V11S Front Fork Tubes/Damping

[Guest tmartin]

Has anyone dissembled the front forks on a 2000 V11S? I changed the oil

in mine and the rebound fork tube worked fine after being put back

together--pushing down there was no damping resistance and on the

up-stroke (rebound) the rate of damping could be felt and modified with

the adjustment screw. The damping on the compression fork tube doesn’t

seem to work. There is no damping resistance when pushing down or when the spring returns it. I tried turning the adjustment screw all the way

to “(+)” with no change. I took it apart twice (including the cartridge) and all the O-rings, shims, plungers seem to be OK. Anyone else had this experience? Tracy…

[dlaing]

When I had my forks off the bike, I pressed down on each fork and noticed that the compression adjustable fork had no apparent rebound damping. As for the compression damping, I could not tell as my effort was trying to overcome the spring.

This inbalance makes me want to get a fork brace, valve reworking, or Ohlins. Not that it handles poorly, but I think the uneven tire wear on the left side of the tire is a result of the unbalanced damping.

I have looked at three other v11sports and noticed wear on the left side of the front tire of each of them.

The 2003 Lemans has the thicker axle which should reduce that effect. Assuming I am correct about the imbalance causing the tire wear pattern.

[Lex]

Dlaing,

 

All bikes in countries that drive to the right wear the left side of the tire faster. In the left side drive countries the right side wears faster. This is caused by road crown (the curvature of the road to help water run off) not the front end design.

 

It is possible that there is a misalignment in some or all V11s, has anybody put one on a Computrack or similar alignment tool? As far as damping causing an uneven wear problem I can't see how it would. All the damping does is slow (slightly on compression, more on rebound) the fork movement. The springs and hard parts (frame, forks, bearings, spacers, etc.) locate the wheels. When you are riding down the road you could drain the fork oil (i.e. eliminate damping) and you wouldn't know it until you hit bump or hole.

 

Above are facts, as an opinion I'd guess you couldn't tell the damping adjustment is working be cause it isn't that strong at the speeds we puny humans can create. Damping increases to the square of speed increases. If it was strong enough to change the speed the fork extends (with the springs in them) at speeds we can create it would be pretty much rock solid at road speeds. Just a guess, I could be wrong. Have you tried making the adjustments while riding the bike? My adjusters make some difference, not enough, but some.

 

Lex

[al_roethlisberger]

...similarly to Lex's points, when I talked to Lindeman engineering about suspension modifications in the "other suspension thread" ... he echoed the same conclusions.

 

He said that while the assymetrical rebound/compression damping is certainly unusual, in general it shouldn't really make any difference mechanically or noticeable subjectively as long as it was tuned appropriately.

 

al

[Frank]

Hello all,

 

I'm not sure one can feel compression damping at the speeds attainable by hand. I believe I read somewhere that the compression damping on forks and shocks is light compared to the compression damping. Others may have to correct me.

 

Not to start a debate, but there is some pretty good evidence that front tires wear on the left side in the US (and the right side in the UK) not because of road crown but because of the fact that US riders ride further around the curve when turning left than right. (The opposite is true for UK riders).

 

check:

 

http://www.rattlebars.com/valkfaq/tirewear/

 

 

Frank

[dlaing]

FWIW the irregular wear is only on the front tires that I have tried. The direction of the tread is another factor in the wear pattern that I am getting.

I have never had this problem on previous bikes. If the Scura and the Lemans with the fatter axle are immune to the problem, then my point may be valid.

Another test would be that increased rebound damping would aggravate the issue.

I don't doubt that you are correct about the differences between UK and USA.

[Lex]

Dlaing,

 

As they say, the proof of the pudding is in the eating. If this is a problem with V11s with the smaller axle and not the later bikes it would be hard to argue against the idea the larger axle fixed a problem.

 

The first thing I would like to do is have a poll, we have enough people on this list to find out if this problem is common or not. I think the poll need to be by chassis group, 2001 and earlier, 2002 and 2003 since Guzzi has made three versions of the chassis. I would also limit the responders to people who have worn out at least one set of tires. Something like:

 

My early V11 wears one side of the tire (front, rear or both) faster than the other:

My early V11 wears both sides of the tire at the same rate:

 

My 2002 V11 wears one side of the tire (front, rear or both) faster than the other:

My 2002 V11 wears both sides of the tire at the same rate:

 

My 2003 V11 wears one side of the tire (front, rear or both) faster than the other:

My 2003 V11 wears both sides of the tire at the same rate:

 

Do you think this would be a good idea? We may not get enough 2003s to get a valid sample but there are plenty of the older bikes on this list. If the tire wear is not common you can look for a problem (a missing, extra or incorrectly positioned wheel spacer* or a manufacturing error) leading to a wheel alignment problem on your bike. An unlikely but possible answer (if this has only happen with one tire) is also a bad tire. If the problem is common we can all look for a solution and, hopefully, one of us will find an answer and share it with the group.

 

Lex

 

* I found a spacer (right side between the final drive and swing arm, about 2 MM think) on my bike that is not in the drawing in the factory manual but looks like it is supposed to be there. You gotta' love the Italians. ;-)

[RichMaund]

After getting 10,000 miles from a set of tires, I feel I really can't bitch about tire wear. I have never gotten 10K from any bike tire in all the 24 bikes I have owned. Usually, NLT 8K miles, I am shopping rubber!

My stock Battle Axes have 10K miles. The rear is worn flat in the middle from too much freeway cruising. Only 1/16" tread left in the middle. The front tire is mildly cupped on both sides and has 1/8" tread left.

A friend of mine with the same bike & tires got 12 K from his. But he lives in an area with twistier roads than I do. He made use of his side tread to more evenly wear the tires out than I could have!

Personally, I am very happy with the tire wear considering how I have used the bike. No complaints on this subject!

 

(Thanks Jaap! I've been looking for a reason to use that new emoticon!)

[dlaing]

Good idea Lex,

Perhaps I am off base and there is no way that axle would bend from damping differences, soooo,

If I can find two other posters with the same problem that I have, I will go ahead and start a Poll.

So if

Your early V11 wears the left side of the front tire faster than the rear or in a cupping like pattern, but mostly on the left,

please post your experience.

And if you know your damping settings that may also be relevant.

Thank You!

So Rich, is your tire wear symetrical?

I am not getting anywhere near your type of tire mileage.

[RichMaund]

It is symetrical.

Since I tear around at 5-6k rpm all the time I tend to use the brakes only lightly. With the light flywheel, this bike has the best engine braking ever. Rolling the throttle on-off is mostly all I need unless I dive deep into a corner. Then I nail the front brake for a second before pitching into the turn!

My Cali and Mille' GT had little engine braking this way. So I greatly enjoyed those dual iron front disks! On those bikes I would often wear out a front tire (Cupped evenly and worn out.) at 5k miles, then I'd get about 8k on the rear.

[Mike Stewart]

In my experience with front tires, I believe tire cupping is caused mainly by the tread design. I have noticed some tires are prone to cupping much sooner than others. The stock Bridgestone tires on my V11S did cup very early and it was more pronounced on the left side. I know that I favor the left hand turns than the right hand ones (in the US.) due to driving on the right side of the road. You can see much further around a left hand turn and one can throttle harder and sooner that any right hander! On my stock Bridgestones the cupping was more pronounced on the left side, but on the Metzeler and Bridgestone 010's the cupping is neutral. Maybe I am getting better at right hand turns in the US!

 

When in doubt, keep the rubber side Down!

Mike