Old 10-17-07, 09:10 AM
  #19  
sfcrossrider
Senior Member
 
sfcrossrider's Avatar
 
Join Date: Mar 2006
Location: San Francisco
Posts: 2,760

Bikes: Steelman eurocross, Surly CrossCheck, IRO Rob Roy...

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Originally Posted by Kogswell
A lot of us at Kogswell are interested carrying weight at the front of our bikes. We like handlebar bags and low rider panniers and the cargo carrying capacity of front racks.

Carrying weight on the rear of a bike is fine too, as long as you're willing to put up with rear wheels that are overloaded.

We aren't. We want stuff up front.

But the problem with front loading is that it affects steering negatively.

That was the case, anyway, until a couple of years ago. Two years ago we started reading what Jan Heine was saying in the pages of Bicycle Quarterly. There he claimed that he had found example of bicycles that had been engineered to carry loads at the front and that did it well.

So we called him and asked him if he'd like to help us design a 'front loader'.

His answer was this: let's make three identical bikes, but make three different forks, each with different amounts of offset (bend) and then test them to see which one carries a front load best.

This was not a shot in the dark. He had looked at and ridden bikes that handled front loads well and he had measured the frames to see how they differed from modern bikes. The only appreciable difference was the amount of fork offset. It seemed like an interesting test and so we made the bikes and tested them.

This photo, taken by Alex Wetmore (thank you, Alex) shows the three bikes during the test:



Modern road bike geometry is fairly standard: a 73 degree head angle and about 45mm of fork offset.

The test bikes had 73 degree head angles and used fork offsets of roughly 55, 65 and 75mm.

And for testing, front racks were attached to all three bikes.

What the testers found was that somewhere in the fork offset range of 65-75mm, front loads become a LOT easier to steer.

The tests were eye-opening for a lot of us. And since then a lot of folks have found ways to re-rake existing fork and the results, in nearly every case, have been bikes that can be front loaded and ridden with ease.

So go ahead and get a rack and load up the front of your bike.

And if it doesn't quite handle the way you'd like, look up re-raking on Google and see what others have done. You may find what you're looking for.

Your bikes kick @ss!!! When my Surly dies for for the last time I'll give you a ring.
sfcrossrider is offline