G'day
I have posted this elsewhere but here in the Bodger Fix could be a better place for info.
The bike is a underbone like the millions of others that infest SEA. With a pillion and touring load the suspension is just not up to the job.Honda Vietnam have no idea on upgrades.
Heaver sprung (Chinese)shocks of many types(quality unknown) are available in our home base of Vung Tau but the fork upgrades could be a big problem with alternative springs/oil weights probably unattainable.
Any Bodger Fix ideas on the forks would be much appreciated.
Cheers, Macca

you can always get a piece of metal tube or nylon tube cut in lets say 5 cm and put it on top of the springs in your fork. if the fork gets to hard, pull out the tube and cut it shorter

have a look at this link. Honda Cd70k1 (general Export Kmh) Front Fork - schematic partsfiche

its a fork parts diagram


i would put the spacer between par nr 5 and 14.

5 cma might be a bit much in such a shor fork. try with 2-3 cm

Changing the 'spring preload' (what putting spacers on top of the springs (or on the bottom) is) sets the 'ride height'. That should be set at about 30% of your suspension travel .. if the total travel is 100 mm then with you, passenger/s and luggage should use 30 mm (30%) of the travel. The 30% value .. changes depending on you, road racers might go to 10%, comfort riders might go to 40%. Your choice.

Changing the 'spring strength' is so that you use the full suspension travel when you hit a very hard bump .. but not more than the full suspension travel. If the spring is too hard .. your not getting the benefit of your full suspension travel. If the spring is too soft you will bottom out the suspension with possible loss of control and damage, most people just slow down. Changing 'spring strength' is a matter of replacing the springs. You can have springs made to your requirements.

The oil? That is selected for the damping .. not ride height nor bump travel. Well not to the first order, it has an effect but it should not be the primary aim of oil selection. the oil is selected so that the wheel stays in contact with the ground.

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So?
Is the ride height too low? Add spring preload.
Once the ride height is correct .. does the suspension bottom out? Get stronger springs.

i used this site to cut my springs,
Motorcycle Suspension
after cutting I used vise grips to position the cut end for grinding(squaring up the spring),these will go limp after heating with a butane plumbers torch this will let you know that they are in position for you to finish grind them, to match the factory end.
I set a table with blocks clamped at the calculated length and cut each spring,heated them ,ground them to equal length according to the tooling blocks ,the rest is explained in the article ,it is very accurate,you can later shim with washer or go online n may find someone with some endcaps for your fork.

Thanks Warin & peter
When we return to Vietnam on 29th August and get the little Honda out of storage we will have a few days to get sorted before we head north
The rear shocks are a definitely maybe probably possibly option If we can get them it would be almost possible to live with the soft forks.Almost
I'm not too hopeful on new fork springs but will take your advice and try to find slightly harder/stronger 20mm longer than standard. Failing that,20mm spacers and hope for the best.
Its a difficult place to sort out anything but standard bits.
The poor little underbone has taken us 12,000km exploring the South and we expect to do about the same in the North, suspension fixed or not

Take it slow and you'll all survive.

Slow is right mate.Even at -30kph some of the un-missable holes and tar ridges will bottom out the shocks. If I can see them we miss them,its the ones that appear from under trucks or we are forced into by mini busses or trucks that cause the big problems.At the normal 50kph its BAD
I wish I had thought to bring a shock/fork spring back to OZ and buy suitable replacements here