Trailer hitches

I'm (still) working on the design for a "recumbent trailer trike",
essentially a delta trike with no front wheel, but a hitch which will
connect to my diamond frame bike. I've got a lot of the details worked
out, but I'm still agonizing over the hitch design. The trailer will
have brakes and a drive train, so it will be capable of both pushing and
pulling, and by the time we add the weight of the trailer, rider and
storage (this is for touring), we might be nearing 200 lbs being pulled
by the hitch (tongue load should be substantially lower if I get the
seat location right).

As I see it, there are 4 options in terms of hitch location.

1) Asymmetrical rear axle mount. Like most of the Burley trailers. A
small hitch is attached to the left side of the axle and the trailer
mounts there. The advantage is that forces are applied low and somewhat
forwards on the frame. The disadvantages are that force is only applied
to one chainstay, and the trailer hitch has to have a substantial bend
in it to prevent striking the rear tire during right hand turns.

2) Symmetrical rear axle mount. Like the Bob Yak. A subframe mounts to
both sides of the rear axle and the trailer mounts to the subframe at a
point in line with the center of the bike, but behind the rear tire.
The advantage is that the force is applied equally to both chainstays.
The disadvantage is that sideways force is applied behind the rear
wheel, which gives more torque on the frame. You also have to worry
about holding up the hitch point if the trailer needs to stay upright
when the front bike leans (which the Yak doesn't need to do).

3) Seatpost mount. Like most trail-a-bikes. A clamp goes onto the seat
tube. The seat tube should be fairly strong and is in line with the
center of the bike, but the attachment point is too high and excessive
force applied during braking could push the rear end off the ground.

4) Bottom bracket mount. Only ever seen on the defunct Chariot
Sidecarrier. From a pure physics point of view, this might be the best,
as external forces are applied quite low and in the center of the frame.
Unfortunately, the practical aspects of trying to connect that hitch to
a trailer are pure hell and it really only works when the trailer is
beside the bike (as in the Sidecarrier).

Any comments or insight into which of these methods would work best for
a fairly heavy duty application? I think #3 is out for physics reasons
and #4 is out for construction reasons. I suspect #1 is the easiest to
build, but that #2 might be a little stronger. Then again, #2 might
exert more torque on the bike frame. If you have real world experience
you can share, that might be even better. Thanks.

On 03/03/14 16:02, Ralph Barone wrote:
I'm (still) working on the design for a "recumbent trailer trike",
essentially a delta trike with no front wheel, but a hitch which will
connect to my diamond frame bike. I've got a lot of the details worked
out, but I'm still agonizing over the hitch design. The trailer will
have brakes and a drive train, so it will be capable of both pushing and
pulling, and by the time we add the weight of the trailer, rider and
storage (this is for touring), we might be nearing 200 lbs being pulled
by the hitch (tongue load should be substantially lower if I get the
seat location right).

As I see it, there are 4 options in terms of hitch location.

1) Asymmetrical rear axle mount. Like most of the Burley trailers. A
small hitch is attached to the left side of the axle and the trailer
mounts there. The advantage is that forces are applied low and somewhat
forwards on the frame. The disadvantages are that force is only applied
to one chainstay, and the trailer hitch has to have a substantial bend
in it to prevent striking the rear tire during right hand turns.

2) Symmetrical rear axle mount. Like the Bob Yak. A subframe mounts to
both sides of the rear axle and the trailer mounts to the subframe at a
point in line with the center of the bike, but behind the rear tire.
The advantage is that the force is applied equally to both chainstays.
The disadvantage is that sideways force is applied behind the rear
wheel, which gives more torque on the frame. You also have to worry
about holding up the hitch point if the trailer needs to stay upright
when the front bike leans (which the Yak doesn't need to do).

3) Seatpost mount. Like most trail-a-bikes. A clamp goes onto the seat
tube. The seat tube should be fairly strong and is in line with the
center of the bike, but the attachment point is too high and excessive
force applied during braking could push the rear end off the ground.

