Front suspension upgrade

[Physic55]

I'm looking into upgrading my front suspension. However, with the cost involved in that like progressive springs, emulators, etc. I can find large amount of used fork for several different types of other bikes for much less. Not to mention, almost brand new. Has anyone done a swap? Can you please point me in the right direction, it would be greatly appreciated. I've already done the rear shock upgrade to a r6. Next I want to do the bandit rear rim with a 150/60/17 rubber.

[Janx101]

Putting forks from other bikes sounds. ... potentially more expensive overall?! ... unless you get an exact diameter/length match.

Might need to also change axle size (which then means bearings also)? , triple clamp change?, not knowing how good the internals of the used forks are etc... by all means have a go and do a great conversion! but it could get complicated!

Most users on here opt for progressive springs or straight rate Sonic Springs. . Simpler!, consult website, choose correct weight etc,  pay, receive, look up how to, install! .. (though I paid a ex racer mechanic to do mine... easier at the time)

Emulators have been used and mentioned recently. .. but I'd test the new springs out first THEN maybe look at emulators....

Emulators are great! Don't get me wrong, buddy put some on his and loves fiddling with the setting till it's 'perfect for the days riding' ... I'm happy enough with just my Sonics and would maybe add emulators for bling factor but don't think I'd bother 'tuning it all perfect' very often...

Depends on how/where you ride and what your real needs are!

[Big Rich]

Janx is on the right track....

A front end swap    isn't as easy as just tossing on some forks and triple tree. The GS500 has an odd steering stem, which complicates the issue. You would basically need to reuse the GS500 stem, pressed into the donor bikes lower triple (and the stem needs to be compatible with the donor bikes top clamp too). After it's all said and done.....you would probably need new springs anyway to match your weight / riding style.

That being said, the Katana swap is documented in the Wiki listed above.

[Rallyfan]

I could swear I saw a local bike with an R6 fork swap a couple years ago. The advantage in addition to the fork is the stronger brakes.

I'd rather work with the existing setup though because of costs and hassle.

[Physic55]

Shucks, I really wanted the better brake set up for the front too. After some thought it does probably make sense to just go with the springs whether that be the sonic or progressive. I'm only 165 lbs. Braking now is pretty good except for the constant dip down due to leaking seals and the poor stock springs when motorists cut out in front of me or the occasional dog running across the road.

Thanks guys 

Any of you live near NJ?? I'm looking for people to ride with.

[Slack]

IMHO dual brakes would HURT performance on a GS500.

As is with the stock setup if you use 600* Motul RBF, SS Braided lines, and HH pads you don't need anything else. The front brakes already have enough power to pick up the rear wheel. And they won't overheat, no matter how hard you hit the canyons.  I brake HARD. I normally wear my front tire out just as quickly as the back. And I've never overheated this set up. (the main reason to have twin disks is to have a larger heat sink, something required on bikes braking from 180 mph, not 100 mph).

That's why it won't help, this is why it will actually hurt. It will harm performance by increasing unsprung rotational weight (the absolute worst kind). Which will cause worse front fork performance, slower acceleration, and even    Longer Braking Distances!!!! {EEEK} didn't see that one coming, did you? (Note: that is ignoring the fact that the forks would be different, and just talking about the effects of having 1 vs. 2 brake rotors)

[Shepa]

Yeah, right.


Sent from my toilet seat using HTC FartPhone

[Slack]

Basic math and logic. If you can already endo the bike and the brakes don't overheat then the only upgrades could be for better feel and modulation.  Add more weight, performance dwindles.  I don't know what you want to argue with.  Why don't you be more specific with your "yeah right"

[Shepa]

Basic math and logic. If you can already endo the bike and the brakes don't overheat then the only upgrades could be for better feel and modulation.  Add more weight, performance dwindles.  I don't know what you want to argue with.  Why don't you be more specific with your "yeah right"

Mkay... for starters, (roughly) double the stopping power, with less effort (one finger lever press) and more longevity/durability of the parts used (rotors and brake pads). - That's the practical/real life experience.

And now for some theory: Since the braking force is now applied on both fork legs simultaneously, there's more in-line braking stability, since there are no offset rotating/counter-rotating forces as with single rotor/caliper configuration.

Finally, I don't intend to argue at all, I'm just sharing my own experiences with dual calipers/rotors installed on my GS.
The difference is very comparable and proven in a number of occasions, in favor of dual system of course. 

Oh yes, I intend to improve the system even further by installing Nissin 4-piston calipers instead of current ones, but that's another story. 

[Big Rich]

Just throwing this out here before I go to bed (and I'm not taking sides by any means): I believe it was Burning1 that said the stock GS brakes were a weak point in racing because of over heating. I "think" it was the rotor that got too hot and had a tendency to warp. If I'm remembering correctly about him saying it, the brakes were tested under racing conditions with little regard for pad longevity.

And Shepa - I have heard that is why modern bikes don't require fork braces like older bikes do..... the dual calipers keeping the inline stability while braking. I've yet to see a comparison to axle diameter, fork diameter, suspension technology, etc when looking at older bikes and newer bikes.

[dgyver]

Front end swaps are not difficult but can be involved. Having a complete f/e from the donor bike is best but you can mix some parts. The additional adjustments on newer forks are a major benefit.

Katana is probably the easiest to do. Easiest way is a stem swap. Pressed in stems are quick. Welded are more tedious. The GS wheel can be reused. They used to have tapped holes on both sides for two rotors. Steering stops and ignition lock may need to be altered depending on the f/e. I had a GSXR f/e on a GS with turing the GSXR stem down to fit the GS.

