Amputees & Trials Competition - One Man's Solutions

Discussion in 'Trials' started by motobene, Sep 11, 2013.

  1. motobene

    motobene Motoing for 44 years

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    This thread documents some solutions or adaptations for right leg amputees doing observed trials riding and competition.

    There aren't many amputee trials riders. I am one, having lost my right (brake) foot up to 7" below the knee, and some fingers on the left hand. The missing bits don't hold me back much. Fortunately I can push hard with my right leg for weighting and dynamic body positioning. I can't actively articulate my foot at the ankle, and I don't directly feel what's under my foot directly. But wearing a prosthesis is like playing tennis. The better players learn how to very precisely control an extension of their body, their racket and feel exactly what's going on out there. A prosthesis is like a racket you learn to control to varying degrees.

    I mostly use one leg for everything, from ranch work to motorcycle riding (thus the very beat up looking leg below). When I compete in trials, I sometimes use a second leg with a lower-performing (less compliant) foot that is 'aligned' to be angled up in the toe. Otherwise, I can catch catch my toe on steps and roots and take points. It takes only one toe smacking incident to knock a fellow down from a solid 1st through 3rd finish.

    As for the hand situation I have just enough left for it to work well. Some friends have joked that I am so 'hands on' that I leave my hands on the work, or that I must be an alien because I have an ET hand:

    [​IMG]

    That hand is really strong. It has to be. I hold on to the left grip with only two fingers, little and ring, and clutch with the short index finger, which is attached to the what was once my middle finger, which is now dust somewhere. My hand doesn't tires out prematurely in events. Rather, heat has always been my biggest problem. I don't compete well in high heat indexes. I have heard amputees don't shed heat as well, but I don't know if it is that or just normal for me, missing bits or not.

    Anyway, this is about leg stuff and left side brakes, documenting some of my left-side brake setups from the `80s until today. It's nice to have the training and skills, and a machine and welding shop at the ranch (as well as an awesome place to ride).

    [​IMG]

    I ride on and off road... dualsports regionally and transcontinentally. I make no changes to bike controls on road bikes or dualsports. I simply heel the rear brake, standing or sitting. When I was racing cross country up to Expert level, I tried several hand brake designs, but they caused more problems than they solved. I learned to not miss the rear brake that I could not feel but every blue moon. And when I did, it was scary flying into corners in the woods! Yaaaoooh!

    Trials competition, however, requires immediate access to the rear brake. Fortunately, the shifter is up and forward on trials bikes, leaving room for a left-side brake. In trials we don't have to fan the shifter, so a left-side foot brake and shifter don't have to occupy the same space.

    I have had many left-side rear brake setups. Some bikes are easier to do this on. Others are harder. Some are really tough. for example, Betas. Betas are right-side chain bikes with a left-side kick start, so with a left-side brake there'd be three functions occupying the same are. They tend also to put the muffler on the left side, which takes up space needed to mount a master cylinder. The easiest bikes are left-side chain bikes with right-side kick starts and the muffler on the right side.

    My first conversion was on a TY350. I haven't found the photo of that one yet, but it was a machined aluminum mount that wrapped around the front sprocket with a steel brake lever pointing backawards. A hefty ATV rear brake cable went from the mount around to the other side, near the rear brake. It worked well considering a drum/cable setup does not stop as well as hydraulic brakes. I could lock the rear wheel up.

    The nexy setup I had for many years was on my `89 Fantic 305/7. This was to set the basic design theme for all future adaptations. That is, brake lever outside the frame rail with master cylinder on the left. here is the setup today, after my third and best rebuild of this bike. Anyone interested? It's likely the best Fantic of that year in the world. Buyers get a bike converted back to right-side brake:

    [​IMG]

    I can't yet find photos of the setups on my Fantic Section, KeyRoo, and Scorpa 250 (yet).

    Then I moved to Shercos. The Sherco frames allowed me to make a modular setup where the only thing left behind after I was done with the bike was two 6mm threaded holes in the frame rail and a groove in the frame rail for the brake line to sneak by. Here is the setup on the 2001:

    [​IMG]

    ...And the 2002, which I had up to about 2010:

    [​IMG]

    On the Shercos I was able to use the stock brake lines and not come up short. This required running the line not through the swing arm but zip tied on to top of the swing arm.

    Here is the 2001-2002 combination aluminum and stainless steel brake lever and an example aluminum blank with pivot hole and bushing:

    [​IMG]

    In 2012, after some years of laying off, I got back into trials. I was the lucky buyer of a particularly sweet 2010 Econo 280. The Econo used an older-version 2008 eliptical-tube frame, which takes up less space than the newer round-tube frames. The Econo also used the pre-2010 sub frame, which does not have the holes, does not stick out as much at the base, and has room to put the master cylinder inside, up against the air box air boot. This left only the lever and a long push rod exposed.

