Friday, January 25, 2013

Redshift


Putting together what I’ve learned

This blog post is somewhat different than those that precede.  Most of those prior posts shared my excitement over an event or an accomplishment.  This one will be similar in those regards.  This post, however, is intended to share a little technology that I have recently put to use.  So pardon me in advance if I get a little geeky.  There is some information here that can hopefully benefit folks with disabilities like mine.  And for others, maybe there is some inspiration of your inner creative genius that will allow others to do more with what they have.

I have used two handbikes for years, a Quickie CycleOne I call, “Tortoise,” and a Top End XLT I call “Hare.”  Tortoise is generally my exercise bike.  It attaches to my wheelchair and is useful for getting around town without having to use a power wheelchair.   Because transferring to a recumbent handbike is more difficult, Hare only got on the road for longer distances including a number of half and full “Harethons.”  I wanted something a little more competitive than Hare and something a little more reliable.  The Top End XLT has a number of features that are less than ideal for me.  I wanted something that would give me better hill-climbing ability, easier turning, and more gears-both higher and lower.

So you understand me a little better, I’m a C-6 quadriplegic, complete.  I’m a little stronger on the left side but I am right handed so I tend to do the more complex tactile functions with my weaker side.   I’m 5’ 11” and around 175 pounds or so.  I have good biceps but no triceps.  I have no grasp but a slight pinch through tenodesis movement of my wrists.

There was not a handbike on the market that would fulfill all of my needs and objectives so I eventually decided to embark upon a project of modifying a new handbike for my unique needs as a quad.  It turned out that several mods would be required to make a bike “quad-friendly,” but it turned out to be the synergy of those mods together that made the outcome so exciting.

The bike

It seems to me that everywhere I go these days, the popular ride of choice is the Top End Force in all its various configurations.  Bike-On also modifies a Force with a set of modifications specifically for quadriplegics.  My hat is off to Scott Pellet at Bike-On for working so diligently to bring the sport to so many us folks with higher-level disabilities.

My own disability is about as high as anyone whom I have seen on a handbike.  Just the cycle of transferring on and off from my everyday wheelchair consumes an hour of my and my wife’s time.  One of my biggest problems with handbike is steering.  There is a blessing/curse in cycling called rotational inertia.  It’s the force that makes a spinning top resist falling over.  On an upright bike, you don’t turn the front wheel to turn the bike.  You lean in the direction you wan to turn and the rotational inertia of the wheels generates a force to turn the bike and counteract your leaning.

On a three-wheeled handbike, the bike doesn’t lean.  You actually have to force the front wheel left or right against its rotational inertia to turn the bike.  There is very little force required at slow speeds.  It is quite a bit at higher speeds.  Most handbikes have condition known as “wheel flop” built into the front end geometry.  Wheel flop is basically a tendency for the wheel to “flop” to the left or right in the absence of rotational inertia.  The tendency to “flop” correlates to a tendency to turn hence it offsets some of the difficulty steering at riding speeds.   On the other hand, at low speeds, the wheel flop itself is difficult to overcome if the front end is quite top-heavy as was the case with Hare. I was hoping for higher speeds so I need a steering geometry that is as easy as possible.   My ‘turning muscles’ are pretty weak.  One of the reasons that I opted not to go with a Force handcycle was that I felt the steering would be harder than I wanted.

I chose the Freedom Ryder FRH-1 because from the limited analysis and observations I was able to perform, it looked like the FRH-1 was about the easiest-steering bike available to me.  It did, however pose some challenges, as would any bike.  I need:
  • Grips that give me positive engagement with the cranks 
  • Grips that I can separate my hands from and reengage quickly
  • Shifting I can operate without taking my hands off grips
  • Thoracic supports for trunk stability
  • Braking I can apply without grasp and without taking my hands off the grips
So, for the techno-geeky types, this blog post is the story about how I implemented these features and how I continue to refine them.  I first rode the Freedom Ryder about 7 months ago without any mods except the grips.  As of this post, I’ve accumulated over 1,300 miles on the bike in various stages of the mods you will read about herein.  I would have posted this article sooner, but frankly, I’ve been having too much fun riding the bike.

