Should 250 Two-Strokes Be Allowed in the 250cc Class? | @Ping 7

B_Rez991
8/6/2021 2:00pm

 

Welcome back to the latest format of @Ping!

In this episode, Ping speaks on the topics of Ping broadcasting in the sport, Dunlop MX53/33 preferred setup, and whether or not 250 two-strokes should be able to race in the 250cc class.

Do you have burning questions that need answering?

We are now accepting video and voice recordings directly to ping@vitalmx.com. As always, you can submit your written questions to the @ Ping VitalMX Forum or send them directly to ping@vitalmx.com.

Related:
Dunlop
David Pingree
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2-stroke
250 two-stroke
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7 comments

View replies to: Should 250 Two-Strokes Be Allowed in the 250cc Class? | @Ping

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tzmike
2 years ago
Always was cheering on Stankdawg with the KTM 125 SX.
RESOUNDING YESSSSS ON THE 250s !!!!!
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boaz
2 years ago
Absolutely on 250 2 strikes allowed in the 250 class. It’s important for the sport. Competitive 4 strokes are simply too expensive for the sport to grow
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cdoggy81
2 years ago
Hey Ping,
Good episode & agree 100% on the 2 stroke issue! Smile

However I would like to correct something you said at the 4:30 mark regarding nitrogen doesn’t bump up (increase pressure) as temperatures go up. That is not true as all gasses increase pressure as temperatures increase. The inverse is true when temps decrease as well. It’s just a good old fact of science. I’m not a physicist or anything so I’m trying to remember back to my school days of which law states this. It’s either Charle’s Law or Lussac’s. Don’t feel bad though as it’s a very common misconception. We use nitrogen in tires for a few reasons:
“Air” to simplify, is basically is 78% nitrogen and just like 20% oxygen & the rest is water vapor, CO2, and super small amounts of other gases. Water (which typically enters in the form of humidity) is a very bad thing to have inside a tire. Whether it’s present as a vapor or even as a liquid in a tire, water causes larger changes in pressure with varying temperatures than dry air does. This is the real kicker & why nitrogen tires don’t “bump up” as much as air filled tires. 😎 When you use nitrogen out of a tank it is usually 99.9% pure so it is super dry & has basically no other contaminants in it. So as you can see water is less of a concern with nitrogen filled tires. Any system that delivers pure nitrogen is also going to deliver this dry nitrogen. Filling tires with nitrogen gets as much oxygen, water, and other gases out of the tire as possible so less likely to bump up as much as pure nitrogen would.

The other benefit is that tires lose some pressure over time from the gasses within them permeating through the tire rubber. Nitrogen does this about 40% slower than regular air & this results in more stable tire pressures over a longer period of time. Oxygen also reacts with the tire rubber as it permeates through it, which leads to an oxidative process that degrades the rubber over time.

Hope that helps clear this myth up for everyone. I think we can be cordial when explaining things to others and I hope you view this as such. Thanks & look FW to the next episode 👍🏻
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450exc115
2 years ago
Ideal gas law is Pressure x Volume =N (Amount of substance) x R (ideal gas constant) x Temperature. So if temperature goes up so does the pressure if the volume is constant. That said it really isn't much and having N2 will greatly decrease the change. You are correct that water vapor is the one that really drives the larger changes in pressure. Locations with dryer climates have less of an issue that humid ones.

Long live the 2-stroke!!
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5050
2 years ago
This is a no brainer. Yes, 250cc 2-strokes should be allowed in the 250 class or just call it a 4-stroke class.

2-strokes are lighter, cheaper to buy and cheaper to maintain.
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