new tires with balance beeds seem unstable at speed.

[riadat]

So i bought new tires for my kymco 125 as it had 6k miles and the original tires were never good to begin with.  i got shinko sr723 tires off amazon 130/70-12 and 120/70-12.
I found a guy who said if i brought him the wheels off my scooter and the tires he would swap them out.  We talked about balancing them and he suggested beads the type you put in.  I didn't know about it but he said it was the best way to balance.  I got the tires back a couple days later and put them on.  He told me he had 3 ounces of beads and put 1.5 ounces in each tire.

With the new tires on i took them for a spin and they had too much air so i took the air in the front tire down from 32 to 28 there was 32 in the back.  There is a section of road with lines in it from the construction process near my house and when i hit those wavy lines (i drove on with the old tires) i could hardly control the scooter at all and i tried it a couple times since then and its very bad with the wavy lines where the stock tires had very little problem.  I have driven the scooter numerous times since then over a couple weeks.  It seems like where with the stock tires i could control the scooter at full speed maybe 50+mph now at high speed it feels unstable and like im floating around on the road.  At lower speeds under 45 and away from the wavy road it seems ok.

So do you think the tires need to break in, or is there an issue with the beads or maybe is it the tires themselves?  Any thoughts or suggestions?  I prefer not to go back to the guy because he beat my rims up when he changed the tires a bit and i like to avoid conflict.  If it is the beads is there a way to take them out without taking off the tires/wheels?

Thanks.

[Stig / Major Tom]

I'd run the scooter at the PSI stated on the scooter's sticker.
Since you did not have a chance to ride the scooter with the new tires installed.....I wouldn't be positive the problem is the balance beads.
Since he wasn't too swift with the tire swap.....maybe he hasn't followed the bead manufacturers instructions for beads in your size of tire?
Then again....maybe your new tires are so poorly made....his beads haven't overcome their imbalance.
Others will give better informed ideas....
Stig

[riadat]

i found the manual which came with my scooter and it shows 17.5 pounds for the front tire psi and 29 for the rear.  taking air out of the tires made more tire contact the road and it seems more stable at speed.  the screwed up road near my house is still really messed up, may just be the road.

[Stig / Major Tom]

i found the manual which came with my scooter and it shows 17.5 pounds for the front tire psi and 29 for the rear.  taking air out of the tires made more tire contact the road and it seems more stable at speed.  the screwed up road near my house is still really messed up, may just be the road.

Thanks for your follow up!
Yeah, turning the front tire of a small or medium scooter into a rock....has ride consequences!...and these scooters really hate crap roads under any circumstances.
Sorry it's close to your home. I religiously avoid rough roads on my outing....one trip on them creates a lasting memory,  "never again!"
Big guy scooters benefit from raised PSI....some say.
Especially when GPing to the grocery store.
😃
Stig

[Iahawk]

I think you're really feeling the difference between different tires / tread / tire construction. Tires can behave very differently on different surfaces. I installed some Heidenau K61's on my Helix and my first ride on our grooved concrete pavement (very common around here) was frightening / butt clenching...the tires followed the grooves in the road as if they had a mind of their own. It was very disconcerting to feel the bars pulling slightly left and right while you're going down the road.

I soon got used to it and just went with it...super light grip on the bars, left the bike do its thing.

But, again, different tires give different feels. Out of balance tires will give you vibration and shaking at speed.

[riadat]

I think you're really feeling the difference between different tires / tread / tire construction. Tires can behave very differently on different surfaces. I installed some Heidenau K61's on my Helix and my first ride on our grooved concrete pavement (very common around here) was frightening / butt clenching...the tires followed the grooves in the road as if they had a mind of their own. It was very disconcerting to feel the bars pulling slightly left and right while you're going down the road.

I soon got used to it and just went with it...super light grip on the bars, left the bike do its thing.

But, again, different tires give different feels. Out of balance tires will give you vibration and shaking at speed.

guy near me has a helix he is trying to sell.  i considered it but i thought parts would be hard to find and they are just old so the electronics concerns me.

[CROSSBOLT]

Balance beads, Dyna Beads, BB's or sand will all balance a tire if enough put in. Within reason, you cannot put too much in but you can put in too little. All you need is just a little bit more than the weight of the imbalance.

How much is the imbalance, you ask? Well, with a new bike, it is equal to the stick-on weights the manufacturer put on there. 1.5 oz for Agility wheels should be enough.

The highway groves parallel with the travel? Any bike is gonna squirm regardless of balance. Like Stig said, if the front tire is rock-hard, it will squirm more. Especially on something as light as the Agility.

[Iahawk]

guy near me has a helix he is trying to sell.  i considered it but i thought parts would be hard to find and they are just old so the electronics concerns me.

before you write off the Helix give it a test ride, if you can. Comfy seat, a wheelbase of a Goldwing, nimble handling and all day cruising comfort. It tops out around 70 but can cruise all day at 65 without breaking a sweat. Like any older bike, parts are getting a little tougher..but all the maintenance items are available and Honda still makes lots of parts. Shouldn't say this on the Kymco forum...but many consider the Helix the GOAT of scooters