1150 suspension & wheels to 750ES - Worthwhile swap?

[QuaiChangKane]

This 1150 on eBay is about 90 miles from my home.... (Please don't snipe me!!!!)

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=4563083989

Would the wheels and suspension be a worthwile upgrade for my '83 750ES?

Doesn't look like the seller's got a reserve set....



The rear wheel on the bike isn't correct in those photos - I sent him an email, and he says that he has the stock wheel which will be included in the auction.



I'm basically looking for a wider swingarm, wider rear wheel, and 17" front for better tire selection. The brakes on the 1150 are the same as mine are, but the forks are a bit better, and the rolling chassis would give me everything I need to swap wheels/calipers/rotors, along with forks/swingarm/rear shock.

I figure I'd need to drop the 630 sprocket from the rear wheel, and possibly work on other issues such as:


1. Are the swingarm pivots the same width on the 1150 and 750ES?

2. Will the forks be a direct bolt-on, or will I need to have new bearings fit and new stops welded on?

3. Will the 1150 rear shock mount up to the 750ES's top shock linkage?

4. What is the widest tire that can be fit to the 1150's rear wheel? 160mm is where the tire options really open up, but 150mm will get me better quality rubber than the 130 I'm stuck with now.

5. How is brake fade with the solid discs the 1150 has? I ride alot of twisties - do the brakes get too hot?

6. Will I need to offset the drive sprocket for the wider wheel? The 750's sprocket is waaaaaaaaay out from the wheel as it is.....

7. Someone has to have done this already - is it worth the money and time? I'm sure I could get a good deal on the parts, and delivery would be free plus 1/2 tank of gas or so....




Thanks in advance,


-Q!

[Billy Ricks]

It's debatable as to whether or not it's worthwhile. If it were me and I was trying to do mods on a shoestring I'd opt simply for the 1150 rear. Then rebuild your front end with Progressive springs. The shock on the 1150 is essentially the same as yours with a stiffer spring most likely. It's also probably just as tired as your shock. If you can get the stuff cheap enough then go for it. Just don't expect enormous handling gains. You can always sell off the stuff you don't use.

[joe.d]

It seems that there wouldnt be much point in the swap,I say rebuild what you have.
the EF has a 16 inch in the front, not a 17" ive just swapped my front end for a Upside down GIXER one, and that is a really easy swap, the rear was a little trickier, I ended up using a GSF 750 Katana rear wheel, bolted right up, I had to mix and match some of the spacers,and I allso had to go to a 530 chain conversion, but kept the standard ef swinging arm. but now I can go to a 150 rear tire with plenty of space, I could probably go to a 170 without too much of a problem, but I went for the factory katana rear wheel tire size.

[QuaiChangKane]

So the 1150 had a 16" front, too???? Damnit.




Figured it wouldn't be much of a gain.



The problem is - a replacement shock sells for around $700.


A swingarm/rear wheel/caliper set up would set me back at least $350, since I haven't been able to find a complete setup.


A fork/wheel/caliper/triples/bars combo would set me back $600 or more....


Then add time and cost for fitment and tweaking........




Not that I'm cheap. Okay, maybe I am.




-Q!

[joe.d]

not to mention I got a deal on the tires on my bike and I splurged $400 for a set of AVON Radials, moddng isnt cheap, but I did ok couse I had the help of a friend who owns a bike wreaking yard, so I had the ability to borrow difernt components till I came up with the right combination, wheels, spacers, calipers, etc, it can get exspensive if you start spending real money on parts you cant use.
Im lucky that I have alot of tools and the finances to play these games, but hey dont tell the misses, what I spent.

$100 on the rear wheel
$170 on the 530 chain conversion and sprokets
$400 on tires
$800 on the front end
$100 on the seals and bearings for the front end

$1570, plus lots of time, and patiance.

[Mario Padilla]

Suspension Mods for GS750ES

Another modification that has not been discussed is somewhere between upgrading what you have and replacing with a GSXR front end, I would call it the hybrid mod.

On my bike, I rebuilt the forks with progressive springs and have all the parts to install a 17x3 GSX front wheel. It uses the same axle diameter as the original so it will be a direct replacement to the 16x2.15 front wheel. The trick is the brakes. Since the rotors are a larger diameter, I'm having to fab a bracket to space out the front calipers. While I'm at it, I'm replacing the calipers with Nissin 4 piston calipers and installing stainless steel brake lines. With the 3 inch front wheel, you can go with a 110/70 size tire. Additionally, I've replaced the bar risers with clipons from a CBR600 Hurricane (37mm). The stock speedo drive will not work with this modification, but I have the drive unit that came with the 3 inch rim.

