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Old 4th June 2014, 14:38   #1
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Default Piaggio 3 wheelers - Camber angle of the rear wheels?

Most of you might have noticed the angled (inward) rear wheel setup of Piaggio APE-3 wheelers. I was told these will straighten up once vehicle is fully loaded with cargo. But still don't understand how can this design (angled wheels/tires) survive without any immediate wear and tear and other damages. Curious to know how it works!

Sorry if this topic was discussed earlier,I could not find it after some search.

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Old 4th June 2014, 15:17   #2
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Default re: Piaggio 3 wheelers - Camber angle of the rear wheels?

That's called the camber angle and I'd suggest you read up more about it. These small goods/people carrying Piaggios use positive camber. I think they use it because with our uneven roads, positive camber allows for better ride even with the rudimentary suspension setup that these vehicles come with. I also believe it makes them easier to steer (not grippier in corners though, that is where negative camber angle comes in)

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Old 4th June 2014, 18:12   #3
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Default re: Piaggio 3 wheelers - Camber angle of the rear wheels?

Quote:
Originally Posted by IshaanIan View Post
That's called the camber angle and I'd suggest you read up more about it. These small goods/people carrying Piaggios use positive camber. I think they use it because with our uneven roads, positive camber allows for better ride even with the rudimentary suspension setup that these vehicles come with. I also believe it makes them easier to steer (not grippier in corners though, that is where negative camber angle comes in)

Cheers!
Thanks Ishaan. I have checked Wiki for Camber angle..Very interesting!! Some key points:


If the top of the wheel is farther out than the bottom (that is, away from the axle), it is called positive camber; if the bottom of the wheel is farther out than the top, it is called negative camber.
Camber angle alters the handling qualities of a particular suspension design; in particular, negative camber improves grip when cornering.
Off-road vehicles such as agricultural tractors generally use positive camber. In such vehicles, the positive camber angle helps to achieve a lower steering effort.
Excessive camber angle can lead to increased tire wear and impaired handling.
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Old 4th June 2014, 18:17   #4
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Default re: Piaggio 3 wheelers - Camber angle of the rear wheels?

Why searching somewhere, TeamBHP carries any info related to automobiles. This topic is well covered in the below thread.

http://www.team-bhp.com/forum/tyre-a...r-set-ups.html
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Old 5th June 2014, 16:22   #5
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Default Re: Piaggio 3 wheelers - Camber angle of the rear wheels?

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Originally Posted by sivadas View Post
Thanks Ishaan. I have checked Wiki for Camber angle..Very interesting!! Some key points:


If the top of the wheel is farther out than the bottom (that is, away from the axle), it is called positive camber; if the bottom of the wheel is farther out than the top, it is called negative camber.
Camber angle alters the handling qualities of a particular suspension design; in particular, negative camber improves grip when cornering.
Off-road vehicles such as agricultural tractors generally use positive camber. In such vehicles, the positive camber angle helps to achieve a lower steering effort.
Excessive camber angle can lead to increased tire wear and impaired handling.
Other than the inputs which you got from wiki, there are some other parameters effecting the vehicle handling like over steer and under steer gradients.

You can read more on this at:

http://en.wikipedia.org/wiki/Understeer_and_oversteer

As you said, positive camber on the front wheels reduces the steering effort bcoz it causes the vehicle to over steer.

Same thing when applied to the rear wheels have a reverse effect i.e. positive camber on the rear wheels produce an under steer effect which improves handling during sudden sharp turn maneuvers and other circus feats our auto rickshaw drivers generally make.

Main focus of any vehicle dynamics or vehicle suspension designer would be to have a slight under steer gradient for the vehicle to handle safe.
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