Thursday, September 27, 2007

Its all here!

The perfect handling bike. How is it acheived? Considering all other factors are a plus (great tubing and geometry, front to rear weight ratio etc) its all in the head tube angle and trail.

1. More trail, more stable handling, especially straight line riding. The input from the user will have to be slightly more to make steering changes.

2. Very less trail, extremely twitchy steering and near instability. You'll probably see the bike wanting to turn on its own with no hands riding. Not too sure.

The perfect handling bike has a trail somewhere between these two extremes. The range you can work with are :

1. 40 to 55 mm for fork rake.

2. Corresponding trail from 40 to 55mm. According to Calfee's website, "57mm of trail is considered by many to be an ideal combination of stability and agility.' Some say a trail of 59-60mm (5.9-6.0cm) gives the best handling.

Most racing forks today are carbon fibre, having between 43-45mm of rake. So I'm thinking that given those two contraints, find out what the head tube angle is for your frame and the corresponding trail generated by plugging in 43mm and 45 mm. You can make an EXCEL spreadsheet if you want. I would just get a protractor from a geometry set and a ruler and draw it out on a paper to know whats really going on. It is important to get a matching fork for your head tube angle to get a good trail for racing. Some people often think that a fork is just another component like a seat post or brake callipers that one can just toss on. Not really true with forks.

Ce vediamo!

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