Ninja Race Prep

[Rexbo]

Hey all, I'm aiming to compete in the 2011 AFM ninja 250 production/superbike series here on the west coast, and lookin forward to getting my ass handed to me by way more talented riders! Definitely gonna be fun.

Anyways, I just wanted to start a thread for some input, if you see things goin wrong, or going right, I'd like to hear about it. Also wanted to provide some useful info for a couple projects I haven't really seen addressed on here yet.

I started with safety wiring most parts of my bike, it hasn't been completed yet though. Started on the front end, moving back. Safety wired the brake banjo bolts at the M/C and caliper, brake mounting bolts, and front axle bolt (theres a cotter pin on the nut side). Drilling all the holes with a #55 drill bit isnt actually all that hard, you just have to be careful, and make sure to buy about 10 of them as you're sure to break a few! Safety wire pliers are about $7 at harbor freight, and a spool of 0.025" wire is about $3, so with a little patience, you can do this yourself.





More pics to come later when I finish wiring up all the stuff in the engine and rear axle. I ran outta time on that and helped TQ aka Nope install gsxr600 rear shocks on our bikes, which turns out to be pretty easy.

Need:
2006-2009 gsxr600 rear shock (9.4kg/mm spring rate, 320mm long)
12mm drill to drill out top and bottom shock mounts on the gsxr shock
Longer 12mm bolts for dogbones
Longer 12mm bolt for lower shock mount
4x spacers (or washers) for dogbones to clear spring



Before:





Support the rear wheel when you take out the shock (makes it easier to put back in).



Grind down the rocker and the metal bushing to fit inside the lower shock mount.





Cut off the bottom of the plastic spray pan at the step, making sure to leave the two squish nuts on each side to mount to the frame!



Re-install everything, looks right at home! The resevoir doesn't interfere with the air box at all, nor the battery! The compression and rebound adjusters are super easy to reach, so this is pretty awesome mod. I had to back off the compression damping about a half turn to make it feel more comfortable, and it turned out to only lower the rear wheel by about 15mm. Makes a world of difference though! Rebound damping is so nice!





Then got angry at the kickstand mount that lowsided me at streets of willow, so took the grinder to it!







Problem solved!

New rear shock feels great, went for a long test ride, and especially when you can find these used shocks on ebay for $20 SHIPPED, pick up a drill bit and some hardware, you definitely have a budget rear shock that is worlds better than the stock one.

Upcoming: Racetech 0.70 springs and gold emulators, Jardine GP-1 exhaust, jet kit, filter and rest of the safety wire, as well as general engine cleanup, weight reduction and cleanup, plus some kind of bodywork.

[sharky nrk]

great thread - looking forward to more.

[RaceBikeRentals]

Nice writeup! I see your snorkel in there... make sure you keep it. AFM requires it

[2WheelGuy]

Originally Posted by Rexbo

Need:
2006-2009 gsxr600 rear shock (9.4kg/mm spring rate, 320mm long)
12mm drill to drill out top and bottom shock mounts on the gsxr shock
Longer 12mm bolts for dogbones
Longer 12mm bolt for lower shock mount
4x spacers (or washers) for dogbones to clear spring

Rule 9.1.6i (linkage must remain stock).

[ChaosFromAbove]

wow...im getting a new shock now!

[Cab305]

Very nice, not to be a nagging nancy.

But, in aviation school they taught us to safety wire around to the outer edge of the nut/bolt so it has tension when its at rest.

Not to nock your wiring, it's definitely super clean and has plenty of tension.
Just pointing out a small difference



Please don't take this sketch as a critique of your wiring, i made a bad wiring first to explain,
it looks nothing like this, this is just for sample.

You sure showed that kick stand who's boss.

[Nemesis]

Good write-up!

Personally, if you weigh more than 170 than I'd opt for a rear shock replacement but the OEM rear shock is fine. Just notch it up to the max. The issue isn't so much the rear but the front. Either thicker oil or a complete suspension job is best IMO.

[Rexbo]

Originally Posted by 2WheelGuy

Rule 9.1.6i (linkage must remain stock).

I was reading that... and emailed the AFM guys.

They said the intention was to prevent changing the suspension geometry, and since I am still using the stock rocker and stock dogbones, just replacing the rear shock, its allowable to space the linkage to clear the spring. So hopefully they dont hassle me, and if other racers bring it up, I'll explain that its still stock linkage geometry, just spaced apart to clear the new spring, changing nothing!

