Suspension Upgrades or Tires?

[JohnnyBravo]

Crank your rear suspension, try heavy oil in your front end

[Manimal]

Update .....

Finally got around taking the 300 to a local suspension guy (Evolution Suspension in San Jose). His assessment:

Front: <edit> aside of my weight (under 160lbs), and due to my riding habits (somewhat aggressive), the front is too soft. He recommended race tech springs.

Rear; was set about right for my weight. However, was unbalanced to the front settings. He softened the rear (adjusted to lowest setting).

This adjustment had helped, and is a bit more confidence inspiring.

I plan to replace the IRC's with better rubber, as suggested. And at some point, add the Race Tech springs. I just haven't motivated myself to making the purchase, as I have other projects going on at this time.

Speaking of the Diablo's, I see there are two tire choices to choose from 110/70-17 and 110/70ZR-17 What is the difference? Or, better yet, which one should I choose?

Thanks for any insight.

[csmith12]

Nice!

I don't know your riding style, but the racetech spring calc doesn't take it into consideration. Some riders are heavy on the brakes, others are not. This needs to be a factor in your spring purchase.

[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.
By the way the front spring of the N250 and N300 is the same with a rate of 0.65 kg/mm (maybe Racetech didn't update their website about this, email attached).
The only difference between those two bikes is that the fork oil level from the N250 is 108 +/- 2mm and from the N300 it is 100 +/- 2mm.

[accumack]

I believe the stock springs are progressive rate. I set the sag on mine with pvc pipe about 1/2" long and I weigh 188 without gear. They feel pretty good but I will get straight rate springs and gold valve emulators next winter to match my 2006 GSXR rear shock i'm currently running.

[Manimal]

@Somchai - I gather he made the assessment based on the follow variables; Knowing the stock spring rate and fork oil wt, seeing the tie wrap position on the fork tubes, assessing my weight on the bike (while suited), and judging by my riding habits.

My riding; I am aggressive, but not as aggressive as some others here and that I know. I can be quite aggressive on the brakes (late braking, and trail brake). I solely use the front. I don't think I ever use the rear. Most of the territory I ride are technical (tight) back roads.

I have not taken the 300 to the track, and don't think I will. I have another bike that I use for track fun. My interest is having the right tires (and suspension) for the conditions of the roads that I ride.

Although, as of late, I have gotten accustomed to the squishy suspension of the 300, in kind of a good way.

[Lemonfresh]

I went with Race Tech (I hear the Sonic springs are nice too!) springs based on the calculator on Race Tech's web site. I cut the spacers to give me 37 mm of sag in the front and did a 125 mm air gap with 15 wt oil.

The difference is amazing. No more bottoming out the forks under the hardest braking I can muster. There is about 1/4 in. of travel left.

What happened was it showed the lack of suspension refinement in the rear. With a little cutting of the undertail, a little grinding, and some spacers and longer bolts, I fitted an '06 GSXR 600 shock. I set the sag to 35 mm by maxing out the preload. The GSXR shock is the same length as the stock 300 shock, but it is valved too stiffly for the 300 and has an incorrect spring rate for me. However, as it is now it's a huge improvement over the stock shock, has adjustable settings, and was fitted for under $100, which included professionally machined, powder coated spacers.

I looked into local professional shock rebuilds (Race Tech wanted $500) with a valve kit and a new spring and it's around $350. If you can add the shock yourself, for under $500 you can have a correctly valved and sprung, adjustable shock for your 300.

Fork springs, 15 wt oil and the GSXR shock made the 300 stick like glue with the stock IRTs. I can take corners on mountain roads much faster than I should or could before.

I was so impressed with the springs, I ordered a set of Race Tech emulators. They made the front feel almost as good as modern cartridge forks. I still need to do some tweaking to them though. If you can do the work yourself, you can get a good front end feel for under $300.

Moral of the story is, just about every penny you put into suspension will pay off in improved feel, control, and confidence. Tires are important, but they won't do much if your suspension won't keep them on the ground correctly.

If you plan on doing any type of riding with the 300 or keeping any type of motorcycle, I highly recommend getting the suspension set up for you. It makes a world of difference.

I started riding on a '94 Ninja 500 and soon "outgrew" it and got the Daytona 675. After coming back to the small displacement bikes, I now realize I never outgrew the 500, I was riding outside the capability of the suspension.

[Sirref]

Originally Posted by csmith12

Nice!

I don't know your riding style, but the racetech spring calc doesn't take it into consideration. Some riders are heavy on the brakes, others are not. This needs to be a factor in your spring purchase.

