Emulsion or Reservoir Shocks; Standard or Progressive Springs

[M1Tanker]

I have a 2008 R1200GSA (non-ESA) and I'm looking at upgrading the suspension system. What are the advantages and disadvantages of:

• Emulsion Shocks
• Reservoir Shocks
• Standard Springs
• Progressive Springs

I've been looking at the following after market suspension manufacturers:

• Öhlins
• Wilbers
• Hyperpro
• WP
• Race Tech
• Penske
• Elka

I'm in Germany and the disadvantage of the North American manufacturers is support here in Europe versus the European companies.

 

[Rasher]

Hi,

I am no expert and googling around or looking at suspension manufacturers sites will get more detailed results, my basic understanding is:

Shock Types:

1. Emulsion shocks are cheap and nasty, just a plunger in oil, the oil tends to froth (cavitate) easily in these shocks and they can overheat and fade quickly.

2. Most other shocks are Gas Shocks, these use a compressed gas to stop the oil from frothing up, the oil and gas is seperated by a piston, there are several variations:

a. Internal gas reservoir - gas in shock body,
b. Piggy back reservoir - Gas is held in a reservoir attached to back of shock body
c. Remote reservoir - The reservoir is attached to a hose

Theoretically remote is the best as the unit is likely to be in a better cooled area, but some top end units are also piggy back style, the internal reservoir types are normally at the lower end of the Gas Shock market.

The gas also provides some springing action, this is non linear as the springing effect is due to compression of gas as shock compresses and is exponential so these shock may have different spring rates to emulsion type shocks, or even other shocks with different gas pressures.

The gas does slowly leak over time and they can need re-gassing, however this is 2-3 years and 20-30k miles on most units. The gas pressure can also be used as part of fine tuning the setup.

Spings:

The experts do not seem to agree on progressive Vs linear springs, I expect some bikes are better suited to one tyoe than the other, in theory progressive are good for the road as it is varied environment and linear is great for the track. The problem is as you alter spring rate you need to change damping to suit, as progressive springs have a varying spring rate it is impossible to accurately tune the damping to suit leaving it underdamped at one end of the stroke and overdamped at the other - I have no idea if this is a big issue and maybe progressive spring suit the GS very well, perhaps they don't - maybe go to an expert with experience of GS motorcyles and ask them, or look at what Ohlins do as they are really the world leaders in suspension.

Manufacturers and Quality:

Every shock manufacturer makes great claims, but they can vary wildly in cost and performance:

At the low end units may not be rebuildable and some probably are no better than OEM (but probably a lot cheaper if your just looking to replace a duff unit)

OEM (and I would guess cheaper) units can vary a lot from bike to bike, I know if you take several standard bikes and check the shock gas pressures they can vary wildly - I assume oil levels may also not be finely controlled either, and for this reason it is often pointless taking other peoples suspension settings and expecting same results on your bike.

More expensive units should have better QC and be rebuildable so after 20-30k and for about £100 you should be able to have the unit serviced and it will be good as new again.

More expensive shocks will probably have more adjustments (I always prefer two way adjustment and remote pre-load adjustment) and high end units such as Ohlins have features such as temperature compensation to keep the damping consistent as the shock get hotter. Having said that a £800 shock with 2 way adjustment is probably better than a £500 shock with 3-way adjustment.

My bike is booked into MCT suspension in the UK later in the year, I trust their recomendations and advice due to excellent work on my last bike and friends bikes and they tell me on the GS the Ohlins kit is excellent. They also say the Wilburs is good, but not as good (or expensive) as the Ohlins.

I see many familiar names in your list, but only have personal experience with ohlins and modified OEM units. Ask around and see if you can find people who have used the other stuff, I expect most of it will outperform the OEM kit and as a rule of thumb you get what you pay for (most of the time) and very rarely get more than you pay for.

I know the Wilburs kit is "modular" so you can decide if you want 1,2 or 3 way damping, or if a remote pre-load adjuster is required. Ohlins offer 2 types of rear shock and 1 front for the standard GS + short options (for lowering the bike)

MCT also tell me they cannot do much with stock GS units so you really have to replace the units if you want to improve the suspension. I was lucky on my last bike as they could re-spring and re-valve front and back of the bike for about £500 - I think the GS is gonna cost me 2-3 times that amount!

 

[peter-k]

That's the best summary I read so far about different suspension systems. And you say you are not an expert ...?

Some opinion to add on from my side.

... snip
Spings:
The experts do not seem to agree on progressive Vs linear springs, I expect some bikes are better suited to one tyoe than the other, in theory progressive are good for the road as it is varied environment and linear is great for the track. The problem is as you alter spring rate you need to change damping to suit, as progressive springs have a varying spring rate it is impossible to accurately tune the damping to suit leaving it underdamped at one end of the stroke and overdamped at the other - I have no idea if this is a big issue and maybe progressive spring suit the GS very well, perhaps they don't - maybe go to an expert with experience of GS motorcyles and ask them, or look at what Ohlins do as they are really the world leaders in suspension.

