Now onto the forks

[dlaing]

Again, when ordering from Wilbers, it's config-to-order and build-to-order. You can specify any eye to eye length and any stroke wanted at no extra cost.

I had asked them for eye to eye 286mm and shock travel of 70mm and they said they could not do it. So, there are some limitations to what they can do.

...which is why I am going with the Penske.

And FWIW Ratchet could very well be right that the Sachs is 280mm. I measured 278mm but it was difficult to measure with my limited tools and limited ability to compensate for paralax deviations.

[Mike Stewart]

I still prefer the Ohlins rear shock over the Penske. The Ohlins is just so much more plush (compliant) to start with. To me the Penske is set up more for a track, where as the Ohlins will work well on both, street and track. Yes, I have done them both.......Just trying to save you $$$$$$$$$$$ The Ohlins is 10mm longer than the Sach unit. I have the length figures around hear somewhere

 

Mike

[dlaing]

I still prefer the Ohlins rear shock over the Penske. The Ohlins is just so much more plush (compliant) to start with. To me the Penske is set up more for a track, where as the Ohlins will work well on both, street and track. Yes, I have done them both.......Just trying to save you $$$$$$$$$$$ The Ohlins is 10mm longer than the Sach unit. I have the length figures around hear somewhere

 

Mike

I am hoping the extra 20mm of shock travel (~40mmwheel travel) that I got compared to your Penske will make a difference in the plush department.

If not, I guess I'll just sulk

I am concerned the seal on the Penske is tighter, causing more static friction, which gives a rougher ride.

The tighter seal is a trade off for fewer leaks.

It has taken me years to arrive at this decision, and I still can't say for sure which shock is the best value. I am amazed that our bike has so many choices.

Mike, your experience and feedback is why I went with the Penske.

I guess I missed a couple of the posts about your prefering the Ohlins.

But I did remember you found the Ohlins more comfortable.

Also, the posts by Dr.Know pushed me towards the Penske.

I hope I am not disappointed.

Maybe if I never ride an Ohlins equipped bike, my ignorance will be blissful

I have the length figures around hear somewhere

I'd be interested to see those figures:

I have Ohlins specifications of 286mm eye to eye and 70mm stroke (same as I spec'ed the Penske)

For the Sachs I have 278mm eye to eye and 60mm stroke

I previously had a note saying the sachs was 276mm, but my rough measurement indicates about 278mm plus or minus one or two mm.

Ratchethack posted 280mm, which could very well be correct.

I'll have a Sachs shock up for sale soon if anyone is interested. I have two of them and will part with either. One has a stock spring and one has a 475# spring. But I won't sell until I know the Penske will work.

[Guzzirider]

I just bought an Ohlins rear shock for Helen's V11 because it was the cheapest option available (thanks Antonio!) and I knew it would very work well as I have one fitted on my Rosso Corsa.

 

I'm due to get the forks back from Maxton next week and will post a report once I have taken a test ride.

 

When I visited Maxton's workshop a few weeks ago, I had a good chat with Richard who was familiar with the forks as he rebuilt the ones that were used in the Tenni that raced in the TT a few years back. I have asked for comfort and quality of ride to be the priority rather than racetrack ability.

 

Basically he is throwing away the old cartridges and internals, and replacing them with Maxton items. There will also be separate adjusters for compression and rebound on each leg.

 

With the Ohlins / Maxton combination I am hoping that the quality of ride improves considerably over standard.

 

Guy

[Mike Stewart]

David,

 

I went through my stack of Guzzi stuff and found the Sach's rear shock length. It measured in at 276mm (center to center). This was for a 2000 V11 Sport, the 02 and later bikes might have a longer Sach shock.

 

The Penske I had was adjustable in length. I played with different lengths and I found that the 2000 V11 Sport felt the best to me with the shock length at the 276mm length. The bike felt more twitchy at lengths above this. Now the 02 and newer bikes with the longer wheelbase, a 10mm longer shock does wonders to the handling department.