Which direction do you go for a rider who is harder on the brakes? Is there a benefit for going the opposite direction?

[Lemonfresh]

You shouldn't select spring rates based on whether the fork bottoms out or not. You should get new springs BECAUSE your forks are bottoming out. Spring rate should be selected for rider weight and riding style, then tailored for the rider and bike using spacers to set the sag. The reason Race Tech's web site only asks for weight and riding style is because that is all you really need to get the spring rate close.

Fork oil air gap is what fine tunes utilization and prevents the forks from bottoming out. Once you get the correct rate springs and set the sag, you need to set the air gap so your forks don't bottom out under the hardest of braking, but come close. Because, honestly, that's when you need the full suspension the most, emergency stopping or hard cornering when the fork compresses. Or ideally, for going fast, the transition between the two.

[Alex]

Originally Posted by Manimal

Speaking of the Diablo's, I see there are two tire choices to choose from 110/70-17 and 110/70ZR-17 What is the difference? Or, better yet, which one should I choose?

If there is a version that you can get without the Z-rating, all that means is that the tire hasn't been tested/guaranteed to perform safely at very high speeds. Z-rating used to just mean, anything over 149 mph. Now there are ratings even higher than that, but it's a moot point for our ninjette. We won't be within 40 mph of having to worry about tire construction at speed. If the 110/70-17 is cheaper, I'd just get that one. If they are the same price, you're fine either way.

[rojoracing53]

Change your front tire to something Radial constructed and leave the stock rear on there if it has less then 4000 miles because the IRC rear is a good tire, it's the front that kills the combo.

With a good front tire an otherwise stock 300 can do more then 99% of riders can so just keep practicing and riding and stop thinking about changes that you don't really need.

By the way a suspension guy who doesn't work with you at the track to understand what you need is only there to take your money and give you a small change that acts as a placebo. The funny thing about a sugar pill is how often they actually work because most limits are in your mind anyways.

By the way, all those online spring rate calculators are total crap for most riding styles and unfortunately most other sources of info regarding suspension for these little bikes is incomplete or simply wrong.

Best of luck getting more in tune with the bike and maybe you can join me for a ride over Mt. Hamilton some time. If you've ridden with @Alex then maybe he can chime in whether a ride with me is a good idea.

[Somchai]

Originally Posted by rojoracing53

Change your front tire to something Radial constructed and leave the stock rear on there if it has less then 4000 miles because the IRC rear is a good tire, it's the front that kills the combo.

With a good front tire an otherwise stock 300 can do more then 99% of riders can so just keep practicing and riding and stop thinking about changes that you don't really need.

By the way a suspension guy who doesn't work with you at the track to understand what you need is only there to take your money and give you a small change that acts as a placebo. The funny thing about a sugar pill is how often they actually work because most limits are in your mind anyways.

By the way, all those online spring rate calculators are total crap for most riding styles and unfortunately most other sources of info regarding suspension for these little bikes is incomplete or simply wrong.

Best of luck getting more in tune with the bike and maybe you can join me for a ride over Mt. Hamilton some time. If you've ridden with @Alex then maybe he can chime in whether a ride with me is a good idea.

Thank you Jason

[Lemonfresh]

I always like learning new things.

I just spent some time doing some more research and it seems I set my rear sag incorrectly. I was always told a range of 35-40 mm front and 30-35 mm rear, but found multiple sources recommending 30% of suspension travel for street use front and rear. That would put the front travel of 120 mm at the correct 37 mm of sag but my rear the rear travel of 130 mm should be around 39 mm of sag. That would give me some free sag and get the preload adjuster from being maxed out. I might not need a replacement spring after all.

Suspension is never a waste of money. If you sell the bike, you can put the stock parts back and on get most of your money back out of the take offs.

The spring calculators may not be the most precise way of calculating the correct spring rate for your ride, but its better than just guessing. Or buying 5 pairs of springs to find the one that's just right for you. You need a baseline to make corrections from, the calculator is a good place to start.

I must have gotten lucky. The spring rate the calculator spat out for me put the front at 10 mm of pre-load and allowed me to correctly adjust the sag. Plus, it feels infinitely better than stock.

Originally Posted by rojoracing53

Change your front tire to something Radial constructed and leave the stock rear on there if it has less then 4000 miles because the IRC rear is a good tire, it's the front that kills the combo.

I would not recommend mixing bias and radial tires. The stock IRTs are bias ply. You might get away with it or you might end up getting an unstable bike. If you replace the tires, you should replace both front and rear with the same brand. They don't have to be IRT's, just both Pirelli, Dunlop, Bridgestone, etc. I wouldn't mix and match brands and types (Radial and bias) to save a buck, the tires are the only thing connecting you to the road and are just as important if not more so than brakes. However, as with all advice, you should take it with a grain of salt and always do your own research.

