Can you please advise concerning a problem with a small motorbike that has been converted for use by a disabled person with minor balance problems?

The original 125cc motorbike is standard construction with a large spring suspension shock absorber on the rear wheel. The conversion was to add 2 large undriven 'outrider' wheels, similar to a young child's bicycle, so that it's not possible to falloff - this is a 3-wheel 'trike'. (These kinds of 'illegal' conversions are popular here on Koh Phangan for riders lacking confidence.

The problem is that the previous user was rather heavy and so their weight pushed the driven rear wheel down onto the road. But now in my case, I'm lighter, and when I sit on this bike, the driven rear wheel hardly touches the surface of the road, because the suspension springs of the outrider wheels lift it off the ground. Therefore, the traction is minimal or even zero! I think the solution is to shorten the length of the outrider suspension springs?

But it looks like the adjustment setting of these shocks is already at its shortest setting. Any step slot adjustment would lengthen the shocks and lift the driven wheel even more off the ground. The idea of these outrider wheels is that they usually sit perhaps 1 cm off the ground and then assist when going round a corner , (but obviously not leaning into that corner).

How do I solve this problem? ChatGPT suggests softer shocks on the outrider but how do I know if I'm buying 'softer' shocks? Or slightly shorter shocks so the driven wheel sits firm;y on the ground all the time.

Any suggestions? - Here are photos of the existing arrangement.

It looks to me that the 'conversion' itself is flawed with three wheels instead of two.

Most 'trike conversions' I've seen on the roads here have just two wheels.

It seems whomever has undertaken the conversion has done so on the 'cheap' without any real engineering knowledge and cut corners.

https://www.facebook.com/profile.php?id=100063727322938&sk=photos

You can buy a rear shock extender for less than 200 Baht.

That would force the rear wheel down.

I think if you set the outriggers to the softest longest setting it will lower the whole assembly.

Lose the giant tractor tires on the outriggers and buy a new tire for the scooter; one with some tread and therefore diameter on it.

Edit: The outriggers attach where the rear seat grab bar is or was. Bunging some washers under there will raise the outriggers. This is my least favourite option.

Contrary to unpopular belief these outrigger additions are quite popular in , say, Pattaya. They can easily be removed when it comes time to retax the scooter.

Edited 1 hour ago1 hr by VocalNeal

Would deflating the outrigger tyres slightly, and fitting a larger profile tyre on the back wheel, help.

51 minutes ago, richard_smith237 said:

It looks to me that the 'conversion' itself is flawed with three wheels instead of two.

For some reason - the facebook link embedded as an unplayable video.

www.facebook.com/profile.php?id=100063727322938&sk=photos

This shop uses two wheels because of the additional hassles of having three wheels - regardless of what VocalNeal mentioned - there's a right way to do things and a flawed way - three rear-wheels is always (even if two are outriggers) is always going to cause you issues - thats why all the shops which do this conversion correctly / properly only do so with two rear wheels across an axel.

Thus: IMO - (which some will undoubtedly disagree with) - is to re-engineer and have two main rear 'drive' wheels and remove the whole issue of trying to balance as perfectly has possible while still have issues riding across uneven surfaces.

51 minutes ago, richard_smith237 said:

It looks to me that the 'conversion' itself is flawed with three wheels instead of two.

For some reason - the facebook link embedded as an unplayable video.

www.facebook.com/profile.php?id=100063727322938&sk=photos

This shop uses two wheels because of the additional hassles of having three wheels - regardless of what VocalNeal mentioned - there's a right way to do things and a flawed way - three rear-wheels is always (even if two are outriggers) is always going to cause you issues - thats why all the shops which do this conversion correctly / properly only do so with two rear wheels across an axel.

Thus: IMO - (which some will undoubtedly disagree with) - is to re-engineer and have two main rear 'drive' wheels and remove the whole issue of trying to balance as perfectly has possible while still have issues riding across uneven surfaces.

This (of course) is an illegal conversion. It works fine with a heavier rider, who compresses the driven wheel down onto the road, but I'm too light! I've examined the outrider shocks and these are too 'stiff' for my use. I need shocks that allow the outrider wheels to float about cm above flat ground. The solution, rather than trying to buy softer shocks, is to buy slightly shorter shocks snd designed for a lightweight bike. The original outrider shocks look designed for a tank! (or enormous fat farang...), and these shocks are 330mm in length. I've ordered a pair of 320mm shocks from Lazada which are made in Thailand and advertised for three wheel conversions. I'll give more feedback when they arrive next week :)

I would go for the shock extenders as suggested by @VocalNeal

Or you could find/hire a chubby companion to ride pillion.

9 minutes ago, simon43 said:

This (of course) is an illegal conversion. It works fine with a heavier rider, who compresses the driven wheel down onto the road, but I'm too light! I've examined the outrider shocks and these are too 'stiff' for my use. I need shocks that allow the outrider wheels to float about cm above flat ground. The solution, rather than trying to buy softer shocks, is to buy slightly shorter shocks snd designed for a lightweight bike. The original outrider shocks look designed for a tank! (or enormous fat farang...), and these shocks are 330mm in length. I've ordered a pair of 320mm shocks from Lazada which are made in Thailand and advertised for three wheel conversions. I'll give more feedback when they arrive next week :)

Are they adjustable ??? My previous Motorcycle had adjustable shocks so I could set for my weight and riding style.