Smallest Wheel Around 7.5" Hub ?

Got a no-longer-used ebike motor that I would like to re-purpose into a
powered trailer dolly in the spirit of
http://www.proud-canadian.com/diy-power-trailer-dolly/

The diff being that my boat weighs a couple hundred pounds with about
25-30 pounds "Hitch Weight" when it's on it's beach wheels.

Consequently I am thinking something more like a powered pack wheel like
this guy made from a muy-expensivo pack wheel:
http://tinyurl.com/jlmbxmu or
http://www.thediyhunter.com/images/j...in-wheel-l.jpg

Cut the seat tube/rear triangle off of a junk bike and go from
there.....

Actually it might work with the existing 26" rim, but smaller would be
better - right down to some scheme that attached some sort of wheel/tire
directly to the hub.

So, The Question: What is the smallest rim I could spoke on to the 7.5"
hub in question?...... I've got couple of Rohloff-based bike wheels and
the spokes are *really* short.... and the Rohloff hub is nowhere near
7.5"....
--
Pete Cresswell

On 26/04/16 10:39, (PeteCresswell) wrote:
Got a no-longer-used ebike motor that I would like to re-purpose into a
powered trailer dolly in the spirit of
http://www.proud-canadian.com/diy-power-trailer-dolly/

The diff being that my boat weighs a couple hundred pounds with about
25-30 pounds "Hitch Weight" when it's on it's beach wheels.

Consequently I am thinking something more like a powered pack wheel like
this guy made from a muy-expensivo pack wheel:
http://tinyurl.com/jlmbxmu or
http://www.thediyhunter.com/images/j...in-wheel-l.jpg

Cut the seat tube/rear triangle off of a junk bike and go from
there.....

Actually it might work with the existing 26" rim, but smaller would be
better - right down to some scheme that attached some sort of wheel/tire
directly to the hub.

So, The Question: What is the smallest rim I could spoke on to the 7.5"
hub in question?...... I've got couple of Rohloff-based bike wheels and
the spokes are *really* short.... and the Rohloff hub is nowhere near
7.5"....


I don't know off hand, but a suggestion is you could work it out by
drawing a wheel using a CAD package that allows you to resize the rim
dynamically and visualise the result. Obviously you will need some
spokes to cross to transmit torque from the hub to the rim.

LibreCAD is free.

I used it to plan my 24 spoke/rim on 32 hole hub rear wheel.

--
JS

Per James:
Obviously you will need some
spokes to cross to transmit torque from the hub to the rim.

OK... that answers one question: spokes need to be crossed to transmit
torque.

Thanks.

I am starting to think in terms of something attached directly to the
hub - like a garden cart tire sewn into the spoke holes, maybe with some
foam stuffed inside. .... I've got some Spectra kite line...tough
stuff....

Or maybe just wrap it with a strip of something....

This thing doesn't have to move faster than a slow walk and the weight
on it will not exceed 50# (more like 25....).
--
Pete Cresswell

On 4/25/2016 5:39 PM, (PeteCresswell) wrote:
Got a no-longer-used ebike motor that I would like to re-purpose into a
powered trailer dolly in the spirit of
http://www.proud-canadian.com/diy-power-trailer-dolly/

The diff being that my boat weighs a couple hundred pounds with about
25-30 pounds "Hitch Weight" when it's on it's beach wheels.

Consequently I am thinking something more like a powered pack wheel like
this guy made from a muy-expensivo pack wheel:
http://tinyurl.com/jlmbxmu or
http://www.thediyhunter.com/images/j...in-wheel-l.jpg

Cut the seat tube/rear triangle off of a junk bike and go from
there.....

Actually it might work with the existing 26" rim, but smaller would be
better - right down to some scheme that attached some sort of wheel/tire
directly to the hub.

