Suspension questions

Santa-2512

Santa-2512

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I'm going to have to get my rear suspension unit refurbed,

But before i press the button i''m after some advice on whats the best option to take

If i refurb the current unit and retain the std spring, will it alter my ride height?

Currently i have a spring thats done 30K ish so will have taken on some natural compression

But i believe its set for a nominal weight rider

Question is i'm not a chubby fecker (honest) and if i shed a few i'm going to be a lightweight :)

Also i was contemplating a lowered spring (approx 30mm) but that would mean i have to hunt down a new centre & side stand.

Also can you just lower the rear and not the front or would that upset the geometry & handling?

But i was to put a softer spring on the rear, same height as stock would i have to change the front as well?


any help would be appreciated
 
In the old sports bike days, if one raised the rear or lowered the front, it had the effect of making the steering a bit quicker/less stable etc.i imagine that it would have similar effect on the GS regardless of the alien type front suspension! Might not be massive but lowering front and back similarly would maintain the geometry if not the wheelbase itself. Side stand may need modding but that would be suck it and see
 
Seriously consider a pair of Hyperpro springs, made a massive improvement to my Hexhead I think mostly because I'm not that heavy (well I wasn't at the time!)
 
I put on Hyper Pro springs to lower the bike by 4 cm but now have to bend/ lower my sidestand so maybe if you lower it the sidestand might just be right!


Verzonden vanaf mijn iPhone met Tapatalk
 
I have a set of lowering Wilbers shocks and corresponding centre stand that I may be persuaded to part with for the right price...the plan was to fit them as father time took his toll on my ability to manage the height of the standard size GS.

Sent from my SM-G935F using Tapatalk
 
Santa-2512 said:
But i want to put a softer spring on the rear, same height as stock would i have to change the front as well?


any help would be appreciated
Click to expand...

what weight are you?
do you ride with luggage?
do you ride with a pillion?

if first is over 75kg with bike gear and or either of the others is yes, then I wouldn't think you want a softer spring
you may have way too much preload on it or the damper screw wound in too much
 
Changing rear height will affect handling. 30mm will have a huge effect. You would need to drop front too

Spring rate is a compromise based on range of use and rider weight. Stock spring is great for one up, no luggage, 80kg road rider. More average weight = stiffer spring; more off-road use = less stiff spring; more lanes and b roads = less stiff spring; more track type riding = stiffer spring. Balance of these factors gives compromise. Race Tech website has a spring rate calculator, although that is more of a guide.

I posted elsewhere on the re-gas work for a non-serviceable shock. To make it serviceable the body has to be drilled and tapped. Personally, I purchased an after market shock which has spring rate chosen for my riding and which has more damping adjustment than stock unit.

If you get unit serviced and want to figure out spring, then measure suspension fully extended on centre stand (mark frame above eg FD and mark FD, then measure distance and record). Do same for static sag (bike under its own weight) and then again for laden sag (you sitting on bike in riding gear). You will need an assistant. Fully extended to laden should be 50-60mm difference (for non-adventure GS. Adventure has more total travel). You can adjust preload up/down to get into that ball park. Also do this with anything you often ride with, so eg pillion or luggage. If you run out of preload, then spring too soft
 
A lot to consider,

Im 89 kg in my trollys and 102Kg full geared up.

And im about 13kg over where i want to be before i add gear ;)

I currently have my preload wound right the way out, brings the bike down a bit to aid getting my leg over and feet near the ground.

I think is leaking, so adjusting PL wont make any difference ;) at the mo lol

"Sgt Cupid" got your pm, interested, just got to run some numbers with the finance dept ;)


Need to get my trainee off his backside to assist my measurements ;)
 
Is it the preload adjuster that is damaged, or leak from shock piston?

If you set rear sag per above you will likely need quite a lot of preload. Bike should handle much better.

Options are to drop front and rear equal amount, buy a lowered seat, or can you get on it when on side stand? Better to have faff getting on than have rear end too low
 
Something I found putting a lower seat on, my knees were a lot higher and bloody uncomfortable. I ended up lowering foot tests.
 