I am just sharing my experience tweaking my ride and the information I've found. Hopefully this helps someone else make their ride more enjoyable and safe. Once you feel how correct springs and adjustment work, you will want to make the rear work as well as the front. After playing around with the suspension on the 250/300 I have come to the conclusion that from now on every bike I buy will have suspension work done before anything else.

All I'm saying is for the price of a set of tires and some elbow grease, you can have a decent suspension that you won't regret.

[liberpolly]

Originally Posted by alex.s

spend money on lessons and track time. it will help you much more with confidence than bike upgrades ever will.

^many times this.

[Somchai]

Originally Posted by Lemonfresh

...The GSXR shock is the same length as the stock 300 shock...

Can you confirm this measurement, bc all information here in the forum and also given from Ohlins and Wilbers or others say that the GSX-R600 shock from 06 until 09 has a length of 315 mm, while the N250 and N300 shock, which are the same, have a length of 320 mm? Thank you.

[Qomomoko]

Originally Posted by Somchai

Can you confirm this measurement, bc all information here in the forum and also given from Ohlins and Wilbers or others say that the GSX-R600 shock from 06 until 09 has a length of 315 mm, while the N250 and N300 shock, which are the same, have a length of 320 mm? Thank you.

for those looking, I can talk about the 05 model

the 05 GXSR 600 shock is not the same lenght, the mod can be done as a mod.
the shock reservoir WILL get in the way for the PREGENS.

there is an excel spreadsheet somewheres on the internets (maybe on this site, or the 250 site, or kawi forums) that has several shocks and their dimensions and other cool info......

I'll measuere the GXRS shock that I used to mod my pregen ninja. I needed spacers on the dogbones and cut/modify the battery box.

that excel file also has the spring rates for the different shocks..

[Somchai]

Originally Posted by Qomomoko

for those looking, I can talk about the 05 model

the 05 GXSR 600 shock is not the same lenght, the mod can be done as a mod.
the shock reservoir WILL get in the way for the PREGENS.

there is an excel spreadsheet somewheres on the internets (maybe on this site, or the 250 site, or kawi forums) that has several shocks and their dimensions and other cool info......

I'll measuere the GXRS shock that I used to mod my pregen ninja. I needed spacers on the dogbones and cut/modify the battery box.

that excel file also has the spring rates for the different shocks..

Thank you Luis,
I didn't ask about that information for me, since I use the YSS-shock which is adjustable from 320 to 330 mm length - I use it with 325 mm what raises the rear by 15 mm and an also lowered front by 16 mm which makes the bike very easy to turn into corners.
My question is about others since there are too many wrong information given everywhere, although this maybe could be right but I can't believe that it is until it's confirmed.

By the way @Alex wouldn't it be an idea to have an extra section for all, every and each technical information (reason see above please)?

[Lemonfresh]

I

Originally Posted by Somchai

Can you confirm this measurement, bc all information here in the forum and also given from Ohlins and Wilbers or others say that the GSX-R600 shock from 06 until 09 has a length of 315 mm, while the N250 and N300 shock, which are the same, have a length of 320 mm? Thank you.

If they aren't the same length they are under 5 mm difference. I was able to run the dog bone bolts through the mounting holes in both shocks side by side without issue. They were so close I didn't measure. Trying to measure to the edge of a bolt is never an exact affair anyway, espically when talking about mm and using a standard tape measure. There was no noticeable change in ride height, but again I have no numbers to confirm.

This was a different case when it was on the 250. I measured a noticable difference between the 250 shock and the GSXR shock length. There was also a noticeable difference in ride height when installed on the 250.

I am at 6400 miles and ride the 300 almost 500 miles a week. When it's down for the valve check I plan on servicing the swing arm bearings. When it's apart I will make as accurate a measurement as I can between the two shocks and post them here.

[Alex]

Originally Posted by Somchai

By the way @Alex wouldn't it be an idea to have an extra section for all, every and each technical information (reason see above please)?

I'm not sure I follow, there are tech sections for each of the 3 generations. Now that the 300 has been out for quite awhile, I am considering collapsing this "300 General" area by pushing its contents into either the 300 tech, 300 farkle, or overall general forum. We have plenty of google search results and no longer would need a separate 300 general section to stay relevant.

