Rear shock option for pre-gen.

Jammerkiller · April 21st, 2014, 10:52 PM

I've seen a lot of posting about rear shock mods on both old and new Ninjas. I have been researching this for a few months and finally made a decision...

Originally I got an SV650S rear shock, for it's adjust-ability, and because it was free! But, after checking out forums where people have installed it, they say it's really too stiff for the pre-gen unless you're a heavy rider. (250+ lbs) So, I went with a new-gen 250 shock. According to the web, this is a direct bolt-in replacement. And, it sure was. Plus, you can adjust it's height and it's a little stiffer than the OEM pre-gen shock. Overall the install was easy. It's best to use a rear stand to hold the swing-arm and the rear of the bike. Then I used a floor jack with a piece of 2x4 under the frame and just behind the engine to stabilize the bike while you remove the upper and lower bolts for the shock. (You may have to pump up the jack a tad for the new shock.) remove the old shock, install the new shock. (I used the original pre-gen bolts) Torque to 33ft-lbs and you're done! The SV shock would have required some grinding and some drilling on the new shock mounts. Not a difficult task, but too much work to install a shock that may be too stiff to begin with.

09EX250 rear shock.jpg
eBay.....$60

Pre-gen new-gen shocks.jpg
New-gen on the bottom. Note the adjustment ring. The upper knuckle and bolt hole line right up. Same for the bottom.

Once I ride the bike later this week, I'll give more info on how it feels. Suspension feels better just by sitting on it.

kirk595x · April 21st, 2014, 11:45 PM

I was gonna go that route but went with the 90's ZX-6C AIR SHOCK instead.

Snake · April 22nd, 2014, 12:24 AM

Quote:

Originally Posted by kirk595x

I was gonna go that route but went with the 90's ZX-6C AIR SHOCK instead.

Do you have any pics? Sounds interesting. Was there any modifications required?

ds650rida · April 22nd, 2014, 12:53 AM

No mods required. Direct swap

Ninjinsky · April 22nd, 2014, 02:11 AM

I fitted a GPZ 500 shock to my '91. Again a direct bolt in. Firmer and adjustable. I was very happy with the result.

InvisiBill · April 22nd, 2014, 05:05 AM

Quote:

Originally Posted by Jammerkiller

Plus, you can adjust it's height and it's a little stiffer than the OEM pre-gen shock.

FYI, that's the spring preload adjustment. It does have some effect on ride height, but its purpose is to provide the proper tension on the spring for optimum suspension performance. The slight change in the unloaded ride height is merely a side effect (and meaningless once you get on the bike if you weigh more than the amount of preload).

I currently have a NewGen shock on my 500, which replaced a modded SV shock. The spring rate is just about perfect for my weight (the newer SV shock with the white spring has about the same rate as the PreGen). It's almost 75% stiffer than the stock 500 spring, so obviously that made a huge difference for me.

kirk595x · April 22nd, 2014, 09:35 AM

Quote:

Originally Posted by Snake

Do[/url] you have any pics? Sounds interesting. Was there any modifications required?

http://s103.photobucket.com/user/n4t...vi8uw.jpg.html
You will need four 1/2 inch washers and thats all.

Snake · April 22nd, 2014, 06:42 PM

Quote:

Originally Posted by kirk595x

http://s103.photobucket.com/user/n4t...vi8uw.jpg.html
You will need four 1/2 inch washers and thats all.

Cool, thanks.

kirk595x · April 22nd, 2014, 07:02 PM

No prob. If you decide to get one be sure change the shock oil. 10-15w would be fine and will only set you back $10-$15.

The only downside is the weight of the shock. It's at least double of the stocker but well worth the adjustability IMO.

Jammerkiller · April 23rd, 2014, 04:43 PM

Quote:

Originally Posted by InvisiBill

FYI, that's the spring preload adjustment. It does have some effect on ride height, but its purpose is to provide the proper tension on the spring for optimum suspension performance. The slight change in the unloaded ride height is merely a side effect (and meaningless once you get on the bike if you weigh more than the amount of preload).

True that. It's not really for height adjustment, but does increase it a little. Good to know...

Quote:

Originally Posted by InvisiBill

I currently have a NewGen shock on my 500, which replaced a modded SV shock. The spring rate is just about perfect for my weight (the newer SV shock with the white spring has about the same rate as the PreGen). It's almost 75% stiffer than the stock 500 spring, so obviously that made a huge difference for me.

The SV shock I have has a yellow spring. (2001) I heard it's pretty hard unless you're a heavy rider.

