I don't understand my suspension. Help!

Warthog

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Reliving bike trips whilst sat at my desk....
Now before I get given a load of "this is a fork" and "this is a spring" tyre responses, I would like to elaborate by saying that I do know what preload, and rebound/compression damping are.

What I need to know is why my bike behaves the way it does and which of these parameters I need to change.

If I brake, heavily, but not necessarily an emergency stop, and the bike hits a bump in the road, I can often hear the screech of the tyre followed by a momentary lapsing in braking as the ABS kicks in.

Having thought about it, I'm reaching the conclusion that the front forks are not extending quickly enough to maintain proper tyre contact, so I think it is rebound damping, but I want to check.
Also do std 1150GS even have front rebound damping? I thought it was only the rear.
Similarly under hard acceleration, if the rear hits a bump, it skips and the revs rise before traction is re-established. Rebound again?

Or am I barking up the wrong tree?

Either way what is the cure?
 
N
Also do std 1150GS even have front rebound damping? I thought it was only the rear.
Similarly under hard acceleration, if the rear hits a bump, it skips and the revs rise before traction is re-established. Rebound again?

fronts have rebound and compression damping (allegedly), but neither's adjustable.

reluctant to get in too deep to something i don't well enough understand (in this instance anyway :mmmm ).

what you have is a lack of control. better quality suspension units will behave better.

i eat lots of pies & still rate decent struts.
 
There you are Nick, aproximately 35,000 posts worth of knowledge, in so few words:eek

TBH, I was gonna just say 'They all do that sir'.............

If I brake, heavily, but not necessarily an emergency stop, and the bike hits a bump in the road, I can often hear the screech of the tyre followed by a momentary lapsing in braking as the ABS kicks in.

Either way what is the cure?

Is there a cure?

It's a large heavy traily, with suspension designed to do as well it can in as many situations as it can.......with a sports bike, they can make faster reacting suspension that might deal with this, but it'd be crap on bigger bumps or off road......a pogo's supension can deal with really big bumps but not the needs of a fast road......

As a compromise, the GS does pretty well on all of this, but given the situation above, I suspect that.......they all do that sir :)
 
Is there a cure?

It's a large heavy traily, with suspension designed to do as well it can in as many situations as it can.......with a sports bike, they can make faster reacting suspension that might deal with this, but it'd be crap on bigger bumps or off road......a pogo's supension can deal with really big bumps but not the needs of a fast road......

That's why on quality suspension you have both low and high speed damping adjustment:thumb
 
Sounds to me like your suspension probably isn't set up too badly. There is no *correct* setting for every condition, regardless of how expensive your units are - only ever a compromise. For instance you could ease off the rebound damping at the front to make it react quicker to bumps in the road specially under braking but then you might find it wallowy at higher speeds (although IIRC you don't have that option on stock front shocks?). Likewise you could ease off the rear damping to the point where the rear tyre remains in contact with the tarmac over every bump but then you'll definately find it too soft at normal speeds especially round bends. Before I upgraded my shocks - I once would the damping right off to "S" on the rear on mine just to see what it would do. Lovely and comfy at slow speeds over bumps, but positively dangerous trying to go round corners at any kind of speed - wouldn't turn :eek:

As the others said though - better quality units definately help - partly because they are more adjustable but also because they damp better than the stock units do even at 'normal' settings - best upgrade you can do I reckon :thumb2

Pluck
 
Hmmmm,

A few pointers towards new units. unfortunately not an option! ££££££££££

However, I could consider rebuilding the existing units and getting them revalved, perhaps. As Pluck suggested, my bike, in most cases, handles beautifully. Rimmed rear tyre, both sides. Always feels in control.

I was just hoping that this was not an indication that I had taken things too far.
 
However, I could consider rebuilding the existing units and getting them revalved

If you can stretch to the extra few quids - I'd definately recommend upgrading rather than renewing the stock shocks - they're not that good to begin with and IME are done after 20 - 30k. The cheapest option for replacements is Technoflex (I've got one on the front - very happy with it - Ohlins on the back, better, but not worth the extra £££). It probably wouldn't cost too much more than a rebuilding the originals (which are not supposed to be serviceable) - and you'll really love the difference.

Pluck
 
Technoflex the motorccyle suspension manufacturer I've heard off. Technoflex the innovative sex toy (as I found out through Google) i had not heard of.

For the sake of clarity, Pluck, please could you clarify which of the two you have bolted to your "front end"?
 
the front shock is only manually adjustable for spring pre-load.

The internal damping is fixed - set by oil thickness and orifice sizes in the valving.

Your fixed damping is therefore tuned for a 'sweet spot' within the spring rate range and adjustment.
As your wheel hits a bump - itcarries on travelling upwards due to mass of unsprung weight that cannot be controlled by the combination of spring force and high speed compression damping.

The rear end damping is adjustable and you have to tune this and the spring rate to suit the load and conditions.

After playing with it for days you'll see that its a basically good cheap commercial compromise and needs money spending to improve anything.

Mine does it too - they all do.
 
However, I could consider rebuilding the existing units and getting them revalved, perhaps.

Is it possible to rebuild the shocks without to much hassle?
Think my rears on its way out after 40,000 miles.:(
 
If I brake, heavily, but not necessarily an emergency stop, and the bike hits a bump in the road, I can often hear the screech of the tyre followed by a momentary lapsing in braking as the ABS kicks in.


Similarly under hard acceleration, if the rear hits a bump, it skips and the revs rise before traction is re-established. Rebound again?

Just a suggestion, FWIW, What do you have your pre-load set at front and rear? Sounds as if the pre-load is set a little hard and is overcoming what passes for rebound damping.

For the front, try minimum pre-load at all times. The thing won't dive under braking like conventional forks anyway.

Same goes for the rear, not minimum, but just try about midway for solo riding.

Almost any bike, no matter how many beer vouchers you throw at the suspension, will break traction momentarily in the manner you describe if the bump to power ratio is right. (and if it don't, then give it more welly!).
 


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