So, The Question: What is the smallest rim I could spoke on to the 7.5"
hub in question?...... I've got couple of Rohloff-based bike wheels and
the spokes are *really* short.... and the Rohloff hub is nowhere near
7.5"....

12.5". Custom spokes of course. Do you a spoke cutting and threading
machine? I see offers on eBay for custom cut spokes and they are not too
bad, about $22 for 40 spokes.

Trying to find something to build with the parts you happen to have is
usually a disaster that ends up costing a lot more than buying the
proper parts to begin with.

A motorized wheel for a scooter is what you really need. No spokes, just
mount the tire directly onto the wheel
http://www.leafbike.com/products/e-scooter-hub-motor/12-inch-electric-motor/updated-version-12-inch-36v-250w-bldc-motor-front-wheel-1052.html.

The idea of attaching a wheel/tire directly to the hub would probably be
more practical. Harbor freight sells 8", 10" and 13" pneumatic wheels/tires.
http://www.harborfreight.com/catalogsearch/result/index/?AttribSel=Wheel+Type%3D%27Pneumatic+Tires%27&CatP ath=All%2BProducts%252F%252F%252F%252FUserSearch1% 253Dwheels&RequestData=CA_AttributeSelected&q=whee ls

On 4/26/2016 8:47 AM, (PeteCresswell) wrote:
Per James:
Obviously you will need some
spokes to cross to transmit torque from the hub to the rim.

OK... that answers one question: spokes need to be crossed to transmit
torque.

Thanks.

I am starting to think in terms of something attached directly to the
hub - like a garden cart tire sewn into the spoke holes, maybe with some
foam stuffed inside. .... I've got some Spectra kite line...tough
stuff....

Or maybe just wrap it with a strip of something....

This thing doesn't have to move faster than a slow walk and the weight
on it will not exceed 50# (more like 25....).


That's an interesting approach. Maybe some smallish rim
mounted between the flanges with epoxy and a few locating
pins through the hub's spoke holes? If a suitably sized rim
can be found with hollow section, locating pins would be
simple. With enough surface contact between hub and rim
epoxy may be enough and a mechanical stop with pins may not
be necessary.

Not ridiculous and perhaps better than extremely short
spokes which would likely be difficult especially as regards
spoke angle at the rim side.

--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971

GNAW BUY A SOLID RIM SOLID TIRE FROM SAY Home Depot for $15/each

https://goo.gl/xzhtV1

On Tue, 26 Apr 2016 09:47:47 -0400, "(PeteCresswell)"
wrote:

Per James:
Obviously you will need some
spokes to cross to transmit torque from the hub to the rim.

OK... that answers one question: spokes need to be crossed to transmit
torque.

Thanks.

I am starting to think in terms of something attached directly to the
hub - like a garden cart tire sewn into the spoke holes, maybe with some
foam stuffed inside. .... I've got some Spectra kite line...tough
stuff....

Or maybe just wrap it with a strip of something....

This thing doesn't have to move faster than a slow walk and the weight
on it will not exceed 50# (more like 25....).

"25 pounds at a slow walk"? "Hands"?
--

Cheers,

John B.

ePer John B.:

"25 pounds at a slow walk"? "Hands"?

Hills.
--
Pete Cresswell

Per (PeteCresswell):
Hills.

Plus moving 220# up same...... 25 is the tongue weight.
--
Pete Cresswell

On Wed, 27 Apr 2016 09:11:57 -0400, "(PeteCresswell)"
wrote:

ePer John B.:

"25 pounds at a slow walk"? "Hands"?

Hills.

Join the army. They'll show you how to carry 40 - 50 lbs. at a brisk
walk. Up hill and down dale :-)

But more seriously, you must have been raised in town as a "bucket" or
"Pail" usually held in the region of 4 gallons and most farm kids
could carry two of them to water the animals. 4 gallons is ~15 Litres,
is 15 Kg., is ~33 lbs, times, two is 66 pounds :-)

HANDS!
--

Cheers,

John B.