QuadGrips

The QuadGrips by James Watson are, simply, the best grips for quads out there.  I did my own trials of Top End tri-pins, Quickie V-grips, the C-5 Grips, and the German-made Stricker quad grips.  After a few years of experimenting, numerous blisters, and more than a little blood spilled, I started trying to design a grip myself which turned out to be a lot like what James Watson came up with.  My approach was to attach the tri-pin grip to a bicycle pedal but attach the front pin vertically vice horizontally.  It worked out pretty good.  James Watson’s grips work far better, though.

Here is my homemade quad grip built from a modified tri-pin grip installed on a Quickie CycleOne
As a quad, I don’t grasp the handle; it grasps me.   The ability to detach your hand and reattach it quickly is the ‘game-changer’ with James Watson’s QuadGrips.  His website is full of pictures and videos of the advantages of his grips.  He is also a great person and willing to share his technical advice and suggestions.  It takes a bit of adjusting to find the best combination of all the adjustments available with QuadGrips.  They don’t come with a foolproof procedure for adjusting them.  All I can say is if they are not working great for you, then you don’t have them adjusted quite right.  I don’t have any specific procedures, either, except to suggest that when you are trying different settings and you don’t know whether to go one way or the other, do both.  Adjust one hand one way and the other hand the other way.  You will find out pretty quickly which one works best.  Also, I found the fit after 15 minutes of use was different than when I started out.  So if you adjust them during your ride, don’t un-adjust them when they seem not to work at the beginning of your next day’s ride.

James told me a lot of things about his grips that I would have dismissed as salesman-speak except that from my own experimentations, I knew to be true.  When he told me about operating an index shifter by extending my wrist, I was skeptical; or at least in my case, with only the slight functionality in my right wrist.  He had turned out to be accurate in nearly every other suggestion he made so I decided to give it a try.  The exact position of the shifter lever turns out to be a very sensitive adjustment, but lucky for James’ reputation, we hit the sweet spot right away.   I could shift up and down the cassette without taking a hand off the grip!  I rode around the neighborhood all night, a shiftin’ fool.

Shifting ‘up’ on the cassette by flexing my wrist
Shifting ‘down’ on the cassette by extending my wrist
I have found that adding a grip to the shift lever improves the traction of my pinkie knuckle on the shift lever.
I added grips to the LX shifter to give a little more positive contact with the back of my hand.

Thoracic Lateral Supports

When I first rode the FRH, I did not have any lateral supports installed.  It felt a little shaky since I don’t have any lower abdominal strength.  After riding the bike a bit, I was starting to enjoy being able to lean hard to the left and right as I set up for turns.  I started to feel like I would not install them.  Logic told me that I could have a lot of fun without them as long as everything stayed under my control, but only a fool would believe that that would always be the case.

As a quad, I don’t have much trunk stability.  Reclining with the FRH’s articulating backrest makes me fairly stable in the fore-and-aft axis but in the side-to-side axis, my stability came from hanging on tight to the QuadGrips.

Riding without lateral supports installed
The FRH has the ability to make sharp turns through corners faster than I am strong enough to control it.  That fact means I can find myself with enough lateral G-force to lose my balance.   If I counteract by pulling against the grips, that will only tighten the turn and increase the force de-stabilizing me.  After I installed the lateral supports, I had two great advantages, one of which I had not foreseen.

The first advantage is the obvious one, the added trunk stability.  The other advantage the lateral supports offer is they enable me to make turns much faster and tighter than without them.  The faster the front wheel spins, the more rotational inertia it builds.  That rotational inertia resists me trying to turn the wheel.  On a handbike, you have to muscle that front wheel against that inertia in order to make it turn.  It literally takes strong muscles in parts of the arms, back, and chest that I can’t use.  Picture yourself holding a heavy book straight in front of you and then moving it to the left and to the right except against strong resistance.  You would be using those ‘steering’ muscles.

Most quads have fairly strong biceps and when locked into QuadGrips, can pull on the cranks very hard.  The lateral supports, when positioned correctly, give the quad the ability to plant one elbow against the end of the pad.  Doing so will allow him/her to lock the crank in that rotational position.   When he/she pulls on the crank with the other arm, it can result in some ‘breathtaking’ turn rates.  I can enter a u-turn on a normal width two-lane road at 7 mph and turn sharp enough to complete the u-turn without running out of pavement.

