Suspension travel length GS Vs GSA HOW???

[Bikerbaz78]

Hey Guy's,

Recently I compared my GS with Dingers GSA... I noticed the angle of his rear swing arm was alot lower indicating that the rear shock on the GSA was predictably longer.

No surprise there and makes sense so far...

Now for the part that I have researched and cannot find an answer to myself;

According to spec the GSA ground clearence is 6cm greater than the GS!

So what the hell goes on with the front shock and the telelever? I notice that with both the GS and GSA the clearence between the bottom of the telelever and the top of the cylinder heads are the same! Both GS and GSA alike, roughly an inch lower on the telelever and it would strike the cylinder!

So with that in mind how can the GSA have longer suspension travel ON THE FRONT compared to the GS?

I did apply the logic that despite the fact the GSA telelever is not at a lower angle it COULD be the compression stroke of the GSA shock that's longer? Meaning quite simply the front shock compresses more providing more travel for off road.

If this is correct then that would mean only the rear of the GSA is 6cm higher than the GS and the front height is the same.

surely not?

Can someone put me straight on this please as I would love to know?

Cheers all! Baz

 

[sockpuppet]

If this is correct then that would mean only the rear of the GSA is 6cm higher than the GS and the front height is the same.

No. Because they are linked so if you raise the rear the front will also raise as the axle is the turning point not the front the bash plate

 

[Welshman]

THE travel is 20mm more from memory on the GSA, and both front and rear shocks are longer, but the suspension components are also better spec on the GSA, not sure where the 60mm comes fromk the movement near the cylinder is a fraction of that at the end of the telelever, due to the principle of levers?

 

[Bikerbaz78]

yeah I had considered that but it still doesn't look enough to me?

Interesting you should say 20mm compared the with 60mm I had read? I'm even more interested in finding out now...

I'm just trying to work out a way of having GSA suspension travel and still being able to touch the floor with out having a leg extension?

 

[Bikerbaz78]

No. Because they are linked so if you raise the rear the front will also raise as the axle is the turning point not the front the bash plate

Right, well based upon what you are saying you agree that the front suspension on the GSA is exactly the same length as the standard GS? The only reason for any amount of height increase on the front is caused by the extended rear shock?

Do I understand you correctly sir?

 

[(RIP) willstatt]

Sounds like twaddle to me. The front and back suspension isn't linked. Shocks on Adv are just longer both ends.

If I put an Adv shock on the rear of my standard GS, the front wouldn't move.... it would stay where it was.

Will

 

[sproggy]

If I put an Adv shock on the rear of my standard GS, the front wouldn't move.... it would stay where it was.

What sockpuppet was trying to say was that if you raise the rear suspension only (not the front) then all parts of the bike to the rear rear of the front axle will also rise, but not all by the same amount. Imagine a pencil lying on a desk - lift one end and the whole pencil will move upwards except for the point where it's still touching the desk.

The closer you are to the pivot point (the front axle on the bike) the less it will rise. But it will rise.

 

[(RIP) willstatt]

Ok, fair enough, but you are still giving your bike a 'nose down' attitude if you were only to raise the rear, and that does affect handling, and rider position. The only way to go is have both ends the same spec... ie Adv or non-adv.

(vice versa if you were to just drop the rear for example)

Will

 

[sproggy]

This is going a bit off-topic but on many bikes the handling can be improved (that is, the steering made quicker) by lifting the rear and/or lowering the front by pulling the (non-Telelever) forks up through the yolks a bit. So there might be perceived benefits for road use in fitting an Adv rear shock and a standard front one - a similar effect to fitting a 17" front alloy, actually. Off-road, though, quicker steering probably isn't desirable in which case you're right - stick to Adv or standard at both ends.

 

[ianboydsnr]

surely the front shock is closer to the front suspension pivot than the wheel, so increasing the length of the shock a small amount will increase the height by much more, the same as it does on the rear

 

[King Rat]

It is all down to the position of the mirrors.

the smoke also plays its part.

Owning both a standard 1150GS and an Adventure 1150...I can see through the smoke and can alter the angle of the mirrors to suit.

The suspension units on th eAdv are longer than those on the standard one - so both front AND rear are higher. If you put Adv boingers on your standrad 1150 you will have a higher seat height. If you want to hav elonger boingy bits but stay with your same length legs...you need to remove some foam from your seat!