Yeah I'm aware my wiring isn't up to NASM 33540, but I did measure the minimum material sidewall requirement that it specifies (I work in aerospace also) and technically I should be alright. They didn't specify to wire per that spec, so I just did the best job I could without going nuts and having to disassemble everything!

I only weigh 150 lbs, so I'm pretty sure this rear shock & spring will be stiff enough! I've already found it to be a little too stiff for the street right now, but going to the track on friday to test it out!

[2WheelGuy]

The club won't care but you might get protested by another racer in the class.

It is a dumb rule. I submitted a rule change to allow linkage modification a couple of years ago but it was denied. My thinking is that changing dogbones is way cheaper than buying an adjustable length shock.

[spicy mayo]

so the shock body is 15mm shorter than the stock unit? Can you provide the stock shock length? I don't know about messing with the aspect ratio of the bike that much. How is the sag? have you measured the ride height with you on it? maybe it is the same overall on the stiffer spring.

[spicy mayo]

hmm still interested in this, from the info I could find on the web the 06-09 gsxr 600 rear shock is 320mm in length, which is supposed to be the same as the 250's stock. can you shed any light on this?

[Rexbo]

Originally Posted by spicy mayo

hmm still interested in this, from the info I could find on the web the 06-09 gsxr 600 rear shock is 320mm in length, which is supposed to be the same as the 250's stock. can you shed any light on this?

the shock length is like 4mm shorter than the ninja 250 shock (approx) and since there's about a 3.5:1 travel ratio from the swingarm to shock, it lowers the rear end about 15mm (measured from the back of the rear subframe to the tip of the rear adjuster bolt). Its really not even a noticable height difference, but a major chage in feel and ride quality.

I backed off the compression damping another quarter (for a total of 1/2 turn) and it feels just about right. Stiffer than the stock shock but not overly stiff.

[spicy mayo]

Thanks for the reply and the nice pics.

I'm going to look into this some more and see whats going on with the geometry, it still doesn't make sense it was lowered that much.

[SPG]

On the safety wiring, take the tips of the wire pliers and curl the cut end into a ring. then the cut end is pointed back at the tie off point, and you will not slice your hand (or the inspectors) if you brush up against it.

Nice write-up on the gixer shock install.

-Sean

[2WheelGuy]

Originally Posted by Rexbo

the shock length is like 4mm shorter than the ninja 250 shock (approx) and since there's about a 3.5:1 travel ratio from the swingarm to shock, it lowers the rear end about 15mm (measured from the back of the rear subframe to the tip of the rear adjuster bolt). Its really not even a noticable height difference, but a major chage in feel and ride quality.

Could be part of the reason you were dragging your kick stand. I run my shock about 9mm longer than stock which raises the rear over an inch. I don't need rearsets and use my kickstand on track days.

[randomwalk101]

Rexbo
Good write up

[JeffM]

Steve, I sent you a pm.

[randomwalk101]

Originally Posted by Rexbo

Need:
2006-2009 gsxr600 rear shock (9.4kg/mm spring rate, 320mm long)
12mm drill to drill out top and bottom shock mounts on the gsxr shock
Longer 12mm bolts for dogbones
Longer 12mm bolt for lower shock mount
4x spacers (or washers) for dogbones to clear spring

It also appears that the two shocks (one on the ground and one installed) are different??

[randomwalk101]

I guess the 06 - 07 gsxr 600/750 shocks has that little red cap (the installed one) and on the reservoir has that little knob.
08-09 one is the blue cap (uninstalled pic).

Does the little extra knob on the 06/07 rear shock is to refill nitrogen as compared to the later model (08/09) which doesn't have one??

[Rexbo]

Originally Posted by randomwalk101

I guess the 06 - 07 gsxr 600/750 shocks has that little red cap (the installed one) and on the reservoir has that little knob.
08-09 one is the blue cap (uninstalled pic).

Does the little extra knob on the 06/07 rear shock is to refill nitrogen as compared to the later model (08/09) which doesn't have one??

This is correct. The shocks are identical minus the nitrogen refill nipple.

2wheelguy: I was dragging the kickstand while tracking with the stock rear shock. This last track day with the new shock, I would definitely have hit it again, as I also was dragging my exhaust shield.

Speaking of track day, the new rear shock is AWESOME. Three of us were running it on our ninjas there, and we all came to the same conclusion that it worked WAY better than the stock one. We all backed off the compression damping about a half turn, while leaving the rebound at the original setting and found that it worked out really well.

