Shock Replacement or improvement

[dlaing]

This is a work in progress.

I have done some research on options, but this is what I'll post today.

The Guzzi OEM Sachs shock.

The manual mentioned some were equipt with White Power, but that does not seem to be the case.

Here is the shock with critical measurements for those that want to make a similar custom shock.

Eye to Eye length is about 276mm (Sorry, I initially wrote 260mm)EDIT I just re-measured and got 278mm...sorry, again.

And Ratchethack says it is 280mm, so my measurement is off, his measurement is off, r our shocks are slightly different.

Travel is about 60mm

The Eyes are a little over 12mm so that a 12mm bolt may be inserted

The face to face thickness of the Eyes is just under 22mm

 

The Spring length out of the shock is about 165mm and its inner diameter is just under 57mm.

The fitting for the ID of the spring are 56mm.

The spring must be compressed to fit on to the shock.

I am ordering a 6 inch HyperCoil 2.25inch 475#/inch spring that I hope will fit without the need of compressing.

 

EDIT It slid in perfectly without compressing it, and snugged right up with ten turns of the preload adjuster. Now I just hope I can add enough preload....

EDIT NUMBER TWO: added preload till I got sag of about 5mm/36mm. This is NOT what I wanted.

I was aiming more for 5mm/30mm, and it bottoms so easily that I think 5mm/25mm may be what is needed. I am guessing a 550# to 625# spring is what is needed....

Thank You Ratchethack for catching my error on the shock to wheel travel ratio! I mis-measured 1:1.66 when it is closer to 1:2

EDIT NUMBER THREE: Thank you Ratchethack once again for helping me get the preload right.

My measurements in EDIT TWO were wrong. Now I am at 5mm/30mm....time to ride!

EDIT FOUR: Went for a ride....ahhhh, that is more like it. Still not plush like other bikes, but a definite improvement for my weight.

EDIT FIVE:

Just to clarify, I measured sag, in jeans and tee shirt, probably at about 215#.

FWIW, the fuel tank was down about 2 gallons from full.

The result is just about what I want. (5mm bike only and 30mm bike and rider)

I suppose if I had my leathers and helmet on and a full tank of gas, the sag would be greater.

If I were to go with a heavier or lighter spring, I would go heavier.

I think the 475# spring is about perfect for my weight for touring.

But I am more of moderate paced sport rider and if I were to order again, I think I would get the 500# spring.

 

The other possible issue is the ID of the spring is just a little bigger, so the spring may not center perfectly. But the OEM was a little loose, too. I suppose something could be machined...

 

The hose is about 455mm long tip to tip. The eye to eye measurement would be a little less.

[dlaing]

The first option for a shock replacement is the

Öhlins shock absorber

Part No. MG 127

Type 46HRCS

Length 286 mm

Stroke 70 mm

 

 

• Type 46PRC with hose mounted reservoir, easy to fit where it is easy to reach.

• Fully adjustable single shock absorber.

• Improved cooling gives more consistent damping and longer damper life.

• Features compression, rebound and hydraulic pre-load adjuster.

 

 

Price, about $850 US

I am wondering if it is available in a 46HRX model so that one could get High and Low speed compression????

They don't list it, but they may be able to build it???

[dlaing]

Other companies that list a shock for our bike are:

Wilbers (German) with adjustable Rebound Damping and High and Low speed Compression Damping for about $775, if you want remote preload, add $200. If you don't want Compression adustability it is only $495.

 

Hyperpro (Dutch)offers a $499 model without compression damping or a $799 model with high and low speed compression damping and rebound damping.

Options include gold nitrit rod $100, length adjustment $100, and remote preload adjustment $200, choice of progressive or non-progressive spring.

 

Hagon (U.K.)is another choice. They start at $375 US for a stock shock. $435 if you want a heavy duty spring and valving. If you want remote preload add $160

 

Maxton makes very nice shocks

 

Other shocks to consider that do not list our bike are:

WP aka White Power(Dutch) $699 from LE with three way damping

Penske (USA)Priced similar to Ohlins(Sweden)

Elka (Canada)Priced similar to Ohlins

Works Performance (USA)Priced similar to Wilbers and HyperPro.

BiTubo (Italy) Our bike is not listed but, they have been fitted on some Ghezzi and Brians and they list 1999 V1100 Sport

The White Power and Penske have definitely been made to work on our bikes.

I am pretty sure the Elka, Bitubo and Works could be made to work.

[dlaing]

Notice the lighting on the Wilbers and HyperPro are similar and other features are similar.

I suspect they are owned by the same company or share a common marketer.

If anybody has more information about available shocks, please add it.

Or corrections! I am kind of guessing at what countries these are made in....They could be made in Antarctica for all I know.

I am particularlily interested in free and static sag numbers that you get, spring rate, travel and eye to eye length.

