"J" series rear shock assembly on "F" series

[Apex]

I read somewhere about someone doing a swap from the F series, non-adjustable, shock to the J series unit.

Anyone ever done this? I do plan on taking it to the track more often. So I think the stiffer shock would be nice. I may get some aftermarket fork springs in the future as well. I just want low budget and decent performance. I don't want to go high dollar for this little 250.

[jonb08]

I personally would not upgrade the rear shock without upgrading the front forks to compliment. I went to a shop in Jersey that builds and races its own bikes and the guys provided me with that advice. It makes sense if you think about how load will get distributed. They said the best thing you can do first is buy better tires.
Posted via Mobile Device

[Apex]

Originally Posted by jonb08

I personally would not upgrade the rear shock without upgrading the front forks to compliment. I went to a shop in Jersey that builds and races its own bikes and the guys provided me with that advice. It makes sense if you think about how load will get distributed. They said the best thing you can do first is buy better tires.
Posted via Mobile Device

My next purchase is a set of tires for track duty (nice DOT tires).

I was going to most likely upgrade the front fork springs and just wanted some adjustment capability for the rear.

[kayfouroh]

I've done it, it's easy and cheap.

[jonb08]

Originally Posted by Apex

My next purchase is a set of tires for track duty (nice DOT tires).

I was going to most likely upgrade the front fork springs and just wanted some adjustment capability for the rear.

Luckily, your in Texas. Those tires wouldn't be able to get into operating temp for about 2-3 months here.

[fjyang]

I've pick up a 08 rear shock for a song on ebay and it was a easy swap onto my classic 87 Ninja 250. The 08 are about 1/4" longer eye to eye compare to 86-87 and 88-07 250's so if you mount a taller 90 series tires you'll not be able to lift your rear tire up with the center stand with a 08 rear shock.

I my rear tire is a 130-80-16 so I just barly have enough gap to spin my rear tire when on the center stand. I have not ride it as I'm rebuilding my front brakes but when I sit on the bike, my old shock will sag 2", the 08 will only sag 1" and I crank the preload 3/4 to max as I'm no light weight but I'm sure this will be an improvement over the older shocks.

[Apex]

Originally Posted by fjyang

I've pick up a 08 rear shock for a song on ebay and it was a easy swap onto my classic 87 Ninja 250. The 08 are about 1/4" longer eye to eye compare to 86-87 and 88-07 250's so if you mount a taller 90 series tires you'll not be able to lift your rear tire up with the center stand with a 08 rear shock.

I my rear tire is a 130-80-16 so I just barly have enough gap to spin my rear tire when on the center stand. I have not ride it as I'm rebuilding my front brakes but when I sit on the bike, my old shock will sag 2", the 08 will only sag 1" and I crank the preload 3/4 to max as I'm no light weight but I'm sure this will be an improvement over the older shocks.

Sweet, then I can finally pull off that centerstand for some weight savings!

EXCELLENT!!

lol

[sometimesido]

Frank, let us know after you ride few miles.
I'm interested in doing this.

What about 2x4 underneath the center stand with 130/90-16?

[sometimesido]

I just noticed two of you who have done it are both "Frank."

[fjyang]

Great Minds (Franks) think alike Just got a 30 min ride over the weekend and the shock is firm but not jarring, my old shock is like marshmellow compared to the 08 shock. What I like the most is that now I have more weight on the front of the bike, I put a 110-70-16 which lower the front and a 1/4" longer 08 shock further the bias toward the front and I like how the bike handles now in corners.

I got progressive springs with no spacer (per instructions) and its a little soft so I put a little more fork oil and 1/2" spacer in each fork and its a little bit too stiff so I might take the spacer off and see how it feels with just the fork oil increase. My 87 E2 only got 35mm fork tubes, 88-07 got 36mm and 08's got 37mm.

If you can find a 08 shock then by all means go for it, its really a bolt on installation. If you go touring with your ninja then stock might be better option but if you like canyon carving a firmer rear shock is always the way to go

[sometimesido]

lower profile front tire?

