Suspension Upgrades or Tires?

[subxero]

^ 1/2 can be made to work but it is more work. Personally I feel like if you are drilling it to 1/2 you need to use a 1/2 bolt as there is too much play for my liking with the 12mm bolt. And if you use a 1/2 bolt then you need to drill out the shock mount in the frame as well and then you run into problems on the lower connecting point as well.

I would advise anyone and everyone to either buy a 12mm bit or a 31/64 bit. Don't use a 1/2" it creates more problems than it is worth... ask me how I know

[sharky nrk]

Originally Posted by Qomomoko

can you elaborate a little? I'll do a search. I saw that I need to bore out some 5/8 inch holes ....

Very similar issue to what happens with and SV. Compression holes when done as the instructions say end up compromising fluid movement at the bottom of the stroke giving you issues with the last bit of travel. You will struggle to get your end of the stroke rebound dampening right when modified as the instructions dictate.

[Lemonfresh]

Originally Posted by csmith12

I know others have used a 1/2 bit as well with success.

1/2 inch is 12.7 mm. You will end up with extra clearance if you use it, probably not that big of a deal.

[ROADandTRACK]

The proper thing to do is drill the frame and add some custom spacers.
Also, I keep saying this but the OEM shock is too short for the track. So the GSXR shock makes the bike worse than OEM.
20150528_104608.jpg

[csmith12]

Originally Posted by Lemonfresh

1/2 inch is 12.7 mm. You will end up with extra clearance if you use it, probably not that big of a deal.

Full transparency... My 250 (#511) gsxr shock top mount hole was drilled out with a 1/2 bit 1.5 seasons ago. 3 or 4 different ninjette members have ridden it on track. ALL have good reviews of how the bike felt and handled but... I aint saying it's right or wrong, but it worked out ok for me showing the bike no mercy. YMMV

Don't forget the blue locktight on the bolt no matter what you do.

[subxero]

^ as long as it is all tight like a tiger I would assume it is all good to go but don't have any experience, however I do remember a member here posting that they went with 1/2" hole with the 12mm bolt and after a few races they noticed damage/deforming of the top shock eye because of the extra space allowed movement and acted like a hammer so to speak. Alas they had no pictures but that is what they said.

still think the best way to go is with the proper bit size, no reason not to IMO

[csmith12]

Originally Posted by subxero

still think the best way to go is with the proper bit size, no reason not to IMO

But of course!

[Lemonfresh]

Originally Posted by ROADandTRACK

The proper thing to do is drill the frame and add some custom spacers.
Also, I keep saying this but the OEM shock is too short for the track. So the GSXR shock makes the bike worse than OEM.
Attachment 36680

Sorry we all don't have $600 laying around to spend on the correct length shock. The gsxr shock may be a little shorter in height but it is miles better than the stocker in damping.

[csmith12]

^^^

ikr.... I have been beaten by riders on stock bits (front and rear) at damn near lap record pace. So not sure why some riders think the stock stuff is 100% garbage for track, because it aint. It's just the rider doesn't like it, which is fair enough.

The pic below tells the story. Take some of the preload out and the bolt holes will line up, then drill it out. Install the proper rate spring and then get custom bones to put the height where you want it, then enjoy the ride.

[sharky nrk]

Originally Posted by ROADandTRACK

The proper thing to do is drill the frame and add some custom spacers.
Also, I keep saying this but the OEM shock is too short for the track. So the GSXR shock makes the bike worse than OEM.
Attachment 36680

Where did you get those spacers? Link? Are they 12mm od 10mm id flanged?

[ROADandTRACK]

Originally Posted by Lemonfresh

Sorry we all don't have $600 laying around to spend on the correct length shock. The gsxr shock may be a little shorter in height but it is miles better than the stocker in damping.

Not for the track

[ROADandTRACK]

Originally Posted by sharky nrk

Where did you get those spacers? Link? Are they 12mm od 10mm id flanged?

They come with the Frankenshock we sell for $450 or you can buy them alone for $20/pair shipped.

[InvisiBill]

For whatever it's worth, I used a 12mm reamer bit on my SV650 shock. It was a tighter fit than the "12mm" hole in my stock EX500 shock with only a few thousand miles on it. Using a 31/64" (12.3mm) is probably just as good as stock. As stated, the 1/2" (12.7mm) bit is adding a bit more slop, but we're still talking about fractions of a millimeter.

[InvisiBill]

Originally Posted by Manimal

What is the weight rating of the OEM springs, btw? Just curious is all.

Don't take it as gospel (especially since the numbers on their site have been changed), but RT's calculator says the stock .65kg/mm springs are good for 96lb on the street or 76lb for racing. The 9.3kg/mm rear is good for 210-220lb. The '06-'09 GSXR 600 spring is just a tad stiffer at 9.4kg/mm.

Originally Posted by Somchai

Manimal, where did your suspension guy get the calculation from about the front spring is to soft for you?
My weight is 175 lbs and when I go to the racetech website to calculate my spring rate it gives a 0.70 kg/mm spring for me.

The NewGen and 300 calculators both give me .746kg/mm street and .783kg/mm race when I put in 160lb. For 175lb, I get .768 and .807.

[Somchai]

Originally Posted by InvisiBill

The NewGen and 300 calculators both give me .746kg/mm street and .783kg/mm race when I put in 160lb. For 175lb, I get .768 and .807.

Your right, I guess this depends on their upgrades since the calculation I'd make was when I changed my setup more than two years ago
But at least I don't see any reason to change my setup (made from a twenty year experienced Irish Kawasaki race mechanic) since suspension setup does not only depend on the spring rate, like told here every time.

