Xmax

[Kwasaki]

Curious :-

Saw an Xmax today with rim & tyres like on a bicycle size,  also many other scoots the same, have never

understood the mentality of why this is done.

I don't post this to be a Thai knocking thread just the why but I guess some funny comments  on the way. . 

[steevjee]

Cheaper tyres ? perhaps quicker steering response too? nothing else would make sense as the brakes would be way less effective,

[thequietman]

I see it on the Honda PCX a lot. Makes the whole bike look terrible.

[Kwasaki]

  On 3/1/2020 at 2:01 PM, steevjee said:

Cheaper tyres ? perhaps quicker steering response too? nothing else would make sense as the brakes would be way less effective,

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Quick steering is from a larger grip area on the road not a small one.

What they do is an accident waiting to happen. 

[Isaanbiker]

It's pure insanity to put such rims and tires on.

 

   Bike's behaviour changes in a way that it's dangerous no matter what you do with it. Not good at high speed, or even higher speed.

 

  Very dangerous in curves, so why would anybody with a healthy brain do something similar? Only that it's a bit cheaper?

 

Please don't tell me smaller tires are cool. And no helmet. That's a 99% chance to have a bad accident very soon.

 

 

 

One time Google and you'll know what's going on.

 

 

[Farangwithaplan]

A great way to improve handling and grip is to reduce unsprung weight which is what wheels, brake calipers, and part of the suspension is.. Although there can be a trade off on grip if the rims get so thin that a smaller cross section tyre means a loss of surface area.

 

Also there will be an increase in performance especially on small bikes. But from what I have seen, locals do it for looks.

[Bruce Aussie]

Same as why change headlights and tail lights to blue.

Police don't care.

????❤????????

[eisfeld]

  On 3/1/2020 at 2:32 PM, Kwasaki said:

Quick steering is from a larger grip area on the road not a small one.

What they do is an accident waiting to happen. 

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Have to disagree with your first point. Larger "grip area" (tire surface touching the road) does not make steering faster. A smaller tire has quicker steering as it has less rotating masses (gyroscopic effect).

 

I agree with your second point though, these thin wheels are a lot less stable and therefor less safe. Probably harder rubber compound as well so less grip.

[eisfeld]

  On 3/1/2020 at 2:01 PM, steevjee said:

Cheaper tyres ? perhaps quicker steering response too? nothing else would make sense as the brakes would be way less effective,

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I suspect "coolness" is the prime reason. Not that I find them cool, I think they are ridiculous, stupid and dangerous. But maybe they are indeed lighter and offer more flickability. Braking performance should only be affected if the compound is harder and offers less grip which well might be.

[Kwasaki]

  On 3/1/2020 at 3:14 PM, eisfeld said:

Have to disagree with your first point. Larger "grip area" (tire surface touching the road) does not make steering faster. A smaller tire has quicker steering as it has less rotating masses (gyroscopic effect).

 

I agree with your second point though, these thin wheels are a lot less stable and therefor less safe. Probably harder rubber compound as well so less grip.

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Sorry wrong in first part if the wheel is a smaller diameter. 

[JonnyF]

Same reason road racing bikes (pushbikes ala the Tour De France) have very thin wheels and tyres. Less unsprung weight, smaller contact patch with the road (less friction=more speed). 

 

Obviously the trade off is grip and stability but Thai teenagers don't care about such trivialities.

 

[Damrongsak]

I like a bike that has a good bit of rubber on the road.

 

 

[VocalNeal]

  On 3/1/2020 at 11:23 AM, Kwasaki said:

Saw an Xmax today with rim & tyres like on a bicycle size,  also many other scoots the same, have never

understood the mentality of why this is done.

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Thais are into drag racing. At some point in history thinner wheels were fitted to reduce weight. 

It has become de rigueur. Same reason Drag rails have skinny front wheels.

 

On the street it says to others "I am a drag racer" 

 

Now if i see a European faux drag bike customization I think "amateur:. Those wheels are too wide. 

[Vacuum]

  On 3/1/2020 at 3:14 PM, eisfeld said:

A smaller tire has quicker steering as it has less rotating masses (gyroscopic effect).

