[python] Re: Geared Steering
- From: chris williams <chriswilliams67@xxxxxxxxx>
- To: python@xxxxxxxxxxxxx
- Date: Tue, 28 May 2013 21:40:39 -0400
Talking about high speeds, has anyone tried having electric assist on a
python? Would not having to pedal at high speeds help controllability?
Chris.
Also from Toronto :-)
On Tue, May 28, 2013 at 8:19 PM, Logan Streondj <weyounet@xxxxxxxxx> wrote:
>
>
>
> On Tue, May 28, 2013 at 2:28 PM, Kelvin Arthur <kelvin.arthur@xxxxxxxxx>wrote:
>
>> Hi all
>>
>> The first version of my python I got up to 65km/h, it was pretty scary,
>> but I flew past a road bike going down the same hill, and I ran out of
>> gearing at 35km/h! I think experience will make the difference. Thinking
>> back, if I had had handlebars, there's no way I would have been touching
>> them, I was concentrating much too hard on what I was doing.
>>
>> I tried putting handlebars on it when I was first learning to ride, but
>> quickly realised that they weren't actually helping me, so they came off
>> and I pushed on.
>>
>> The idea may well have merit, but I think one of the posts had a good
>> point, handlebars are naturally counter-intuitive on a python...
>>
>
>> My 5 cents worth...
>>
>> Thanks for your contribution,
> that's what I thought, in terms that handlebars probably wouldn't be of
> much help,
> though again, it's hard to say since you didn't have them.
>
> That's why I figured that the geared alternative can make going at high
> speeds on the python a less scary proposition, since holding the levers
> converts it from a wavy-boom to a rigid-boom, or at least rigid enough to
> keep it straight with fine adjustments possible.
>
> Currently none of the handle bars that have been implemented to my
> knowledge worked with the pivot, I think in DF bike terms that would be
> like having a handle on the front fender.
>
> Also I'm not a "speed demon" I'm simply safety-conscious, and prefer to
> have a safely controllable bike riding experience at all speeds, including
> high ones that come with the terrain.
> I live in Toronto near the Don Valley, and the speeds going through it
> mean I usually achieve equal speed to the cars when going through, which is
> around 50-60km.
> It means if I was to use a python it would have to be safe at those speeds
> to do it regularly, and loaded with heavy cargo like groceries.
>
>
>
>
>
>
>
>> Sent from my iPad
>>
>> On 29/05/2013, at 5:25, Patrick van Gompel <
>> patrick_van_gompel@xxxxxxxxxxx> wrote:
>>
>> Ah ok. Well sorry, I have no experience with driving 66+km/h on a Python.
>> Even on a recumbent (Condor) I get a little scary when driving 70km/h and
>> whould never take my Python that far.
>> So I am sorry I can't help you much with those speeds and I can't tell
>> what the effect of a normal handle bar would be.
>> You were talking about a 'low-walker', so that confused me, because I
>> don't think that a Python is slow. I have never been able to pedal my
>> Python faster than I could handle, but hey, I am no speed machine ;-) And
>> there aren't hills around here to get 66+km/h speeds.
>> Patrick
>>
>> ------------------------------
>> Date: Tue, 28 May 2013 12:17:57 -0400
>> Subject: [python] Re: Geared Steering
>> From: weyounet@xxxxxxxxx
>> To: python@xxxxxxxxxxxxx
>>
>> well I was thinking mostly to stabilize things like going downhill very
>> fast,
>> I read a review online that said it was "puckerish" and he could only
>> achieve a speed of 66kph vs 90+kph with rigid boom, had to engage the break
>> and even then it wasn't pleasant.
>> http://www.recumbents.com/forums/topic.asp?TOPIC_ID=4226
>>
>> I like the python center-steering, but I'd also like to be able to go
>> fast downhill without having to do too much work getting it to go
>> straight. There are a bunch of hills in my area with relatively high speed
>> traffic, so it's important that can maintain control.
>>
>> If ordinary handlebars are enough to make it easy to go downhill at high
>> speed, then I guess that'll be enough,
>> it was just my understanding from that post that it wasn't, though
>> perhaps they weren't using handlebars for that downhill testing.
