One pedal on a crank not two!

[gar]

I still can't think how to render one pedal inactive while pedalling with the other foot.

Can anybody suggest how I would have one leg permanently resting.....on a foot rest instead of a pedal?

Saw off the shaft just outside and bolt it somehow and make an entirely independent foot rest for that side?

[TATANAB]

That's the old "swinging crank". In recent years Longstaff has made such things.

[gar]

One pedal would be a fixed wheel pedal
to maintain momentum using only one leg.
The other pedal (the whole crank)would be removed and a foot rest mounted .

gar

[gav]

Velovision magazine has done some articles covering self propelled vehicles for people with various mobility difficulties. They have the articles as free PDF downloads.

www.velovision.co.uk/cgi-bin/show_comments.pl?storynum=559

If it’s your left leg that has limited articulation it would of course be easier to manufacture a foot rest than if it’s your right leg which is on the drive system side of most bikes. I would agree with TATANAB that “swinging cranks”, also called “pendulum cranks” are maybe what you need as if the pendulum is mounted onto the crank near the bottom bracket there will be hardly any movement at the pedal.
It maybe possible to do something with an external Unicycle bearing, or to tap the thread on the bottom bracket so that a pedal can be attached directly to the bottom bracket.

[gar]

That is an interesting drive on the velovision recumbent picture but not mine for choice as the
handcranking chain has to go down and then back to the rear shaft... a lot of chain. Everything hsappens on the front wheel of mine.... if anything too much.. two sets of brakes, steering, gears the lot!

howeveri should like to use the leg that is working well and use my balance with a two wheeler. Tat's comment about "which leg" is very relevant (thank him) and of course on left hand side roads being able to put one's right leg through the bike to touch the ground... so essentially to have a ladies style bike handle bar
othewise one is alway balancing down and outwards.... into any traffic.

Paul butterworth sent me a reply last night and he is something of an expert. I don't know whether he actually makes the bike up but I am rather keen!

Thanks Tatanab!

[gar]

The Raleigh ladies bikes range have an excellent
non cross bar... very low indeed where I can put my right leg through to avoid toppling over.

I thought that I would be able to use gears AND
a fixed wheel but of course a fixed wheel bike only has the one gear.

If anybody knows otherwise please say!

Consequenlty I have to think of a way of bringing the pedal back up the other side,
where the other leg would have been pressing down.

A toe clip is all I would consider but then I would at least have derailleur gears.

A folding bike might be better for the job
as even the men's verion are easier to get the leg over inwards!
www.discountbicycles.co.uk/biz/product.php?xProd=1932&Source=kelkoo

[gar]

Your jargon is extra Rr! I could not think what you meant by stunt pegs! Yes! One stunt peg for the left leg positioned to get the best balance for only pedaling with one foot.

Getting off and pushing uphill with only one leg on the ground is not that difficult because the bike acts as a rolling leg! I am expert at it with Waitrose trolleys.

I am nearly there on the specs now.... ladies bike Raleigh Metro XL (very low bar indeed)
one pedal free wheeling 18gears....one STUNT peg! £280! Back on the open road in the spring! Yaroooooo!

[gav]

There are bikes with incredibly low step through frames such as the VeloCross by Heintz-Bikes. It’s frame forms a footboard that is about half a foot off the ground and this would give you somewhere to rest your foot.
Although “Stunt pegs” are designed for standing on they fit onto the ends of your axles so I believe they would be out of reach, unless you have very long legs.

[gar]

I think it is going to be Raeligh Ladies Metro bike
with a stunt peg. Fitting it in there would suit me very well. It has got really low space there to put my right leg through in emergency.

Thanks. I did not know that is where they fit in.
I only know about hybrid touring bikes really!

[gar]

I have also been thinking of the comparative advantages of using the hand cranked machine I currently use with a single pedal bike organised in the way that I envision(!) above.

How much more efficient would one fairly healthy leg be compared with the use of just two arms?

I think just one leg would be about 15% more
efficient than two arms, without going to the
science analysis site. The real problem is returning the pedal back up again , say on a steep hill, when only one leg is pressing down....
Even stevens..... that is merely a 50% loss.

I assume that the amount of power lost is equal to the amount of total weight bearing of the two limbs divided by two.

The amount of power engendered by the arms
and hands,may only be about 15% of that by the legs and feet, so I am much better off using a leg instead of two arms...... probably about 25% better off

I did used to walk 100 paces on my arms and hands but I could not keep that up for 50,000
turns of the handals ...... about 25% better of with one leg, rather than two arms..

(I have considered combining the three limbs into one hand AND foot cranked machine,
which Greg in Vancouver says he will build for me. He did this hand crank for me so he will give me a good price for the double machine. TJ points out that it could hardly be more like swimming!)

The difference is price £250----£2500
for the two machines but if I do want to be a circus act wherever I go, the more expensive version would be the most interesting.
I am already a circus act with five year olds who have only just escaped the tricycle .....
they think it is hilarious for an old man to be riding what they have just been glad to give up.... and what is more to be using his arms to do it and not his legs! Ha! Bloody Ha! Ha!

I'll post the hand/foot crank photo again

[gar]

www.garethhowell.net/Gardner_on_handfoot.jpg

I hope it is still on my remote

[gar]

Yes looking at that if I came off that at any speed I would break an arm and then where would I be?

Thanking you for your suggestions. That machine would need to be a trike recumbent hand AND foot cranked to be safe and effective for a one leggéd man. the xtra mass would be worthwhile.

Alternatively a high bike ( which Greg is good at designing ) like the Raleigh Metro ladies bike
with that chain system installed.

The one in the picture would be positively dangerous. It would have to be trike
recumbent with the two chain sets, for pedalling and handalling too at the same time, then balance is not really an issue.

[TJ]

I'm sure in gar's case it is one crank on a pedal!
Sorry, couldn't resist it.

[gar]

One leg I cannot use or exert downward pressure
My bike mechanics jargon is always bad
I should have said only one pedal on the shaft
I am right in thinking am I not that the crank goes from the pedal to the shaft, So I would have either
1) a swinging crank
2) a stunt peg

If the crank could move around and the pedal
but not for pedalling/cranking purposes,
it might be better than one's gammy leg
slipping off the stunt peg from time to time.

[gar]

I just cannot do without gears, even with only one useable leg. Modern cycling is what it is, due to derailleurs.

A stunt peg with a bit of the stuff which holds things together... velcrose

that will be ok