4) Bottom bracket mount. Only ever seen on the defunct Chariot
Sidecarrier. From a pure physics point of view, this might be the best,
as external forces are applied quite low and in the center of the frame.
Unfortunately, the practical aspects of trying to connect that hitch to
a trailer are pure hell and it really only works when the trailer is
beside the bike (as in the Sidecarrier).

Any comments or insight into which of these methods would work best for
a fairly heavy duty application? I think #3 is out for physics reasons
and #4 is out for construction reasons. I suspect #1 is the easiest to
build, but that #2 might be a little stronger. Then again, #2 might
exert more torque on the bike frame. If you have real world experience
you can share, that might be even better. Thanks.


I have no real world experience, only gut feel after some thought. I
would like to build a single wheel trailer, like a Bob design. My gut
feel tells me this is the best approach. I have yet to construct or
test anything though. I think a slightly longer draw bar might be
beneficial, to put more weight over the trailer wheel and less on the
tow point.

Interested in how you go.

--
JS

You fellows might look at Utopia, the makers of my everyday bike. They've tried several hitching strategies. They're perfectionists who test everything until they find the best system. Eventually, I think -- I wasn't really paying attention as I have no interest in a trailer -- they adapted someone else's hookup and built their own trailer, now highly regarded. The reason I like them is that my patience with incompetents and chancers is three microns long and these people make bikes and peripherals that just work without bother, like a Rolls. www.utopia-velo.de

Andre Jute

GooImage is outstanding design resource. Type in 'BICYCLE TRAILER HITCH.' Menu will derange into pop BTH search categories...saving electrons...

http://goo.gl/AksHHq

I'm working into a CDT trail mode. Bikepacking.net comes up covering rides from your side over the mtns into the desert. Looks like there's a trail down to SP spring from the Sunrise Hwy area.

building urown trike may be cost effective !

On Monday, March 3, 2014 7:47:27 AM UTC-5, wrote:
GooImage is outstanding design resource. Type in 'BICYCLE TRAILER HITCH.' Menu will derange into pop BTH search categories...saving electrons...



http://goo.gl/AksHHq



I'm working into a CDT trail mode. Bikepacking.net comes up covering rides from your side over the mtns into the desert. Looks like there's a trail down to SP spring from the Sunrise Hwy area.



building urown trike may be cost effective !

...........


Plumbing 301

http://goo.gl/uJ06Ao

On Monday, March 3, 2014 8:23:52 AM UTC-5, wrote:
On Monday, March 3, 2014 7:47:27 AM UTC-5, wrote:

GooImage is outstanding design resource. Type in 'BICYCLE TRAILER HITCH.' Menu will derange into pop BTH search categories...saving electrons...







http://goo.gl/AksHHq







I'm working into a CDT trail mode. Bikepacking.net comes up covering rides from your side over the mtns into the desert. Looks like there's a trail down to SP spring from the Sunrise Hwy area.







building urown trike may be cost effective !



..........





Plumbing 301



http://goo.gl/uJ06Ao

........................

http://www.race-car-replicas.com/rcrp4_photo_album.html

In article ,
wrote:

GooImage is outstanding design resource. Type in 'BICYCLE TRAILER HITCH.'
Menu will derange into pop BTH search categories...saving electrons...

http://goo.gl/AksHHq

I'm working into a CDT trail mode. Bikepacking.net comes up covering rides
from your side over the mtns into the desert. Looks like there's a trail down
to SP spring from the Sunrise Hwy area.

building urown trike may be cost effective !

I have been Google image searching for the last month. I believe that I
have seen every form of hitch known to man. Rubber tubing, air hose
quick connectors, spring steel clamps that pop off (safety!) if
overloaded. Unfortunately, what's awfully thin on the ground is a
technical discussion as to the advantages and disadvantages of each type
and personal experience with using these different styles with a trailer
that weighs essentially the same as the bike towing it.