The left thoracic lateral support is seen behind my elbow.  They can significantly aid in turning by allowing the rider to turn using the stronger biceps muscles.
The added turning ability the lateral supports offer makes them a must for a quad, in my opinion.  There is a significant risk with their use, however, but a greater one if they are not used.  The risk is that the quad becomes dependent on using the supports for faster turn.  The faster the turns, the more wear and tear the equipment experiences.  If the lateral supports break, it will be at a time of maximum stress, i.e., fastest turning.  Hence my ‘don’t try this at home’ disclaimer:  If you wish to copy my application of the lateral supports, keep this fact in mind as you design them and maintain them.

The supports I used have some modifications.  The model I use has the swing-away feature which is very handy for transferring, but the swing away bracket significantly reduces the strength of the bracket and is much more prone to catastrophic failure.  If the swing-away bracket were replaced with a solid aluminum bar, the danger of breakage would essentially be eliminated.  My brackets also have a quick-release feature hence the entire bracket slides out when you retract a retaining knob.  Simply removing the lateral support using the quick-release feature would be adequate to give you the clearance necessary for transfers.

There are also some quick-release brackets without the swing-away feature that should also eliminate the failure mode.  I simply haven’t had time to research the dimensions to select an equivalent replacement.

The FRH-1 back has an aluminum sheet metal plate that is not strong enough for mounting the lateral supports directly.  I had Bircher, Inc., make a stiffener from high-strength aluminum. The stiffener attaches to the seat back and the mounting brackets for the lateral supports install on the stiffener.  The photos below show the design.  Again, a caveat:  note that proper surface treatment and corrosion prevention are important when using the high strength aluminum.

Backrest stiffener shown with lateral supports attached.  Depressing the red lever allows the pad to swing outward.  Pulling the silver pin on the bracket mount allows the bracket to be positioned inward or outward or completely removed.
The stiffener is attached to the back plate and will carry the load of the lateral supports directly to the FRH-1 frame.  The holes in the stiffener are threaded.  The screws pull the back plate up tight against the stiffener; the screws are then secured with self-locking nuts.  The longer screws extend through the mounting holes on the bike frame.
The front of the back plate.  The screws are flat head with finishing washers.
All assembled and ready to install.
Once I got the lateral supports installed and operating on my FRH-1, I started losing skin in large areas on my elbows and forearms.  I immediately had to modify the lateral supports to keep from bleeding to death at my second favorite activity.  Notice in the picture above how there is a Z- bracket attached to the padded part of the lateral support.  The mounting brackets stick out and the padded supports are positioned inward with the Z-bracket.

I wanted the mounting bracket moved inward and wanted to reverse the offset provided by the Z-brackets so as to get the swing-away brackets out of the way of my elbows.  Step one was to shorten the quick-release brackets so I could slide the swing-away bracket in closer.  The quick-release bracket was longer than needed and it was limited in its depth it could adjust because it would bottom out against the FRH backrest mount.   I had Bircher, Inc., shorten the bracket.

This picture shows the various mods and features for the Thoracic Lateral Supports.
With the brackets shortened and adjusted inward and with the Z-brackets offsetting the pads inward, the spacing would have been too narrow for my trunk.  It was not simply a matter of flipping the Z-brackets.  The Z-brackets would not install on the pads in that direction.  So I flipped the entire pad with Z-bracket attached.  I installed the left one on the right and the right one on the left.  That took care of the offset but because the pads are curved, they were then curving outward.  I used a sophisticated metal bender, a Ford model E-250.  I placed the pad under the wheel such that the weight would reverse the bend.  It did the trick.  The picture below shows the finished product with the mounting brackets shortened and moved inward.  The pads are swapped and the curvature is reversed, all of which has moved the hard metal parts well inward and away from my elbows.  I also added D-rings to the back of the seat to attach a Camelbak.

