Hi all,
I am 175 lbs with no gear, and ride mostly in town and in canyons. Which fork spring rate should I be looking at ?
Also, how tricky is swapping a front end from a DR650 ? I would swap the fork, brake, wheel, and levers... Is that reasonably straightforward ? Which year front end should I be looking for ?
thanks!
No a dirt bike FE would most likely not work. They are super super long and take a 21" wheel and is the DR the same fork diameter and spacing ? The only way to swap a FE that's not same dia and spacing of fork legs would be to machine spacers for the stem and if the bearings ID's are the same as the GS - 25 and 30mm then you can fit the whole thing, triples downward, but then guages have to be fitted up some how.
Many of us here have done katana 600, 750, GSXR etc, but again its a lot of work, and leaves you with a lot of kluge parts that dont work or looks stupid. For example, lock wont work with a katana swap, unless - well I made it work, its easier if you use the stem out of the GS, either press it out, or grind it out (depending on how it is, GS stems are both kinds with no rhyme or reason.
Gauges dont fit - unless of course you make a weird bracket to fit them. Brake lines need a bracket to fit em to the lower triple, headlight needs longer ears, and the collar around the forks fit without grommets etc etc. I have made it all work but it took me years to conjure up some one off's. And that is an "easy" FE swap. 89-95 Kat 600.
I've fit a KX250 front end to a savage 650 but I had to make 9 degree triples and fit it with the axle trailing to get it to handle well, and man did it clean up the retarded handling of the savage. But a savage has no gauge in the triple its in the tank, the neck lock is in the frame and headlight bolts to lower triple with a bracket. So just drill a couple holes and you're good.
I actually experimented with a Yamaha maxim fork leg set in a savage too. They are the same dia but yamaha had wider spacing, I may have with a lot of machining parts made it work. But its usually easier to fit to a bike that's a bit wider than one that's narrower. So I gave up.
Basically for a legs swap you need same diameter, and the bike you're getting it from will need to be slightly narrower spacing than the GS. But then, you gain nothing. That FE will be no improvement over the GS. A better FE will need to be beefier, and have to have come out of a bigger bike.
Cool.
Buddha.
Oh, never mind, these were welded up "brackets" for gauges. I made some that were "unboltable" after this iteration.
Anyway savage pics are here.
This bike is almost a foot longer than stock, but handled like a charm after flipping the legs left to right.
You see how the neck is angled to the fork leg - I'll add a pic that shows that angle better.
Cool.
Buddha.
Quote from: crowned on October 27, 2021, 05:26:53 PM
Hi all,
I am 175 lbs with no gear, and ride mostly in town and in canyons. Which fork spring rate should I be looking at ?
Also, how tricky is swapping a front end from a DR650 ? I would swap the fork, brake, wheel, and levers... Is that reasonably straightforward ? Which year front end should I be looking for ?
thanks!
Don't quote me on this, but I think the Pre '96 DR650 front ends used the same bearings as the GS500. I think the swingarm too. Again, check that before you rely on it because I just sorta remember that being a thing.
Are you trying to make a dualsport GS500? If not, just put some .85 springs in the stock GS500 forks. The stock forks are okay if they are correctly sprung for your weight. Even better if you can afford the Racetech gold valve emulators.
Quote from: crowned on October 27, 2021, 05:26:53 PM
Hi all,
I am 175 lbs with no gear, and ride mostly in town and in canyons. Which fork spring rate should I be looking at ?
Also, how tricky is swapping a front end from a DR650 ? I would swap the fork, brake, wheel, and levers... Is that reasonably straightforward ? Which year front end should I be looking for ?
thanks!
BTW I am near 175 too, and I 100% think a Kat600 FE is the way to go.
I was near 240 and had a 90 with racetech springs in it. My 2nd GS. My first was an 89 with a lindemann FE. And it was beautifully stiff and compliant at the same time. It was the 2nd best FE I ever rode on with the Kat ones being the best.
The kat fe makes it more compliant without being harsh or overly stiff. The 90 with racetech was no were near how good either kat or lindemann were.
If I dont have a Kat FE on my bike, I'd run it stock, I'll not do racetech or any springs alone.
Now maybe with those emulators/valving etc etc you can experiment with it enough and get it to behave closer to the lindemann - No idea.
