Powerchair Wheelie and Curbs

[Burgerman]

Just found an old vid from my GFs camera. A slowish 3 or 4 mph wheelie. Just trying to show here it cant turn over no matter how hard I hit the anti tip wheels on the deck on purpose.

image http://www.wheelchairdriver.com/images- ... r-1200.jpg old chair in video (but rebuilt +slightly modified etc)
image http://www.wheelchairdriver.com/images- ... rchair.jpg new chair...

http://www.wheelchairdriver.com/images- ... eelie.mpeg vid of old chair...

This was an old chair with "normal" wheels (although tubeless tyres, reprogrammed, seat relocated, etc). And "normal" anti tip wheel position but replaced by smaller skate wheels so they are high enough to wheelie. But still long enough to hit everything...

This tippyness (with a little more finness) and less forward speed than shown here, with just enough height to just lift the front wheels over the curb is how I approach up to 3 inch curbs too. Now 4 inch+ with the newer fatter rubber chair.

It means that just the two rear wheels have to climb it and you have momentum. With the latest chair and its fat soft all terrain tyres http://www.wheelchairdriver.com/ultimat ... rchair.htm these rear wheels easily go up with hardly any bump. They just absorb the curb... Its pretty smooth. I go off curbs the same way. Will get a vid one day soon.

But the anti tip wheels are now shorter, higher etc. (see pics) It CAN now be turned over if you are really enthusiastic, if you just shove the stick forwards like a loony and hold it there... Or go up too steep of a ramp forwards! Bit like a sports manual chair. Bit lively!

Obviously its (both chairs) also got a bigger and seriously re-programmed controller too. So its very controllable. Unlike all stock powerchairs.

[Lord Chatterley]

Can you climb subways and your van ramp without flipping backwards or do you need to reverse?

[Burgerman]

Depends which of the three chairs. All very slightly different. All can just do the van ramp forwards, but it means more manoevering to get straight on to the drivers position. Better to reverse in and just turn to face the front and move to the steering wheel. Which doesent work in mid drive chairs. You need to do a little "shuffle" in those...

Subways? Are you in the US? We dont have subways. But anything even slightly steeper than my vans ramp and reversing is prudent! The anti tips would be too short / high in that situation...

This is why its a bit like a sports manual chair. It can do all sorts but you have to understand and control it, and understand the physics of a tippy chair. Its got many advantages but get it wrong and you will fall out! I can go up and down a 4 inch plus curb (actually more like 7) in a manual wheelchair. Without tipping out of the back, which looks impossible on the face of it.

We were made to practice it in the spinal injuries unit in sheffield if brave enough. But its about momentum and control and physics and feel.

Well I can do much the same tricks in a controlable tippy responsive powerchair. Its no good for grandma but if you can accept responsibility for your actions it does give you more control.

Then again before I landed in a wheelchair I used to be able to wheelie a big 1100cc Suzuki for half a mile at a time in the first 4 gears and mid 3 figure speeds too! Its a "control" thing. You either have that or you dont. Actually I wasnt "able to do it" but really couldnt stop myself!

I see some guys doing backflips and forward flips in manual wheelchairs lately. Well its the same thing. But rather them than me I am 50 this year!

If I sold this chair to a less "adventurous" type, I would move the seat forwards 30 to 40mm, tone down the programming lots, fit slightly bigger anti tip wheels, etc. And make it "safe" controllable but less exciting!

Remember the chair in that old vid is a lot less lively, and has hard skinny tyres, and "safe" (but longer and lower) anti tip wheels. And I was much fatter then. The new fat tyre version is shorter and even more wheelie prone and has a shorter overall length.

Which makes it easier to pick the front wheels up with the new one, even at say half speed when you spot a tree root or other less than smooth paving slab/pot hole, ramp start, threshhold, drain cover, small child etc. So just the big soft tyres hit the obstacle, curb, or whatever.

Rearward C of G (and some power and instant control) makes wheelies and control massively easier, steering more responsive, Increases speed on a road edge (edge of camber or anywhere not flat,) improves range noticibly, and also easier to tip out the back! Its all a compromise of your choice.

You have to "get" and accept responsibility and decide on your preferences. Just like a sports manual chair. Its another reason I have 3! All different, depends where I am going, what I am doing etc.

[Lord Chatterley]

Rrrrriiiiight. All that makes sense.

Apart from this part...

Then again before I landed in a wheelchair I used to be able to wheelie a big 1100cc Suzuki for half a mile at a time in the first 4 gears and mid 3 figure speeds too! Its a "control" thing. You either have that or you dont. Actually I wasnt "able to do it" but really couldnt stop myself!

...which makes no sense at all!!

Lunatic!!

I finally get it - the balance thing is really something that has to be tailored to each individual, and with thought to terrain, seat angle, seat position, anti-tip position and length, occupant weight, battery weight etc. .

Speaking of batteries - did Valence provide you with any idea of the minimum order number?

[Burgerman]

No. They will only supply big organisations...


>>> ...which makes no sense at all!!

Its fun. I spent ten years racing "street" drag bikes. Which were also road bikes. With Big turbos and Nitrous injection, and 300nhp plus. Lots of tyre smoke and wheelies at almost any speeds up to speeds you really wouldnt believe are impossible to avoid. You just learn throttle control/balance. After a while your brain gets sort of recalibrated and you are used to it and everything else just feels slow/broken.

[Lord Chatterley]

Thanks.

If I knew of a big outfit they supply, I'd visit them and try to scrounge one!