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Jan. 27, 2016, 3:42 a.m. -  Jimmy Dee

#!markdown What a strange idea. Do something "for science" and yet include no scientific data or measurements of any sort. Here are some scientific approaches to this: Use a measuring tape from the center of the rear axle to the center of the BB. This will show chain growth or shrinkage through the travel. Note that some linkage type suspension designs Use a piston to slowly apply pressure downwards at a fixed rate of movement. Place a scale or sensor against the piston. Observe and chart the changes in pressure as the piston keeps a constant speed. This will show the progressiveness of the compression stroke. Lock out your rear suspension. Place 100kg of weight on the saddle. Observe compression. Increase to 200kg, observe. Increase to 300kg, observe. Now remove 200kg and slowly add the weight for one second and take one second to remove the weight. This will mimic pedaling under high load by a strong rider on rough terrain riding uphill. Now openly mock people who believe that pedaling platforms are better than real lockouts, because "science". Also, there are 17 brands of full and bikes here, but there aren't 17 suspension systems. When considering chain growth, there are only 4. Single pivot, BB pivot, vpp and etsx (aka maestro after it was shamelessly ripped off by Giant). Single pivot shrinks chain under compression. Horst and other 4 bars too. BB pivot is not used by anyone anymore, not even Wal-Mart, but the chain does not grow. VPP has an S shape, usually shrinking, then lengthening, usually with th changeover occurring at the sag point. And etsx grows the chain under compression. Maestro is a ripping of etsx, so it also grows, but they linkages are much shorter, so the chain growth is minimal. If your chain shrinks under compression, your pedaling travel will be lost into your drivetrain and be returned to your bikes position when the pedaling force subsides. If your chain grows under compression, the chain growth will drive your rear wheel against the ground, returning against no resistance and putting the slack possibly against the freewheel like a ratcheting effect… If you have low enough engagement points or a silent clutch instant engagement system… If there are two pivots between the fixed point on the bike and the center of the rear axle (not AT the rear axle), then your bike is not a single pivot. Even if you have fancy linkage up top, but one pivot on the chain stay, that's still a single pivot in terms of chain growth. Beyond that, linkages can affect how progressive your suspension travel is. On my perp for example, it has some linkage to make it more progressive, so even a lower grade shock provides progressive travel if it is sprung correctly. But don't confuse that with aggressiveness in the shock itself, which can also be an important factor in real world use.

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