    The enabling solution on the Econo was to share the lower master cylinder mounting hole and the lower-left sub frame mounting, using a long FHCS M6. I welded a bracket from the frame to the upper master cylinder mount. The high mounting required a long push rod, which I made a little thicker to prevent buckling or bending:

    [​IMG]

    And a view from the back:

    [​IMG]

    The only negative I found with the solution was it really squeezed the air box boot. I about went nuts trying to get the boot on with the Dell'Orto-required rubber donut in the boot, until Stoodley told me to put the donut on the carb first (Doh!). Thereafter it was a tight fit, but I could remove and replace the sub frame with only a little extra care.

    During the Econo conversion I went back to an all-stainless-steel brake lever. I fabricated it from a prosthetic 'foot horn', which is a stout tool used to remove and replace the tough foot covers (called shells) on prosthetic feet. The toothed foot contact portion was made from laser-cut pieces I had made in bulk in the `90s when I was making extended-platform pegs for RYP:

    [​IMG]

    During the very first trial after the conversion, I smacked the brake lever hard on a rock sticking up on a steep hillside. Enough to almost knock me over. The lever bent a little but did not fail. Thereafter, it survived a number of competitions and is seeing use on the latest bike.

    I really like GasGas bikes, but this year I lusted after the pretty yellow 2013 Sherco 300. In a test ride, I found the Sherco wonderful, but a touch wide between the calves. My prosthesis, which is inset in the lower socket, can hit the right side of sub frames (you normal folks don't have this problem). Concerned that may be a problem, I opted for a 2011 Raga 300. I then found out the newer GasGas design is close to as wide at my prosthesis bulge as the Sherco. My leg is chewing up the sub frame stickers. The Sherco would have also been a viable choice. Oh well.

    The next photo shows the collision problem. The prosthetic foot is a well used College Park Soleus. This particular foot was developed from another amputee's patent. My design team struggled to make the complexities work within the interpretation of the patent. Took us 4 years, but the result was - in my very experienced opinion - the best do-everything prosthetic foot sold in the world today. The design is a bit wide at the attachment. That and the inset to my carbon-fiber socket tends to beat up sub frames. I correctly don't hug the sub frame, but with all the dynamic body movements of trials, stuff happens.

    [​IMG]

    The later-model GasGas design presented a challenge over the previous design. I could not put the master cylinder inside the sub frame. The only place for it short of something more complex was to mount the master cylinder under the sub frame. I assumed at first I could not, because the master cylinder would have been too exposed, or the brake and reservoir lines would get into the upper travel of the chain.

    During mock-up of the simpler choice, (mock up is when I put all the bits together and tack weld things in place), I found mounting below the sub frame was a very good option:

    [​IMG]

    The new mount tab turned out to be very simple. The Econo's lever was re used, but I had to tweak some details. I also re used the custom Speigler brake line that runs through the swing arm as the stocker does. I was not able to use the new style integrated-reservoir master cylinder, however, because the exit for the brake line is on top instead pointing to the rear. That pushed the master cylinder too low.

    Here follows a view form the rear:

    [​IMG]

    I had to machine another pivot from a old chunk mild steel form the ranch's scrap pile, as the previous one stayed with the Econo:

    [​IMG]

    Here it is clamped to the frame, ready to rack on:

    [​IMG]

    I'll update as things progress.
    #1
  2. nevgriff64

    nevgriff64 Super Moderator Super Moderator

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    Excellent work their, motobene. :clap :clap

    Another way around the rear braking issue is the use of a Clake. Its designed in Australia and incorporates the use of the rear brake and clutch using the one lever. I don't have anything to do with the company, just a very impressed and satisfied customer. Just thought i'd share with you, not to take anything away from what you have achieved. :thumb

    [​IMG]

    Here's the link to the company if you wish to check them out.

    http://www.clake.com.au
    #2
  3. motobene

    motobene Motoing for 44 years

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    Nevgriff, if you got through all that you definitely have an attention span! And thank you.

    Nice photo of the Clake. I know about it. I investigated the thing a couple of years back, even talking to them on the phone. The high cost and hugeness of the mechanism was a turnoff, plus some tech issue I'm trying to pull up from my old grey cells.

    And there's that thing about not wanting anything in the way of a super easy pull clutch. Might wear out my nubby finger :cry
    #3
  4. DerViking

    DerViking Shred

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    I don't have any need of a left brake, both legs intact and all.

    But.

    As a fellow fabricator of things I am impressed and honored that you would share with us. Your posts of late obviously represent considerable investment of time, we owe ya.
    #4
  5. jonnyc21

    jonnyc21 Trials Ninja

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    I agree, the considerable investment of time you have put into your posts are well worth the read! :D

    Thanks for all the sharing and you have a fan here in ID reading every post all the way through always eager for more. :ear
    #5
  6. laser17

    laser17 Been here awhile

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    Mad respect for people who just do it. (Sorry for the Nike rip-off, but very fitting) Besides, Im a sucker for pretty pictures - so keep it coming Chris. Great stuff!:clap
    #6
  7. motobene

    motobene Motoing for 44 years

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    Thanks, lurkers and responders all.