InvisiBill · April 24th, 2014, 04:46 AM

Quote:

Originally Posted by Jammerkiller

The SV shock I have has a yellow spring. (2001) I heard it's pretty hard unless you're a heavy rider.

Yeah, that shock is quite different from the newer one with the white spring. If I remember correctly it's longer but has a shorter stroke. The spring is quite a bit heavier too - the white one is 430# (similar to the stock PreGen spring) while the yellow one is like 500 or 550 (around the NewGen spring's rate).

Jammerkiller · April 24th, 2014, 08:51 PM

BTW, I rode her last night to a bike night. Rides much smoother than the stock shock, and it's preload is at minimum. I may notch it up a bit.

April 21st, 2014, 10:52 PM	#1
Jammerkiller lurking about........ Name: Mike Location: Tucson, AZ Join Date: Mar 2013 Motorcycle(s): 2004/2005 Ninja EX250, VFR750, Shadow ACE750, NC700X Posts: 33	Rear shock option for pre-gen. I've seen a lot of posting about rear shock mods on both old and new Ninjas. I have been researching this for a few months and finally made a decision... Originally I got an SV650S rear shock, for it's adjust-ability, and because it was free! But, after checking out forums where people have installed it, they say it's really too stiff for the pre-gen unless you're a heavy rider. (250+ lbs) So, I went with a new-gen 250 shock. According to the web, this is a direct bolt-in replacement. And, it sure was. Plus, you can adjust it's height and it's a little stiffer than the OEM pre-gen shock. Overall the install was easy. It's best to use a rear stand to hold the swing-arm and the rear of the bike. Then I used a floor jack with a piece of 2x4 under the frame and just behind the engine to stabilize the bike while you remove the upper and lower bolts for the shock. (You may have to pump up the jack a tad for the new shock.) remove the old shock, install the new shock. (I used the original pre-gen bolts) Torque to 33ft-lbs and you're done! The SV shock would have required some grinding and some drilling on the new shock mounts. Not a difficult task, but too much work to install a shock that may be too stiff to begin with. 09EX250 rear shock.jpg eBay.....$60 Pre-gen new-gen shocks.jpg New-gen on the bottom. Note the adjustment ring. The upper knuckle and bolt hole line right up. Same for the bottom. Once I ride the bike later this week, I'll give more info on how it feels. Suspension feels better just by sitting on it. __________________________________________________ Fast....Cheap.....Reliable...... You can only pick two.
	1 out of 1 members found this post helpful.

April 21st, 2014, 11:45 PM	#2
kirk595x ninjette.org guru Name: Robbie Location: Sacramento Join Date: Jan 2013 Motorcycle(s): 03' Ninja 250ex Posts: 333	I was gonna go that route but went with the 90's ZX-6C AIR SHOCK instead. __________________________________________________ Perform Random Acts of Coolness!!ATGATT

April 22nd, 2014, 07:02 PM	#9
kirk595x ninjette.org guru Name: Robbie Location: Sacramento Join Date: Jan 2013 Motorcycle(s): 03' Ninja 250ex Posts: 333	No prob. If you decide to get one be sure change the shock oil. 10-15w would be fine and will only set you back $10-$15. The only downside is the weight of the shock. It's at least double of the stocker but well worth the adjustability IMO. __________________________________________________ Perform Random Acts of Coolness!!ATGATT

April 24th, 2014, 08:51 PM	#12
Jammerkiller lurking about........ Name: Mike Location: Tucson, AZ Join Date: Mar 2013 Motorcycle(s): 2004/2005 Ninja EX250, VFR750, Shadow ACE750, NC700X Posts: 33	BTW, I rode her last night to a bike night. Rides much smoother than the stock shock, and it's preload is at minimum. I may notch it up a bit. __________________________________________________ Fast....Cheap.....Reliable...... You can only pick two.

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April 22nd, 2014, 12:53 AM	#4
ds650rida ninjette.org member Name: rich Location: new jersey Join Date: Nov 2013 Motorcycle(s): 636 250r Posts: 183	No mods required. Direct swap

April 22nd, 2014, 02:11 AM	#5
Ninjinsky ninjette.org certified postwhore Name: Paul Location: UK Join Date: Apr 2014 Motorcycle(s): Ninja 250, Yamaha RS200 (classic) Posts: A lot.	I fitted a GPZ 500 shock to my '91. Again a direct bolt in. Firmer and adjustable. I was very happy with the result.