The only downside is that installing it really just made my stock front forks feel even worse. With the amount of grip that the bt-003s have, and the amount of loading that I was putting into them, any bumps no matter how small would put the forks down onto the bumpstops and cause the front to chatter some. Even when there weren't bumps, the front end would feel somewhat floaty and disconnected, and not as progressive as it should feel when the tire began to chatter.

[ChaosFromAbove]

good to hear...can't wait to see what you do about the front suspension. There's no way to adjust the pre-load on the stock ones right?

[nope]

GSXR front end swap. Done.

[08ninja250]

Do you have pics of the gsx-r front end swap?

[JeffM]

Johnathan, you have board mail.

[nope]

I do have pics but I'll post my own thread. This is a good thread that Steve has started.

Jeff I'll get back to you.

[JeffM]

Thanks.

[ChaosFromAbove]

Originally Posted by nope

I do have pics but I'll post my own thread. This is a good thread that Steve has started.

Jeff I'll get back to you.

feel free to link the thread

[nope]

To add to Steve's instructions:

1. Those dogbone spacers are 0.5" wide each, and that's exactly what you want. Also, it's ideal they have a flange like that to keep the steel sleeves centered inside the linkage. You could also just use a stack of washers here.

2. Grab some Nylock nuts for the longer bolts you buy. Typically hardware stores don't carry the fine pitch M12 bolts that the ninja uses, so the stock nuts won't work.

3. Go easy when drilling out the steel side of the GSXR shock as it'll be harder and heat up more. Use plenty of coolant and go a little bit at a time taking breaks so the rubber bonded around it doesn't cook.

Honestly, easy mod. We did this both in a machine shop (fly cutter, lathe, mill) and in the garage (hand drill, angle grinder) and the results were virtually identical. So you can definitely do this at home with 2 tools.

[Rexbo]

Originally Posted by nope

GSXR front end swap. Done.

sticks you directly into superbike yo

[nope]

Damn straight, for maximum self inflicted pain.

[randomwalk101]

Originally Posted by nope

GSXR front end swap. Done.

Why not just add spring & emulator or intiminator instead? It's cheaper. I heard a lot if hardcore racers got good results.

[nope]

Because I get godmode braking.

[randomwalk101]

Nice. Really like to see some pics &infos

[ztrack157]

Originally Posted by nope

gsxr front end swap. Done.

not production legal

[ztrack157]

Originally Posted by randomwalk101

Why not just add spring & emulator or intiminator instead? It's cheaper. I heard a lot if hardcore racers got good results.

John this is what the fast guys do. The other option is doing the ohlins front end kit which is over $1000 but it is awesome.

[Rexbo]

Originally Posted by nope

Because I get godmode braking.

This is true. Getting rid of one caliper = megabrakes. Also the fact that he got his front end complete for like $300 makes it about the same price as springs + emulators, only now you also get a 120 front wheel, way better brake caliper & MC, inverted forks, and adjustable compression + rebound not to mention they're GOLD

[nope]

Also, clipons are way lower and the whole set up is just a tad lighter.
Aite posting a thread with a pic now.

Steve, keep building this thread up with your progress for other people interested in a Production Class race setup. Great start so far.

[nope]

Here's my personal thread:
http://www.ninjette.org/forums/showt...044#post233044

[Rexbo]

Originally Posted by nope

Here's my personal thread:
http://www.ninjette.org/forums/showt...044#post233044

word. TQ is scary fast now at the track with that race slick front tire. I had to convince him to just romp on it harder to put more heat into it to get it to stick better. MAYBE i'll let him use my front tire warmer next time.

Now to jack the thread back, here's moar pics:

Front M/C banjo bolt:



Rear M/C banjo:



Now I gotta figure out how to wire these two bolts that hold it to the rearset... I dont think loctite is good enough



Rear Brake caliper banjo:



Rear axle nut:



Rear axle adjusters:




Found some interesting things after going to chuckwalla racetrack last weekend! Dragging stock exhaust, definitely time to go:



Also starting to crack my front brake rotor between the holes. Not a good sign! I guess I'll have to start carrying spares to the track!



I'm going to go back and take care of all the sharp ends on the safety wiring and probably re-do some of them to make them look cleaner or get a little tighter. Hopefully the emulator/spring installs will be coming up next, along with more engine safety wiring during phase 2 of the build...

[ithaca00]

Look into an aftermarket front rotor. It should be in the rules next season to allow them.