GS500F Rake angle

[burning1]

Hey Twinners,

I recall hearing a while ago that the steering head angle (rake angle) was changed around the transition to the GS500F model frames. A little research suggests that the steering angle is steeper, but that trail overall is similar between the two bikes.

Does anyone have any information on that change? Exact rake numbers, old/new, and what year the change was made?

If the newer model frames have a steeper rake angle, I'd be interested in obtaining one for my race bike.

[adidasguy]

Not really any change.
Trail went from 3.7" to 3.82".  Wheelbase 55.5" vs 55.7"
Same I think as far as most people would say.
What minor difference there is probably due to different brand of forks so a tenth of an inch somewhere.
Rest is the same.

[burning1]

From what I've gathered, trail increased slightly, rake decreased... So, I presume that offset increased. I've seen a lot of contradictory information, but the photos make it look like the forks are slightly steeper on the newer models. Could be totally wrong through.

[adidasguy]

I have old and new. Plus spare frames for old and new. Can't say there is any difference other than color and the tail for mounting the different tail plastics.
The different tails make the angle at the front look different.

The Suzuki manual indicates what I posted (which is where I got the numbers) and all other numbers are the same.

What difference there  is probably is due to a very minor difference in forks from a different manufacturer. Raising or lowering the forms a MM or so could easily account for that extremely small difference in the specs. Part may be due to the added weight of the fairing and larger gas tank. A slight difference in rear shock could account for it.

That difference by the book is extremely small. Bikes side by side: they look the same. Jumping from one bike to another: no difference other than what seat I have on them and rear sets and which OEM clip-on type.

Quite often I get home and jump on a different bike - just because I can - I guess.

Maybe people say they are different because the side stand is shorter making the bike lean more when on the side stand?

[burning1]

I'm finding conflicting info online. Pretty much everything says that the GS500E has a 25 degree rake angle. I've seen some specs for the GS500F saying 25, and others saying 23.9.

I've noticed, even with the GSX-R front end, it can take a little bit of effort to turn in at track speed.

[adidasguy]

Well, there's nothing more I can offer except what I read in the Suzuki specs and what I see (and feel) in my bikes.

As we each have conflicting information, I guess it is up to you to get a bike or two and see for yourself what is correct.

[burning1]

You know your stuff Addidasguy. Just hoping that the information in the manual specifically spelled out the rake angle, rather than overall trail.

[gsJack]

I've always believed the change was from 25.5* to 25.0* between the 00 and 01 years.  I still have the Owners Manual for my old 97 GS and it specs 25* 30' Caster.  I never had an OM for my current 02 but picked up the fact it had the 25.0* rake somewhere but don't recall where.  Guess I'll be searching the rest of the nite now.   

[noiseguy]

Interesting. A few degrees makes a big difference on feel.

Burning1: If you're trying to steepen the headtube angle, what about dropping the fork tubes within the triples? That has the effect of sharpening up the handling. Or do you not have room for that? For the 1 degree you're looking for, this might suffice. Plus it's a lot easier to accomplish.

Calculator here... for choppers, but your project is just a special case. LMK if you find a better one

http://www.rbracing-rsr.com/advchoppercalc.html

[gsJack]

Found a copy of a 89-09 GS500/E/F service manual in my old computer.  Specs for 01-02 models is 25*05'.  Also checked 04 and 09 F models and they are the same 25*05'.  That's close enough to 25* for me but it is slightly less than .5* change, 25*05'=25.08*.

I've run so many different tire sizes I've run many rakes.     I do remember when I had my 1st GS a decade or so ago I ran a couple of 130/90 rear touring tires for long milage like I used on my previous Hondas.  They raised the rear about an inch which reduced the rake about 1 degree and the quicker steering was very noticeable. 

[adidasguy]

The manuals mention what jack said. I wish I could help more, but for me doing just street riding I have no more information.

I understand how just a little change can make a difference for racing. Sorry I can't be of more help in this area other than what the manuals say, and by looking at the bikes I have in my herd (flock, school, gaggle, pod, cluster, group...)

[gsJack]

There's an old time racer named Fog over at EX-500.com, a Ninja 500 forum, who sells "Fog Bones" and claims an EX500 doesn't handle properly without them.  Simply a pair of shorter suspension links that raise the rear a bit.  Seems that would be the easier way to decrease the rake and quicken the steering of the EX/GS500 bikes than a frame change.

[burning1]

Thanks everyone for checking on this. I do have raising links for the rear, and I'm doing quite a bit with the rear geometry with the RGV swingarm swap. I'll see if that's enough to get steering the way I like it.

I don't like lifting the rear end too much - it changes a bunch of stuff relating to rear geometry. Lowering the front end has some impact on the rear, but also hurts cornering clearance. Clearance has been a significant issue for me in the past - generally, I turn by leaning until stuff drags.

[noiseguy]

Modify trail with adjustable triple clamps?

What is the trail of the GS500, anyway?

[SAFE-T]

There is supposed to be an optimum angle for the rear swingarm in relation to the rest of the bike ~ I assume this is what you are referring to

[burning1]

Modify trail with adjustable triple clamps?

What is the trail of the GS500, anyway?

I have a GS stem pressed into GSX-R triples. To be honest, I haven't measured the trail with this setup.

There is supposed to be an optimum angle for the rear swingarm in relation to the rest of the bike ~ I assume this is what you are referring to

Yes, that's a major factor. Raising links also tend to make the rear suspension a little more progressive... Which honestly isn't a bad thing on a race bike.

[noiseguy]

Of course, I'm wondering if the combination of GSXR triples and GS headtube angle aren't given you an overly large trail. Time to get out the tape measure.

The GSXR should at least have adjustable triples available... geez, they are expensive though.