Suspension set up

[pugster]

Hi all,

have toured a fair bit and off round the alps and in a couple of weeks, I'm having trouble with the 1200's suspension. New to gs's and am trying to prep the bike for quick touring 2 up with kit. Rider around 17 stone in gear and pillion around 12 1/2 stone in gear plus a 3 box givi, so fully loaded.

Haven't touched the front but rear on full pre load and still squatting like hell and is very vague mid turn - doesn't want to hold a line. I do ride at a fairly spirited pace and don't want two weeks of comprimising pace on the passes because of bad suspension setup.

Standard GS1200 on road attacks running 34psi front, 36psi rear. Suspect the rear is squatting under static weight and is lowering the rear ride height / increasing the fork angle. Short of changing the spring I can't think of what to do.

Any help appreciated but no suggestions of replacement with Ohlins please!!!!

thanks Graham

 

[Schtum]

The easy bit - up the tyre pressures to 36 / 42. The harder bit - at the very least, it looks like you'll have to go for a harder spring on the rear shock. You'll probably need to give it another full turn on the damping screw on the bottom of the rear shock, as well.

But to get the most out of the bike with that kind of weight on board, you really need Wilbers, Ohlins or something comparable front and rear.

 

[Peak Rider]

Pugster, you don't need an expensive aftermarket shock, you just need more spring. Given the loads you've stated simply installing a set of Hyperpro springs will sort it. There's a thread on this at: http://www.ukgser.com/forums/showthread.php?t=154761&highlight

As Schtum noted you need to up the rear tyre pressure to 42 psi. If you don't have the manual you can find the recommended tyre pressures on the back of the small black plastic panel above the injector on the left side of the bike. At 36 psi with pillion and loaded panniers your rear tyre must be squirming and you'll be shortening its life.

 

[GSband]

Check tyrepressure - preload - damping.
If correct settings don't help, you'll have to look at new springs and/or dampers. Standard BMW suspension is not designed for really heavy loads.

I have Wilbers, the difference (esp. 2 up with luggage) is impressive. Feels nimble, handles sooooooo much better. Perhaps expensive, but you will definitely not regret it.

 

[Sgt Bilco]

Pugster, you don't need an expensive aftermarket shock, you just need more spring. Given the loads you've stated simply installing a set of Hyperpro springs will sort it. There's a thread on this at: http://www.ukgser.com/forums/showthread.php?t=154761&highlight

As Schtum noted you need to up the rear tyre pressure to 42 psi. If you don't have the manual you can find the recommended tyre pressures on the back of the small black plastic panel above the injector on the left side of the bike. At 36 psi with pillion and loaded panniers your rear tyre must be squirming and you'll be shortening its life.

+1 with the spring. I had the same issue as you with my GS-A and it was wallowing in fast corners and when loaded. I put Hyperpro compression springs on (front and rear) and the bike is transformed. About £70 each if I recall.

Well worth the effort

 

[Big Lee]

I put a WP Spin rear shock on mine and it was so much better that my 72 year old dad on his yearly pillion jaunt said how much better the bike was

 

[edmac]

Howdy Folks,
I need to set mine up for a 2up spin with gear also, i wonder could anyone post the settings that are listed in the manual as mine got wet and is unreadable
thanks
ed

 

[pugster]

Thanks for the help guys, all stuff I'd thought of but I only have 2 weeks to the trip so didn't fancy experimenting to find the solution.

I think I'll up the pressures and go for the hyperpro rear spring first as that's where the issue is really and sort the front if it becomes a problem after I've done a test ride. I'm amazed the standard kit isn't upto the job considering what the bike is marketed as being capable of.

I've emailed my local stockist to get the kit ordered and will post after I've fitted it to let everyone know my thoughts.

Cheers Graham

 

[pugster]

Hi All,

Just spoke to Hyperpro and they said they have one in stock but when I tried to give him the weights of rider + pillion (108kg + 95kg in our gear, wifey wasn't happy with what she saw on the scales so I feel a diet coming on!!!!) they said that hey don't need it as its a progressive spring.

I fully understand what a progressive spring is but are there any other srings out there that are weight specific?

Thanks Graham

 

[GSband]

Ohlins and Wilbers (to name only these) do springs with different spring strengths, e.g. 140Nm, 150Nm, 160Nm.
Wilbers specifically asks for rider and pillion weight in order to supply right spring. My R12GS has a 150Nm Wilbers rear spring.
On Ohlins website you'll find different rear springs for R12GS, with same features; they have different spring strengths. BM536 = 160Nm, BM436 = 140Nm.
I'm sure there are other manufacturers who do the same.

