Need info

[Sipper']

Can someone with a stock rear suspension give me the height from ground to top of passenger handrail, or various other point with the bike upright but not on the centerstand?

Thanks.

[choneofakind]

I apologize, at one point I had these measurements, but I seem to have misplaced them. My tail is raised about 2", and I love it. I didn't go as high as my dogbones would allow because I wanted to leave some adjustment to keep the geometry the same if I ever chose to go back to a 90-profile set of tires.

Are you looking to raise the tail? Or are you thinking there's something wrong with your bike? If you're looking to raise the bike know that you can go a long way before it becomes unstable. Only thing to remember is that once you raise it to a certain height, the center stand become useless.

Also interested in this thread because I'd like to have a solid number to compare to in order to know how much my tail is raised. I know my nose is dropped 3/4" from WC risers and Tapered Roller Bearings, but all I know about the rear is that it's raised "about" 2".

[Sipper']

I initially installed Soupy's bones to be able to raise the rear, which I did 1" and that was with the 130-90-16 Pirelli Demon. I now have the Pirelli MT75's and a 120-80-16 rear which I know is shorter and I'd like to correct the height to bring it back up. BUT, I now have an Ohlins on it and since it uses far less wheel travel I was wondering how much I could raise it without the chain hitting the center stand mounting point.

Running 30mm total sag now and the centerstand is almost totally useless unless I put shims under the feet.

I could put the stock shock/bones back on to get the measurement but was hoping someone would have it.

What I'm running into with the handling is, it doesn't matter if I have 30 or 40 mm of total sag, if I am running the rebound light in order to keep the rear high in the stroke the bike turns with zero effort, but the bumps make the bike unstable.

If I run the rebound in a couple clicks where it will accept/hold load then it is stable over bumps but turns like a truck.

I was thinking of raising the rear since it seems a few mm can make the difference, and setting rebound where it will hold load and be steady over bumps but turn like it should.

My only other problem is the centerstand mount point and possible chain contact. Might have to get clipons and lower the front instead.

Going to PM you.

[choneofakind]

Heh, you're in a bit over my head. I'm running a shock off an '09 bike, and it works for me and gets about the right sag, so I've left it at that.

Paging @rojoracing53 because he knows a good deal about suspension and did a nice write-up the other day.



PM'd you back. Are you able to adjust the compression damping on your Ohlins shock as well? From my MTB experience, the rebound damping controls how much the bike squats/pogo's over repeated hits, while the compression damping is what controls how much 'feel' or bounce the bike intially has on the bump. Sounds like when you remove rebound damping, the bike bounces back up too quickly and upsets it? Is that what I'm getting here?

sag should be in 30 mm according to rojo.

[Motofool]

Originally Posted by Sipper'

..........What I'm running into with the handling is, it doesn't matter if I have 30 or 40 mm of total sag, if I am running the rebound light in order to keep the rear high in the stroke the bike turns with zero effort, but the bumps make the bike unstable.

It seems to me that you are mixing steering geometry and suspension here, which are two different things.

Do you have a pre-gen?

[Sipper']

Yes, pregen.

The preload, compression and rebound are all I have adjusted so far. Doing a run and making one change per run.
When I change preload I will then ride it making one damping change at a time until it feels similar and then go +- on compression or rebound to feel how it affects the bike.

Each round of preload, the bike can made to feel just as it did previously with the damping changes needed to get the the wheel speed over the road the same, but with more preload it is riding higher.

But, with the preload set light, to where the rear end never looses any ride height, the bike turns with little effort.

[choneofakind]

I'm thinking it'd be best to first decide on the shock settings that feel best over bumps while leaned over and have the proper seg, etc.

Then raise the rear back up to where it was before the tire change with your adjustable links.

Again, sorry I'm not a suspension pro. Hopefully Jason gets on here soon to help out with the details of adjustments vs how it feels. He's former AMA and knows his stuff.

[rojoracing53]

I'm going to take this one step at a time because I already feel a little weird about giving advise to someone who's stuck running 16" tires which I have no experience with. I know I'm going to come off as a total elitist so please just take my words with a grain of salt

1.First are you fast? And when I say fast I mean are you battling for race wins in your local club races?

2. What's been done to your front suspension? Springs, emulators, oil, preload, sag?

3. Is you rear shock length adjustable?

4. How much do you weigh?

5. What's your rear springs rate and how much preload did you have to run to get your 30mm of sag.

6. Are we setting up for racing, trackdays, street or like myself a combination of all three?

Lets start with those.