The 2nd problem IMHO is the higher rise tube bars over clip on's of the 89 or the katana. I think the angle, the position and the fact it puts more of your upper body weight on the FE helps load the suspension to where it behaves especially under braking.
The more upright 90 and later bars leave the FE too lightly loaded till you hit the brakes and it then suddenly becomes too heavily loaded.
TBH try getting yourself some 89 clip on's, dont get euro high rise - US spec 89 stock clip on's. Will cost you near $100 and shipping. If you dont think it improves it, you likely will get all your $$ back.
I think the clip on's followed by the larger fork tubes on a kat FE are the biggest benefit. Then maybe the 2 disk 4 opposed pistons per disk make a huge difference. Of course you can put a GSXR upside down with larger disks and 6 per side for a total of 12 pistons and you can stoppie at will. BTW even with that setup the bike doesn't feel too stiff or harsh. But I only rode it briefly, you may want to wait and see if anyone with a GSXR FE responds to this post. I'll poke the one guy I know and ask, he's not posted in a few yrs.
Cool.
Buddha.
As per werase643 (ken) the numerous FE swaps guy, those 92-94 GSXR 750 were the stoppie ones. Not newer GSXR like I thought. Just 4 piston per side and 310mm disks. Not 6X2 like post 2001 750.
But on a GS FE experimenting with oil and this and that and maybe emulators are what would get the thing to be compliant when needed as well as stiff when needed. But if you have that much knowledge and time - more power to you. The better forks have more adjustments and also the legs dont rust as easily as a GS one does.
Cool.
Buddha.
I think to do a DR fork swap, you have to press the GS's steering axle out of the GS triples and put it into the DR triples. Of course, the only reason you'd do that is if you are trying to turn the GS into a dual sport. And if you are doing that, then you must be an extremely competent hobbyist who is just trying to spend time in the workshop tinkering, because it's way cheaper and easier to just sell the GS and buy a DR650, and you'll wind up with a way better dual sport.
Likewise, if you are considering a fork swap for braking or handling improvement, then rather than trying to find a GSXR fork, just sell the GS and buy a whole GSXR or even a Bandit. Or any 650-class sport bike or naked bike with upside down forks. A Ducati M620 would be a huge upgrade in the entire chassis and the difference in price between what you can sell the GS for and what you can buy the unpopular Duc for is less than what a GSXR fork/brakes/wheel/etc plus machine shop costs will set you back.
So unless you are just fishing for a project, fork swap makes little sense.
But spring swap makes a ton of sense. I suggest a Katana rear shock and swapping to about 0.85kg/mm Sonic Springs for someone your weight. If you ride harder or plan to put more weight on the bike, go with 0.90kg/mm. My GS with 0.90kg/mm sonic springs and a Katana rear shock has a much more compliant and smoother ride than my Bonneville with Progressive front and rear, FYI. But the Bonnie handles a lot better, mostly due to much lower CG and stiffer chassis all around, plus way better tires.
Anyway, if you are really considering fork swap vs. springs, springs are the obvious choice. If you have to ask, springs are the answer. If you are equipped to do the fork swap, you wouldn't likely be asking. IMHO.
I've heard this sell the GS and buy a GSXR stories a lot. Now yes, DR makes sense. If you want to even dream of dirt, you need a DR. Not gonna cut it with a GS DR FE or not.
Sadly, the GSXR suspension is terrible for a GSXR. (PS - TBH, I dont know about new GSXR's, but in the old days of air cooled, we would swap the 1100 one for the 750 ones, both the USD and the right side up were superior - front and rear, my 90 1100 has a 89 750 showa rear shock in it)
We are constantly swapping suspensions from the next bigger bike.
GS -> Katana -> GSXR etc.
SV guys are swapping out SV suspensions for GSXR - That I know runs in the 100's almost as much as the GS people putting in Katana/GSXR ones.
Its almost like the suzuki gods gave us just too little, and the next bigger model just the right amount for us.
Yea, Yamaha, kawi, Honda too. Just that I dont know those as well.
Really a GS suspension is about adequate for 175lb rider. Just try the clip on's and yea Kat600 rear shock, 2 minute swap.
Cool.
Buddha.