The rear change is similar to the changes previously discussed. I'm installing a 17x4.5 GSX rear wheel. It uses the same axle diameter as the original and will be a direct replacement to the 17x2.5 rear wheel. With this rim, a 150/60 or 160/60 size tire is acceptable. Once I get into this one, I'm suspecting that I'll have to play around with spacers to center the wheel and maybe have to space out the front sprocket so that the chain clears the tire. Brake caliper torque arm mods will also be necessary. The GS1150 rear wheel was either a 3 or 3.5 inch rim depending on the year. Radial tire selections for these rim widths are limited. I believe with the 3.5 inch rim you can go up to a 140/60. There is a race tire available in that size but I haven't seen much else. Either way, a 17x3.5 GSX rear wheel is also available if you chose to go that route.

Upgrading the rear shock is another area that I'm looking into. I have a Fox Twin Clicker off a GSXR that will require an adapter for the lower link connection. My options here are replacing the lower mount with a mono-ball type mount or fabricating an adapter that will connect between the shock and the swingarm mount. I'm leaning towards that later because the Fox shock is shorter than the stock shock so I'm going to need to increase the length of the Fox shock anyway. Another option that I'm looking at is a shock off a Honda SuperHawk. It has the same mounts as the stock shock and it's about 1/4 inch longer than the stock shock. I picked up a cheap one (>$20) off ebay and plan on doing some load/compression tests to see how it compares to the stock item.

My cost breakdown is:
$100 to overhaul the front forks (springs/seals/oil)
$75 for the front rim with rotors
$75 for the front tire (110/80 Pirelli Dragon)
$50 for the front calipers with new pads
$50 for two stainless steel brakelines
$20 for the clipons
Bracket fabrication is cheap, I have access to machining equipment

rear conversion costs are no different than those previously discussed. I paid $100 for the Fox shock and a mono-ball mount is ~$25.

Hope this helps or maybe I'm making things more confusing by throwing in another option.

MP

[Billy Ricks]

The 750 uses a smaller axle diameter front and rear than GSXR wheels. The front bearing is smaller both inner and outer diameters and is a mess to try to deal with as far as adapting it to the stock 750 front end. The rear wheel is easier to deal with. Just use the GS750 bearings in the new wheel whether it's the 1150 or a GSXR wheel.

As Mario already stated the rear shock is not that hard to deal with. When I have time I'm going to fab a transition piece for the bottom of a '97 GSXR shock I already have. If that goes well I'll pick up a used Fox or Ohlins for the same GSXR model and use my transition piece with that.

[oldschoolGS]

The 1150 rear is an easy swap- 1985 and 1986 models had the 3.5in rear. You can run a 140 rear max on that rim within the stock swingarm. The only mod is to fabricate a narrow single sided rear caliper torque arm to clear the tire. I have used this setup since the late '80's on my 750. Photo below shows the 140 rear with the moded brake arm. All hardware including sprocket hubs interchange.

The 1150 rear shock will bolt right up. I have also used one, it is a little stiffer than stock but only offers marginal improvement. In my opinion, I would not spend major $ on a rear shock. These bikes will never be canyon carvers in the modern sense, if you are outriding the suspension on the street, you are flirting with disaster. Just crank up the preload for ride height and put your $ in the motor.

The best way to do the front is to do a complete swap as many have done. You may be able to pick up a Katana front end- as I did for dirt cheap. The 41mm tubes, floating dual piston discs, and 17" front will be a definate improvement. If $ is tight, don't worry about using late model GSXR inverted forks, they are overkill- you will be flexing the frame on your GS well before approaching fork limits. Keep it simple and enjoy, Ed.

1983 GS750ED
2005 GSF1200SZ

http://groups.msn.com/SuzukiGSGarage/gs750edbacktolife.msnw?action=ShowPhoto&PhotoID=3199

[Billy Ricks]

My old GSXR front end will be available in the next few months. It would be fork, Daytona bar mounted to the top of the triple, rotors, and the full triple. I have a 3.5" Kat rear wheel with sprocket carrier and I believe all the cush dampers are there and good. It would match the GSXR front from those years.