After many years of racing I've come to realized suspension is 90% rider and what I mean by that is a good rider can ride a total stock bike wether it be a ninja 250 or an R1 to within a few seconds of the pros times. So unless your trying to break through those last few seconds then its hard to justify a bunch of changes to a bike suspension. But I also understand that when each rider starts out myself included we need to mess with the suspension to get ourselves confidence and experience so that one day we can have a better understanding of the riders influence on the bike.

A quote from the factory Yamaha tuners that helped me when climbing through the ranks when I'd come into the pits complaining about all sorts of suspension quirks after only doing 10 or so laps on a new track "Shut up, get back on the bike spot thinking and just ride, it'll start to work out after you relax and go faster" I hated when those guys were right

[Sipper']

Originally Posted by rojoracing53

I'm going to take this one step at a time because I already feel a little weird about giving advise to someone who's stuck running 16" tires which I have no experience with. I know I'm going to come off as a total elitist so please just take my words with a grain of salt

1.First are you fast? And when I say fast I mean are you battling for race wins in your local club races? No, but I like a certain feel from my racing days (94-97)Probably not as fast as I used to be, but ran 1:03's on a GS500 at TGPR and 1:23's at RRR.

2. What's been done to your front suspension? Springs, emulators, oil, preload, sag?RT .7 springs/32mm sag and 20w oil

3. Is you rear shock length adjustable?Yes as well as the links

4. How much do you weigh?162 without gear

5. What's your rear springs rate and how much preload did you have to run to get your 30mm of sag. 457lb spring with 22mm preload on spring

6. Are we setting up for racing, trackdays, street or like myself a combination of all three? Street/trackday

Lets start with those.

After many years of racing I've come to realized suspension is 90% rider and what I mean by that is a good rider can ride a total stock bike wether it be a ninja 250 or an R1 to within a few seconds of the pros times. So unless your trying to break through those last few seconds then its hard to justify a bunch of changes to a bike suspension. But I also understand that when each rider starts out myself included we need to mess with the suspension to get ourselves confidence and experience so that one day we can have a better understanding of the riders influence on the bike.

A quote from the factory Yamaha tuners that helped me when climbing through the ranks when I'd come into the pits complaining about all sorts of suspension quirks after only doing 10 or so laps on a new track "Shut up, get back on the bike spot thinking and just ride, it'll start to work out after you relax and go faster" I hated when those guys were right

Yes, it is all about confidence, and I have not had it in this bike so far. Lack of tire feedback, especially from the front tire.

[Motofool]

Originally Posted by Sipper'

Yes, pregen.

OK, I just went to measure my pre-gen.

Both tires touching the ground, weight of the bike only, rear tire 130/90-16, from the ground up to the tip of the tail cowl = 30.5"

Eliminating the variable of the tire:
distance measured from the top of the end of the swingarm (not the tensioner bolt) to the bottom corner of the second hook = 18"

[Sipper']

OK, mine measures 32.75" and 19.625"

[Sipper']

Friday I came up 5mm on ride height and it felt like a change in the right direction so I left it alone. Saturdays 280 mile ride made me feel like it still needed a preload adjustment as I had to come up on compression to get the chassis to hold a certain geometry and feel balance wise. Felt pretty good on the smooth twisty roads, but back in the city it was obviously way over damped. So I stopped and came up a round on preload, off 2 clicks on compression and in 2 clicks on rebound and she is feeling much more controlled geometry wise but without such a harsh feel. Now I think I am within a click or two of having her perfect, BUT, I am at full soft on compression.

Time for a new shim stack.

[Motofool]

Originally Posted by Sipper'

OK, mine measures 32.75" and 19.625"

You have now a new problem to take care of:

http://www.ironbutt.com/ibmagazine/IBMag12-p64-67.pdf

[Sipper']

Originally Posted by Motofool

You have now a new problem to take care of:

http://www.ironbutt.com/ibmagazine/IBMag12-p64-67.pdf

I actually disconnect the shock and line up all three points prior to adjusting the chain, each time. Yes it takes time, and I have had to modify the slack amount to coincide with free/compressed slack. Chain does not touch anything it shouldn't.

Took all this into account before the changes were made to try and make sure everything is safe. Have done this on every bike I've owned, but I like to measure things anyway. Always been a 'numbers' freak!

Good link for those that don't know.

[Somchai]

IDK if this is what you're looking for, but maybe it could give you some informations or there you'll find what you need
http://motorcycleinfo.calsci.com/Suspension2.html

[Snake]

Originally Posted by Motofool

OK, I just went to measure my pre-gen.

Both tires touching the ground, weight of the bike only, rear tire 130/90-16, from the ground up to the tip of the tail cowl = 30.5"

Eliminating the variable of the tire:
distance measured from the top of the end of the swingarm (not the tensioner bolt) to the bottom corner of the second hook = 18"

Thanks for the pictorial measurements Herman. Very useful.