suspension setup and service

[acebobby]

Does anyone know if there is a place in the North East that specialises in motorcycle suspension servicing and setup?

[dude900]

SPEED MACHINE i think its someone from this this site that runs it . i think its www.speedmachine .co.uk but not sure ?

[Dickie]

What's on your bike just now and what are you looking to have done?

[acebobby]

What's on your bike just now and what are you looking to have done?

I Have a CBR600RR-5, suspension is stock showa parts all round, I have done 19000 miles with the bike and I am starting to feel like the rear end is getting bouncy so am looking for advice on getting parts serviced or tweaked to suit my weight and riding style.
I have been trying to educate myself on motorbike suspension, by reading books and webpage setup reports but I totally lack the confidence to mess with my bike, and would be happy to pay an experienced specialist to go over it with me and help me find the correct set up!

[Dickie]

The only local 'specialist' that I know who could do the whole ride-in, ride-out service is Bob Grant at Knockhill.

The alternative is to send your forks and shock off to a specialist like Kais or K-Tech and have them rebuild it to your own spec, that should cost about £650. Then, at your next trackday down south, pay the suspension guy £50 to spend the day with you and experiment with the settings to suit you. I'm 99% sure that's what I'll be doing

The sky's the limit with this stuff though, you could go the whole-hog and spend £1500 on an Ohlins TTX shock and a 25mm fork kit.

[dyz]

Don't want to start a new thread.

My Falco needs the suspension set up, I've emailed Bash but no reply yet and mobile goes straight to voicemail. Do I remember correctly that he works off shore?
Any other places I could get this done?

Cheers.

[al]

Don't want to start a new thread.

My Falco needs the suspension set up, I've emailed Bash but no reply yet and mobile goes straight to voicemail. Do I remember correctly that he works off shore?
Any other places I could get this done?

Cheers.

Have you tried setting the bike back to the standard settings (they are in the manual) then adjusting the sag to get the pre-load correct?

Big Kneed Al (master of the emergency stop & "stand up" comedian).

[dyz]

Have you tried setting the bike back to the standard settings (they are in the manual) then adjusting the sag to get the pre-load correct?

Big Kneed Al (master of the emergency stop & "stand up" comedian).

To be honest, no. When I got it, it was set up for 2 up but I've managed to improve it a bit + it has a Mille R Ohlins in.

[al]

Have you tried setting the bike back to the standard settings (they are in the manual) then adjusting the sag to get the pre-load correct?

Big Kneed Al (master of the emergency stop & "stand up" comedian).

To be honest, no. When I got it, it was set up for 2 up but I've managed to improve it a bit + it has a Mille R Ohlins in.

It is well worth setting the damping of the forks back to standard settings. The ones on mine were set rock had wich is no use on a road bike. I set mine to standard then back off the rebound and compression damping one click. Set the static sag to about 25mm (change in for extension from fully extended to compressed with just the bikes weight standing vertically.

The rear suspension damping I set to standard with the static sag set to about 12mm. I don't know what effect the Millie rear shock & linkage will have on the setup.

Big Kneed Al (master of the emergency stop & "stand up" comedian).

[al]

This is an article I previously had posted in the workshop section of the site which may be of interest to some -



MOTORCYCLE SUSPENSION

The main purpose of suspension is to keep the wheels in contact with
the ground it should allow the wheels to move up and down absorbing
bumps and smoothing out dips and let the tyres get on with the job of
providing grip. The rest of the motorcycle should remain undisturbed
by the vibration and impacts caused by the road surface staying level
and comfortable.

Suspension Adjustments

PRELOAD
This compresses the suspension springs so lighter springs can be
used any changes alter the amount of sag front and rear allowing the
suspension to work in it's most effective range the middle two thirds
of suspension travel. Too little preload causes the spring to work in
the soft part of its range and so needs more damping. Too much preload
causes the shock to top out over bumps and reduces the working range
of the suspension.

