Tire pressure?

[Cortez]

Anyone think it's strange (and almost impossible to be correct) that the user manual for DT300 calls
for same tire pressures regardless of load (with/without passenger)?

Is there a logic behind that that I'm missing or?

[juanpauk]

The only logic that I see is that they want the reader to be sure that they have not forgotten about one of the two possible scenarios.

[Vivo]

Please don't over react   I have good info here....



Load is determined by the load rating of a tire at maximum tire pressure.

A load index of 57 means the tire can handle a maximum of 507 lbs at max tire pressure.




Example : the Pirelli SL60 120/80-10 tire has a "J" speed rating and a 57 load index.

The tire can handle 507 lbs. max. and a top speed of 62mph.

SO THE HIGHER THE LOAD INDEX, THE SAFER YOU ARE EVEN WITH LOWER TIRE PRESSURES AND NOT TO WORRY WHETHER OR NOT YOU HAVE A PASSENGER(S)




NOTE: THE CHARTS ARE FOR MOTORCYCLE/SCOOTER TIRES ONLY.

[Cortez]

I understand what you're saying, but it still doesn't make any sense why I should
use 2.25bar at the rear when I'm alone, and SAME pressure when carrying a passenger,
and my best friend is a 240lbs bloke (and I'm no light weight at 210lbs). That rear tire
looks like it's flat when he jumps on the back of the scoot, so that can't be normal.

[racewalker]

You are over the rated max load by more than 100lbs. I would set tire pressure to max for the tire to carry it.

[Vivo]

I understand what you're saying, but it still doesn't make any sense why I should
use 2.25bar at the rear when I'm alone, and SAME pressure when carrying a passenger,
and my best friend is a 240lbs bloke (and I'm no light weight at 210lbs). That rear tire
looks like it's flat when he jumps on the back of the scoot, so that can't be normal.

I think if you inflate your tire to the max and your load index is 54 or more, you're on the safe side even if you see that the tire looks a bit flat. 

Our company has a fleet of delivery vans and we don't use the same tire pressure all the time. We vary the tire pressure depending on the weight of the load. Maximum tire pressure if the load is heavy and lower if the load is light.  This is an industry practice and not seen in any manual. Tire information are the maximum. You can be flexible with it as long as you don't go over it.

This is not a problem with us "light" people. But if I'm 200 and my wife is 200, then, I might be seriously considering monitoring my tire specs and condition in every ride. 

[Cortez]

My Fiat van has specs for different loads (up to 2000lbs+) and the differences in tire pressures are rather big.

[Vivo]

My Fiat van has specs for different loads (up to 2000lbs+) and the differences in tire pressures are rather big.

Hmmm...going back to your original question referring to the DT300 manual. Maybe its a general statement by Kymco in their manuals because they will never know what brand, speed rating, or load rating your next tire would be or the tire that will become OEM of Kymco when they created the manual. Different countries even use different brands of tires for a single scooter model.  Maybe the best thing is to get information from the tire and not from the manual. My manual is even incomplete, I have to search the net (forums) to find out how to set the clock of the Super 8. Turned out its very difficult to do.


I think tire manufacturers are aware of all the beatings a tire gets... rocks, gravel, heat, oil/gasoline, UV rays, water, mud, cornering flexes, hard brakings, acceleration, load, speed, etc.  A good brand of tire with the right specs and preferred tire pressure, I think, would be safe.

[wheels]

On previous bikes I usually ride solo and add 10% to the minimum pressure.

On the DT300 I keep the front at 28lbs and the rear at 32lbs.
The weight distribution on this scooter really keeps the front end
too light for my liking therefore the 28lbs.  When the front tire
gets worn I will definitely switch to a different tire, it feels kind
of twitchy to me.

[Cortez]

I like them on good pavement, but yeah, I've tried better.
The rear is a non-issue on most scoots.

I've been using 28/33.. but went to 29 on the front for today since
I knew I was gonna do a lot of good pavement miles (just did a 500 mile day).

[ailixhomes]

Tyre is very important part of any type of vehicle so we should take proper care of it. Proper wheel blowing up is important in order for your vehicle to work securely and successfully. Automobiles with properly-inflated wheels are at a lower risk for injuries and accident.

[boo]

A little additional information if I may.
A few years back I belonged to a motorcycle forum.
Some of the members were doing tire test to see for themselves how tires react at different pressures and temperatures.

Their findings were:

Tires filled to the high side ran cooler. " checked with thermometer ".
 
When tires are warmed up from cold to hot, tire pressure can raise as much as 2 psi.

[Vivo]

I use nitrogen.  Nitrogen is inert, stable, and ...well... expensive....