Suspension Adjustment

[Guest Nogbad]

My V11 handles pretty well and is stable in turns, but is rather harsh on bad surfaces. I weigh 160 lbs and mostly ride solo. My girlfriend is 140 lbs. The bike is definitely more comfortable 2 up and handling isn't affected that much athough the front does get flappy if you press on. (Having my ribs punched occurs before the bike gets too out of shape though. )

 

I could reduce the rear preload for solo riding, but you can't alter preload at the front, only the damping, and I don't want to make the front light.

 

Is there a compromise setting? It doesn't look easy to alter rear preload, and I haven't dared touch anything else in case it turns the bike into a pig.

 

I have the Sachs shock.. I think.... Hard to tell

[Guest freddy]

I don't know settings for your bike, but i think there is some on the web site tramas.it. May be it can help you.

 

[txrider]

Recommend as a first step setting static sag. Racetech has the procedure outlined here-

 

http://www.racetech.com/articles/SuspensionAndSprings.htm

[Guest Nogbad]

Recommend as a first step setting static sag.  Racetech has the procedure outlined here-

 

http://www.racetech.com/articles/SuspensionAndSprings.htm

46612[/snapback]

 

Looks quite straightforward. I'll have a go at the rear sag when I get the bike back from its tranny recall later in the week. I don't really want to start stripping the forks and fiddling with spacers though! (Being as there is no preload adjustment)

[dlaing]

As the others said, start with sag.

When I first got my bike, I thought the springs were too heavy even for my #200+,

but then from advice on this forum and others I quickly understood I was undersprung, had too much sag and was bottoming out.

The solution for my low budget has been to jack up the rear sag to the point where there is no bike only sag which still leaves me with over 30mm of total sag....curses! I need a heavier spring! But since I am on a low budget, I have to keep the compression damping fairly high.

It works ok, but not great.

You said the bike is smoother two up. I would not jump to conclusions too quickly based on this.

Two up will indeed smooth things out until the point of bottoming out. But it does not mean you are not bottoming out.

The extra weight of two up is probably smoothing out the damping.

If your sag is right or even stiff, simply dial the compression damping out, and only give it enough rebound to keep it from oscillating.

Too much rebound and not enough compression damping or spring rate, and the spring will work its way down towards bottoming out.

On the front if you have too much sag you will need overkill damping to prevent bottoming, especially the compression.

If you have too little sag in the front try dialing the damping out, especially the compression.

That is my low budget fix....

I just ordered an OE sachs shock from eBay to re-spring.

I'll have to search the old threads for a part number...

Let us know how your sag turns out.

 

A quick and easy to measure sag, although not nearly as accurate as the racetech method, is to put zip ties on one of the front forks and measure how much it moves from the weightless state.(bike on lift, or held up by two strong people while you measure)

Or do what I do an yank up on the handlebars to get a visible estimate(highly inaccurate)

On the rear shock, simply slide the bottoming bumper up, gently sit on bike while balancing on tip toes, measure the difference of the weightless measurement, and multiply the movement by 2.(since the shock travel roughly half as much as the wheel movement.)

[dlaing]

I could not find the rear spring part number or brand.

I know I can get the spring through Lindeman Engineering and possibly Evoluzione, so unless someone knows otherwise, that is where I will have to shop.

But I did find Lex' great suspension setup guide.

http://www.geocities.com/motoguzzi1064/Guz...ensionSetUp.htm

For the front end, any spring that works in a Yamaha FZ1 should work in our Marazocchi forks.

1.0 KG front and 500 LBS rear seem to be good numbers for a 200 LB rider.

I am not sure what a 160 lb rider would need. Perhaps a 0.9 KG front and 450lbs rear.

[Guest Nogbad]

Given that riding 2 up takes the rider weight from 160 to 300 lbs, it seems to me that there would be no possible compromise setting, or even one that enables correct setup by adjustment of the preload only when going from solo to 2 up.

 

It looks as if my best bet is to set the bike up slightly on the firm side of touring for solo use given the utterly crap British road surfaces, and then ride gently 2 up, maybe making a preload increase and a compression damping increase to suit.

 

From a physics point of view I need to eat all the food in the house to attain 200lbs, while starving the g/f down to 100lbs.......