Reinforced sidewalls = Gyro effect?

[Tinkererboi]

While going through tyre specs to find a offroad tyre for my 16x, I began to notice a trend. Tyres with known "Gyro effect" tend to be the more expensive ones like the H-666 which retails for about $26 on a chinese site. The H-5167 which everyone loves because it has no gyro effect however is a much cheaper tyre costing only $8. I have had two 2.5 inch tyres bought locally which are absolutely lovely to ride and super grippy in mud and had no gyro effect. Today I found them online and turns out they were cheap tyres as well. 

Tried looking for differences which boiled down to this: Expensive tyres like the H-666 have reinforced sidewalls which prevent pinch flats and are much stiffer in hard cornering which is desirable in the intended use case: for two-wheeled bikes. This however isn't a good thing for EUCs as we need the wheel to conform to road surfaces and follow our movements instead of pushing back against us when we try to make it lean.

Thoughts?

[Aneta]

Nailed it, bravo!

I think this analysis of different tires can also suggest to us that when comparing wheel A to wheel B of the same tire size/class, one should consider mounting the same tire from A on both A and B, and comparing wheels as apples to apples, as well as doing the opposite swap - tire from B on both A and B - oranges to oranges. Oftentimes, the different feel of different wheels is simply due to different stock tires, which are relatively cheap to replace with better ones.

[UniVehje]

Interesting find and great topic. You might be on to something that needs to be looked at more. I've found that tire choice affects riding feel more than wheel choice. 

My 18XL Chaoyang H-5102 doesn't have gyro effect and seems not to have reinforced side walls. 

[Gaz Bon]

4 hours ago, Tinkererboi said:

While going through tyre specs to find a offroad tyre for my 16x

Would love to hear what you find 

As I have also been looking .really want a knobbly like shinko 241

Have purchased 2 tyres so far 

1st was a shinko may give it a go but it's a very hard compound 12 x 2.50 

Other is cheap Chinese 12 X 2.75 but quality is very poor so will not even try it

 

[null]

Interesting observation, I thought it was linked to the curve profile where more flat / larger radius => wheel has to raise to tilt, but this also works with sidewalls that dont give in to pressure, making the same effect of wanting to stay upright. /speculation

Edited November 5, 2019 by null

[Planemo]

Rotating weight differences aside, 'gyro effect' is pretty much down to tyre deformation during cornering. The stiffer the tyre and/or sidewall, the more pronounced the effect will be.

Tubeless tyres have stiff carcasses all round, hence these types being the worst. And the Z10 for instance has such a low sidewall that it's deformation is virtually non-existent. Combined with it's tubeless carcass, it's likely the reason why it has the most 'gyro effect' of any wheel, even those with bigger diameters. Probably even more than the Monster I would wager. In short, I am not convinced that it's the width of the Z's tyre that is responsible for it wanting to stay upright. If a lightweight, skinny carcassed tubed tyre were available for it, it would be interesting to put this theory to the test.

[Hsiang]

I can confirm that the z10 has more 'gyro effect' than the monster, significantly more so, i am still a bit weirded out by the lack of resistance in a corner riding the monster. I wonder if I can get the same feel on the monster by going with a reinforced sidewall tire since I actually like the feel of the gyro effect. but it probably won't be the same since the weight distribution on the monster is very different from the z10

[Tinkererboi]

On 11/5/2019 at 11:36 PM, Planemo said:

The stiffer the tyre and/or sidewall, the more pronounced the effect will be

I think you hit the nail right on the head. Stiffness should be the correct term to use. 

I decided to test out the idea of cheapass tyres being less stiff and therefore having no gyro effect, and ordered this:

https://m.tb.cn/h.eHJNWyt?sm=2ddb7b

Its the same tyre I have in 2.5 Inch for my GT16 and grips like mad, mud or no mud. In fact i used to whine about it being too grippy as it prevents me from doing 180 degree flicks. For about 7usd, you probably can't go any lower.

The rubber doesn't seem to last long as a consequence but i'm fine with it. Hell back when I used to mountain bike I had to pay more for race tyres that have these characteristics.

[LanghamP]

The tendency to stay upright (the gyro effect?) mostly comes down to tire profile, as flatter tires stay upright. You can confirm this whenever you switch tires of the same model...the newer tire, now having a pointy profile, is less inclined to stay upright.

So why do reinforced tires have less gyro effect? It's not their weight but rather their resistance to high tire pressure, that is, the reinforced tire with extra belts running along the center of the tire keeps its flat profile even under very high air pressure.

In contrast, single or double belted Nylon tires (what you see in many mountain bike tires) bulge under pressure to make a very pointy profile.

I found the Z10 silly hard to turn. You shouldn't have to crank your body way over just to make a gentle constant turn. 