 

 

Mike

[Guest ratchethack]

Hm. I measured mine very carefully on my bench. I got 280 mm, +/- ~.1 mm.

[dlaing]

Hm. I measured mine very carefully on my bench. I got 280 mm, +/- ~.1 mm.

Sachs quality control

[dlaing]

snip

I played with different lengths and I found that the 2000 V11 Sport felt the best to me with the shock length at the 276mm length. The bike felt more twitchy at lengths above this. Now the 02 and newer bikes with the longer wheelbase, a 10mm longer shock does wonders to the handling department.

Thanks for the input.

To get the 286/70 measurements, I had to pass on the height adjuster.

So I'll be limited to using preload to set the ride height.

Which should work fine as long as the spring is not too long or short.

Getting the ride hide right is a challenge.

When going down hill, I wish it were lower.

When going up hill, I wish it were higher.

I have played alot with the front, and the front likes to be low, but that is because it both quickens the steering and balances the bike better, so it is more nimble, yet more stable.

Changing the rear has more trade offs.

Too low in the rear and the steering gets too slow, and I lose travel.

Too high in the rear and it gets nervous, especially going down hill.

Also, I already slide too far forward with my Corbin, and going high in the rear increases that problem.

I may end up stretching the rear sub-frame to lower the rear.

Last time I saw Ratchet, I mentioned that idea to him...back when was polite and held off on the Remulac comments .

I already stretched it about one or two millimeters, with no noticeable difference.

To go further back and down, I'll have to have material added...so much for that power to weight ratio.

[FuelCooler]

I managed to change the shock oil but it wasn't pretty. I will explain here in general for those who think I am crazy and in hopes that it qualifies me for a bodge point!

After depressurizing the shock (which I measured at 150 psi) I removed the spring, shock dust seal / cap, resevoir cap and did some measuring of the gap in which the nitrogen fills.

After much knuckle busting I couldn't remove the retaining clip that holds the damper together. So I decided to try something I have never done and wouldn't recommend: Filling the shock through the resevoir hole in the shock body. :!:

I spent over an hour pumping air bubbles out of the shock (thats a workout!). Then I filled the (disconnected) remote reservoir and line, installed the piston in it and worked the air out of that assembly. then I quickly attached the line to the (nearly full compressed) shock while slowly forcing the reservoir piston to bleed though the fitting as I tighten the banjo bolt. I then put the reservoir end cap back on and refilled with dry nitrogen to 190 psi. I don't know what the pressure spec. is but the lowest I remeber seeing is 175 psi for one of the shocks I have done before. Disclaimer: YOU MUST USE AN INERT / NOBLE GAS!!!!! Specifically pure nitrogen.

Well it is mounted back up appears to be functioning fine. I used my beloved Bel Ray HVI suspension fluid. 10 wt. I will give a ride report after I do the forks (I had to put the back end together before turning the bike around on my stand to do the forks. Worst case scenerio, I will have to buy a new shock sooner than latter. Oh yeah, I am waiting for my 500# spring to arrive. Backordered.....

Fork update to come later this week.

Cheers,

Steve

[Guest ratchethack]

I managed to change the shock oil but it wasn't pretty. I will explain here in general for those who think I am crazy and in hopes that it qualifies me for a bodge point!

This is NOT a bodgery, my friend!

 

But may I offer special recognition for perseverance, self-reliance and innovation!

 

Who needs a specialty suspension shop, eh??

 

Nice work!

[dlaing]

Disclaimer: YOU MUST USE AN INERT / NOBLE GAS!!!!! Specifically pure nitrogen.

 

You got a good permanent result so one might not think it qualifies as bodgery, but I think you should be elligible for a bodge point for your methodology. Getting an elephant through a keyhole should merit a bodge point. Nice work. I nominate you for a Bodge Point

 

Why MUST one use pure nitrogen rather than atomospheric air?

