indyfabz

Reminds me of a thread in the forum that was recently locked. Something about being an impassioned maverick.

elcyc

Seriously, though, does any forum , movie, novel or tv series remain interesting and fresh if there is no dissonance? No drama?
It mostly in the nuances and tacits.

Ironfish653

So….you ask for advice, then announce that anything that doesn’t jive with your initial idea is irrelevant because…….you’re trying to prove some moral point?

Look, man; I’m an iconoclast, I get it; I appreciate unique solutions, especially if it’s done with some panache. Headshok Cannondales, SoftRide beam frames; Iused to own a Buell, for crying out loud.
I never claimed that they’re some secret sauce, and everyone else is too close-minded to accept my vision.

Hope you own a good raincoat; I hear those hair shirts get really itchy when they get wet

Duragrouch

Whole thread is TL: DR. Just a few quick things from experience.

I used a B.O.B. trailer on a tour. It is unique in having the pivot point completely behind the rear wheel, like a car travel trailer, and half the load on that pivot. On a (very) Long Wheelbase Recumbent, it was stable, unless descending at a good speed (even mild grades), I had to LOCK the steering, tight grip, and make slow steering movements, or the trailer would get into sway "amplification". Now this was with a touring load, but not huge, tent, sleeping bag, cookset, water, etc. When I later tried pulling behind my roadrace bike (a VERY rigid Cannondale frame), it was uncontrollable at low speed, felt like a wet noodle when climbing out of the saddle and rocking the bike (which I never would do on the recumbent, impossible).

Most trailers are two wheel and attach to the left chainstay or left rear axle; Either is fine if it has a flex joint, to only allow pulling and stopping with no bending force on bike, and not high trailer weight for high loads fore and aft. All have trailer weight centered on trailer axle, so very low hitch weight at bike, so low polar moment of inertia. Also, because hitch is near rear bike axle, it behaves dynamically like a 5th wheel trailer which is much more stable than a rear trailer hitch like noted above for the B.O.B./travel trailer.

The trailers that look like a hand truck: Look reasonably stable fore/aft, but if hitched high up at the bike seatpost, that means more lateral movement when climbing and rocking the bike; Check for stability during that, and also fast descents.

Years after I toured with my B.O.B. and LWB 'bent, I took a 40 hour course in vehicle dynamics of heavy truck and trailer systems, and came to understand the hows and whys of all of the above.

Lastly, if I toured now, it would be panniers, because moving a bike with trailer up or down even the smallest stairs, or through a doorway, or traveling with it, can be near impossible. LWB 'bent and trailer... comfy? Oh gosh yes, no hand pressure, no bent neck, could see the sights, etc, luxurious space, I didn't overpack, but never had to squeeze down my sleeping bag, just toss into cavernous rubbermaid container on B.O.B., and totally rainproof and had vent holes on underside of handles. But a lot of weight up hills, even worse on a 'bent, and a bear to transport unless by pickup truck or van.

I second the notion of looking for a used kid trailer, they are often dirt cheap at goodwill or on craigslist or garage sale.

indyfabz

It’s threads like these that make BF uninteresting and stale. Seriously.

But thanks for fessing up.

elcyc

Which trailer has a chainstay attachment?
For my GF, I have used several HQ kickstands -- one Japan-made Specialized glass-fiber; the other German-made aircraft metal -- that clamped on chainstay AND seatstay. Robust and confident design, but all routinely came loose and ultimately broke. Nevertheless, these dual-clamp kickstands seemed to have been very gentle on the bike frame.


All things held equal, this type of load distribution is what may lead to central- , seatpost-mounts being gentler on bike frame. Nice fat/chunky seatpost, meant to support typical obese American males. The seatpost being geometrized by four (4) frame tubes.

Duragrouch

The Bike Friday travel bike, which is sold solo or with a travel suitcase for it that converts to a two wheel trailer at destination, uses a trailer connector which is a male quick-disconnect pneumatic air fitting, and.... y'know I originally remembered it welded to the left chainstay, I think some came that way and there was I think on BF website about them sending bolt-on(?) replacements if that broke off, but it may have been welded to a steel plate that fit under the axle QD skewer, someone here started a thread, had seen the part, to ask what it was. Anyway, never seen it, but from what I understand, the trailer end of it was a piece of flex air line (braided-fiber reinforced, tough stuff, and cheap to replace) connected to the trailer tongue, with the forward end a female pneumatic QD connector, and probably a short cable safety leash in case that comes undone. Sounds like a good and cheap system with off-the shelf parts.

shelbyfv

Now that it's been established this thread is a show-n-tell rather than OP seeking help, maybe it would be a better fit in "Utility Cycling." Will make OP's motivation clear if he keeps posting this stuff in "General."

Duragrouch

I think the two-kid trailer I have in storage, has a rubber-lined clamp that clamps around the left chainstay, and a u-joint between it and the trailer tongue. Early trailers aimed for a simple hookup without special parts, like the special B.O.B. skewer or Nutz required to hook one of those up.

elcyc

100-mile update on the $135 trailer.
Amazon description: "Aosom Bike Cargo Trailer, Bicycle Trailer, Heavy-Duty Bike Wagon Cart, Foldable Compact Storage, with Universal Hitch, 16" Wheels, 88 lbs. Capacity, Black"
I don't have Amazon Prime but still received the Aosom, a day after order, at $135.
Assembly was fairly straightfwd, but diagrams very small and hard to read/see.

