Chain pull, the true story.
Suspension isn't black and white in terms of performance, there are many shades of grey. On the other hand, there are certain properties that are constant yet there are countless companies that fail to realize just exactly what they do. The best example of this is chain pull as the suspension compresses. It is amazing to read that designers are proud of the fact that they made a suspension system that stops chain pull. That is exactly what the unified rear suspension systems did and whre are they now?
Proper chain pull is what makes a 8" travel frame sprint like a hardtail. Too much pull and the bike will actually slinky up with every pedal stroke and too little will bob the bike down with every push of the pedals. Pushing down hard on one pedal while sprinting will try and compress the back end because your dropping your whole body weight down on the pedal but at the same time the force is adding tension to the chain. This tension will try and lift the bike because the effect of chain pull means tension in the chain will force the suspension up.
If the down force from pedaling is matched to the lifting force from the chain the result is a bike that doesn't bob when sprinted no matter how hard. Because the forces are balanced the suspension is still free to move up and down, its just been pre-loaded and counter-pre-loaded. Most advertising call this whole effect isolated pedaling but that is a bad misrepresentation of how it works. |