I'm wondering if the firmer shock will help with the weight of all the extra gear in the back for touring.

[fjyang]

Originally Posted by sometimesido

lower profile front tire?

I'm wondering if the firmer shock will help with the weight of all the extra gear in the back for touring.

Stock front tire is 100-80-16 if you put 110-70-16 then its a lower profile tire then stock and just lower the front just ever so slightly.

I personally feel 250 is bit small for touring purpose but that's just my opinion and many people have turn the F series into Iron butt rally contender. If you can find an 08 shock for little money then you got nothing to lose by trying.

[Grn99Kawi]

I bought one last week on ebay.. it should actually be here today, and I am 'planning' on getting outside to install it. I'll post up my impressions of it.

[sometimesido]

looking forward to it.

[ninjammin]

I installed an 08 shock on my 2003 yesterday and love it. I like a firm ride, and this has done just the trick. I was going to start a thread on this with my pictures, but why not just post them here. I've gained a pretty substantial amount of height. My stock shock had 16,300 miles on it, and was extremely mushy. Let me know if you guys have any questions. The photo's are arranged before/after, before/after if you can't tell.

[Apex]

Originally Posted by ninjammin

I installed an 08 shock on my 2003 yesterday and love it. I like a firm ride, and this has done just the trick. I was going to start a thread on this with my pictures, but why not just post them here. I've gained a pretty substantial amount of height. My stock shock had 16,300 miles on it, and was extremely mushy. Let me know if you guys have any questions. The photo's are arranged before/after, before/after if you can't tell.

Thinking about doing anything up front?

[ninjammin]

I'm very satisfied with how it rides right now, so it's not in the plans. The forks will need to be serviced before too long though, so I may look into my options at that point.

[Grn99Kawi]

Originally Posted by Apex

Thinking about doing anything up front?

I am... I have read that someone put RaceTech .75 kg/mm front fork springs up front to complement a rear EX500 shock.. I figure it might be worth upgrading mine as well.

FRONT FORK SPRINGS
Recommended Fork Spring Rate for Street: 0.724 kg/mm (use closest available)
Stock Fork Spring Rate: .440 kg/mm (stock)

FRSP S2938080 RT FRK SPR 29.0x377mm .80kg $109.99

hmmmm

[jonb08]

Originally Posted by ninjammin

I'm very satisfied with how it rides right now, so it's not in the plans. The forks will need to be serviced before too long though, so I may look into my options at that point.

Definitely do that. Go to someone that really knows their stuff about suspensions and try to match the forks to the rear shock for a more well balanced bike. I bet that rear shock was toast after that many miles!!

[Apex]

16k is a lot of miles?

Wow, that is right around the corner on mine. I'm almost there.



I need to race mine.

[jonb08]

Originally Posted by Apex

16k is a lot of miles?

Wow, that is right around the corner on mine. I'm almost there.



I need to race mine.

Wow, you really racked up the miles. I guess you get to ride pretty much all season down in TX.

[Apex]

Yup. The only time I don't ride is when it is too dangerous (lots of lightning, flooding, chance of hail, chance of ice/snow, etc). I don't really care how cold it is, I'll still cruise around out there.

[ninjammin]

I got my bike with 8k on it about 9 months ago. I haven't even gotten a summer's worth on it right now. I plan on adding around the same since it's finally riding season

[Verus Cidere]

Quick question on the dead thread! Do you need to get the whole shock mounting piece for this mod or can you just get the spring? I'm really interested in doing this, but I don't want to get the wrong things.

[kkim]

You need the entire shock (shock and spring) from the new gen, otherwise it wouldn't be adjustable.

the one on the left in this picture...

[Verus Cidere]

I didn't say that right did I? I meant, can I just get the shock or do I have to get the mounting bracket for it too? Is the newgen shock a direct bolt-on replacement for the pregen shock?

[kkim]

Originally Posted by Verus Cidere

Is the newgen shock a direct bolt-on replacement for the pregen shock?

yes

[Verus Cidere]

Sweet. Thanks.