Can using too heavy of a tire be dangerous?

[Denny Paul]

Hi guys, could use some opinions.

So I'll be adding a Michelin city pro to my Monster pro. I bought two different sizes and will probably get this done sometime next week. Ones in a 2.75-18 and the other is in a 90/90-18.

They're both the same outer diameter on appearances, but the 90/90 looks way beefier because it's much wider. The 90/90 weighs just about 7.7 pounds (3500 grams) while the 2.75-18 weighs much less at 6 pounds (2700 grams).

I imagine the stock tire is probably a good pound or two under even the lighter Michelin tire. Should I be concerned at all about this additional rotating mass? Can I trust that the top speed beeps will still leave adequate safety margin?

Overthinking or legitimate concern?

[mrelwood]

Considering that the wheel is successful in hauling the wheel’s weight on top of your weight to very fast speeds, a tire that weighs a few lbs more is barely even noise in the statistic.

 If the wheel is burdened more, the voltage will dip more and hence the beeps will come earlier.

[Denny Paul]

28 minutes ago, mrelwood said:

Considering that the wheel is successful in hauling the wheel’s weight on top of your weight to very fast speeds, a tire that weighs a few lbs more is barely even noise in the statistic.

 If the wheel is burdened more, the voltage will dip more and hence the beeps will come earlier.

gotcha, yeah I totally get that if it's an extra couple pounds of non-rotating mass this would basically have no real effect.

I'm not a physics buff by any means. I've heard others talk about reducing rotational mass in the racing/motorcycle world as the ultimate way to increase performance. Reducing weight there has a magnified effect than the rest of the bike. So adding weight with a heavier tire has got to be extra bad right?

Let's do a thought experiment. Let's say I fill my tire with solid lead, and I get on and lean forward. I'd think that an over-lean would be very easy to achieve. Maybe the wheel would be so heavy now that the motor doesn't have enough torque to self balance a person even at zero speed. I'm told Gotway/Begode alarms are speed dependent, they wouldn't make a sound here. So following that logic, perhaps adding some reasonable amount of pounds to the rotating mass would cause an over-lean at higher speeds before the beeps kick in?

Edited February 5, 2022 by Denny Paul

[Eucner]

1 hour ago, Denny Paul said:

I'm not a physics buff by any means. I've heard others talk about reducing rotational mass in the racing/motorcycle world as the ultimate way to increase performance. Reducing weight there has a magnified effect than the rest of the bike. So adding weight with a heavier tire has got to be extra bad right?

Correct. When accelerating you got to get the wheels mass in linear and rotational movement. It is double duty. Monster Pro has enough power to keep you up in regular riding situations. The additional rotational mass will have any meaningful count only if you are seriously racing, want to have the absolutely snappiest wheel (Mpro was wrong choice), overweighted for the wheel or chase wheels speed limit in unhealthy manner.

[Darrell Wesh]

20 hours ago, Denny Paul said:

Hi guys, could use some opinions.

So I'll be adding a Michelin city pro to my Monster pro. I bought two different sizes and will probably get this done sometime next week. Ones in a 2.75-18 and the other is in a 90/90-18.

They're both the same outer diameter on appearances, but the 90/90 looks way beefier because it's much wider. The 90/90 weighs just about 7.7 pounds (3500 grams) while the 2.75-18 weighs much less at 6 pounds (2700 grams).

I imagine the stock tire is probably a good pound or two under even the lighter Michelin tire. Should I be concerned at all about this additional rotating mass? Can I trust that the top speed beeps will still leave adequate safety margin?

Overthinking or legitimate concern?

It’s very simple to test this out. I just bought a Michelin Pilot Street that weighs around 8pounds for my monster pro. I just put it on yesterday. 
 

Using a lift test with the stock tire at 100volts I got 64.7mph top speed on darknessbot. When I swapped to the Michelin pilot tire at 100volts I got 63.5mph top speed. So you’ll lose around 1mph.

[.....]

9 minutes ago, Darrell Wesh said:

It’s very simple to test this out. I just bought a Michelin Pilot Street that weighs around 8pounds for my monster pro. I just put it on yesterday. 
 

Using a lift test with the stock tire at 100volts I got 64.7mph top speed on darknessbot. When I swapped to the Michelin pilot tire at 100volts I got 63.5mph top speed. So you’ll lose around 1mph.

Unless the newer tire has a slightly larger outter diameter. I can only guess the sensor is displaying speeds, dependant on an equation that includes the tire. I think a heavier tire is more likely just going to result in what one would expect. A little more rolling mass. Probably a slightly more solid feeling ride with a little loss in accel and decel. However, traction is probably more a factor, once you start comparing max output of motor characteristics. If it takes more effort off the line with a heavier tire, that factor con be mitigated by the rider, until traction or peak output requirements are overloaded.

[Darrell Wesh]

6 hours ago, ShanesPlanet said:

Unless the newer tire has a slightly larger outter diameter. I can only guess the sensor is displaying speeds, dependant on an equation that includes the tire. I think a heavier tire is more likely just going to result in what one would expect. A little more rolling mass. Probably a slightly more solid feeling ride with a little loss in accel and decel. However, traction is probably more a factor, once you start comparing max output of motor characteristics. If it takes more effort off the line with a heavier tire, that factor con be mitigated by the rider, until traction or peak output requirements are overloaded.

Quite the opposite from my observations. The Michelin gives me similar range so far, and the acceleration is seemingly better. But what is noticeably better is the deceleration. I guess all that grip is really helping with the stopping power. 
 

It’s much stiffer then the stock tire, so I assume that’s why acceleration and braking are better. BUT! Somehow with all that stiffness even with similar tire pressure (35 vs 37) it cushions the bumps much better. It’s a much more comfy ride over rough terrain then the soft stock tire somehow. (This is Michelin pilot street, not the city pro)

Edited February 6, 2022 by Darrell Wesh

[Darrell Wesh]

On 2/5/2022 at 12:11 AM, Denny Paul said:

Hi guys, could use some opinions.

So I'll be adding a Michelin city pro to my Monster pro. I bought two different sizes and will probably get this done sometime next week. Ones in a 2.75-18 and the other is in a 90/90-18.

They're both the same outer diameter on appearances, but the 90/90 looks way beefier because it's much wider. The 90/90 weighs just about 7.7 pounds (3500 grams) while the 2.75-18 weighs much less at 6 pounds (2700 grams).

I imagine the stock tire is probably a good pound or two under even the lighter Michelin tire. Should I be concerned at all about this additional rotating mass? Can I trust that the top speed beeps will still leave adequate safety margin?

Overthinking or legitimate concern?

Also, the 90/90 is so thick the stock mud guard will not work with it. 

[digithom]

On 2/6/2022 at 6:39 PM, Darrell Wesh said:

Also, the 90/90 is so thick the stock mud guard will not work with it. 

it is not also too wide ?
90 is 3,5" wide, does a so wide tire fit in Monster Pro ?