Andre Jute wrote:
You fellows might look at Utopia, the makers of my everyday bike. They've
tried several hitching strategies. They're perfectionists who test
everything until they find the best system. Eventually, I think -- I
wasn't really paying attention as I have no interest in a trailer -- they
adapted someone else's hookup and built their own trailer, now highly
regarded. The reason I like them is that my patience with incompetents
and chancers is three microns long and these people make bikes and
peripherals that just work without bother, like a Rolls. www.utopia-velo.de

Andre Jute

Looked and saw nothing hitch related there.

On Monday, March 3, 2014 12:02:31 AM UTC-5, Ralph Barone wrote:


Any comments or insight into which of these methods would work best for
a fairly heavy duty application? I think #3 is out for physics reasons
and #4 is out for construction reasons. I suspect #1 is the easiest to
build, but that #2 might be a little stronger. Then again, #2 might
exert more torque on the bike frame. If you have real world experience
you can share, that might be even better. Thanks.

I have (significant) experience only with the left side rear axle hitch scheme,
your #1. It seems to have become the most common for two wheel trailers. I
haven't used any 200 pound, self-powered trailer, but I've ridden a few hundred
miles with luggage towed behind a Bike Friday. I've had no significant problems.
Neither has my good friend who used that scheme to haul his large dog for many,
many hundreds of miles.

I don't think you'll have a problem due to the asymmetry of the hitch. Yes, in
the top view, you'll see a counterclockwise torque when the trailer is being
towed, and a clockwise one when the powered trailer is pushing the bike. But
the moment arm is small, and the necessary resisting lateral force from the
front tire should be very small. I certainly never noticed any instability
when braking my bike+trailer on a steep downhill, and that situation is
similar to your "powered trailer" mode.

Further thoughts on scheme #3, the seatpost mount: It requires a lot more
metal for the tongue, and for the weights you're describing, might give
an opportunity for some serious flexing. It will be a bigger trailer overall,
perhaps complicating storing and transporting.

There's a modified version of your #2 that's been used, essentially a stretched
tetrahedron supporting a hitch point just behind the bottom of the rear
fender. Picture an extra pair of stays, roughly parallel to the chainstays
and extending from the rear dropouts to a dummy rear axle behind the fender.
Now run a pair of stays from the seatpost or seat cluster down to that dummy
rear axle, to keep it at the proper height. That's sketched in the
"Cycling with Love" chapter of _Effective Cycling_, towing a kid's bike.
With your trailer, the hitch could be a ball & socket. But I don't see any
great advantage over the left-side axle hitch.

I've got a couple other books with trailer designs that I could describe.
But I think you're well beyond due diligence in examining prior art. By
this stage, the crusty old guy who taught me machine shop techniques would
be yelling "Just do it!"

(That was way before Nike said that, BTW. He should have copyrighted it.)

- Frank Krygowski

There's a Class 4 on muh truck's stern. When I begin thinking abt towing I am lost even to the wording/nomenclature.

I would do the usual find significant words/phrases then search those terms

also...http://goo.gl/0N3KGz

you see I get right off hand no further than 'joint' having nutting todo with Colorado but general deconstruction.

as for pro's and con's...there in the search terms and related blogs....I'll try 'towing for fun' next....wheeeeee....

often a 'no comment no discuss' zone arises from: nothing to say, no way to say it either from energy, subject or no language skills. Where was Earth before Sacko and Vanzotti did their NPR work ?

but could be at the cycle level there's not much difference to report.

Tho I would deafinitly go with the bent-rerod-in-hole design...on permanent display at MOMA...and other select locations...the release when crashing has merit with exception you then need to look for it !

have yawl been down the hill ? I found that at the duhduh California 400 ???

YES !!!!!!!!!!!! https://www.google.com/#q=towing+funny+quotes