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Shock/suspension questions

5K views 61 replies 15 participants last post by  Manzanita 
#1 ·
Hi,

I have a 2003 919 and looking for cheap alternatives to the rock hard rear shock--will the cbr600 or cbr1000 rear shocks be an improvement? I see these on ebay for less than $150 (which is about my budget). Any real-world reports from people who have tried this?

Also, what is the deal with the front forks--they also feel hard as a rock. I weight 180, and have 0.90 kg/mm spring in my cx500, and that bike is correctly sprung. So what is the stock spring rate on my 919? Is there any improvement going to aftermarket linear (or progressive) springs? Or does it just need the shim stack adjusted? I've only had older damper rod bikes until the 919 (so I have no clue what I'm talking about) :surrender:

Sorry if this treading a well-worn path, my searches have not found good info...

Thanks,

-Alan
 
#2 ·
IIRC, the adjustable suspension didn't come about until 04. I swapped the later adjustable suspension (front and rear) on to my 02.

Like you, the bike beat me to death until I changed over to the later suspension. (I weigh 165)

Take a look on eBay and ask here for the later parts. You can sell your parts (some people prefer them) to balance out any costs.
 
#3 ·
I weight about the same as you and I find the stock suspension on my 02 (same as your 03) fine with all the preload taken out of the rear. The rear spring is stiff and the front springs are soft, progressive springs so unless yours have been changed out I'd be surprised if they were hard. Maybe they need a cleaning and fresh oil?
 
#7 ·
Thanks for the replies. I will check my preload.



How is the 600f3 shock as far as ride quality? Does it have rebound and dampening adjustments?

I have won some great deals on ebay using auctionsniper.com, try it out, they charge just a few bucks, usually...
 
#8 ·
I went out this morning and checked the preload on my rear shock. I think I was at least 30 lbs heavier than the previous owner, so I figured he would have tried to adjust it... I was wrong. It was set to two clicks from max preload. I was able to adjust it with some big pliers to min preload and yeah, it's a definite improvement.

So I would not be surprised if the fork oil has never been changed. Will try that first...

Thanks!
 
#9 ·
Not much you can do with the shock apart from making sure your spring rate is correct. Measure your sags properly. My guess is the stock 850ish lb rear spring is to light. Harshness you are feeling is the shock speeds being to high for the valving so the shock cant flow. Im 200lb and ran a 1000lb spring but I should have been 1100lb for street.

Same will be the case for the fork.
 
#10 ·
So I've read here that the front fork is soft, but it seems 'hard' to me. I measured my sag at 25mm, but the entire travel (using zip-ties and bouncing the bike as hard as I could) was 75mm (3")--that sounds small to me, it is definitely an inch less than any other bike I've owned.

Also under hard braking I don't feel the bike dive that much, so maybe I work through whatever travel I have quickly. I have not completely unloaded the front end to see the true travel, maybe an inch of travel is being taken up by just the weight of the bike? Or maybe the fork oil level is too high?

But also, I get the sense it does not absorb small bumps well and is not moving quickly enough to respond to small bumps. So will this be addressed by taking it in to be tuned? The fork oil may be in extremely bad shape, but I live near Catalyst Reactions, which has a great reputation for race tuning bikes, so thinking of just pulling the tubes and letting them take care of it. I also need fork seals... thoughts?
 
#12 ·
Okay, an update. New 0.9 springs in front, rebuilt by Catalyst Reaction. He did not change the valving, and thought it felt okay. Did some windy roads after work and although the front is an improvement, the bike just does not feel right. Hard to put my finger on it. But both my cx500 and my new Zero just feel easier to ride, and I feel I can ride faster, easier on those bikes.

I just increased my sag (cut the spacer), lowered the front tubes on the triple tree by 20mm, and got rid of the handlebar risers this morning... just experimenting...

A somewhat separate question: would a power commander help with smoother throttle roll on, or is this just my crappy technique? I suppose if I hit at the right entry speed I could get on the throttle sooner, but yeah, cracking open the throttle to just get maintenance throttle through a turn feels like I'm upsetting the suspension. The 919 is the most powerful bike I've ridden so maybe that's part of the deal?
 
#17 ·
A 20 mm tube raising in the clamps is a mega one step drop of the front.
The 919 is a nominal 26 degree steering head angle bike, drops that sacrifice trail to get it towards a 23 degree bike is not an ideal approach.
0.90s in a 919 should have a starting point installed preload of 15 mm, 10 mm being a minimal amount.
If you cut a whack off and still have some installed preload, they began with too much installed preload.
What oil grade went in ? Nominal stock viscosity ?
I'd stay at nominal stock viscosity on stock valving.

There's many good threads on this site covering suspension in general, plus front ends and shocks.

Good luck with it all.
 
#15 ·
Thanks for the replies. One more thing to buy... if I don't just give up and sell the bike. I need to ride it some more and maybe do a trackday before throwing more money into it...

Yeah, I spent a few hours reading old threads here on rear shock options. The el-cheapo option of my choice seems to be buying an ebay f3 shock ($60) and having it rebuilt by Catalyst Reaction ($175 labor + parts).

I actually made a $400 offer on a Ohlin F4i shock on ebay, and the seller came back with a counter-offer of $500 (there was a thread here saying that this shock will fit, but is a tad longer). Although this would have to be setup/rebuilt also (right?), so that is another $175.
 