All of the HARD-ware is now tucked in behind the seat.  With the support pads reversed, the lateral supports are about as compact as you can make them.
I made a few other mods based on my experience with lateral supports.  I took out the hinge pin and replaced it with a socket-head cap screw with a self-locking nut.  I had experienced problems with the hinge pin backing out in the past.  Again, if you try to copy me, note that the pin is tapered so you can only remove it in one direction.  I also removed and replaced all the attaching screws and added medium strength thread locker.  I did the same for all the mounting screws attaching the backrest stiffener to the back plate and the screws attaching the quick-release brackets to the backrest stiffener.  Again, if anyone tries to do this, I recommend you forego the swing-away feature and its wear problems unless you have a specialized need.  For transferring, the brackets can be removed with the quick-release knob.

A lot of work went into the lateral supports.  For a high quad like myself, turning is difficult because muscling the cranks left and right demands the use of muscles unavailable.  However, by bracing one elbow against the end of the lateral support (left, in this case), the cranks will not rotate.  When the rider pulls with the other crank using biceps, the front end turns (to the right, in this case) and the rider can literally achieve the maximum turning speeds available from the ultra-nimble FRH-1.

Bike-On Quad Brake

I sat on these ideas and read and researched for a long time before I started fastening metal.  The first thing I did was to get on the bike and ride with the brake/shift levers installed on an accessory bar that Mike, from Freedom Ryder, gave me with the bike.  It is an arrow shaped device made of 3/4 " welded steel tubing.  I had it installed with the brake/shifters installed forward of the crankset.   There is a lot of adjustability in the position of the crankset on the FRH-1 and that makes this a great choice for a quad.

Literally the first ride on the new Freedom Ryder with the brake and shifter levers mounted on an accessory bar in front of the crank.
One constraint for a quad like me is no triceps.  That means you want to minimize the need to push anything and position everything that you do have to push lower than shoulder level.  That was all possible with the cranks and brakes on the FRH.  By lowering the crankset until there is only about 1/2 " clearance between the chainring and my belly, I had the cranks as low as they could go and minimized the amount of pushing necessary in the top/forward sector of the cranking circle.

I was enjoying riding the FRH with the Deore brakes and shifters so much that I was riding when I should have been engineering.  I got hot on the project after trying to make a sharp left descending turn on a steep hill and had one hand on the grip and the other on the brake.  The wheel was turned hard over and there was no way to straighten from the turn without releasing the brake to move my hand to the other grip and committing to the drop.  I could envision many scenarios where braking and turning simultaneously would not be optional.  The Bike-On Brake was a necessity.

Mike made a crank spindle for me that was 2 inches longer than the standard FRH-1 spindle.  I had Bircher Machine make a sleeve for me that slides onto the 3/4” diameter spindle.  One end of the sleeve is reduced in diameter to fit inside the bottom bracket lock ring.  The other end is drilled and tapped for set screws.

The sleeve is not visible but it adapts the 3/4” dia. spindle to the 30 mm bearings.  On the right end, the sprag bearing extends up against the bottom bracket lock ring.  Since the cable lever is normally not rotating and the cranks are rotating I placed a thrust bearing on the left next to the lever and added shims to cover the sleeves where the set screws are applied.  A 3/4” inch washer holds everything in position.
To prevent the brake levers from sliding on the sleeve, the right end of the sprag bearing butts against the bottom bracket lock ring.  I placed a thrust bearing and shims against the cable pull lever and slid a 3/4” I.D. washer over the spindle to hold the entire stack-up in place.  I found a gap of about a fingernail thickness when I installed the crank arm allowed the sprag bearing to rotate with little drag.  By swapping the left and the right cranks, the extra length of the spindle is approximately compensated.

I added a 7/8” tube under the cable lever to provide a rest for the lever.  I padded the end with a ring of rubber cut from the end of a handlebar grip.  I attached the tube with a cross clamp from a set of aero handles.  For a brake cable stay, I added a second tube mounted into a handlebar stem.  Bircher Machine fabricated a plug for the end of the stay with one face milled flat.  The plug is drilled and tapped for a adjusting barrel and locking nut.