CONS:
(in order of seriousness and caution!)
(1) The trailer can tip over on to left or right (but not fully) in a ridiculous "uni-cycle" position ... IF... one side ( left or right wheel) encounters pylon, large rock, medium-sized pothole, or (especially) curb of street or sidewalk. EVEN AT LOW SPEEDS. EVEN WITH MEDIUM LOAD, WELL SECURED WITH BUNGEE . Maybe it's the large 16" wheels? But the center of grav. still pretty low compared to child/pet carrier. Dunno folks! Not sure if other trailers -- such as better-rated Burley or axle mount or child /pet carriers (!!!) -- succumb to this dangerous maneuver. But this is major flaw. Not for off roading or rough city streets or (especially ) inattentive towing.
(2) Not light. And mass more spread out throughout trailer (not tight and centered). Maybe Burley or Topeak or DIY trailers are better, lighter design.
(3) Not foldable; despite ad/description. If you get one, you'll find out why!


PROS:
-Large wheels make up-down stairs and steps easy. Frame never scrapes. In and out of my 2nd story condo units (multiple flights of steps) in seconds.
-Despite large size, using its "handle bars" to maneuver just bikeless trailer, such as move inside garage or home, with tight corners, is very easy.
-Quick disconnect works well. (not sure how long it'll last).
-For commuting; grocery-getting: Better than panniers on smooth roads/paths. Because: I can use light road bike to locomotive. Which responds better and more agile than my decked-out Gary Fisher hybrid mod (4 panniers; heavier; less maneuverable ). Overall: light steel road bike + trailer = less rolling resistance, better aerodynamics and maneuverability than my GF hybrid . Again, on smooth roads/paths, with proactive foreknowledge/planning/AWARENESS and attentiveness that one is towing a trailer that might tip. Maybe a learning curve thing ????

OTHER:
The spring hitch mech that allows trailer to turn does not inspire long-term confidence. Then again, this is my first experience with any bike trailer.
Bungee or secure all content. This will help stability FEEL and confidence of bike+trailer.
At standstill, don't move the hand-move trailer - -as when you may be locking up both units -- with it attached to the (bike); you will easily topple a light road bike (even on a roubust kickstand).
The quick -lock keys rattle. You'll need to bungee them to quiet the beast down.

It may become second nature once the CONS are planned for.

Duragrouch

It's not the wheel size per se, but that the load is all above wheel center at that height. Smaller wheels would lower the CG with respect to track (width between tire centers). My guess is they use a solid rod as axle across both wheels and run the rod under the frame? If not, if the wheels secured to brackets at each side, I would have mounted the wheels higher on the frame. The other issue is the wheel hitting an obstruction and it's relatively light without much ability to absorb energy (no suspension except the tires) so bounces high, tipping the trailer.

To address both issues, the trailers I've designed (not for bikes) have the wheels on trailing arms and torsion springs or spring/damper units for better energy absorption and dissipation, with the wheels more alongside the frame for lower chassis center of gravity. Somebody made an ultralight trailer like that for boats and kayaks and such, can't recall if for car or bike. Ah, here's one, can't recall if that is the one I saw years back or different, you can just barely see the spring/damper units. I personally would have designed it for the load to sit lower between the wheels:


However, with a long enough trailer, you may then scrape front or rear, up and down incline transitions.

With a tracked vehicle (like a tank), I can get the CG real low, and not scrape at either end, but the tracks wear so bad on pavement and take a lot of power to execute vehicle turns.

elcyc

Like I noted, the CG is about the same as the Burley, and lower than kids/pets carriers. Dunno how often kids tip over. I have see posts on forums about it.
No chassis-wide connecting axle rod, as on Burley. But I like the Aosom wheel-to-chassis design better than Burley -- see photos.
Taller wheels do help when not connected to bike; maneuvering the Aosom up down stairs and around inside furniture. See prev. post.

Since the Aosom does not do off-road and rough roads all that well with stock tires, why not optimize trailer for smooth paths and roads? Ergo: Looking for skinnier tires to lower rolling friction on the 16" trailer wheels. Anyone know of a source?

BOTTOM LINE:
How many reading this post have experienced trailer tipping ? What trailer are/were you using?

squirtdad

Maybe having high mount vs the recommend lower mounting position has a difference in the tippyness ?

Duragrouch

You may have something there. I first considered that and then dismissed it. But thinking now... A low hitch at same height as wheel center, one wheel goes up, would rotate laterally about that hitch point; A much higher hitch will rotate laterally about that higher hitch point, which may cause the trailer to move laterally in the direction of the raised wheel, increasing the propensity to tip over onto the unraised wheel. Just a theory.

Ironfish653

Something like that; not only does the high hitch make the "load triangle" taller and narrower than an axle height drawbar, but since it's effectively hanging from the upper mount, the hitch doesn't really contribute much if the load starts to tip. The low drawbar holds down the front of the trailer, meaning you'll have to get probably 50-60 degrees of roll before the trailer wants to turn turtle rather than coming back down on it's wheels.
Also, small wheels are more likely to hang up on obstacles than larger ones. A 20" like many better models use, will climb a curb, for example, with much less abrupt of a bounce than the OPs 16s.

I had a Chariot Cougar 2-seat model for many years , which uses 20" wheels, and has them mounted on a 1/4-leaf suspension, mounted at the back edge of the chassis, above the frame rail; made for a very smooth, stable ride.
I had a couple incidents where I hooked a wheel on something (curb, bollards, trees) hard enough to take my bike out from under me, but never was the trailer anywhere close to rolling over.