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If they're smaller diameter, they also rotate faster (quicker steering)

[Farangwithaplan]

  On 3/1/2020 at 3:00 PM, Farangwithaplan said:

A great way to improve handling and grip is to reduce unsprung weight which is what wheels, brake calipers, and part of the suspension is.. Although there can be a trade off on grip if the rims get so thin that a smaller cross section tyre means a loss of surface area.

 

Also there will be an increase in performance especially on small bikes. But from what I have seen, locals do it for looks.

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Here is a couple of links that outline the benefits of unsprung weight in lay terms without getting into the physics.

 

https://www.cycleworld.com/fundamentals-unsprung-weight/

https://motoress.com/ride/moto-savvy/unsprung-and-sprung-weight/

 

If you at all interesting in getting better suspension and handling performance, it is a good concept to understand.

[Kwasaki]

  On 3/2/2020 at 3:00 AM, VocalNeal said:

Thais are into drag racing. At some point in history thinner wheels were fitted to reduce weight. 

It has become de rigueur. Same reason Drag rails have skinny front wheels.

 

On the street it says to others "I am a drag racer" 

 

Now if i see a European faux drag bike customization I think "amateur:. Those wheels are too wide. 

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Surely they don't know that more rubber on the tear would be better for a drag bike. 

[Kwasaki]

  On 3/2/2020 at 8:05 AM, Farangwithaplan said:

Here is a couple of links that outline the benefits of unsprung weight in lay terms without getting into the physics.

 

https://www.cycleworld.com/fundamentals-unsprung-weight/

https://motoress.com/ride/moto-savvy/unsprung-and-sprung-weight/

 

If you at all interesting in getting better suspension and handling performance, it is a good concept to understand.

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Yeah text stuff like 16.5 front rims on MotoGp bikes,  my bike has a 130/16 front it steers much quicker than 120/17.

[eisfeld]

  On 3/2/2020 at 1:48 PM, Kwasaki said:

Yeah text stuff like 16.5 front rims on MotoGp bikes,  my bike has a 130/16 front it steers much quicker than 120/17.

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Not sure one can so easily tell the difference. I suspect it's more about the rest of the geometry of the bikes. My AT 21 inch front still can steer relatively quickly. What bikes are those two?

[Kwasaki]

  On 3/2/2020 at 2:17 PM, eisfeld said:

Not sure one can so easily tell the difference. I suspect it's more about the rest of the geometry of the bikes. My AT 21 inch front still can steer relatively quickly. What bikes are those two?

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If you're  on a track with a bike it does notice.

Yeah sorry I'm talking sportsbikes,  there a lot to it,  I suppose my answer to my question of why Thais do this rediculus things with bikes is it's downright dangerous. 

[Damrongsak]

Skinny tires were in ... 100 years ago.

 

   

[Farangwithaplan]

  On 3/2/2020 at 1:48 PM, Kwasaki said:

Yeah text stuff like 16.5 front rims on MotoGp bikes,  my bike has a 130/16 front it steers much quicker than 120/17.

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I'm not sure what you are trying to say there. Speaking only of wheel size when referring to handling is akin to saying that because someone has the same shoe size as Usain Bolt, they must also be a world record sprinter.

 

No one characteristic of a motorcycle can be attributed to handling. Rake and trail play a major part in suspension. Look up those two thinks and do some reading on it if you want to begin to understand handling characteristics.

 

 

 

 

[Kwasaki]

  On 3/3/2020 at 12:23 AM, Farangwithaplan said:

I'm not sure what you are trying to say there. Speaking only of wheel size when referring to handling is akin to saying that because someone has the same shoe size as Usain Bolt, they must also be a world record sprinter.

 

No one characteristic of a motorcycle can be attributed to handling. Rake and trail play a major part in suspension. Look up those two thinks and do some reading on it if you want to begin to understand handling characteristics.

 

 

 

 

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If you're not sure then I rest my case from my racing & track days  experience. 

[Kwasaki]

Vocal Neil is the one who gave a good answer to the question why others get into rake and trail and race set up configuration is silly. 

 

We are talking scooters so I will ask again is it a good idea to put skinny tyres on a bike that was brought out with the correct tyre & rim size designed for the bike.

IMHO it is dangerous. 