Shows the brake cable stay on the left held in place with a handlebar stem.  The brake cable lever on the right rests on a rubber donut cut from the end of a handlebar grip.  The rest tube is clamped in place with an aero bar clamp.
In use, I find it more practical not to engage the plunger into the hole in the actuator lever.  Instead, I leave the plunger extended and let the outside edge of the actuator lever rotate around and contact the plunger.  This gives me approximately 3/4 of a rotation backwards before the brake engages.  This “play” is particularly useful on a steep hill when I can’t complete the crank rotation over the top.  Instead I can row crank my way up the hill or at least for a few strokes to rest until I can make a full rotation.

Another reason for extending the plunger outside the actuator lever rather than in its hole is that it allows me to choose the spot in the crank arc at which the brake will engage.  If the brake engages on a hill when I am rolling backward and the cranks are at a point in their circle where I have no strength, then I will be unable to crank the bike forward out of that spot.  By starting my reverse cranking from the spot of my choosing, I can apply my brakes at a point in the crank circle where I have the power to pull out of the stopped position.  I can also position the cranks in a favorable steering position when I need to brake and steer simultaneously.

Note that Scott really doesn’t wish for folks to be tinkering with something as critical as his brake.  Hence he doesn’t sell the brake to the general public except as installed on his Quad-Elite bikes.  He does sell it to Freedom Ryder these days.  If you need a Freedom Ryder and a Bike-On Brake, they are available now, to the best of my knowledge, installed at Freedom Ryder.

Shifter and accessory bar

Finally, I added some accessory mounts.  In one of the previous pictures you can see some D rings I added to the back of the upper seat back.  They are for attaching a Camelbak.  I also used an arrow-shaped tubing bracket Mike gave me with the bike.  It installs into the horizontal positioning tube on the bottom bracket.  I cut the ends off to reduce its size and weight and added 7/8” tubing to it to mount the brake levers.  With the disc brake operated by the Bike-On brake actuator, I have the caliper brake wired into the brake lever.  I added a cross brake lever to the other side to give me two levers to operate the caliper brake.  There are times when it is preferable to use one hand instead of the other because of road crown or other factors.  I now have the Bike-On brake for a primary brake and the caliper brake can be operable with either hand as my secondary brake.  This whole accessory bar is going to be modified at a future date to be a little lighter and more aerodynamic.  I’ll offer one observation regarding placement of brake levers.  For a quad without use of triceps, they should be mounted below the height of his/her shoulders for maximum effectiveness.

I also added a short tube perpendicular to the frame to mount accessories. That mount gives me room to mount the lights, GPS, etc.  If you notice a number of these pictures are taken at night.  I ride at night to avoid the heat that dominates our summer days here in the south.
I’m enjoying shifting the gears with the shifter mounted on the QuadGrips.  However, I experience muscle spasms sometimes that make my hand clench on the grip.  When that happens, I have difficulty flexing my wrist.  I may change out the LX shifters in the future to the trigger shifters and relocate them to a bar that I can reach with my chin.

Acknowledgements

My quad mods turned out to be better than I expected in terms of the functionality they provided me.  It was a lot of work on my part and on the part of my wife, who I might add has demonstrated a considerable bike-mechanic prowess.  I need to extend some thanks, however, to some people without whose help, this project would have never started.

My one-of-a-kind Freedom Ryder FRH-1.
First of all there is the incredible bike, the Freedom Ryder FRH-1, that inherently makes a great handling platform for quads.  Its adjustability allows you a lot of options in accommodating specific ergonomic needs.  Mike Lofgren spent many evenings in conference with me over the telephone helping me get things the way I needed them.  If you are a quad considering a handbike, consider the FRH-1 before you buy.  Although, he doesn’t have a web page yet advertising his own quad mods, He has taken these lessons and his own experience to put together his own version of Quad-FRH-1.  Visit his website and contact him to learn more about how he has adapted the Bike-On Brake to the Freedom Ryder.

Speaking of Bike-On, I could have never gotten this bike up to speed without Scott Pellet’s Bike-On Brake.  I see a lot of European handbike makers with an extensive offering of handbike options for quads.  Scott is giving them a run for their money in the USA with his Quad Elite set of options for the Top End Force.  The Bike-On Brake is a game-changer for quads.  Without the dexterity to squeeze a grip lever, the Bike-On Brake gives you a simple ‘coaster-brake’ operation in a derailleur-geared bike.  Look for more great things for quads in the Bike-On inventory in the future.