That will give you piles as you will be sitting on the hard parts of the seat base. With the standard set ups you still get piles, but they are well padded.

 

[elevensies]

the shock BODY length is 20mm longer, but the spring is the same.

this is the same front and rear,

the travel is the same.

 

[Welshman]

the shock BODY length is 20mm longer, but the spring is the same.

this is the same front and rear,

the travel is the same.

Bollocks

 

[Bikerbaz78]

A good thread... lots of ideas of which most I had already considered!

Still no certain answers yet though?

Has any one noticed that boinger unit or spring lengths are not detailed on any documentation? I have an e-copy of the workshop manual and its not detailed. Not shown on the fiche on a couple fo the sites either?

DING!!! maybe the Ohlins website will give some answers?

Come on guy's keep up the arguements and eventually we may get the facts!

 

[rockchunk]

having changed my boingers from standard to adv and having laid them beside each other i can assure you the adv ones are longer and your feet will be a tad further from the ground,,,,seen a dwarf at the bulldog he rode in on a virago not the highest of bikes but he had kinda platform boots on worth considering

 

[Bikerbaz78]

"oh surprise"! Ohlins dont list the shock or spring dimensions either!?

However this site list what appears to be the GS specs as detailed below;

http://micapeak.com/bmw/gs/gs_1150.htm

Front suspension

Travel/dimensions 7.46 inches (190 mm) total travel, 5-position preload.

Rear suspension

Travel/dimensions 7.81 inches (200 mm) travel, hydraulic adjust. 40 positions

Ground clearance 7.8 inches (200 mm)

Seat height 33.1/33.8 inches (840 / 860 mm)

Right...I'm off to find the GSA specs or at least something thats different!

 

[Bikerbaz78]

Even that same site wasnt so informative regarding the GSA config?

QUOTE;

The difference vs. the R1150GS are:

suspension travel 20mm longer
adjustable White Power rear shock

UNQUOTE:

http://micapeak.com/bmw/gs/gs_adv.htm

 

[Bikerbaz78]

The Verdict!

This site is "The Don"!

http://www.bmbikes.co.uk/specpages/R1150gsadventure.htm

GSA

Seat Height
900 mm / 35.43 in (special equipment low seat bench: 860mm / 33.85 in)

Travel Front/Rear
210 / 220 mm (8.26 / 8.66 in)

GS

Seat Height
840 / 860 mm (33.07 / 33.85 in)

Travel Front/Rear
190 / 200 mm (7.48 x 7.87 in)

So despite the apparent "same" visible clearance between the telever and the cyclinder head the front shock of a GS and GSA the GSA IS actually 20cm longer than the GS! Front AND Rear

A whopping 60cm maximum difference between seat heights at the extremes!

Does this mean I could touch the floor with GSA shocks and the low BMW seat?????????

FOOK knows?

 

[rockchunk]

This site is "The Don"!

http://www.bmbikes.co.uk/specpages/R1150gsadventure.htm

GSA

Seat Height
900 mm / 35.43 in (special equipment low seat bench: 860mm / 33.85 in)

Travel Front/Rear
210 / 220 mm (8.26 / 8.66 in)

GS

Seat Height
840 / 860 mm (33.07 / 33.85 in)

Travel Front/Rear
190 / 200 mm (7.48 x 7.87 in)

So despite the apparent "same" visible clearance between the telever and the cyclinder head the front shock of a GS and GSA the GSA IS actually 20cm longer than the GS! Front AND Rear

A whopping 60cm maximum difference between seat heights at the extremes!

are you sure 60cm thats two feet in old money

 

[Welshman]

This site is "The Don"!

http://www.bmbikes.co.uk/specpages/R1150gsadventure.htm

GSA

Seat Height
900 mm / 35.43 in (special equipment low seat bench: 860mm / 33.85 in)

Travel Front/Rear
210 / 220 mm (8.26 / 8.66 in)

GS

Seat Height
840 / 860 mm (33.07 / 33.85 in)

Travel Front/Rear
190 / 200 mm (7.48 x 7.87 in)

So despite the apparent "same" visible clearance between the telever and the cyclinder head the front shock of a GS and GSA the GSA IS actually 20cm longer than the GS! Front AND Rear

A whopping 60cm maximum difference between seat heights at the extremes!

are you sure 60cm thats two feet in old money

Why does seat height equate to suspension length, the seats and mountings are totally different?