Just stay away from the '88 750 front end, shortest ever for Suzuki. First generation wheels should fit and match the last GS pattern.

[BrianDamaged]

Ahh..thanks Billy. That narrows it down! Time to start combing the breakers for some prices

Something lke this should fit at the rear ( though I do NOT like his torque arm.... )

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&ih=012&sspagename=STRK%3AMEWA%3AIT&viewitem=&item=220051390694&rd=1&rd=1

[Dink]

I have my 82 Katana set up for two finger stoppies. First remove the hose from the calipers to the antidive units. Use the banjo bolt from out of the antidive unit to fit the line into the caliper. Fit Vesrah pads!!! Bleed the brakes. Enjoy!!!
May want to have a good look at the condition of the forks as well, measure "Static sag" ; the difference between the length of the fork completely extended, and laden (with you on the bike in riding gear in your normal seated position, a couple of mates helps here) if the difference is over 30mm time for new springs, Flushing and replacing the fork oil anyway will not hurt (I recommend 15w oil).
I cant help on 19" tyres as mine runs 18" spokes both ends, most guys here run Metzeler ME33's and like em, I have Pirelli Sport Demons on mine, and am really impressed with them.

Dink

[terry]

I cant help on 19" tyres as mine runs 18" spokes both ends, most guys here run Metzeler ME33's and like em, I have Pirelli Sport Demons on mine, and am really impressed with them.
Dink

That sounds like a nice set-up mate, I've got new alloy rims in my garage for my project bike, but haven't had them laced up yet. I've got a 3.5 x 18 rear and a 2.5 x 18 front, and the intention is to run a 140 rear tyre and a 110 front, is that similar to yours? I do like Bridgestone BT45R's, but I know the Metzlers and Pirelli's are good too. Cheers, Terry.

[Cassius086]

BrianDamaged



Look closely at that ad...he said that swing arm wil fit directly into GS1000.GSX750/GSX1100....

That is not the case, at least with the GS's. May fit the early Kats, though??? Some grinding is required to make the gsxr swing arms fit GS frames (but not much...like 1/16" on either side of the swing arm pivot). That rim pictured in the add will fit in the stock swing arm of my 82 1100EZ. I imagine it will fit yours as well. I am using my swing arm, torque arm for the caliper, my cush drive/sprocket carrier, the gsxr rim/rear brake. Just need to make an offset for the counter sprocket. That will probably be the trickiest part for me (making measurements and having one made).

Good luck with the mods, sir!!:-D

[80GS1000]

BrianDamaged


Just need to make an offset for the counter sprocket. That will probably be the trickiest part for me (making measurements and having one made).

http://z1enterprises.com/detail.aspx?ID=1886

and

http://z1enterprises.com/detail.aspx?ID=1887

[Cassius086]

Ah, YOU RULE!!!!\\/

Thanks.

[Dink]

That sounds like a nice set-up mate, I've got new alloy rims in my garage for my project bike, but haven't had them laced up yet. I've got a 3.5 x 18 rear and a 2.5 x 18 front, and the intention is to run a 140 rear tyre and a 110 front, is that similar to yours? I do like Bridgestone BT45R's, but I know the Metzlers and Pirelli's are good too. Cheers, Terry.

It is a nice set up!! When I got the bike, it had a 110/80 front & a 130/80 rear. It was a pig!!!! it was hard to turn in hard to keep on line, would push wide, stand up under brakes. Admittedly I must tell you I didn't look at tyre sizes I had thought it was just the difference between the handling of two different generation 1100's; remember I also have a GSX1100EF.
When I finally did notice, I replaced the tyres with the correct sizes, 100/90 & 130/90 Pirelli Sport Demon's the bike was instantly transformed!!
I have always liked Pirelli's (admitting bias8-[ ) but these tyres have really impressed me. I had been running Metzeler's but they didn't like the heat up here ( almost evaporated off the rims ) I am not a big believer in fitting "phat"tyres to bikes, but if 110 &140 fit the rims widths you are going for at least it is a balanced increase.

Dink

[gsgeezer]

brake improvement

I always put on stainless brake lines on the old bikes I've gotten.
Big improvement and easy to do!