Cruze Scooters Sport 50 made by Kymco Taiwan

[DaveG]

 It runs fine, stops well but the tag states 40psi front and rear tire pressure. It's super skittish and can't handle pebbles even, when set there.  I rode it myself with the 40psi and it was indeed horrible in terms of stability. Through natural air depletion both tires got down to 20 PSI. I took it for a ride and it's a whole different bike, stable, able to transition even from grass to paved contours with some gravel and just plain rides great. Knowing 20psi is probably too low I raised the rear to 30 and the front to 25. It still handles decent, not skittish but I notice the front kind of dances as if a bit hard over anomalies,not side to side but over things as if a bit hard. The rear is fine, could even maybe do 32psi.. I'm wondering if 20 psi is really too low for the front ? By the way it only has 10" wheels. 3.50x10 tires I believe.

[mousejunks]

30 psi sounds about right. 40 is too high. What brand are the tyres, this has a huge effect on what pressures to run and handling.

[DaveG]

30 psi sounds about right. 40 is too high. What brand are the tyres, this has a huge effect on what pressures to run and handling.

Not much on the tire for a name actually, GP.R and 56 J . Other than that the typical 40lb max pressure, 480lb weight. There is a Tai, I assume meaning Taiwan but a stamp Made in China. Good looking tire ( I'm talking about the front here ) 3.50x10 and for the rim 2.50x10.
Looks like street tires, wide groove cyps rounded shoulder, not knobby. Tubeless.

I've been looking in various forums, Vespa seems to go 32 rear 28 front. Honda Metro 50 lowers the front to 18 psi. I'm not concerned about the rear, I'm quite sure 30-32 will be fine there.  This isn't my scooter though I do ride it. We bought it for my wife ( transition from bicycle) and she rode it, dumped it on pebbles in the driveway with 40psi in the tires. I saw right away why when I got on it, at 40psi in the driveway it's like riding on marbles. But not so at 20 psi or even 25 where it becomes very stable.  It tracks better too. I think I'll try 20-26lb tests with the front. We both weigh about the same but I'm taller . She won't ride till maybe April so there is time to mess with it.
Thanks for replying !

[Stig / Major Tom]

Very rarely is that sidewall PSI figure the correct pressure to use.
I've only heard of one owner's manual that disagrees with me.

Stig

[DaveG]

Very rarely is that sidewall PSI figure the correct pressure to use.
I've only heard of one owner's manual that disagrees with me.

Stig

The manual with this one is basically a parts catalogue, the specs on tires just gives size. I went online to download a PDF of the manual and it came up with the same thing. In this so called manual, it showed tire wear patterns. for tires run too soft and too hard but no PSI spec. suggestions That brings us back to the plate on the bike which states 40 psi. Only a person inviting personal injury would ride this thing with the tires at 40 psi. It's really quite nasty when set there.

Then there is an assembly manual, basically just says where to put the parts.

[Iahawk]

you're on the right track..tires should not be run at the max sidewall pressure in almost all circumstances...

My S200 was 25 front, 29 rear, bumping the rear up a few lbs if riding with a passenger. My motorcycles are 28/32 and 32/32, my Helix is something like 24/28?

Lower the tire pressures to where the bike is comfortable to ride and handles well enough. Too low of pressure may cost you some tire life..but if you're happy with the ride, who cares?

[DaveG]

you're on the right track..tires should not be run at the max sidewall pressure in almost all circumstances...

My S200 was 25 front, 29 rear, bumping the rear up a few lbs if riding with a passenger. My motorcycles are 28/32 and 32/32, my Helix is something like 24/28?

Lower the tire pressures to where the bike is comfortable to ride and handles well enough. Too low of pressure may cost you some tire life..but if you're happy with the ride, who cares?

That's good info. I suspect the 24 front and 28-30 rear is where I'm headed.
Thanks all.

[JJJoseph]

The process here is usually what everyone goes through trying to find the ideal tire pressure.  The front can be much lower without causing a lot of trouble because it naturally wears much more slowly than the rear.  The only downside is that a hard bump at 20psi could damage the alloy rim.  So I tend to s-l-o-w to almost a stop when crossing sidewalk bumps. That seems to work.

[DaveG]

The process here is usually what everyone goes through trying to find the ideal tire pressure.  The front can be much lower without causing a lot of trouble because it naturally wears much more slowly than the rear.  The only downside is that a hard bump at 20psi could damage the alloy rim.  So I tend to s-l-o-w to almost a stop when crossing sidewalk bumps. That seems to work.

Thanks ! The difference in handling between front pressure being 20 or 40 is startling. And it seems every setting in between has it's own feel But. Very tame at 20 even over stone driveways, very smooth riding. And unmanageable over the same at 40 psi. 25 is still very good with unstable or uneven surfaces it seems. Doesn't ride as smooth at 25 vs 20. I'm sensing 23-24 will be very good all around  . At least it's a ball park setting with me riding it, can fine tune for my wife in the spring. As I mentioned, it's really her scooter. But if she is off in the car 80 miles away visiting relatives or singing for church, I'd take the scooter for a run to the hardware store or whatever . It's all paved roads where we go around here, if we take the back road the mile or so it runs out of the way, that's old pavement with dips and patches etc. but keeps us out of tourist traffic in the summer and still gets us down to the shopping centers, post office, drug stores etc..