CYCLINGFORUM.COM - Where Cyclists Talk Tech --- Return To Home

 

    Register FAQ'sSearchProfileLog In / Log Out

 

****

cyclingforum.com ****

HOMECLUBS | SPONSORS | FEATURESPHOTO GALLERYTTF DONORS | SHOP FOR GEAR

Return to CyclingForum Home Page CYCLING TECH TALK FORUM
          View posts since last visit

Lean angle when cornering
 

Author Thread Post new topic Reply to topic
Nick Payne
Joined: 10 Jan 2004
Posts: 2625
Location: Canberra, Australia

8/4/13 4:40 PM

Lean angle when cornering

I seem to remember reading of a test that Specialized did quite a few years back where they coated a board with road bitumen and tested tyre adhesion by inclining the board at increasing angles and attempting to ride a bike along the board. The figure of 45 or 47 degrees is in my mind as the maximum angle they could incline the board from the horizontal before the tyre started to lose adhesion and slip. However, motorcycle tyres seem to be able to grip at considerably greater angles than this: when I used the measure tool in GIMP to measure the angles in the photo below, Casey Stoner has his Honda cranked over at about 60 degrees, give or take a degree or so. The few times that I've slid out while cornering on a bicycle, my lean angle has been nowhere within cooee of that. The other photo, of Jobst Brandt cornering, he has his bike cranked over at about 41 degrees from the vertical, and that's the best bicycle cornering photo I could find.



 Reply to topic    

Dave B
Joined: 10 Jan 2004
Posts: 4511
Location: Pittsburgh, PA

8/4/13 5:12 PM

Racing motorcycle tires use very soft rubber compounds and they are heated before they ever leave the pits and kept very hot while at racing speed. Their adhesion is fabulous but their service life is measured in two to very low three digit miles.

 Reply to topic     Send e-mail

walter
Joined: 11 Jan 2004
Posts: 4391
Location: metro-motown-area

8/6/13 11:39 AM

motogp and lean angle

the premier class is a "spec" series for tyres now, all being made by bridgestone who started eating michelin's lunch in about 2009. despite being round and black they are amazing pieces of engineering and chemistry, very grippy donuts indeed. the tires have made massive strides in the last 10 years, and the last 5 in partucular. durability is definitely less than 100 miles.

the max lean angle right now is ~65 degrees from vertical. that is low! they've recently (this year) started fitting their leather suits with ELBOW SLIDERS in addition to knee-sliders.

the lean angle is primarily driven by the tire design...it wont lean any farther than that, as you'll either go slower or fall off. in fact, pretty much everything about racing motorcycles is driven by tyre design...with manufacturers converging on a fairly common set of chassis and engine design parameters.

the grippiest combination would be slick tires on a track surface made of freshly cleaned sheet glass....TONS OF GRIP, but not so good to crash on.

 Reply to topic     Send e-mail

Nick Payne
Joined: 10 Jan 2004
Posts: 2625
Location: Canberra, Australia

8/6/13 3:24 PM

If such a tyre compound were available for bicycles, one would expect that it would get used for racing, particularly at the elite level. I remember reading an interview with Phil Anderson where he said that in the TDF they would get a new set of tyres on their bikes for every stage. If a tyre gives better grip in racing conditions, what does it matter if it only lasts a few hundred kilometres when it's being replaced on a daily basis.

 Reply to topic    

walter
Joined: 11 Jan 2004
Posts: 4391
Location: metro-motown-area

8/6/13 3:43 PM

grippy rubber requires temperature...

...as dave mentioned.

most moto racing (and car racing for that matter) use tyre warmers and even with that it usually requires ~1 hot lap to get them up proper operating temp to maximize grip. rain tyres compounds require less temperature, but if it's dry they can be destroyed in a lap or 2 as their temperature skyrockets.

mfgs could certainly use grippier compounds for cycling, but they wouldnt last for sh!t and their rolling resistance would be quite high -- a problem for human powered conveyances especially if you're trying to be first across the line!

 Reply to topic     Send e-mail


Return to CyclingForum Home Page CYCLING TECH TALK FORUM
           View New Threads Since My Last Visit VIEW THREADS SINCE MY LAST VISIT
           Start a New Thread

 Display posts from previous:   


  
Last Thread | Next Thread  >  

  
  

 


If you enjoy this site, please consider pledging your support

cyclingforum.com - where cyclists talk tech
Cycling TTF Rides Throughout The World

Cyclingforum is powered by SYNCRONICITY.NET in Denver, Colorado -

Powered by phpBB: Copyright 2006 phpBB Group | Custom phpCF Template by Syncronicity