[Somchai]

Originally Posted by Alex

I'm not sure I follow, there are tech sections for each of the 3 generations. Now that the 300 has been out for quite awhile, I am considering collapsing this "300 General" area by pushing its contents into either the 300 tech, 300 farkle, or overall general forum. We have plenty of google search results and no longer would need a separate 300 general section to stay relevant.

Thanks Alex and yes you're right that there are many places but what I mean is ONE central place for all that information like length of shocks etc. etc., since many guys start their search and mods from new for many times.
Just one example like @garth285 now is doing that very good thing to come up with all infos about valve springs. Let's say he is done and some time has gone, somebody else who doesn't search, because thinking he's doing something important and new, will start just the same thing. I hope you understand my D-English enough to know what I mean?

[Alex]

I think I understand, but I don't agree. I think it is helpful to have the tech areas separated by generation, with more pros than cons with that setup. With that in mind, setting up yet a separate forum for something like "suspension" seems superfluous.

[Manimal]

Originally Posted by rojoracing53

Change your front tire to something Radial constructed and leave the stock rear on there if it has less then 4000 miles because the IRC rear is a good tire, it's the front that kills the combo.

With a good front tire an otherwise stock 300 can do more then 99% of riders can so just keep practicing and riding and stop thinking about changes that you don't really need.

By the way a suspension guy who doesn't work with you at the track to understand what you need is only there to take your money and give you a small change that acts as a placebo. The funny thing about a sugar pill is how often they actually work because most limits are in your mind anyways.

By the way, all those online spring rate calculators are total crap for most riding styles and unfortunately most other sources of info regarding suspension for these little bikes is incomplete or simply wrong.

Best of luck getting more in tune with the bike and maybe you can join me for a ride over Mt. Hamilton some time. If you've ridden with @Alex then maybe he can chime in whether a ride with me is a good idea.

Hi Jason,

I've ridden with both you and Alex, a few occasions. Having knowing your experience on and off the track, I trust and value your input. That goes for Alex as well.

" ..... most limits are in your mind anyways." You are ABSOLUTELY right! My head is so wrapped up in thinking that the IRC's are sub-par, that my mindset starts tripping and affects my riding (cornering) .... I then tend to dial it back some.

Additionally, is that I don't get enough riding in to consistantly maintain muscle memory and mindset (confidence within myself and the bike). Therefore, the times that I do get out and ride, it's almost like a refresher coarse ........ sad, I know.

If you guys plan a ride, let me know. Even tho' I will not be able to match your pace, it will still be fun to be out there with you guys none-the-less.

As for the other replies, very insightful. I appreciate your contribution. Not only for myself, but for others as well. I will keep this thread up to date if / when I make any further changes, and share my experience.

[CycleCam303]

Manimal just throw a decent front up there. It'll make the bike feel so much better.

It really doesn't matter what's on the rear. Bike doesn't make any real power to spin it up. so enjoy the great tire life.

[Manimal]

Pirelli Rosso II front on order I figured to go ahead and give it a try, being I tend to wear out the front much sooner than the rear .... and that I was already ordering a set of rubber for my Grom. Update to follow soon

[csmith12]

Originally Posted by Manimal

I tend to wear out the front much sooner than the rear ....

Hmmmm why do you think this is? Unless there is something outside the norm going on here that you haven't posted, I would think you should be going through 1 to 2 rears for each front.

[tooblekain]

Originally Posted by Manimal

Or both?

I'm tossed.

Granted, I have not had the 300 for that long, and only have a few rides on it. I'm just not quite coming to grip (partially pun intended) with the handling, or corner confidence. At times, I lack confidence through some corners. Not sure if the OEM suspension is too soft, or it's the OEM tires.

Will switching tires (Diablos's) help boost my cornering confidence, or adding Race Tech springs do it, or both? Or do I just need to stop being such a wussy, put in more seat time and just need to adapt / adjust and accept what the OEM 300 has to offer?!

Now! Keep in mind, I love a good riding pace, but ride nothing like a couple (or a few) of others here on the forum. Additionally, the last couple of Ninja's I had owned had suspension upgrades. I had never ridden or owned a Ninja with "stock" suspension. So, this is a first.

Both!!! But if I had to choose just one, I would go with tires first. The Rosso IIs are a solid tire.

I would then get a good rear shock. You can do the OEM Gixxer or OEM R6 shock if you want a cheap upgrade. Or splurge the money and get a good purpose-built aftermarket shock like a Racetech, K-Tech, Penske, Nitron, Ohlins, etc.

Immediately after I would then get the correct springs for your weight. You can get them from Sonic Springs or Racetech, or even K-tech.