>>
>>
>> On Tue, May 28, 2013 at 11:13 AM, Patrick van Gompel <
>> patrick_van_gompel@xxxxxxxxxxx> wrote:
>>
>> My thoughts:
>> A Python is a leg/hip steered bike. You can have handle bars anyway you
>> like, but for a newcomer it might be even more confusing. You really need
>> to learn to steer in a different way and forget about steering with your
>> hands.
>> I did have and still have a handle bar on my Python(trike). When I learnt
>> to cycle I always got rather tired arms, because my legs would go one way
>> and my arms tried to correct that (which was bad). Now I use the handle
>> bars for extra stability and sharp cornering.
>> Looking at your drawing:
>> Unless you succeed in making this a durable construction I doubt it will
>> survive the big forces for much time.
>> I am not saying you should't try it, but why do you prefer this
>> construction above a simple handle bar?
>> Why are you worried for the forces at high speeds? I am more worried for
>> slow speeds and when you legs go one way and your arms try to go the other
>> way. At high speeds you don't need much force to steer imo.
>> I am not entirely sure, but if you have a 1:1 ratio I think you will have
>> a hard time steering your bike with your arms only. Though, it also depends
>> on the lenght of your levers.
>>
>> Patrick
>>
>> ------------------------------
>> Date: Tue, 28 May 2013 10:44:57 -0400
>> Subject: [python] Re: Geared Steering
>> From: weyounet@xxxxxxxxx
>> To: python@xxxxxxxxxxxxx
>>
>>
>> hmm, well the ones I linked to are 3:1 and I think it's already too much,
>> I think 1:1 is okay considering have levers at both arms, and it also would
>> make it the same refinement of motion as on a normal bike.
>>
>> Based on your recommendation, you might have a different Idea than I
>> about how the gears are to be implemented, so I've drawn a crude crayon
>> diagram to hopefully get us ":on the same page" [image: Inline image 1]
>>
>> I made it based on the picture of the pivot at
>> http://www.python-lowracer.de/pics/kick_stand_with_steering_stop.jpg
>> the gear would go approximately where the bell is now.
>>
>> Also I realize having the diagonal levers may make it too close to the
>> seat, so could probaly make them kinda like L's so they give enough
>> clearance.
>>
>>
>> On Tue, May 28, 2013 at 9:34 AM, Peter Švančárek <
>> peter.svancarek@xxxxxxxx> wrote:
>>
>> to low gearing ratio probably... long lever would be better.
>> Maybe planetary gear would be better? with ratio at least 1:10-20
>>
>> Dňa 28. 5. 2013 15:15 Logan Streondj wrote / napísal(a):
>>
>> Hey,
>> I was wondering if can improve the steering at high speeds,
>> perhaps by having some kind of gearing mechanism on the pivot,
>> that would for instance move levers on either side,
>> the levers could be used to hold the pivot at a certain angle, or change
>> it to an appropriate one.
>>
>> perhaps bevel gears could be used.
>> If for instance the lever gears are mounted on the back boom,
>> and the pivot gear controls the front boom,
>> then could have very precise control of the front-back boom angle.
>> main issue I guess would be finding good mounting options,
>> and making sure it has enough strength to withstand the forces at high
>> speeds.
>>
>>
>> That way can finally achieve the inital goal of using it as a low-racer,
>> rather than a low-walker as it kinda is now.
>> who knows, might even win at some recumbent bicycle races.
>>
>> It may also make it easier to learn for newcomers, since there would be
>> some kind of steering available.
>>
>> Perhaps something like the larger of these gears could be used
>> http://www.ebay.ca/itm/5-9mm-Pinion-Shaft-Dia-Straight-Bevel-Gear-Spare-Parts-/390574215222?pt=LH_DefaultDomain_0&hash=item5af0099036they
>> are $10 on ebay and I saw some for 6 not too long ago, would need
>> three, one for the pivot, and two for the levers on either side.
>>
>>
>>
>>
>>
>
Other related posts:
