Autoplatform

Nov 2, 2012 at 15:19
by stephan schneider  
This poor thing s had a lot of crazy crap done to it.
Okay, I'm quite proud of this one. Who's had this problem? You set the platform/lockout on your rear shock for a big climb, get to the top, stretch out, put your seat down, etc., then hare off down the other side and only remember to turn the lockout off when you get to the bottom. Maybe you don't, but I do, constantly, to the point where I sort of wash my hands of the idea of flipping the stupid lever, and then that fancy platform function becomes entirely useless. Not to mention the fact that you end up riding down all the hills with your suspension off. Pooey. Anyway, reaching down and constantly flipping levers is a pain. In California it was ok, because climbs and descents are both long, and you're probably going to stop at the top for a bit anyway. But when we found out we were coming back to Ontario, where trails are very fun but the climbs and descents are super short and constant, I knew I needed a better solution. A handlebar remote could be cool, but I've got enough nonsense cluttering up my handlebars to begin with. So I knew I needed something better. Enter the Autoplatform.
Remote platform adjuster
What you're looking at here is a Shimano derailleur adjuster threaded into a hollow 12mm shoulder bolt. I know what you're saying - that thing looks like a rusty cam cover bolt off a supercharged 95 Previa! Well Eagle Eyes, you're right. They tend to break off after a few hundred thousand. As luck would have it, though, the shoulder portion left behind after the stupid threads break off fits right snug into the cylindrical well in Fox Float. Normally there's a nice anodized red snail-cam adjuster in here, pushing on the rebound adjust rod, but now there's essentially a cable driven adjuster doing the same thing. Picture a tiny silver chalice for a tiny silver king, derailleur cable running through it, coil spring nested in the part where the wine would go, and extending into the hollowed-out portion of the old cam cover bolt. The chalice was milled from a section of 3/8 aluminum rod, and the brazed end of the cable milled down and fixed in the base, so when the cable pulls, the wedge of the chalice handle slides up and down, pushing the rebound rod in and out.
Now obviously, in a normal Float this would be adjusting the rebound only. Well, this is no normal Fox Float R. It's a whole nuther lecture, but this damper got a complete re-working, so now the rebound plunger is adjusting rebound and low-speed compression simultaneously. I calibrated the ProPedal setting for the much lower leverage ratio it needed on this Diamondback Recoil (2 to 1, instead of the factory tune for the 3 to 1 on the Mission it came on), and using the rebound circuit as a simple two way valve. The lads in the Fox factory would be horrified, but it works amazingly well, and by the way, after 10 months or so the charge is holding fine.
Anyway, now we've got a cable adjustable platform setting, and we can run it off any other cable driven function on the bike. I've set this bike up with a double in front, 24/34. It's a versatile little set of gears, and for Ontario's quick little steep hills, the 24t granny's just the thing for sprinting up, in combination with a 7spd 11-32. So using the binary nature of the double crankset, which co-varies nicely with the need for platform, I ran the cable off the front derailleur. Shimano's multi-fit derailleurs are perfect for this, having the ability to pull the cable from either direction.
Derailleur return boost spring and remote cable routing
So now the front derailleur controls the platform cable. There's a V-brake noodle clamped into a little block I machined from aluminum and steel, with a nice little boot to keep out the muck. The derailleur needs a return-assist spring, because the rebound plunger puts a surprising amount of force into the cable with a 200 psi charge in the damper, but with the boost spring, the derailleur shifts flawlessly. The spring's definitely the jankiest looking part of the system, but it's pretty well hidden away down there. Yes, it flew off once, when I was tucking the bike into the car at Coulson's Hill, but I replaced it with something that's a little more solidly attached and hasn't caused any trouble since.
So - after five months of testing back in the constant up-down cycle of the Ontario woods, I'm happy to report it does just as intended. You slam the front shifter back and you've got seven easy climbing gears and a very solid pedaling platform. Not locked-out, but certainly no bob or power loss. When you get to the top, slam the chain onto the big ring and you've got seven 'high' gears and a pretty open shock setting. The Autoplatform is kind of Ideal with the Recoil's high-ish single pivot, eliminating the annoying single-pivot-feedback that's most noticeable in the granny, and allowing the benefits of that feedback when it's muted and useful in the 34 tooth, where the chain lines up pretty well with the pivot.
Sprints up and down the hills in the Don, and you never forget to turn the shock on or off. Brilliant!


18 Comments

  • + 5
 Genius. Thought of the same - but linked to a fox dos seatpost so it softens the shock on drop and locks it when the seat rises... put our ideas together and we could rule the world!! Big Grin
  • + 2
 Cool, I like that idea too. I have a project with a seatpost that raises and lowers itself via a gripshift. Perhaps I can tandem it up with a shock or a fork travel adjuster! Just let me go and grab some more parts off the van...
  • + 1
 Holy Hannah, That is a great idea!
  • + 5
 Well done sir. Well done
  • + 4
 Nice! You better patent that before someone at FOX does haha
  • + 1
 I love doing custom fixes. If you can find an aluminum bolt to thread into the shock you might have a happier future. Also, dis you get rid of your mission or is this a back up bike?
  • + 1
 The bolt doesn't actually thread in, just fixes with the original tiny set screw from the rebound adjust hardware. What I really need better bolts for is the cam cover on the van! And no, I still love my Mission - use it every day!
  • + 3
 i am guessing big companies are already crowding the Patent Office, after You mentioned this stuff in a comment on CCDB Smile
  • + 1
 You sir, have made a brilliant thought a reality. If only bike companies had people like you at r&d dept...I see you have a schrader valve at ifp charger. Im trying that too.
  • + 1
 Thanks! I wish it were a schrader valve. It's actually a 1/8 brass pipe union with a presta valve core stuck inside. The Fox IFP charger threads are 5/16 (where'd you go, metric system?) and the union fits right in. About 3 USD at a good hardware store. Stick the right size O-ring in the bottom and you're ready to re-build Fox dampers at home!
  • + 4
 Nice
  • + 3
 Very crafty my hat goes off to u sir
  • + 3
 That's damn clever, and super resourceful. Bravo!
  • + 3
 Go go Gadget Scheider! Very brilliant.
  • + 3
 Thanks guys!
  • + 3
 Very impressive work
  • + 3
 Keep it comming :-)
  • + 1
 Top notch idea and execution

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