If you're getting springs, might as well get emulators from Racetech. Or if you want to splurge even more, get a cartridge kit from Racetech or K-tech
I would then

[Manimal]

Originally Posted by csmith12

Hmmmm why do you think this is? Unless there is something outside the norm going on here that you haven't posted, I would think you should be going through 1 to 2 rears for each front.

from experience. When I had my 2009 Ninja 250 (which included suspension upgrades), I wore out my front more often than the rear.

Keep in mind, most of my riding include tight, technical back roads more often than sweepers, and or the freeway (or flat roads), for that matter.

As for the suspension replies, I certainly am not excluding the idea. I have other projects going on, so I am spending the money where I see fit. I will eventually get there, but just not now.

Once I get there, I will certainly inquire for details, and or ask more questions. I do appreciate the insight as to set up recommendations; race tech, possibly emulators, and best shock conversion.

[Qomomoko]

Racetech counts too!!

"I told him I wanted stability, the MF got some Ohlins!"

[ROADandTRACK]

If you are pretty fast or want to go fast safely you need to, at a minimum, get GVE's and springs for the front. Also go to a reputable suspension shop to do it because the RT instructions are not correct for a 250/300.

The OEM GSXR shock is better than stock but it is way too short. When wanting a well handling track bike the shock needs to be quite a bit longer than you can make the gsxr shock. We use parts from 2 different bikes shocks to make it work properly and those "Frankenshocks" win races in CMRA and WERA.

[Qomomoko]

Originally Posted by ROADandTRACK

If you are pretty fast or want to go fast safely you need to, at a minimum, get GVE's and springs for the front. Also go to a reputable suspension shop to do it because the RT instructions are not correct for a 250/300.
The OEM GSXR shock is better than stock but it is way too short. When wanting a well handling track bike the shock needs to be quite a bit longer than you can make the gsxr shock. We use parts from 2 different bikes shocks to make it work properly and those "Frankenshocks" win races in CMRA and WERA.

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

[Lemonfresh]

Originally Posted by Somchai

Can you confirm this measurement, bc all information here in the forum and also given from Ohlins and Wilbers or others say that the GSX-R600 shock from 06 until 09 has a length of 315 mm, while the N250 and N300 shock, which are the same, have a length of 320 mm? Thank you.

Well I finally got around to tearing the rear apart on the 300. The GSXR shock is slightly shorter than the 300 shock, but it's less than half the diameter of the 12 mm bolt. I would estimate the difference at 3 mm but no more than 4 mm. I don't have calipers long enough to measure. I'll post pics soon.

[ROADandTRACK]

The stock shock is too short

[Somchai]

Originally Posted by Lemonfresh

Well I finally got around to tearing the rear apart on the 300. The GSXR shock is slightly shorter than the 300 shock, but it's less than half the diameter of the 12 mm bolt. I would estimate the difference at 3 mm but no more than 4 mm. I don't have calipers long enough to measure. I'll post pics soon.

Thank you

[Manimal]

Originally Posted by rojoracing53

Change your front tire to something Radial constructed and leave the stock rear on there if it has less then 4000 miles because the IRC rear is a good tire, it's the front that kills the combo......

Originally Posted by CycleCam303

Manimal just throw a decent front up there. It'll make the bike feel so much better.....

I got the Rosso II mounted up front. Took a ride up (and back) Mt Hamilton yesterday. Thanks for the recommendation, guys! What a difference, and very confidence inspiring!

The focus of my ride then became more of what was coming around each blind corner, and wicked it up on the corners with decent and or good sight lines. In short; made for a more enjoyable and fun ride

[Lemonfresh]

Here are the side by side '13 300 and '07 GSXR-600 shock length comparison pictures.

[Manimal]

Thanks for posting Hard to tell, will the upper eye of the Gixxer shock accept the upper 300 bolt as well?

[csmith12]

Originally Posted by Manimal

Thanks for posting Hard to tell, will the upper eye of the Gixxer shock accept the upper 300 bolt as well?

Plan on drilling it out, 12mm drill bit needed if memory serves me correctly.

[Lemonfresh]

Originally Posted by csmith12

Plan on drilling it out, 12mm drill bit needed if memory serves me correctly.

Exactly what needs to be done.

[subxero]

^ this, and I think 31/64" bit in a standard size would work as well and give you around 100th of an inch of clearance. Not sure how much clearance a 12mm bit gives but it would probably be close. IDK? I think other people here have used the 31/64 bit though. Just a thought if you don't have a 12mm laying around but then again 31/64 is kind of an odd ball size to have laying around as well

[csmith12]

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