Now speaking of burning up the telephone lines, discovering James Watson turned into immediate friendship.  Although we never met face-to-face, we hit it off immediately, finding we had a lot of mutually common background.  His QuadGrips are another game changer.  I’ve tried a number of other solutions, but so far, his are the best grips out there for quads that I have been able to find.

Locally, I couldn’t have done it without a couple of great gearheads.  A big shout of thanks to Steve at Beaufort Bicycles.   Steve is never hesitant to take an old bicycle and turn it into some kid’s pride and joy.  Steve is never hesitant to tackle any of my wildest experiments and was invaluable getting the Bike-On Brake cabled up and running.

Another bikeshop that has kept me on the road is Crystal Coast Cycles.  Bruce has literally adjusted my brakes and shifters every way conceivable and has solved every problem I could invent with my shifter cables.

I could never have gotten the shifters fine-tuned without the patience of my friends Bruce and Tricia at Crystal Coast Cycles
 Bruce and I met last April at a charity ride for Hope For The Warriors (you know I had to squeeze in a mention of my favorite charity).  I blew a tire in the first mile of the ride and he got me back on the road.  No easy feat with Hare.  The front wheel on that bike doesn’t come off without a BIG fuss.  Since I was essentially left behind by everyone else in the event, Bruce rode with me the whole way.  We got to be friends, having the whole course to ourselves.  I think we chatted on every bike subject imaginable.

I’ve never a lot of metal working before so this was a unique design experience for me.  I can say that Jim Bircher at Bircher, Inc. machine Shop made the process much less painless.  He wasn’t free, but his services were top quality and reasonably priced.  He helped me understand his metal working capabilities and understand how to integrate that knowledge with my design needs.  Visit his website and check out his unique naval armament!

A bike this nice shouldn’t be on the road without a nice paint job.  Dan at Roberts Body Shop made this happen for me.  The pictures in this post don’t do Redshift justice.  Yellow is the theme color for my 2008 Miles of Hope campaign (see there, I worked in a mention of my own fundraising).  My Freedom Ryder came with a beautiful candy red finish.  Dan was able to blend the red in the front into a beautiful yellow-metallic-pearlescent aft end.  I’d love to give Dan’s business a plug but he’s retired now and he sold his body shop.


Finally, I no longer had the billboard space of my bike basket on Hare to post my Hope For The Warriors decals, patches and memorabilia.  Instead, I have had to streamline my “signage.”  I have to thank Ralph at Ralph’s Sign Shop for making the decals for my new ride!

Conclusion

I hope the insight I’ve provided here helps readers appreciate the value of the products that it takes to get quads on the road.  I regret that we live in a world where large companies that can afford to offer products for quad economically choose not to because it’s not profitable or glamorous.  I also hope there is some value and insight conveyed by my work and that it may help others offer better products for quads.  The combination of the Bike-On Brake, the FRH-1 handbike, and the QuadGrips is a game changer for quads.

If you’re a handbiker and have an appreciation for this project, leave a comment below.   Hopefully you and I will meet in person sometime.  Hopefully it will be on the road.

Fort Macon State Park, Atlantic Beach, NC
Riverwalk Trail, Columbus, GA
Virginia Creeper Trail, Abingdon, VA
-LetsRoll!

5 comments:

Tyler said...

Great post! Loved learning about the technology you use!

LetsRoll said...

Thanks, Tyler! Hope to see you out on the road some time!

-LetsRoll!

Scott Pellett said...

Hey Paul,

Real nice write up on your bike. It is my pleasure to have been able to have a part in your success. Thanks for spreading the word.

Bike-On!!
Scott

James Watson said...

Wow! Paul you never cease to amaze me in your drive and tenatiousness. I'm glad we met via email and phone and hope we can meet in person. Great job on your blog too!

Thanks for the good words on the QuadGrips.


James

LetsRoll said...

Thanks, James and Scott for putting products out there to enable quads to get out there. Keep up the good work!

-LetsRoll!