Puzzled by a new trailer hitch ?

Joined
Feb 7, 2008
Messages
3,762
Location
Nottinghamshire England
Hi all

Bought one of these :-



Seemingly a standard bicycle trailer hitch , however I am puzzled by the fact I can barely bend it ?

The culprit seems to be a piece of plastic rod , the green item in the left picture that goes all the way through the spring ?

As a trike rider I want the trailer to turn through at least 45' either side of centre to reduce my turning circle and I doubt it will as made.

So what's the plastic rod for ? as there is already a safety strap between the spring ends ?

Is it to reduce the tendency for the trailer to snake when being towed ?

Or some other purpose ?

Could it be removed ?

or

replaced with something more flexible ? e,g a bit of garden hose

regards Paul
 
Joined
May 31, 2013
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3,486
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South Benfleet, Essex, England, UK
My comparable "Hitch Section" on my "Skiidii" (100Kg load capable) trailer has a similar semi-flexible plastic rod through it and is difficult to bend.

In general terms I think manufacturers/designers select materials for components for good reasons (even though they don't tell us what those reasons are maybe).
I think the material is chosen to be FIRM and yet able to yield when sufficient pressure is applied and also strong enough not to elongate under a tensile load.
If it were just the outer spring taking all the load what happens to a spring when you over bend/stretch a segment of it? It deforms and goes past its "elastic limit" and never returns to the original shape/size (Hook's Law).
My trailer hitch was horribly abused and the spring was indeed deformed, so I know they can be damaged.
The stiff & resilient inner core is there for a reason perhaps?
I guess you remove/exchange/substitute it at your peril. :) It would be tragic to see the trailer disappearing in a different direction in your wing-mirrors. :eek:
 
Joined
Mar 2, 2022
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Location
Nottinghamshire. UK
The plastic prevents side load on the spring, stopping it deforming as the 'attachment' is mounted on the axle at an angle.

You could do away with the spring and plastic and have a metal peg, (thinking how you may use it).
Forces will be transmitted to other places that may or may not be able to withstand them.
I'd suck it and see.
 
Last edited:
Joined
Oct 19, 2012
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1,887
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Wakefield, UK
I'd assume the spring and rod are there to imitate a U/J. A spring alone would likely be too flexible so the rod acts as a damper.
 
Joined
Mar 2, 2022
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Location
Nottinghamshire. UK
Yes Popshot, it's used like an up and over garage door spring, but they don't tow anything ,lol. I'd guess SB will do away with it. I'll volunteer any machining if wanted.
 
Joined
Feb 7, 2008
Messages
3,762
Location
Nottinghamshire England
Hi guys

Thanks for the input , I assumed damper ?
i may and try something with more flex when I have it assembled maybe a bit of garden or car heating hose it only has to fit in the spring and have 2 holes in it.

Paul
 
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