 

[tommygun]

Howdy Folks,
I need to set mine up for a 2up spin with gear also, i wonder could anyone post the settings that are listed in the manual as mine got wet and is unreadable
thanks
ed

Turn spring preload clockwise all the way in till you can't turn anymore. Set damper at bottom of shock all the way towards the 'h' and then one and a half turns back. I haven't touched the front spring as I believe its already set to road riding and you only have to tinker if you go off-road. Obiously please correct me if I'm wrong chaps.

 

[pugster]

Hi all,

I have asked for cost/availability on the Ohilns and Wilbers replacement springs so we'll see what they say and go from there. I think I would prefer to have a spring that is designed for a specified weight rather that the Hyperpro progressives.

Any thoughts on this?

Anyone out there with engineering knowledge of the subjest to tell me why the progressive spring doesn't require a specified weight other than the obvious "it gets progressively harder when compressed" answer.

Cheers Graham

 

[Pukmeister]

In my 5 years of owning a 1200 and fitting bling and farkles, the biggest single improvement was to fit Wilbers replacement shocks built to my own spec (as they all are).

The standard suspension is built to a compromise to suit a wide range of riders, and does its job okay. Aftermarket bespoke suspension is built to suit you and the way you ride and use your bike and thus is no compromise in either spring rate or damping(its actually a revelation when you first ride after making the change).

IMO its the damping (ie spring control) that is poor on the stock rear suspension (non-adjustable on the front), setting up the Wilbers I noticed a change for even a single click of damping control, it works so much better (especially being able to alter front damping and feel).

 

[cookie]

IMO its the damping (ie spring control) that is poor on the stock rear suspension (non-adjustable on the front), setting up the Wilbers I noticed a change for even a single click of damping control, it works so much better (especially being able to alter front damping and feel).

that's my view too. ohlins, wilbers, WP is the way to go IMO.

can't see how putting a stronger spring on a shock with inadequate damping can help matters at all. but i've not tried doing it, and those that have are impressed as we have heard.

 

[pugster]

I hear what you are saying about replacing the whole unit. I raced 250's at an amateur level and the diference Ohilns units made to my RS250 (Honda) was amazing and that was a pure bred race machine with a great chassis so I'm sure the improvement would be 10 fold on the GS.

My issue with a full replacement are two fold:

1. Can't afford a full replacement unit!
2. In my case I don't think my particular problem is the damping as the bike feels the same on any surface. I believe it is a ride height/geometry issue.

A replacement spring may well do the job I need it to do at £80. My thinking is possibly that the Hyperpro would be the way to go as that is the best comprimise whether I am two up, two up with bags or solo.

Ofcourse when I get back and do a track day on it I may say differently

 

[Pukmeister]

Ohlins are top dollar and still might need some fettling eg spring changes to suit.

Wilbers however are bespoke hence require no more money spent on them, work very well on the road on the supplied settings, and cost a fair bit less than the Ohlins units.

I can't vouch for Ohlins or aftermarket WP as I've never used them, but I was suitably impressed with my Wilbers units compared with the stock BMW badged WP units.

I know that Margus (Tsiklonaut) fitted Wilbers to his GS for the tour of South America and had leaks and problems but in his case I think he gave the bike one hell of a workout which would test any suspension to its limits (and beyond).

If the stock damping can't control the spring action properly, it as sure as hell isn't going to control the bike properly. Replacing the spring is only doing half a job, and may not be of any real world benefit to you.

 

[stephenm]

I replaced the stock rear spring with a stiffer one as I always have a pillion and panniers. The damping was fine. Ride height was restored, no more dragging metal when cornering on bumpy bends etc. If the shock has 40,000km on it, it will benefit from a service anyway, to maintain efficient damping etc.

Stephen

 

[pugster]

Bike has only done 7K so the shock is in good condition. I am going to go ahead and order a Hype pro and see what happens. If it is the damping aswell as the spring then I'll go down the replacment shock route when I have the funds, just don't want to spend me Jagermeister money on a shock a week before I go to the alps!! G

 

[pugster]

Mmmmmmmmmmmmmmm my nice Hyperpro springs arrived today!!!!! Looking at the bike I think it's a fairly straightforward job, other than having to remove the exhaust at the cat.

Am I right or woefully wrong? Anyone got a different experience of fitting new springs? Doing it tomorrow night aswell as fitting an acerbis road book holder, then less than a week to the Grimsell, Stelvio, Furkha et al!!!!!!!!!!!!!!!!

 

[bumpy]

Mmmmmmmmmmmmmmm my nice Hyperpro springs arrived today!!!!! Looking at the bike I think it's a fairly straightforward job, other than having to remove the exhaust at the cat.

Am I right or woefully wrong? Anyone got a different experience of fitting new springs? Doing it tomorrow night aswell as fitting an acerbis road book holder, then less than a week to the Grimsell, Stelvio, Furkha et al!!!!!!!!!!!!!!!!

How you going to compress the spring to change it?

Also do you know the range of 'weights' they offer for front and back on GS.