Sunday, June 04, 2017

What the fork?

Prior to last year's epic failed-to-launch CO trip, I'd purchased fork springs and rear suspension to match my weight.  With this year's epic CO trip looming, I finally got around to installing the fork springs.  But alas, this bike is not spacer-under-cap as all the other bikes in which I've swapped springs.  This bike has the cap screwed to a rod with a jam nut.  To remove the spring, you first have to compress the spring enough to reveal the jam nut, which is under the white-colored spacer in this out-of-focus pic:

The careful observer will note that there is some paracord tied on each side.  That's 50% of my spring compressor.

I looped one side of the spring wire with a bowline hitch.  The cord then goes down the outside of the shock tube, thru the axle hole, back up the other side, and is tied with a taught line hitch to a point opposite the bowline hitch.  The taut line hitch allows you to snug down the cord as much as possible, then take up slack after an initial stretch.

The other 50% of my spring compressor is a quick clamp, configured as a spreader.  It's placed between the two lines so that actuation will force them apart, like drawing a bow string - well, maybe like drawing two bowstrings in opposite directions.  1000 words' worth:

...which reveals the prize:

The problem with this approach is that the clamp has a trigger release.  That means that all that tension is let go instantaneously when the trigger is pulled.

It seems like there's a possibility for injury - altho the coils are opening, so pinching is not likely; and the spring is secured by the line.  It pops back to full length violently, but the cord keeps it from shooting out of the fork tube, bouncing, or any other such craziness.  As long as you don't have any meat around the top of the spring when it lets go.  Anyway, I managed to pull this off four times in a row without drama (old spring out, secure new spring in, x2 forks).

The 2014 stock Supere Tenere spring is on top (progressive wound), the Sonic 1.0kg is on the bottom (straight rate).

I made several changes during this maintenance - front brakes, handle bars, and pegs.  Also, I hadn't ridden for several days.  So that said, I was surprised that the upgraded, stiffer, Sonic springs initially felt WORSE than stock.  I had noticeably more brake dive.

I'm not sure if there are other factors at work: the new brakes may be grabbier than what they replaced, and having not ridden for several days, I was hammering the throttle pretty hard.
I wonder if maybe my weight had the progressive section of the stockers coil bound all the time, such that the straight rate section was always the only factor in play.

After a few days of playing, I don't really notice a difference.

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