Wednesday, June 30, 2010

Let's talk about my fat ass

    Can we talk about my out of control obesity? Certainly, the years have ravaged my once boyish figure; but it was still to my surprise that I all but bottomed out my suspension when I first sat on Plan B with the new subframe. I built the subframe around a shock I've had laying around for a while, a spiffy Malossi RS24 shock (by Paioli) originally designed as the front swingarm shock for an Italjet Dragster.  I suspect  the difference in geometry is to blame, and my addiction to transfats and sweet, empty carbs.

    Regardless, I needed to find a beefier shock with similar dimensions to the one I had, but that was a bit tough, and most quality shocks of this sort go for around $400, even a good spring for a motorcross application retails around $120, and the dimensions would still be a rough fit. Luckily, I was able to get a couple of random industrial springs with appropriate specs for not very much money. The thinner one is rated at 470lbs. and the thicker at 790lbs. Both springs match the outer diameter of the original and are 8in. long.

    But that's where it gets complicated, as the shock will accept a spring of a maximum 5 3/8" long and has a travel of about 2". I'm having a tough time staying in front of the math on this one, as I'll have to cut off some length to allow the shock to fit, but also compress the shock enough to keep the sag within a usable range. So, I'm willing to accept a fair bit of trial and error through this process.

   I headed down to Naz & Phil's shop to use the press to get the spring on, but it was a smidge more involved. After trimming an inch off each spring, I cooked the coil top with a torch to flatten it out. Ultimately, I need to fab up a tool to help rebuild the shock. This process had a few false starts and took nearly all day. After the tool was done, the spring installed easily. Knocking an inch out of it's length reduces the spring's max load to 347lbs, but that will hopefully prevent my massive girth from dragging the motor across the asphalt.


spookytunee said...

OH HOLY SHIT. you and phil should go on tour.

terrydean said...

if you notice how short the swing arm is on the bike the shock was meant for compared to the swing arm you put it on, you can see where the problem lies. i'd bet even brendan would bottom that thing out with all that leverage!