Many if not most bikes come with weak springs on the front, in particular from Japan. But western butts keep on getting fatter. Any spring that matches better to the rider weight will be an improvement, front or rear. Progressives are better on the front in long travel telescopic forks such as found on adventure tourers. They are not good an bikes that are used for racing. With the BMW telelever a progressive spring is redundant, too. For the rear it is better using a fitted straight spring in conjunction with a shock which has gas and oil separated, as what Rasher described.

Manufacturers and Quality:

As long as we are talking about reputable vendors, more important than the vendor name is the expensive suspension is properly set-up.

 

[Rob Farmer]

We have one of the best bike Suspension companies here in the UK, they make fantastic, high quality suspension units for hundreds of pounds less than Ohlins units with a service cost that came in at £55 for my 1150 GSA shock. They will build the units to suit your bike, riding style and your weight.

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

Look at the news section on their site if you need proof of their pedigree.

The 1150 rear shock was around £500 including VAT.

 

[peter-k]

Almost everyone who's business is suspension technology can service any brand shock absorber.

 

[M1Tanker]

Rasher, Thanks for the detailed and quick response.

peter-k, Good to hear from you again and thanks for the additional comments.

Zweirad Norton Touratech-Mitte is not far from where I live and they sell both Öhlins and Hyperpro. They recommended emulsion type shocks. I do ride mostly on roads and the autobahn currently but when I rotate back to the U.S. I'll have more of an opportunity to ride off-road.

This is a good start. I was hoping that that some of the UKGSER members could also provide some technical expertise and perhaps related personal experiences regarding the various suspension types I have described and the advantages and disadvantages of each in various motorcycle operating environments (road, off-road, etc.).

 

[Rasher]

Only ever had sportsbikes, I have used:

Maxton - Reworked forks on two previous bikes with great results

Race Components - Reworked FZR400RR Track / hack bike and again spot-on

MH Racing - Sorted YZF600 Thundercat forks again for track day use and also spot on.

MCT Suspension - Reworked forks and shock on ZZR1400, top notch work, best customer service, ride-in ride-out service at lower price than by post with Maxton.

The main point is all of these specialist companies made a great deal of difference and I would recommend all of them, although MCT get my vote for the GS and any future work due to the friendly nature, honest advice and full start-to-finish service & post sales advice (if needed)

 

[M1Tanker]

Thanks. I'll probably pursue a suspension system from a dealer here in Germany so I don't have to pay the VAT.

 

[ducatiparts.110mb]

I can't add anything technical to what Rasher has said - top write up, agree completely.

However I would add a cautionary note:
Having had standard Showa, WP & Ohlins on previous bikes, some as standard, some as aftermarket, I feel that there is a lot of hype surrounding "Quality" suspension. Having thought my way through it I am convinced that the amount of benefit you'll feel from premium brand suspension is in direct proportion to how aggressively you ride, so think carefully if you actually need to spend premium money on what may not offer you a benefit.

If you throw the bike into a corner, suddenly hit the brakes hard, and snatch at the throttle, then I suspect that you'll feel more benefit that someone who rolls the bike in and out of corners and applies and releases brakes and throttle progressively. It's not a case of applying less cornering (or traction / braking) force, just working up to it and down from it less quickly and aggressively.

My riding falls firmly into the smooth & gentle camp, and I think that this is why I have been disillusioned with premium brands in the past. This is also why I'll be gettnig my standard esa shocks refurbished by MCT when the time comes rather that buying Ohlins or Hyperpro.

I think the same principle applies to tyres, and once I got over the stigma of buying Maxxis tyres instead of Michelin & Pirelli, I have to be honest and say that I can't feel any difference when riding hard enough to go to wear out both f&r in 4000 miles and going to the edge of the tread (sometimes with panniers on).

Anyone agree?

Mark

 

[peter-k]

On my '07 GS a WP (front) and a Wilbers (rear) made an immidiate difference right driving off from the workshop place. I felt the suspension working much more sensible. It irons out all the small road bumps, like a flying carpet, without making the suspension soft. Two-up and with load the original rear was close to it's end. Incomparable better with my WP/Wilbers setup. Your mileage may vary.

BTW. The '04 + '05 R 12 GS had WP which were pretty good, almost the same as the WP Emulion series. Just not the same neat housing, etc. The '06 + '07 came with Showas, which were overly soft and plush like grandma's sofa. The Showas used from '08 are quite good but still not as good as the WPs from the beginning. Compared the WPs are more sensibel, and they have a better adjustment range.

 

[Rasher]

I felt the suspension working much more sensible. It irons out all the small road bumps, like a flying carpet, without making the suspension soft..

+1

This has been my experience on several bikes in the past, stock my ZZR knocked my teeth on on bumps and the ABS kicked in when braking over bumps, two up the bike wallowed and understeered badly on the gas, no amount of twiddling could resolve this.

The MCT / Ohlins setup made the bike float over small bumps, completely cured the ABS issue when braking on rough roads and also with a few clicks here and there the bike could be ridden to my limits without any issues two-up with luggage. Feedback was amazing, I knew exactly what the tyres were doing (Laughing at my inability to get anywhere near the limits)

You do not need to be Rossi to notice quality suspension, most people I know who have had professional setups have found themselves going a bit quicker, whilst feeling a bit safer and normally gaining some comfort as well.

There is a big difference between "thinking" your not near the bikes limits , and "feeling" your not near the bikes limits.