NicD said:
Is it the preload adjuster that is damaged, or leak from shock piston?

If you set rear sag per above you will likely need quite a lot of preload. Bike should handle much better.

Options are to drop front and rear equal amount, buy a lowered seat, or can you get on it when on side stand? Better to have faff getting on than have rear end too low
Click to expand...


I think the piston is leaking, (pretty sure ;)

I have a lowered seat allready,

I'll do the sag stuff tommorrow, but ive got a suspicion getting the sag correct will raise the bike to much for me to get my toes down ;)
 
Santa-2512 said:
I think the piston is leaking, (pretty sure ;)

I have a lowered seat allready,

I'll do the sag stuff tommorrow, but ive got a suspicion getting the sag correct will raise the bike to much for me to get my toes down ;)
Click to expand...

HPA should still work as it just winds the spring up or down.

Idea of setting sag is to get the spring, with rider on bike, to be 1/3 of the way through travel. This is because it then has 2/3 of travel to absorb bumps, and 1/3 to extend into depressions.

Theoretically, you could set sag to 2/3 of travel at rear and then do same at front to keep geometry same. This would leave suspension much mroe likely to bottom, which then means any further compression woudl be transferred directly to chassis and you will feel a 'kick'. (Although to be fair you will anyway with piston seal dead on shock).

If you can't get toes on ground with sag set correctly then def better to lower front and back and set sag correctly. Important to have enough unused travel to absorb compression, and to have geometry correct with front and back adjusted similar amounts
 
OK, just been out with my lad to do this

Not sure if the results are right, trying to get him to keep the bike balanced whilst trying to do a measurement was a right faf,

he dosent understand the concept of leaning into things to brace them :blast

Anyway the figures were


Unladen 511mm (on stand )

Laden Rider +gear 431mm

travel for the GS rear is 200mm 30% = 60mm

So 60mm is my target

With the figures i have i'm starting at 80mm

so i need to increase preload to get to get the missing 20mm

taking my preload from bottom to mid point got me to 71 mm

but going from midpoint to wound all the way in only gave me another 3mm of so at full preload i was at 69mm

9mm off target.

I'll try it tommorow on the way to work but it felt like i'm right on tiptoes, so not best for me

definatley looks like a shorter spring is in order
 
Did you notice a handling difference?

Sounds like rear spring rate too low. Even if you get lowered suspension, you probably also need a stiffer spring.

Handling question also touches on the front end - ie if handling wasn't relal ybad, then implication is front was similar to rear. You can do a similar check for the front. Easiest is cable tie around fork slider tube and use that to measure - can do by yourself as cable tie will stay in highest position. In short term if you ride with more preload on rear, then you need to adjust front otherwise front will be too low. In medium term if you get lowered front then also check spring rate.
 
NicD said:
Did you notice a handling difference?

Sounds like rear spring rate too low. Even if you get lowered suspension, you probably also need a stiffer spring.

Handling question also touches on the front end - ie if handling wasn't relal ybad, then implication is front was similar to rear. You can do a similar check for the front. Easiest is cable tie around fork slider tube and use that to measure - can do by yourself as cable tie will stay in highest position. In short term if you ride with more preload on rear, then you need to adjust front otherwise front will be too low. In medium term if you get lowered front then also check spring rate.
Click to expand...

Tried it into work this morning .

definatly smoother over the daily route, not so wallowy..

But and the big but, waaaay to high, though i'd forgotten to put the side stand down when i went to get off.

So deffo need to lower. before anything else, or reduce the static sag slightly to find a happy medium
 
tuftywhite said:
Did you watch those videos I sent links to? There's one on how to set sag.
Click to expand...

Yes i did :),

As you can see i cant get my sag to 60mm 70mm was the best i could get and the bike is waaaay to high.

Just waiting for some funds to move around then i need to have a chat to Cupid ;)
 
Nippy Normans supply Touratech, Wunderlich, Desert Fox and many other makes of accessories.
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