[eisfeld]

  On 3/3/2020 at 11:38 AM, Kwasaki said:

We are talking scooters so I will ask again is it a good idea to put skinny tyres on a bike that was brought out with the correct tyre & rim size designed for the bike.

IMHO it is dangerous. 

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Well you know and gave the answer already ????

 

Could also ask "Is it a good idea to change your red/amber lights to blue?" or "Is it a good idea to have three 13 year olds ride on one bike without helmets?".

[Kwasaki]

  On 3/3/2020 at 12:16 PM, eisfeld said:

Well you know and gave the answer already ????

 

Could also ask "Is it a good idea to change your red/amber lights to blue?" or "Is it a good idea to have three 13 year olds ride on one bike without helmets?".

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No thin tyres after market tyre put on scooters that's question cor blimey. 

[Damrongsak]

  On 3/3/2020 at 12:16 PM, eisfeld said:

Well you know and gave the answer already ????

 

Could also ask "Is it a good idea to change your red/amber lights to blue?" or "Is it a good idea to have three 13 year olds ride on one bike without helmets?".

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3 on one bike is OK, just have to have the tires pumped up to 50 PSI.

[eisfeld]

  On 3/3/2020 at 1:55 PM, Kwasaki said:

No thin tyres after market tyre put on scooters that's question cor blimey. 

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Hm sorry didn't quite get that. Can you rephrase?

[Moonlover]

  On 3/3/2020 at 11:38 AM, Kwasaki said:

Vocal Neil is the one who gave a good answer to the question why others get into rake and trail and race set up configuration is silly. 

 

We are talking scooters so I will ask again is it a good idea to put skinny tyres on a bike that was brought out with the correct tyre & rim size designed for the bike.

IMHO it is dangerous. 

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Quite so. I did read, with interest, the articles posted by @Farangwithaplan and they did strike cord.

 

Now the only way we can really judge whether there is a benefit to fitting pram wheels to our motor scooters (scooters are kids toys) is to try it out, but we're a sensible lot aren't we and we're not going to do that are we.

 

But I can recount some experience. We have two motor scooters, a Honda Click 125 and a Yamaha Earox. And it's quite obvious that there is a noticeable difference in wheel and tyre size between the two.

 

The Earox is a great cruiser when I'm out on the country lanes. It keeps a straight line with little steering effort and holds a stable line through the bends. But, when it comes to going downtown for a bit of shopping, the Click comes into its own.

 

True, it needs to be steered more than the Earox, but it is much more maneuverable when it come to negotiating city traffic and it saved me more than once due to its flexibility. It's no surprise to me why they are so popular.

 

So my view is that smaller wheels may well have some benefit and maybe the Thai kids know more than we think. But I won't be doing any mods to my rides anytime soon.

 

Safe riding all.

 

 

[eisfeld]

  On 3/3/2020 at 3:01 PM, Moonlover said:

But I can recount some experience. We have two motor scooters, a Honda Click 125 and a Yamaha Earox. And it's quite obvious that there is a noticeable difference in wheel and tyre size between the two.

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  On 3/3/2020 at 3:01 PM, Moonlover said:

So my view is that smaller wheels may well have some benefit and maybe the Thai kids know more than we think. But I won't be doing any mods to my rides anytime soon.

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When you say smaller, do you mean less wide or smaller diameter? As far as I can tell from the specs both Click 125 and Yamaha Aerox have 14 inch diameter wheels. But the latter has wider tires (80mm vs 110mm). Not sure how much of a difference this will make. I suspect the real reason why you see the Click as more maneuverable is probably because it has a shorter wheel base of 1280mm vs the Aerox' 1350mm. Maybe the Honda also has a sharper steering lock angle and overall more favorable geometry for low speed though I can't see that in the specs.

 

What I'm trying to say is that there is much more than wheel width or diameter when it comes to defining how a bike steers.

[Farangwithaplan]

  On 3/3/2020 at 11:21 AM, Kwasaki said:

If you're not sure then I rest my case from my racing & track days  experience. 

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NO.. because you sentence did not actually make sense.

 

If you would clarify then maybe others have a chance to understand what you are attempting to say.

 

Your comments so far in this thread have not lead me to believe you have even a general understanding of motorcycle geometry and handling.

 

Care to concisely prove me wrong? Or will you just make another idle post with a claim that has no real substance?