Dual caliper brakes are a huge improvement over the single GS caliper. The dual six pot calipers I had were overkill on a GS. But then that GSXR f/e is on my SV now and the GS has a Kat f/e again. The Kat uses dual opposed 4-pot calipers and doesn't the GS use a single sided caliper?

Also, you will need a master cylinder sized for the dual/ larger calipers.

[Slack]

Mkay... for starters, (roughly) double the stopping power, with less effort (one finger lever press) and more longevity/durability of the parts used (rotors and brake pads). - That's the practical/real life experience.

And now for some theory: Since the braking force is now applied on both fork legs simultaneously, there's more in-line braking stability, since there are no offset rotating/counter-rotating forces as with single rotor/caliper configuration.

Finally, I don't intend to argue at all, I'm just sharing my own experiences with dual calipers/rotors installed on my GS.
The difference is very comparable and proven in a number of occasions, in favor of dual system of course. 

Oh yes, I intend to improve the system even further by installing Nissin 4-piston calipers instead of current ones, but that's another story. 

More longevity yes, twice the longevity, then twice the replacement cost. So it all evens out.

You can't double the stopping power without doubling the front tire contact patch, since that is what forms the limit.

One finger braking, yes, like I said: Better Feel is the only upgrade you can hope to achieve. I suppose I was wrong, your comment about having better inline braking stability is of course true. But, would you rather have more stability and a longer stopping distance? A 120 front tire will help your stability issues too, but again, your increasing rotational unsprung weight. And therefor will increase your stopping distance.

It may be true that on a track you can overheat the stock system (caliper and rotor), but not on the street (with pad and fluid upgrades).

I've never noticed my Katana 750 braking straighter then my GS 500.

Just my humble opinions.

[gsJack]

.............................I believe it was Burning1 that said the stock GS brakes were a weak point in racing because of over heating. I "think" it was the rotor that got too hot and had a tendency to warp. If I'm remembering correctly about him saying it, the brakes were tested under racing conditions with little regard for pad longevity..........................

........................It may be true that on a track you can overheat the stock system, but not on the street......................

I turned my 97 GS front rotor blue once dicing in the mountain twisties and another time on a long hard twisty downhill run out of the mountains turned it blue again and completely faded it out, no front brake as I came up on traffic.  I had the EBC standard pads on at those times and later went to the EBC HH pads . 

So if you're running hard in the mountains with less than HH pads I'd say you can overheat the front brake without going to the track.  The rotor turned blue but never showed any sign of warping and the blue wore off on the way home.

I had the Z4/Z2 radial tire combo on at that time so braking traction was not a problem but I'm sure you could reduce brake fade if that's a problen with dual front brakes.  I traded a 85 Nighthawk 650 that had dual front discs on my first GS.

[Slack]

What temp fluid were you running and how old was it?
Standard fluid is only good for ~350F when new (depending on brand) and WILL cause brake fade with hard braking. 600F Racing Brake Fluid will hold up to the abuse much better. And last much longer without fade.

[gsJack]

I've always used the dot 3&4 synthetic brake fluids like Prestone, Valvoline, etc which meet dot 4 specs called for by Suzuki for the GSs.  Their specs are about 500-510F dry boiling point.  All my old Hondas only called for dot 3.

Although boiling fluid can cause brake fade so can overheated brake pads which I would think was my case due to the level of pad/rotor friction heat indicated by the rotors turning blue.  I've always popped the pistons and cleaned them everytime I change pads due the crud buildup on them from year around riding requiring bleeding with fresh fluid.

I doubt they would have faded like mine did with HH pads instead of the standard ones.  I put like new low mileage calipers on my 02 a couple years ago and they came with HH front and FF rear pads which started with the F models I think, pads wern't marked for friction grade on older models before required by fed regs.  Best to go with the HH fronts at least if your going to ride hard in the mountains with the GS.

[Slack]

oh, I see. thank you for your insight! We completely agree    where you quoted me there, by "stock system" I was referring to the stock caliper and rotor, not pads, lines, or fluid. I will edit my post, thanks.

I'm just sharing my own experiences with dual calipers/rotors installed on my GS.
The difference is very comparable and proven in a number of occasions, in favor of dual system of course. 

Oh yes, I intend to improve the system even further by installing Nissin 4-piston calipers instead of current ones, but that's another story. 

Did you swap just the right fork or swap forks from a different bike? (might seem like a silly question, but it's doable with a bandit 400 leg, or some bike like that).
Do you have a thread talking about your brake setup?
I'd be interested in checking it out, in case the track is in fact too much for my current set up.

[Big Rich]

Post #508:

http://gstwins.com/gsboard/index.php?topic=55753.msg805160#msg805160

I remember it stumped me when I saw it without the explanation. Very creative fella!

[Slack]

Very cool!
Sherpa, can you show a few pics of the welds? Did you weld it or take it to a shop? How did you get the alignment perfect?

[Shepa]

Well, to take a picture of welds, I'd have to take off the front fender/mudgard (whatever the correct term), so, maybe later...
Caliper alignment, or fork brace alignment?

Sent from my toilet seat using HTC FartPhone

[Slack]

I figure if you only align one then the other won't be right. So, I assume you have to align both simultaneously? At least get the caliper in the proper plane, so that it could then be spaced out (with the washers) the proper distance.
I was thinking the easiest way would be to bolt everything together, so that the caliper holds the fork leg in the proper orientation and the brace holds the tabs in the proper location, tack it together, remove, and weld it up. But I wasn't sure if there was a better way.
Does it need to be Tig welded?