[sharky nrk]

Originally Posted by ROADandTRACK

They come with the Frankenshock we sell for $450 or you can buy them alone for $20/pair shipped.

how much of that is shipping? I am in San Antonio area from time to time. You can PM me if you would like. I think I asked about the Frankenshock before but can't really remember the conversation. Does the 450 include a service/freshening, and is it resprung/revalved for each customer's needs or is the 450 a "one size fits all based off the shelf jobber"?

[ROADandTRACK]

None of it is shipping and it is set up for you with the proper spring and valving.

[supersport]

Is the GSXR shock mod really that bad?

[GregS]

Originally Posted by supersport

Is the GSXR shock mod really that bad?

Can't speak for the stock GSXR shock, but I have the GSXR Frankenshock that Keith Hertell at Road and Track sells and it made a big difference. Money well spent!

[sharky nrk]

Originally Posted by GregS

Can't speak for the stock GSXR shock, but I have the GSXR Frankenshock that Keith Hertell at Road and Track sells and it made a big difference. Money well spent!

I want to get one, its likely to be my next track bike purchase but money is so tight

[accumack]

No it's not bad at all I use it. It is rebuildable and lot less than an Olins and is head and shoulders above stock for less than $100.

[Lemonfresh]

Originally Posted by supersport

Is the GSXR shock mod really that bad?

Some seem to be saying it is terrible on the track. I wouldn't know I have only used it on the street. I can say this, it is much better than the stock shock for that purpose.

It is less than 5mm shorter than the stock shock. It will affect the trail and anti-squat of the bike. Trail can be compensated for by adjusting the fork height in the triples.

Will you feel the change in anti-squat on the street? Probably not.

For an upgrade less than $100 including hardware, it's a no brainier.

[howlinhoss]

I did tires first then suspension. However, if I were to do it again I would have done suspension first.

[sharky nrk]

Originally Posted by Lemonfresh

Some seem to be saying it is terrible on the track. I wouldn't know I have only used it on the street. I can say this, it is much better than the stock shock for that purpose.

It is less than 5mm shorter than the stock shock. It will affect the trail and anti-squat of the bike. Trail can be compensated for by adjusting the fork height in the triples.

Will you feel the change in anti-squat on the street? Probably not.

For an upgrade less than $100 including hardware, it's a no brainier.

I think the answer is almost always "it depends" lol. I mean your weight, riding style, other mods, etc all will dictate whether its an "improvement" or not for your particular application.

On the track, that 5mm difference is a BIG DEAL. I have the shorter dogbones and if your considering the GSXR shock for track work, getting that rear geometry change back is a must.

On the street for commuting/regular riding purposes....I suppose if the spring was in the right range and you had the shock adjusted properly it could be better, and certainly the adjustment flexibility is nice. But a "better" / "more adjustable" shock that is well out of range for the rider/riding style is not a "better" shock at all

[InvisiBill]

Originally Posted by sharky nrk

I think the answer is almost always "it depends" lol. I mean your weight, riding style, other mods, etc all will dictate whether its an "improvement" or not for your particular application.

On the track, that 5mm difference is a BIG DEAL. I have the shorter dogbones and if your considering the GSXR shock for track work, getting that rear geometry change back is a must.

On the street for commuting/regular riding purposes....I suppose if the spring was in the right range and you had the shock adjusted properly it could be better, and certainly the adjustment flexibility is nice. But a "better" / "more adjustable" shock that is well out of range for the rider/riding style is not a "better" shock at all

I think this is precisely it. The '06-'09 GSXR600's spring rate is nearly identical to the NewGen/300 stocker (I'm not sure if that's a carefully researched feature or pure coincidence). However, most signs indicate that this rate matches a ~215lb rider. Also, other GSXR shocks have a variety of spring rates. Depending on exactly which GSXR shock you buy, you may or may not be matching the stock spring rate, which may or may not work well for your weight.

I've seen very little mention of the NewGen/300's relatively stiff rear spring (I brought it up in another thread). If the rear can't properly absorb bumps, especially with too-soft fork springs, it'll bounce around like a rocking horse. If you're replacing the crappy, way-off stock parts with better, way-off donor parts, I wouldn't expect much improvement. The fact that they're better parts might even exacerbate the fact that they're mismatched.

Shock Swap Myth points out some issues with swapping in a shock from some random bike. There are many ways to skin a cat, and Suzuki's way might vary greatly from Kawasaki's. The GSXR shock is made for the GSXR suspension, not the Ninja suspension. On the other hand, they seem to be close enough that many people are very happy with the GSXR shock swap. If you're starting with bottom-of-the-barrel non-adjustable parts, it's not hard to find something that does work better, even if it's not perfect. If you can spend $35 and get a drop-in shock with better features and a good spring rate, that sounds like a great value upgrade (even if you spend another $35 on a second shock to get a donor spring with a better rate). I've personally used multiple shocks from other bikes on my 500, and been very happy with the results given the cost. If you spend nearly $500 trying to make that wrong shock into the right shock, you're now into the price range of good aftermarket shocks, and most likely will still be ending up with something not all that great.

I think it's around 3:1 for height changes at the shock compared to the axle. So the shock being 5mm shorter equates to the rear end being over 1/2" lower. While I'm sure it's a much bigger deal on the track, it will still affect the steering on the street too. It'll just be slower to turn and feel less flickable overall. While I'm sure a pro racer wouldn't just toss in a different shock like this, the 5mm difference shouldn't alter the angles in the suspension geometry much, and the rear height can be corrected via dogbones (R&T said above that even stock is too low anyway).


Overall, I think this can be a budget way to get a decent upgrade. Depending on the specifics of your mod, it's possible to do things in a way that will actually make things worse though. If you do some research and/or testing, I think you can end up with something quite cheap that will perform quite well.