#16 · (Edited)
I have an 07 so not much help with your suspension. I haven't used a PC but just working on controlling the throttle can make a big difference, also taking out any play in the throttle really helps because you at least get a consistent response for your input; and reduce wrist fatigue IMHO. give that a shot, and when you get back on it in a turn, think "ggennnnttlllee". it's really satisfying when you get it all right.
**
just want to add. i've been bouncing around like a bouncy ball on my niner for quite a while. Finally started fiddling with the front end and it's making a big difference. the rear shock has been a pain to adjust but messing with the damping has helped some.
there are probably better riding bikes out there, but i like this one pretty much.
good luck
 
#18 ·
Oh, yes, this was with 5 weight oil (Maxima). That was my call, given that racetech recommends this with gold valves and the comments here that the valving is restrictive.

Right now with all my changes it's definitely better--although the small bump absorption is still not ideal, increasing the sag seems to have put the travel in a region where the shock is moving and responding to smaller bumps. Before I increased the sag, it still seemed like the fork was not moving.

The thought was that the new stiffer springs will have reduced my sag, as so the rake similar to what it was before, I could lower the fork tubes some. I knew 20mm was a big leap, I'm going up to maybe 12mm, although I was not feeling any instability. But yes, with both the increased sag and lowering the fork tubes, the net effect is the rake is reduced from the previous OEM setup. I have done this experiment on other bikes and have had it lead to some instability under certain conditions (accelerating over bumps).
 
#20 ·
That's strange. When you say 'they were pogo sticks' you mean there wasn't enough dampening, I assume. I still feel like the fork isn't responding to small bumps enough, so maybe it is a different in the model year or my particular fork... I do have a 0.90 spring in my cx500 and it weighs about the same and has 7.5W oil, and absorbs small bumps better. And as another reference, I rode my Zero in today, and man, do I appreciate the suspension on that bike now; it's dialed up to be really stable, but still absorbs the bumps.
 
#21 ·
Correct, pogo = lack of damping.
Lighter oil reduces damping force.
Stiffer springs increases required rebound damping force and reduces required compression damping force.
919 forks are super stiction design, so are not very compliant on initial bump.
Fork seals are an element, they are too good, make sure they are greased between the lips.
Check to make sure the front end build up is nice and square, to minimize binding.
Assumed is that all involved parts are straight.
 
#23 ·
Racetech Super Slick Seal Grease or similar.

Also.
Mirror finish tube polishing is not ideal on stock sealed 919s.
The seals are so good, the tubes run on the dry side.
Some grease between the lips, and a wee bit of cross hatch, barely detectable is the way to go.
 
#26 ·
Bouncing the front end with the top seal up on the tubes so they are not affecting movement, the forks can definitely move easier. Now it feels awesome, can't wait to try it out. I was out of ideas, so thanks for the input!

However, the synthetic grease I tried seems to be too thick, will buy the racetech on amazon.

@Pvster, it seems like this could be applied after the fork is assembled if it is the top seal that is causing most of the stiction. You could unweight the front end and get it down there.
 
#40 · (Edited)
BTW, honda is not the only one. For example Ducati and Aprilia are doing the same, using whatever suspension showas had sitting on the shelf. Same with production Ohlins for that matter. SBK Ohlins valve kits for Ducati Ohlins forks work just as good in Aprilia or RC51 Ohlins. FG series Ohlins forks are designed the same for RC51, Aprilia, Ducati etc etc (obviously different length, caliper clamps and a few minor differences) I don't think they were concentrating on the frame design while designing the suspension.
 
#41 ·
is this really an argument? :blink:

On a serious note, I finally started assembling my forks, but now I'm having a leak out of the bottom bolt on the bottom side of the fork which bolts the damper assembly to the lower tube. Has anyone replaced the washer on that bolt? Is it a crush washer? It's number 19 on the fiche, part number 52442-ka3-711. I'm worried that I may have tightened it down too much and created a crack if the washer is not the problem.

The other fork is fine, so I don't know what's wrong.
 
#42 · (Edited)
is this really an argument? :blink:

On a serious note, I finally started assembling my forks, but now I'm having a leak out of the bottom bolt on the bottom side of the fork which bolts the damper assembly to the lower tube. Has anyone replaced the washer on that bolt? Is it a crush washer? It's number 19 on the fiche, part number 52442-ka3-711. I'm worried that I may have tightened it down too much and created a crack if the washer is not the problem.

The other fork is fine, so I don't know what's wrong.
It's a copper washer. Similar to banjo bolt washer. If it's not totally damaged, run it on flat surface sandpaper or replace with copper or aluminum from local hardware store
 
#50 ·
Okay, thoughts on the Ohlins KA 906 (It's 290mm but no external reservoir). Any obvious reason why it wouldn't fit? Seller that will take $400 for it... brand new, never used.

https://www.ohlins.eu/en/motorcycle/street-performance-line-KA-906--4455/

Thoughts?
The Ohlins specs for the 919's HO201 is 283mm and 50.5mm stroke. The KA906 is 290mm and 51.5mm stroke. It's for a Kawa ER-6 and I strongly doubt the eyelet size is the same.

So in other words, I'm doubting it will fit.
 
#53 ·
Trimmed the top spacer and got the shock on. Biggest problem was the reservoir on the OEM shock preventing it from being removed--I ended up cutting the reservoir line--I figure I'm just going to toss it in the trash anyways. Some washers on the bottom, I still need to button it up and test ride it. Super excited.

I did have to raise the bike slightly to get it on but it didn't seem more than 1cm...

I have only done 5 C group trackdays, and was ready to move up, but the 919 feels so different, I am going to stay in C and take it easy and try to figure out the bike.
 
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