Quote:
Originally Posted by pranay
Forks/Springs being softer mean that the they 'suppress/depress' more. If a bike with such a setup hits corners you will get less 'feedback'. Feedback in the sense the feel of the front and back end on the bike sticking on the road because you will be bouncing around all the time. This will mean lesser control over the corners.
A stiffer spring setup will give you more feedback. Which in turn, will give you a better response during the turns. There are more aspects than just springs which effect bike's handling, but if you take just the springs, then this is basicallty what it is.
Simple eg:-
Take a straw and try to draw a circle in sand. Take a wooden stick and do the same. Which one will draw a better circle?
In terms of road comfort, you would ideally want softer forks/springs (opp of what you would want above). A softer fork/spring would depress easier so in case of a bump or a pothole, you would get less 'feedback' from the road, making you not groan everytime you go over uneven surfaces. A stiffer fork/spring would depress lesser so the vice-versa would happen.
Simple eg:-
Take the same straw and press it over the surface ground and keep going for a hundred meters or so. Take the wooden stick and do the same. After which one would you feel a bit weary on your wrists?
Bikes would like to have an ideal compromise between these two. There are mechanisms which bridge the gap between these two as well nowadays. (The R15 has a varying dampening system, with the monoshock stiffening with increase in load)
|
Pranay: 'Softer' or 'stiffer' suspension and its effects on braking and road-holding are two different things. I'll just be skimming on the surface of the topic here.
Braking: Softer springing allows the weight transfer induced on braking to load up the front trye quicker than the tyre can adjust. And this weight transfer also compresses the springs more, taking up suspension travel, altering bike steering geometry towards instability and pulling the rider further and deeper into a 'dive'. All these effects hinder the rider from utilizing the full braking potential of the braking system/tyre combo. So for braking, a stiffer spring set-up is preferable.
Road-holding: This is about how well the suspension keeps the tyre contact patch in contact with the road. Stiffer springs ALLIED with firm damping will keep the wheel pressed harder to the tarmac allowing for a sure-footed ride. 'Feedback' will be there in both the cases but what comes as feedback with softer springs will be sort of vague and will have a pretty high pucker factor
for the rider. The bike will feel like its wallowing all over the turn.
The 'straw and stick' analogy was a bit extreme there
. I guess the straw is for softer springing but it gives the impression that softer springing also means flexible non-rigid forks
that bend at their knees (wherever they are for 'forks) when the rider brakes.
Yes, suspension set-ups are a use-oriented compromise. A commuter or tourer would want a fair percentage of comfort even if there is a slight depletion in road-holding and braking at the extreme limits of the bike's performance. Likewise, a road-racer would want his suspension set-up optimized for road holding and braking, comfort be damned.
The 'varying' damping is what we call 'pre-load' adjustment for suspension. The suspension 'spring' is pre-loaded as if there is already some force pushing it downwards. This makes the spring effectively stiffer. For 'gas-springing' or nitrogen filled shocks, the pre-load is increased by increasing the gas-pressure inside the shocker-damper unit.