There have been discussions on nitrogen in tires and the general consensus was that it is not worth upgrading motorcycle tire to nitrogen.

Of course for a tire, you probably won't be able to increase the nitrogen content above maybe 90% without multiple refills, but with the shock, there is higher ratio of nitrogen to air in one fill, because of the higher pressurue, and MAYBE you can squeeze out much of the air in the shock by compressing it???

[FuelCooler]

You got a good permanent result so one might not think it qualifies as bodgery, but I think you should be elligible for a bodge point for your methodology. Getting an elephant through a keyhole should merit a bodge point. Nice work. I nominate you for a Bodge Point

 

Thanks,

We will see if it feels OK, and lasts! I will gladly forgo the bodge point if it was successful.

 

Why MUST one use pure nitrogen rather than atomospheric air?

 

I am not an expert (even though I do work for a specialty gas company) so I error on the side of safety.

N2 is cheap and has the temperature and compression properties that shocks are (I believe) designed to handle and use. I believe pure N2 gas has the properties most similar to atmospheric air, which is mostly nitrogen so why wouldn't it, but does not have things that can hurt the shock or be physically dangerous.

 

1. Moisture. In this shock there is no rubber bladder that seperates the gas from the oil, instead it is set up like a brake caliper with an o-ringed piston that moves in a bore (the reservoir). The moisture could rust the bore. Yes there is some moisture in the reservoir from the air that was in it before filling, but only as much as 15 psi of atmosphere had that day.

 

2. Oxygen. Oil and high pressure oxygen is an explosive combination. Again this shock has no bladder, so the gas has direct contact with the oil film on the reseverior wall.

 

It used to be hard for me to get N2 to use when I built other shocks (that had rubber bladders) but I used it anyway.

[FuelCooler]

This is NOT a bodgery, my friend!

 

But may I offer special recognition for perseverance, self-reliance and innovation!

 

Who needs a specialty suspension shop, eh??

 

Nice work!

 

Thanks Ratchethack,

I was a little embarrassed to post this shock oil change method, but I figured what the hell, someone would get a chuckle out of it. Yours and dlaings support (and criticism) is always considered by me, and appreciated.

 

OK,

I have the forks off my bike and one (rebound side) measured and emptied.........update to come!

[FuelCooler]

Now the fun stuff

I measured several things while changing the fork fluid today:

 

Blue locknut (that tightens against the cap):

Rebound Fork- 22mm

Compression Fork- 21.25mm

 

Spring spacers:

RF- 109mm

CF- 110mm

 

Spring (straight wound):

RF- 295mm

CF- 294mm

 

Air Gap

RF-128mm

CF-114mm

 

My forks haven't leaked in the 5000 miles I have put on it, so the level was never set (volume method?) or not set correctly, i.e. the rebound side wasn't purged properly. The rebound side would be the side one would most likely screw up, because of the stronger damping force, making it harder to purge.

I just set my levels to 102mm with HVI 5wt. I am 'freaking out' a little bit because I have changed so many settings / variables at once:

1. Fork oil viscosity from an unknown to 5wt.

2. Fork air gap from 114 and 128 to 102mm.

3. Shock oil from an unknown to 10wt.

 

I was going to use an air gap of 105mm or 110mm to start but I figured the 5wt. would/ could/ should increase my bottoming due to less compression damping. And Ratchethack runs 100mm IIRC.

So 102mm it was.

I am going to leave the forks off until tomorrow so I can recheck the levels and perhaps change them if advised otherwise.

Ease my mind, Oh gods of this forum.

[big J]

Just remember,Ratchethacks settings are right for Ratchethack only.Everyone has different needs and riding styles which would require different set ups.Dont be afraid to experiment with a different method of setting up your front end.

 

It should be reiterated here that what works for one rider will be complete anathema to another.Find what works for YOU,not somebody else.