Talk:Bicycle and motorcycle geometry

From Wikipedia, the free encyclopedia

Cycling Portal
This article is within the scope of WikiProject Cycling. WikiProject Cycling is an attempt to build a comprehensive and detailed guide to cycling on Wikipedia. If you would like to participate, you can edit the article attached to this page, or visit the project page, where you can join the project and contribute to the discussion.
B This article has been rated as B-Class on the quality scale.
WikiProject Motorcycling Bicycle and motorcycle geometry is within the scope of the Motorcycling WikiProject, which aims to improve Wikipedia's coverage of motorcycles and motorcycling. If you would like to participate, you can visit the project page, where you can join the project and see a list of open tasks.

Contents

[edit] Merger candidates

I've tried to incorporate all the details from

into one comprehensive article. Any reasons left not to redirect them all to here now? -AndrewDressel 16:21, 12 December 2006 (UTC)

Done. -AndrewDressel 22:26, 13 December 2006 (UTC)

[edit] Steering Geometry

This article should really be called bicycle and motorcycle steering geometry. The "geometry" of a bicycle also refers to the length of its various tubes, which is of more concern for ergonomic fit than for its effect on handling characteristics. -- pde 23:30, 13 December 2006 (UTC)

Those other parameters could certainly be added. They don't exist anywhere yet, as far as I know. That would also keep the title from becoming unwieldy. -AndrewDressel 23:37, 13 December 2006 (UTC)

This could look something like this:

  • Ergonomics
Other geometric parameters influence the rider's experience. These include:
  • Bicycles
-Seat tube angle influences the position of the seat relative to the pedals. This can be countered somewhat by sliding the seat forward or back on its rails.
-Hanglebar height
-Top tube length and stem length control the cockpit length. Along with handlebar height and seat position, this influences how far the rider stretches to reach the handlebars.
-Chain stay length, along with seat tube angle and seat position, influences how close the rider is from directly over the rear wheel which impacts ride comfort.
  • Motorcycles
-Seat height
-Handle bar position
-AndrewDressel 17:12, 14 December 2006 (UTC)

Hmmm. The bicycle frame article already has a good discussion of these other aspects of frame geometry. I've cross linked the articles. Is there an equivalent for motorcycles? I can't find it. -AndrewDressel

[edit] How geometry affects handling

It would be a valuable addition to this article to add information about how each characteristic influences the handling ("behavior") of bicycles and motorcycles and which geometries and characteristics are best suited to different types of riding.

For example, I believe that a bicycle with more trail is more stable at higher speeds while a bike with less trail is easier to handle at lower speeds and/or when there is a load on the front wheel.

Steeper head angles are used on time-trial bikes and less steep on touring bikes.

Etc.

There is already a good start in the Bicycle frame article. Perhaps it should be moved here and expanded, as necessary. -AndrewDressel 14:01, 26 June 2007 (UTC)

[edit] Errors?

I might be misunderstanding, but in the picture of the chopper, doesn't it have an unusually long trail? The rake doesn't seem that different. —Preceding unsigned comment added by 144.212.105.66 (talk) 20:19, 22 April 2008 (UTC)

I cannot tell what the trail might be, the fork is turned and it is difficult to guess where the steering axis might intersect the ground, relative to the front wheel contact point. However, the angle of the steering axis, which in motorcycles, is called the rake and is measured counter-clock-wise from the vertical when viewed from the right side, appears to be quite a bit more than usual. It might be as much as 45° instead of the 23.7° (with 3.8 in of trail) listed for a 2007 Honda CBR® 600RR, or the 29° (with 4.5 in of trail) listed for a 2008 Harley FXD Dyna® Super Glide®. -AndrewDressel (talk) 21:25, 22 April 2008 (UTC)