How to:- Transform the handling of your bandit and save £350 quid

[jonnywombat]

This is based on a 99 bandit 600, but the theory is good for any bike whose suspension lacks adjustment, or is getting a bit tired, although amounts need to be tailored to individual models.


Ever since I got my second hand bandit the handling ain't been up to much. The suspension is soft when new, and the passage of time does it no favours.

Whilst everything functions correctly, no leaks from the forks or rear shock, the springs sag, and everything just gets softer. Mine was like riding a trampoline!!!

So to remedy this "properly" would be £250 ish for a new rear shock, and another 90 odd for progressive fork springs.... Which is 350 quid i don't have...


So what to do... well as all the damping bits still damp it is just a case of giving the old components a helping hand.

FRONT END

This is the easier bit... What we need to do is increase the preload on the front forks... But the bandit (600) has no preload adjustment. So it was off with the handlebars and remove the fork tops. A bit of educated guess work lead us to believe we needed to compress the springs by 15mm, so 15mm worth of 35mm washers were placed on top of the fork springs and the caps replaced (you need two people to do this).
If you wish to adjust the compression of the forks this can be done by increasing the amount of oil in the forks. In a bandit there is 521cc of oil per fork... by adding more oil so the top of the oil is 4mm closer to the top of the fork leg will give a suitable increase in the compression... and using 15w oil instead of 10w will adjust the rebound to match.

The cost of this 10 quid for oil, and the washers were free.

THE BACK END

By shortening the link arms in the rear suspension linkage (dog bones) you increase the rear ride height of the bike. you also change the gearing of the suspension, which means the rear shock has to work less hard than before, which makes it stiffer.
I ordered a 40mm lift kit, but the one that arrived was for even more lift (i guess around 60mm).

Fitting is simple enough, you have to support the bike with the rear wheel in the air and not supported on the swing arm. The dog bones have one bolt at the top and another at the bottom, but the gear lever and guard have to be removed to access the top bolt.
Fitting is simply the reverse of removal.

This has transformed the rear end.. to give you an idea before the change on max preload the rear end (measured at the rear foot pegs) would sag 50mm when I sat on the bike. Now I get a little less than 50mm sag in minimum preload!!
Also because the front forks are a little more perpendicular to the road this speeds up the steering a little too.

Cost £12.50 for new dog bones.

Overall these changes have transformed the bike, and it can really be thrown around and it just feels so much more stable...

[jonnywombat]

Now for the photos..changing dog bones..

1) Support the rear end NOT on the swinging arm.


2) Remove the gear lever


3) Remove the bolts from the dog bones


Note These bolts are very tight (75Nm) so you may need to improvise a long bar.


Refitting is the reverse process..

and the end result...

[grotbag]

Nice one jonny, another one I can understand and follow!

[jonnywombat]

Originally Posted by grotbag

Nice one jonny, another one I can understand and follow!

Why thank you... never seem to take enough photos though... once I get stuck in I forget to take more...hence no photos of the lower bolt, or any of the front end....

Weird thing is you kinda don't realise you've stopped taking the photos until you come to download them... I'll get the hang of it in the end

[druidsam]

who was the assistant in pic 4?



..............................Sam

[jonnywombat]

That would be George the Rotty X.... he is a keen mechanic. Unlike our Jack Russell who knows sweet FA about bikes.



He was especially interested when someone said the words "dog bones",
he thought he was in for a meaty treat (of a non bestial nature)

[robertall]

I purchased a riser for my scooter, it won't fit on the cg, because it is a twin shock, and the rally is a monoshock.

And actually on the aprilia rally it doesn't improve handling it makes it very weird.

Rob

[jonnywombat]

Originally Posted by robertall

And actually on the aprilia rally it doesn't improve handling it makes it very weird.

Rob

That would because the moped lacks rising rate rear suspension, so you will not gain the handling benefits in the same way.

[robertall]

Originally Posted by jonnywombat

That would because the moped lacks rising rate rear suspension, so you will not gain the handling benefits in the same way.

If you leaned even a bit then the front end would try and dive into the corner and will try and push you even further, in the rain this would be suicide because i had dry hard tyres for long life.

Rob

[jonnywombat]

Hi Rob...

see what would of happened is...

1) on the back end you have altered the load on the rear shock, and depending on how exactly the lift kit mounts will alter how you have to compensate for it..

2) by raising the back, you increase the load on the front forks and wheel, so you need to compensate by increasing pre load and compression settings on front forks.

3) by raising the back you tilt the whole machine forward so the front forks would be nearer the vertical.. this increases the speed of the steering. In a big bike like the bandit this is good, but on a 'ped with a short wheel base then this could be quite extreme.

The combination of the three will of led to the handling you describe... Like i said in the original post this had some educated "guess work" thrown at it, and you have to adjust both ends not just one end.