    I document things with photos. It helps a feeble mind to remember things :jjen

    I always carry a pocket camera. It's pull and shoot. I upload and organize photos with a great little Dutch photo program, PIE Studio, then tweak them in Photoshop. Years of doing this has made the process fast. The last piece fell into place recently when I finally listened to my son and signed on to Smugmug and its great embeddable links.

    The amount of time I spend may not be as much as it looks. This and the other Raga projects have been a great distraction from unending ranch projects in this enduring, infernal heat. My breaks are to do engineering-like work.

    Can't wait for the weather to cool and to ride the 'new' bike.
    #7
  8. Night Falcon

    Night Falcon Adventure NZL

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    Love your work and inspirational attitude motobene. I'm a big fan of threads with lots of pics and stories bout things folks do to their bikes...my wife calls it a sickness :D keep it coming cuzzy :clap
    #8
  9. Nodabs

    Nodabs Been here awhile

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    And I thought that I had it bad with one missing finger on my left hand. You rule!
    #9
  10. motobene

    motobene Motoing for 44 years

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    We were given all these spare parts. It doesn't hurt to lose a few. The brain just re maps and the body adapts.

    Why does it hurt to pee? I ask myself that sometimes....
    #10
  11. motobene

    motobene Motoing for 44 years

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    Appreciate you appreciating my work! It's not a sickness to enjoy an interesting read :1drink

    It's rare for me to focus on what's missing or focus on the few technical adaptations. But I thought maybe it might help someone with solutions they may benefit from.

    As for the 'inspirational' part, I've never thought of it that way. To me it's no big deal and normal. For many years I worked in prosthetics and dealt with amputees and amputee issues. I recall my first Amputee Coalition of America meeting in the early `90s where I caught myself thinking, "What am I doing here hanging around all these handicapped people?" Then it was like, "Oh wait, someone might think the same of me."
    #11
  12. AteamNM

    AteamNM Wonna Be ADVrider

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    Chris you are the bomb in many ways.

    About 22 years ago, I finished a trial at Red River moto park in N. Texas. I knew Chris and had been riding with him a year or two :ear. I went walking by his truck and he was sitting inside the enclosed shell in the back. There was a leg laying on the tail gate and he was chilling with his half leg laying across a boot. I was :huh. I believe he beat me that day as I recall thinking I just got beat by a one legged trials rider. :cry

    Chris handed me my hat again 20 plus years later in June 2013 at Sipapu. :D

    We have Willy Brown in our club same as Chris, he has been riding forever with one leg. I also remember a national rider and a minder during world rounds who was missing his arm from below the elbow. He had a cup installed on his handle bars and he could shred a section. Amazing people :clap

    Edit, never knew till now that you were missing digits........:fyyff:thumb
    #12
  13. motobene

    motobene Motoing for 44 years

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    'The Bomb!' Lingo from the ABQ and Breaking Bad. I am meth? Well I'm missing some brain cells, but that's another story.

    Love 'the finger' post digits! Sometimes if I waive with the left hand folks think I'm flipping them off.

    As always, a pleasure riding with you, and I speculating as to who you are are, Sir ATeam. Maybe T H? :1drink
    #13
  14. AteamNM

    AteamNM Wonna Be ADVrider

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    :thumb
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  15. HolyCannoli

    HolyCannoli Adventurer

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    Incredible fabrication skills!
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  16. motobene

    motobene Motoing for 44 years

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    Thanks so much!

    Yesterday I finally got a Roundtoit and TIG welded the frame's new left-side brake tab and pivot. There was also a minor dent in a frame near the upper shock mount. I filled it in and filed it back smooth to the tube's profile. Over this spot will go a new black side frame rail sticker, the black grip-looking strip that protects the frame rails from boots.

    Today the frame gets painted. It'll look all spiff and new when done. Instead of matte black it will be red. While I appreciate the few leading-edge bits of Raga models, I've never preferred the color schemes which in my opinion are a step down from the Racing and TXT models. I prefer the primary colors to gold bling or black. The latest Replica frame color scheme white, which is better., but I still prefer more color. I sure like that Sherco yellow!

    Cosmetics are secondary to function for me, however.

    Some data about the frame: the late-model round-tube frames are the same from roughly 2010 to the current 2014 models. It weighs just under 13 pounds. Those side frame rails, BTW, are thinner than one may imagine, so if you do any welding on them it should be low heat or pulsed.

    Another interesting bit about the steel frame are the left-right bottom structural members. The foot peg mounts and swing arm pivot portion are one cast piece. The intricate geometry you can observe is made possible without machining by a more pricey casting process called investment casting (or lost-wax casting). Originally developed for jewelry, the parts are made first in wax, then a ceramic coating is formed around the wax part, which gets melted out or 'lost'. Then the hot metal fills the cavity. The ceramic gets busted off the outside and voila! Parts with intricate geometry. modern production methods use injection molds to make the wax parts. If you look on their cored-out backsides of those pieces you will find the ejector pin marks from that manufacturing process.
    #16