[Tinkererboi]

Agree with you on the Z10. Its looks cool but rides terribly. 

9 hours ago, LanghamP said:

So why do reinforced tires have less gyro effect?

I think you might have misunderstood. Reinforced tyres, thicker tyres, overly-filled tyres and new tyres before breaking in all have more of a gyro effect, not less.

The Z10 alone is an example of all of the above.

Edited November 8, 2019 by Tinkererboi

[LanghamP]

45 minutes ago, Tinkererboi said:

think you might have misunderstood. Reinforced tyres, thicker tyres, overly-filled tyres and new tyres before breaking in all have more of a gyro effect, not less.

The profile of the tire determines the tendency of the tire to stand straight. All that other stuff makes little difference.

Flat profile tires go straight.

Pointy profiles don't.

Stiff or soft sidewalls, low or high profile, double belted or not...those make little difference. It's the profile of the tire.

This is very very easy to confirm. Just take your old tire and roll in downhill without a wheel. It goes straight. Then take your new tire and do the same. It's less straight. The difference between those two tires is simply profile. This holds true with motorcycle and bicycle tires. The most dramatic example is the car tire, which is perfectly flat when inflated. 

The reason your h666 tires like to go straight is that the reinforced belt (not sidewall) keeps its low profile even under high pressure. The reason the Z10 goes straight is because its tire is as flat as a pancake, with higher tire pressure simply making the tire bulge its sidewall outward, as the belt is stronger than the sidewall.

If this isn't convincing, then simply take both your tires and measure their absolute outside circumference under low and under high pressure. The one without belts will show the greatest difference and therefore the pointiest profile.

Edited November 8, 2019 by LanghamP

[alcatraz]

If I may borrow the thread. 

Wider tire without reinforcement or narrower with reinforcement?

Is 3inch too wide for a 65kg rider? 

I'm trying to decide what too look for to get best of all worlds. I don't ride offroad but I do encounter occasional nasty potholes and I'd prefer not to be on 2.125" when that happens.

Looking at 16x3, 18x2.5, 16x2.5, 18x3.

[Tinkererboi]

1 hour ago, alcatraz said:

Is 3inch too wide for a 65kg rider? 

I'm even lighter than you, and both the 3 inch msx and 16x rides perfectly for me. 

If in doubt, the current 16x tyre (h-5167) is already close to perfect for almost every situation.

I'm just looking for that extra little bit of grip in extreme mud, which is a rare encounter to begin with.

No reinforcement for me as I like to carve way low and put my weight on the outer leg as I do so. I'm sure pressure on the inner leg during carving (the only way to get a 16x and z10 to budge) is just as safe with a large tyre but it's just preference really.

[Aneta]

14 hours ago, Tinkererboi said:

I think you hit the nail right on the head. Stiffness should be the correct term to use. 

I decided to test out the idea of cheapass tyres being less stiff and therefore having no gyro effect, and ordered this:

https://m.tb.cn/h.eHJNWyt?sm=2ddb7b

Its the same tyre I have in 2.5 Inch for my GT16 and grips like mad, mud or no mud. In fact i used to whine about it being too grippy as it prevents me from doing 180 degree flicks. For about 7usd, you probably can't go any lower.

The rubber doesn't seem to last long as a consequence but i'm fine with it. Hell back when I used to mountain bike I had to pay more for race tyres that have these characteristics.

I want to get this tire for my GT16, too. I can't neither read Chinese nor shop on Taobao - what are the search keywords to find it on Aliexpress or Amazon? (Thanks!)

[Tinkererboi]

No idea, i've never seen it anywhere else before. You could try to google translate the whole page on chrome and buy from taobao though. 

There are options to pay shipment from their warehouse to you in advance and that's the end of your worries, or pay a second time after they are done consolidating your order, which is a little bit cheaper. 

Just be careful not to pick the sea shipping option (always the cheapest) or you will be waiting a long, long time before it arrives. 

[Planemo]

5 hours ago, LanghamP said:

The profile of the tire determines the tendency of the tire to stand straight. All that other stuff makes little difference.

Flat profile tires go straight.

Pointy profiles don't.

Not saying you're wrong, but if this is the case why does a pumped up Z tyre (which will indeed have a pointy profile compared to say an Mten) still want to stay upright?

Further, if the Z10 tyre was fitted to a moped, there would be no issue leaning it as far as you wanted without any effort. In either case I am not sure that the Z profile could be considerd 'flat' at all. Its actually quite a pointy profile IMO, like most motorcycle tyres.

[LanghamP]

4 hours ago, Planemo said:

but if this is the case why does a pumped up Z tyre (which will indeed have a pointy profile compared to say an Mten) still want to stay upright?