[big J]

Interesting,so the Ohlins is 26mm longer than the stock sachs and has 10mm longer stroke. Are the Ohins kitted bikes fitted with different mounting points on the frame/ swingarm? Will fitting an Ohlins shock to a sachs equipped one jack up the back end?

[Guzzirider]

Interesting,so the Ohlins is 26mm longer than the stock sachs and has 10mm longer stroke. Are the Ohins kitted bikes fitted with different mounting points on the frame/ swingarm? Will fitting an Ohlins shock to a sachs equipped one jack up the back end?

55376[/snapback]

 

Just popped into the garage to have a look and it seems that the mounting points are identical for the Ohlins and Sachs.

 

My Ohlins bike is, in comparison to a Sachs bike, jacked up at the rear. The bike is visibly higher and I do not suffer any of the ground clearance problems that some complain of.

 

I have recently ridden a Sachs V11 and the Ohlins is light years better in terms of ride quality.

[dlaing]

SORRY, I blew it! Eye to Eye is about 276mm on the Sachs.

I had gone to this thread, http://www.v11lemans.com/forums/index.php?showtopic=4870&hl=

and read that the White Power Shock was 280mm and that the Sachs was 2cm shorter.

Still the Ohlins is a centimeter longer and has a centimeter more shock travel. 1cm shock travel is about 16-17mm of axle movement. If the ride height is too high, you could always increase the sag.

I want to do some testing with swing arm movement to determine the maximum travel.

[big J]

Good stuff, but I'd imagine joint deflection would be a limiting factor. Anybody know what the maximum angle is? From my time building off road racing buggies, 18degrees was about the maximum a normal joint could take before premature failure.

[big J]

Sorry, rechecked my notes, 18deg constant, 22deg momentary delection

[Admin Jaap]

Upgraded from Sachs to Öhlins. I didn't even notice the bike had a higher tail and there are no joint problems.

[dlaing]

So, I took some measurements and from what I can tell, the triangulated part of the swing arm is just about to bottom out where it at the parallever link support.

(Here is a link to a picture of it bottoming,

http://img49.imageshack.us/img49/5382/bottoming0br.jpg )

So, I would not extend the maximum travel in the compression direction, one iota. And you might not want to cut down your bottoming rubber, as I did...

Maybe that is why some of the Sachs lower eyes break off...because of the asymetrical impact when bottoming.

As for the extension direction I would not go any further than the 286mm that Ohlins specified.

I could not measure the angle, but the shaft would bind at what I measured to be 289mm.

I did not try turning the rear wheel to see if the bind point changed, but that is possible...so beware.

I know that when Mike Stewart ordered his Penske, they shipped it to him such that It was too short or too long...I forget which. But they fixed it for him at no charge, of course...

So, the bottom line is if you order a custom shock, make sure that it is no longer than the Ohlins, and that the combination of length minus travel is no less than the Ohlins or Sachs.

That is to say 286 - 70 or 276 - 60, ie. the minimum compressed length is at least 216mm.

If I order a custom dimensioned shock, I'll ask for something like 285mm long and 69mm travel.

But, shock body length choices may be limited...So, I might end up with 284/68,283/67,282/66,281/65,280/64,279/63,278/62,277/61,276/60,etc.

For now, I'll try the Sachs with the 475# spring. I did not go for a higher rate because the high speed compression damping is so firm on the Sachs. <_>

I'll post the sag numbers...

 

Here are links showing the angle of the shaft bottomed out

http://img153.imageshack.us/img153/8532/compangle9hf.jpg

And fully extended to the maximum length of the Sachs shock

http://img148.imageshack.us/img148/3082/extangle8np.jpg

[callison]

Upgraded from Sachs to Öhlins. I didn't even notice the bike had a higher tail and there are no joint problems.

55464[/snapback]

 

I put on the WP unit from a Sport 1100i and I did not like the resultant height, handling or the inability to make the TLM centerstand work. The Sachs is back on for now. Further experiments are due, but not for a while. FWIW, the WP seemed to be much heavier sprung than the Sachs. With the Sport 1100i frame, V11 Sport triple tree and the WP shock jacking up the rear, the bike just plain felt weird. The WP forks work pretty well though.

[dlaing]

Very, interesting, Carl!

Here is a diagram of the WP

That 90N/mm implies that it is a 515#/inch spring.

It is somewhere between the Ohlins and the Sachs for length.

It may just need less pre-load and compression damping.

I have to hop on a Sporti and check it out

[dlaing]

Here is another option,

http://www.maxtonsuspension.co.uk/

400-480 UK Pounds built to your needs.

BigJ posted about it.

[gallo_se]

for everyone interested, I can get you in contact with a guy near MIlan, Italy that makes shock absorbers locally with the same characteristics of the Ohlins, same kind of technology, at the cost of 450 euro plus delivery charges.