Path: news.eternal-september.org!eternal-september.org!.POSTED!not-for-mail
From: AMuzi <am@yellowjersey.org>
Newsgroups: rec.bicycles.tech
Subject: Re: Getting old is not for sissies
Date: Sat, 1 Mar 2025 14:44:07 -0600
Organization: Yellow Jersey, Ltd.
Lines: 54
Message-ID: <vpvrim$cmno$1@dont-email.me>
References: <vpslph$3noh2$1@dont-email.me> <vpsncj$3o02g$1@dont-email.me>
 <gjmwP.3138$SZca.1726@fx13.iad> <vpsrss$3om5n$1@dont-email.me>
 <0jt3sj9iofpo2ru3abmi7ddrt4uk5btc9t@4ax.com> <vpta8s$3rj0t$1@dont-email.me>
 <j2d4sj1ju5h4qj8l64v92jp2pbfg44podl@4ax.com> <vpthh1$3spru$2@dont-email.me>
 <eci4sj1ppvglfuut24ahtdg789fkd2v3mj@4ax.com> <vpv2to$848g$1@dont-email.me>
 <47h6sjdvehovbadru4cv210eha609mospn@4ax.com> <vpvl7m$akr9$11@dont-email.me>
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 8bit
Injection-Date: Sat, 01 Mar 2025 21:44:07 +0100 (CET)
Injection-Info: dont-email.me; posting-host="1c3fdb1218d44bbc245bf004782d02cc";
	logging-data="416504"; mail-complaints-to="abuse@eternal-september.org";	posting-account="U2FsdGVkX1+LrntZi846HjvyTC76vFXC"
User-Agent: Mozilla Thunderbird
Cancel-Lock: sha1:aF9qTey5cZhW1ri8EbYmrGxYBO0=
In-Reply-To: <vpvl7m$akr9$11@dont-email.me>
Content-Language: en-US

On 3/1/2025 12:55 PM, Frank Krygowski wrote:
> On 3/1/2025 1:22 PM, Jeff Liebermann wrote:
>> On Sat, 1 Mar 2025 07:43:22 -0600, AMuzi 
>> <am@yellowjersey.org> wrote:
>>
>>> On 2/28/2025 5:52 PM, Catrike Ryder wrote:
>>>> I was thinking about fixies just the other day on my 
>>>> ride and thought
>>>> maybe I could set up a fixie on the Catrike. Then I 
>>>> considered how
>>>> often I coast. Keeping my legs moving the whole ride is 
>>>> not something
>>>> I want to do.
>>>>
>>
>>> I thought about your comment this morning.
>>>
>>> While almost everything humans can imagine is possible when
>>> time and money have no value, there's no practical
>>> straightforward way to make a Catrike fixed gear.
>>
>> Hardly straightforward, but certainly possible.  Remove 
>> the gears,
>> chain and sprockets and replace them with a hydraulic gear 
>> pump, two
>> hydraulic hoses, and a hydraulic motor on the wheels.  
>> This is nothing
>> new.  There are motor vehicles and construction equipment 
>> that use a
>> hydraulic pump at the engine, T junction, and a hydraulic 
>> motor on
>> each wheel.
> IIRC, hydrostatic transmissions are standard features on 
> zero turn mowers. But as you noted, the mechanical 
> efficiency is lousy. That's not a concern if you have a big 
> enough engine and low enough use hours. It's a huge concern 
> for a cyclist.
> 

I agree.

The long run may be an application for one of teh modern 
geared shaft systems:

http://projecthunters.blogspot.com/2013/11/shaft-driven-bicycle-project-ideas.html

perhaps with a chain drive from crank down to hub height. 
I'm looking at extremely long chain runs and thinking about 
chain weight too.

-- 
Andrew Muzi
am@yellowjersey.org
Open every day since 1 April, 1971