You didn't read fully what I had posted earlier about the Z10. 

The reason the Z10 goes straight is because its tire is as flat as a pancake, with higher tire pressure simply making the tire bulge its sidewall outward, as the belt is stronger than the sidewall.

The Z10 is flat, extremely so; you may be mixing up front and rear motorcycle tires, as motorcycle front tires are triangular while rears are quite flat. The Z10 is like a flat rear, and increasing tire pressure just makes it flatter due to the reinforced belt.

[Planemo]

1 hour ago, LanghamP said:

You didn't read fully what I had posted earlier about the Z10. 

The reason the Z10 goes straight is because its tire is as flat as a pancake, with higher tire pressure simply making the tire bulge its sidewall outward, as the belt is stronger than the sidewall.

The Z10 is flat, extremely so; you may be mixing up front and rear motorcycle tires, as motorcycle front tires are triangular while rears are quite flat. The Z10 is like a flat rear, and increasing tire pressure just makes it flatter due to the reinforced belt.

I did read it, I just didnt understand it. And still dont.

The Z has virtually no sidewall to speak of, and it certainly isnt very flexible. I cant see it moving much at all (if any) relative to the running surface of the tyre. Unless your reference of sidewall is different to mine.

And I still dont get how increasing the pressure (on any tire) will make the contact patch less pointy. Not unless the sidewalls are made of balloon rubber. Even then, increasing pressure wont make the contact patch any less pointy, it just wouldnt increase.

Maybe I need to take a photo of my Z tyre at 5psi and 50psi. I would wager that that it probably doesnt look much different, but if anything, my money would be on it looking more pointy, not less.

[LanghamP]

1 hour ago, Planemo said:

Maybe I need to take a photo of my Z tyre at 5psi and 50psi. I would wager that that it probably doesnt look much different, but if anything, my money would be on it looking more pointy, not less.

Are you changing the Z10 tire to another tire that is a less round profile?

[erk1024]

On 11/7/2019 at 11:56 AM, LanghamP said:

I found the Z10 silly hard to turn. You shouldn't have to crank your body way over just to make a gentle constant turn. 

The only wheel with no gyro effect I've ridden was the 18XL. On the Monster, I think I tilt the top of the wheel with my leg to get it to turn. How do people deal with the gyro effect?

 

[Planemo]

33 minutes ago, LanghamP said:

Are you changing the Z10 tire to another tire that is a less round profile?

No?

I was just talking about taking photos of it at 5psi and 50psi to see if the profile goes flatter as you predict.

I think it will get more pointy personally just as every other tyre I have come across does. Even car tyres.

[LanghamP]

4 hours ago, erk1024 said:

The only wheel with no gyro effect I've ridden was the 18XL. On the Monster, I think I tilt the top of the wheel with my leg to get it to turn. How do people deal with the gyro effect?

The easy way is to simply adjust tire pressure so eventually the profile of the tire is neither flat nor pointy. This has worked with most of my wheels, subject of course to wear.

Now if that doesn't work, just get a tire that just a bit wider so the rim pinches it to a more triangular profile. Or if your wheel is too unstable, just get a tire less wide.

[LanghamP]

4 hours ago, Planemo said:

No?

I was just talking about taking photos of it at 5psi and 50psi to see if the profile goes flatter as you predict.

I think it will get more pointy personally just as every other tyre I have come across does. Even car tyres.

When you inflated your z10's tire high enough so the profile becomes pointy, then does the wheel stand up more or is it unstable?

[Tinkererboi]

Update for you @Gaz Bon 

Put about 200km on the new tyre, its just as grippy as on my GT16 as expected. 

Personally this is as knobby as i'll go, the tread really digs into mud and i see no need to lose range with a full knobby like the shinko. 

Gyro effect is completely non-existent, wheel runs perfectly true now with the new tyre, even when I let it free spin in the air until cutoff. Those who have tried this before know how the stock tyres will shake the bejeezus out of you if you did that.

Finally hit the top speed, with ease I might add. The stock tyres were simply too wobbly for me beyond 40kph and it felt like the wheel wanted to fling me off when I exited turns at speed.

Also has much less rolling resistance, which really helps the 16x feel lively as it should be. No longer have to crank the wheel hard to maintain top speed. 

All in all, I'm loving this super cheap tyre. Hope more users go this route so we can have the data needed to test my theory more thoroughly

[Planemo]

On 11/8/2019 at 9:56 PM, LanghamP said:

When you inflated your z10's tire high enough so the profile becomes pointy, then does the wheel stand up more or is it unstable?

Sorry, only just seen this. I havent looked at it at all tbh, and probably wont now given I am hardly riding due to winter. If I get a chance, I might still do the pics at 5 and 50psi though.