On 15 Apr 2008 22:37:38 GMT,
[email protected] wrote:
>Carl Fogel wrote:
>
>> "Handbuch des Bicycle-Sport" from 1885 has a curious section devoted
>> to rear suspension for the highwheeler's rear wheel.
>
>> Odd upside-down spring mounting:
>
> http://i30.tinypic.com/2ewiliw.jpg
>
>> Denne & Palmer versions of the "anti-vibrating fork":
>
> http://i27.tinypic.com/2ev6791.jpg
>
>> Wood's ram's-horn "rear-wheel spring (feather)":
>
> http://i32.tinypic.com/317cs3b.jpg
>
>> These rear-wheel suspension schemes never caught on, but they do
>> show how the small trailing wheel actually suffered the most.
>
>> It was the little rear wheel, not the huge front wheel, that
>> commonly suffered broken spokes, ruined tires, and destroyed
>> bearings.
>
>> The rear wheel carried about as much weight as the front wheel, but
>> it rolled about three times as far, it hit every bump at a steeper
>> angle, and it sat low enough to catch the mud and dust flung up by
>> front wheel (whose ivory-tower bearings were two feet in the air).
>
>If you look at pictures of these bicycles, you'll note that the rider
>is sitting with his CG closer to the center of the large wheel than
>half way between, where the wheels would be equally loaded. If you
>have a highwheel rider around, try lifting the rear wheel manually
>when he is sitting stationary, hand against a wall.
>
>I think your line of reasoning is the same that spawned these
>"curious" suspension schemes. Being a trailing wheel, its small size
>cannot make it sustain road shock loads, much like todays bicycles
>where the rear wheel easily traverses a rolled curb that otherwise
>causes an endo if hit head-on (unless the rider lifts the wheel as
>when jumping square curbs).
>
>Jobst Brandt
Dear Jobst,
The height of the highwheeler was as much to blame for the frequent
headers as the rider's position. Raise the seat of a modern bicycle to
50~55 inches, and braking will get trickier.
That's why the "safety" highwheelers were miniature highwheelers.
They used gearing to overcome the penalty of the smaller front wheel.
Some used tricks to keep the feet behind the front axle, but just
lowering the seat was usually enough to reduce the header danger
significantly on the Facile, Kangaroo, Columbia, American, and
Xtraordinary safety highwheelers.
Highwheeler racers leaned forward and down to cut wind drag, sticking
their elbows up behind like the hind legs of grasshoppers, so their
weight was more over the front wheel.
But for normal riding, a substantial amount of weight still ended up
on the small rear wheel. How much depended on the frame, the seat, and
the weight of the bike versus the weight of the rider.
The closer the backbone followed the rear wheel, the more weight
rested on it. The highwheeler equivalent of a modern touring bike
would trail farther behind the rear wheel than a highwheel racer's
rear wheel, which was usually tucked as close as possible to the front
wheel, like a short-wheelbase modern racer.
Here's a photo from "Collecting and Restoring Antique Bicycles" of a
rider in a normal upright position on an 1880's highwheeler:
http://i32.tinypic.com/t7leeo.jpg
As drawn, the distance between the axles to the center line is about
44% versus 56%.
The line for the center of gravity is just a guess--I put it a little
forward of the rider's hip joint, but it could easily be closer to the
front axle.
There's certainly more weight on the front, but there's a surprising
load on the rear.
It's easy to forget that a highwheeler's handlebar is already slightly
behind the front axle and that the rider sits behind the handlebar.
The cranks were usually around 6 inches or less, or 150~155 mm. The
throw was less than a modern crank because it let you use a slightly
larger (and therefore higher-geared) front wheel.
Of course, the lighter the rider, the more the center of gravity moves
toward the big wheel. Riders tended to be lighter over a century ago.
A heavier bike would move it forward, too--highwheelers could weigh
anywhere from over 50 to just under 12 pounds.
Anyway, the load on the rear wheel and tire was enough that they wore
out and broke far more often than the front. That's not theory--it's a
common practical observation of the 1870s and 1880s.
As you've noted yourself, small tires on modern bicycles like the
Moulton make suspension practically mandatory, and highwheeler tires
were solid, not pneumatic. (Except for a handful of oddball
highwheelers around 1892.)
The rear wheel's solid tire was only 12 to 18 inches high, so it hit
every bump on the awful roads at a much worse angle than the 50 to 60
inch front wheel. The rear wheel also had only 12 to 20 spokes,
instead of the 50 to 100 of the front wheel.
To make things worse, the rear tire was usually narrower than the
front. Some racers had solid rear tires only a quarter inch wide.
After you look at a few hundred photos of old highwheelers, you start
noticing how often rear spokes are broken--the rear wheel damage
surprised me at first because I mistakenly assumed that the itty-bitty
wheel and tire would last forever.
Thomas Stevens carried no spare front tire, but he carried an extra
rear tire on his round-the-world trip, wrapped (along with other
stuff) around the inside of his front wheel. It was the rear tire that
highwheel riders expected to replace, not the front, since it was so
much smaller and narrower, but still had to cover the same distance as
the front tire. (Stevens also mentioned how his rear wheel was
half-buried in hot dust in Ohio, where no rain had fallen in two
months.)
Browse the London Bicycle Club Gazette in Google Books, and you'll
find repeated comments about hind wheels and their troubles--rear
tires coming off and wearing out, destroyed rear bearings, and broken
rear spokes.
Here's part of an LBCG report about mud destroying the primitive
bearings in an 1879 race. Note the amazing play in the small
rear-wheel (far more than in the much larger front wheel) and the
broken rear spokes:
"MACHINES AND THEIR CONDITION AFTER THE BATH RACE. The writer_of these
notes spent the morning of the 8th inst. in examining the various
bicycles which had been used in the Bath Race, and left in the Club
Room at the Club Depot, Kew Green. These notes may be useful as
showing the destructive effects of muddy roads.
58-inch "W. Keen" (painted green). — Front wheel bearings (rollers or
balls) very gritty, and so stiff as to prevent a free revolution of
the wheel; treadles jammed immovably with grit and rust; hind wheel
bearings (cones, very common) cut up by grit into strips at small end
of cone side shake [side-play] about l 1/2 inches."
Being interested in this machine, I trust the owner will pardon me for
having taken the hind wheel to pieces. I found the cones, etc., so cut
up that the former sunk right into the bushes, and it was impossible
to adjust the wheel without some makeshift washers. Some fifteen or
twenty minutes' hard work in rapidly turning the front wheel, and a
plentiful application of paraffin oil, rendered it clean and free.
N.B. No attempt had been made to exclude grit, etc., by binding
flannel or anything else round either bearing.
66-inch "Carver" [a gigantic racer--few highwheelers reached even 60
inches] (bright) [meaning nickel-plated]. — Front wheel (registered
bearing), quite free and no shake, carefully packed with wadding by
rider; hind wheel (coned) all to pieces, many spokes broken away, and
felloe [rim] touching side of back fork.
--London Bicycle Club Gazette
http://books.google.com/books?id=enFMAAAAMAAJ&printsec=titlepage#PPA127,M1
Today, genuine antique highwheelers rarely suffer this kind of
horrifying damage in a single ride of the same distance because
they're ridden on much smoother modern pavement, not on muddy roads
littered with stones.
Cheers,
Carl Fogel