Search found 10 matches

by bobkarol
Sat Aug 17, 2019 8:50 am
Forum: General Motorcycle And Non-Motorcycle Talk
Topic: Physics question about lean angle
Replies: 12
Views: 12085

Re: Physics question about lean angle

I previously concluded, "The difference between the chassis-measured Cg lean angle and the CCg data-calculated lean angle represents the degrees that the rider is hanging off." I forgot to mention that the chassis-measured Cg lean angle includes any sliding the rear wheel does, which the CCg data wo...
by bobkarol
Thu Aug 15, 2019 7:37 am
Forum: General Motorcycle And Non-Motorcycle Talk
Topic: Road racing motorcycle aerodynamics
Replies: 14
Views: 26310

Re: Road racing motorcycle aerodynamics

Way back in Nov.30, 2014 elkka asked: "does anyone know research, an article, a book, anything, concerning road racing motorcycle aerodynamics?...What I am looking for is comparison or description what are the reasons road racing machine looks like it does." Even though this an old thread, I can con...
by bobkarol
Tue Aug 13, 2019 11:47 pm
Forum: General Motorcycle And Non-Motorcycle Talk
Topic: Physics question about lean angle
Replies: 12
Views: 12085

Re: Physics question about lean angle

Speedog also references Geonerd's original discussion of the prevailing error of using a bike's chassis-measured Cg, instead of the combined Cg of bike+rider (CCg), in order to determine the correct effective cornering lean angle that produces maximum lateral g-force. This brings up an interesting q...
by bobkarol
Tue Aug 13, 2019 11:23 pm
Forum: General Motorcycle And Non-Motorcycle Talk
Topic: Physics question about lean angle
Replies: 12
Views: 12085

Re: Physics question about lean angle

Speedog writes, "the more the track is banked, the larger the actual corner g-force for a given angle from vertical." It doesn't matter if the given angle of lean from vertical is on a horizontal or banked track. The effective cornering g-force and speed will be the same. The track banking serves a ...
by bobkarol
Tue Aug 06, 2019 7:12 am
Forum: General Motorcycle And Non-Motorcycle Talk
Topic: Physics question about lean angle
Replies: 12
Views: 12085

Re: Physics question about lean angle

Hanuman, above, asked about the effect of mu: Mu would be the combination of tire composition (for conformity to track surface and durability), braking load thus contact area, and track surface condition (moisture, texture, temperature). The actual limit of Mu for any set of condtions can only be de...
by bobkarol
Thu Jul 05, 2018 7:30 pm
Forum: General Motorcycle And Non-Motorcycle Talk
Topic: Physics question about lean angle
Replies: 12
Views: 12085

Re: Physics question about lean angle

It might be interesting to know how GPS bike telemetry works: GPS defines the position of the combined Cg of the bike/rider at three points along the bike's line in small increments of time. Given the change in angle of the bike's direction over that measured distance, a standard dynamics algorithm ...
by bobkarol
Thu Jul 05, 2018 6:55 pm
Forum: General Motorcycle And Non-Motorcycle Talk
Topic: Engine Braking - Guy Martin
Replies: 5
Views: 7543

Re: Engine Braking - Guy Martin

A final note: Coordinating either the power or the braking force you apply with the lean angle you choose defines the future radius of your line. How you do that depends on the configuration of the corner and where ahead you want to place your bike.
by bobkarol
Thu Jul 05, 2018 6:46 pm
Forum: General Motorcycle And Non-Motorcycle Talk
Topic: Engine Braking - Guy Martin
Replies: 5
Views: 7543

Re: Engine Braking - Guy Martin

"..turning the bars on a bike does nothing to turn the bike, only lean angle can do that," overlooks the process of turning the bars to turn the front wheel. The front wheel is turned to offset the bike's Cg and cause it to lean into the corner. Because the bike is an unstable platform, the purpose ...
by bobkarol
Thu Jul 05, 2018 6:45 am
Forum: General Motorcycle And Non-Motorcycle Talk
Topic: Physics question about lean angle
Replies: 12
Views: 12085

Re: Physics question about lean angle

In order to know what the correct lean angle is, we have to know how the lean angle is measured. If it is measured via a gyro-accelerometer affixed to the chassis, then the actual lean angle will be greater than measured, due to the unsensed angle added by the rider hanging off. However, if the lean...
by bobkarol
Thu Jul 05, 2018 6:08 am
Forum: General Motorcycle And Non-Motorcycle Talk
Topic: Engine Braking - Guy Martin
Replies: 5
Views: 7543

Re: Engine Braking - Guy Martin

I agree with Tourn46. If you miss shifting a gear while slowing in a turn, it takes a couple of seconds to realize it and recover. The bike runs wider than your intended line, because the engine isn't contributing any drag to help tighten your line. The more you slow while following a constant radiu...