REBOUND DAMPING
Controls the speed that suspension springs return to their full length
after being compressed. Without rebound damping suspension would bounce
up and down uncontrollably. Too much rebound damping slows down rebound
and causes the front of the bike to pump down over bumps. Too little
rebound allows the front to bounce back too quickly reducing control.

COMPRESSION DAMPING
Controls the speed the suspension is compressed. The amount of feel
and feedback from the front tyre vary with the amount of compression
damping. Too much compression damping causes the wheel to be deflected
by bumps and the tyre has to work harder absorbing the bumps it's self.
Too little compression damping allows the wheel travel too much over
bumps and dive too much under braking.


Suspension Setup

Before you start to make adjustments to a motorcyles suspension make
sure all of the basics are right first.

TYRE PRESSURES
Check the tyre pressures with a good quality gauge and adjust them
to the manufacturers recommended figures incorrect tyre pressures can
cause numerous different handling problems.

WHEEL ALIGNMENT
This is simple for bikes with single sided swinging arms as wheel
alignment is assured as long as all of the bearings are in good condition
and the bike hasn’t been bent in an accident it’s probably still a good
idea to check the alignment though. Ignore the adjustment stampings
on the rear swingarm or adjusters as they are always inaccurate instead
use two long straight edges which are longer than the wheelbase of the
bike and clamp them either side of the rear wheel then with the bike
upright adjust the rear wheel until the spaces between the front wheel
and the straight edges are equal both sides. Wheels that are out of
alignment can cause wobbles and steering problems.

STEERING HEAD BEARINGS
Steering head bearings are crucial to good handling as all the steering
and braking forces act through them. There should be very little resistance
and definitely no notchiness. New bikes tend to come with the bearings
set too tight from the factory so they are always worth checking. Lift
the bike so the front wheel is off the floor and turn the bars left
and right and feel for any knocking (too loose), resistance (too tight)
or notchiness (worn out). If they need adjustment loosen the lock nut
and use a c spanner to adjust then until they run smoothly. If the bearings
are worn out they need replacing have them replaced with taper rollers
by a competent motorcycle mechanic as they can require some specialised
pullers and drifts.

CHAIN ADJUSTMENT
A tight chain will stop the rear suspension from working. The Suzuki
TL1000 rear suspension is especialy prone to locking if the chain is
too tight.

WHEEL BEARINGS
Worn wheel can cause the bike to wobble and weave as the wheels can
move independantly

LADEN AND UNLADEN SAG
The laden and unladen sag are set to ensure the suspension works
in its most effective range and has enough travel to let the front wheel
follow both the bumps and hollows in the road. Laden sag should be set
to 25% of the wheel travel both front and rear. Unladen sag should then
be checked it should be 15% of the wheel travel at the front and between
5 -15mm at the rear the lighter the bike the less sag required. If the
unladen sag is to small then the springs are too soft and the suspension
will top out when the suspension is unloaded. If the unladen sag is
to large then the springs are too stiff.

REBOUND DAMPING
The rebound damping controls the way the suspension returns to its
original length. Front suspension can be set by applying the front brake
and pushing down on the bars the rebound damping should control the
return so that the suspension extends and then settles to its original
length without bouncing. Rear suspension is a little more difficult
to feel and it is set by holding the rear tail unit and pressing down
hard the supension should compress and then return slightly slower with
no bouncing. Check the rebound balance by pressing down just behind
the fuel cap to compress front and rear together and make sure that
the rear returns slightly slower than the front.

COMPRESSION DAMPING
The compression damping is down to personal taste so start small
and work up. Increasing compression damping improves feel and reduces
dive but too much makes the suspension to hard over bumps.

EXPERIMENT
If in doubt don’t adjust anything. The easiest way to feel what difference
each type of damping makes is to note the current settings and then
adjust rebound damping to half way between hard and soft chnage compression
damping to minimum and ride he bike over a familiar section of road.
Adjust one setting at a time and work through the whole range of adjustment
on the front and rear separately this will give you a good idea of what
affect each of the adjustments have. Once you have finished return the
suspension to the standard settings and you should then be able to adjust
out any problems based on your experience.


COMMON PROBLEMS

BIKE DECKS OUT EVERY WHERE
The suspension is too soft. Increase the preload or change to stiffer
springs. adjust the ride height if possible.

BIKE SKIPS OVER BUMPS
Reduce rear comression damping and/or preload

BIKE WALLOWS AROUND CORNERS
Increase rear rebound damping

FRONT END SHAKES IN CORNERS
Increase fork rebound damping

FRONT END SHAKES OUT OF CORNERS AND OVER BUMPS
Reduce fork preload or compression damping

FORKS JUDDER UNDER BRAKING
Reduce compression damping or preload

FORKS SHOOT UP AFTER BRAKING
Increase front rebound damping

FORKS DIVE TOO FAST
Increase compression damping

FORKS BOTTOM OUT
Fit stiffer springs, decrease air gap, apply more preload

REAR SHOOTS UP WHEN BRAKING
Increase rebound damping

REAR SQUATS ON BUMPY ROADS
reduce rebound damping

[Dave]

The article posted above is great a great reminder for those that have a good idea of what they are after, or to introduce the less experienced to the art of setting up a bike.

But it didn’t mention riding technique, and how that has a good bit off influence on the bikes ability to take a corner and ride smoothly.

A well know advanced instructor made some comments on an opening evening, about the need for some people to tinker with their bikes by adjusting suspension, buying new bits, blame the bike for not corning well, when all they need is to adjust their riding technique.

My post it not aimed at the majority that have posted on this thread, as they will know more than me about suspension, but to those that are looking on and thinking about spending big lots of cash on bits they might not need.

[al]

Exactly why these days my preference is for bikes without twidly bits.

With the Falco I just wanted to get the bike back to the factory settings and not the rock hard settings that were dialed into it.

[dyz]

Aye, but I think you will agree that suspension should be set up to suit riders weight etc... unfortunately I have to be helped with the set up. Big Kneed Al (master of the emergency stop & "stand up" comedian) will know how a firm SL feels like...
Anyway, thanks for the suggestions.

[al]

Aye, but I think you will agree that suspension should be set up to suit riders weight etc... unfortunately I have to be helped with the set up. Big Kneed Al (master of the emergency stop & "stand up" comedian) will know how a firm SL feels like...
Anyway, thanks for the suggestions.

The riders weight is taken into account for selecting the correct spring rate for the forks and rear shock. As you are changing neither then as far as setting for the riders weight goes, set the static(unladen) sag as per the guide then only adjust if the bike bottoms out, either as a result of the riders weight or, in the case of forks, under braking.

Big Kneed Al (master of the emergency stop & "stand up" comedian).

[al]

I believe that these are the standard Falco settings -

Fork Setup
Installed height 3 spaces (12 mm)
Valving-
Rebound screw setting 1.5 turns out
Compression screw setting 1.5 turns out
Spring rate 1.01 kg/mm
Preload cap 5 lines (10 mm)


Shock Setup
Rebound screw setting 16 clicks from full-in
Preload 41 mm threads above lock ring

The rear shock is an emulsion type unit so you can think of the adjuster as being a combined rebound and compression screw. As you have a shock from a Millie on there it will probably have separate compression and rebound adjustment.

The above settings should be a good starting point for the forks. As I said the spring is the part of the suspension that should be set according to the riders weight and riding style. It is the part that determines how hard or how soft the suspension is. The 1.01 kg/mm standard spring is too hard for the road in my opinion and, in my opinion, are too hard for my weight for road riding. A 0.95 kg/mm spring would offer a better ride for the road. The damping control controls are not there to harden or soften the suspension but to control the spring.

As the old saying goes, you can only piss with the cock your given, so unless you change the fork spring the best thing to do is set the suspension to the sock settings and work from there.

If you need a hand then let me know.

Big Kneed Al (master of the emergency stop & "stand up" comedian).