I salvaged an old bicycle trailer. I have one concern though. The bar that goes from the trailer to the bike, I believe it's called the tow hitch, ends with a small rubber coupling, to allow for movement in all directions. The rubber has gotten brittle, and I don't trust it. Is it possible to either buy a new one or in any other way fix this issue?

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    Knowing the brand of the trailer might be a good starting point. Or was this custom built? – renesis May 26 '15 at 19:47
  • I found it in a scrap container. There is only the frame and the wheels left. No box. And no name or model or nothing. I think I remember seeing this kind of coupling before, on other bikes, I thought it was sort of generic. – Mads Skjern May 26 '15 at 21:22
  • Give us a report on this when you've tried something. I'm wondering if the rubber fitting is covering some other connector. – andy256 Jun 1 '15 at 9:06
  • I certainly will give a report, but I'm afraid I wont get to it anytime soon. – Mads Skjern Jun 1 '15 at 12:06
  • Take the part out and take it to an auto parts place, or maybe a place that sells parts for tractors. See if they have something similar. – Daniel R Hicks Jul 27 '15 at 11:34

I suggest undoing the bolts that hold the rubber piece in place.

Obtain an old car tire, and with heavy shears, cut a couple of pieces the same size and shape. The idea is to put them back to back to make up the width.

You'll need to make holes on each end for the bolts. A large drill could be used for this; I suggest a drill press, rather than a hand-held drill, for safety reasons (the drill bit may bind in the rubber).

You may need to have a few tries to get it all to work right.

Good luck :-)

  • Andy an old tire is not gong to be better than what he has now. – paparazzo May 28 '15 at 3:42
  • @Blam My main purpose in suggesting a solution was to get the ball rolling. While I think it's workable, do you have another suggestion? – andy256 May 28 '15 at 3:56
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    Its a good idea using a car tyre. I got it myself after posting ;) I googled a bit and apparently its quite easy to cut the "side" of the tyre with a sharp knife, and I think 2-4 layered together would be strong enough. The part of the tyre facing the road surface is cast with a steel mesh inside. This makes it super strong and ideal for the purpose. But its quite difficult to cut, and with my tools probably not viable. – Mads Skjern May 28 '15 at 7:27
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    Modern car tires are mostly "radials" meaning that they have radial threads in the side wall. So if possible cut your sections in that direction for strength. Maybe someone at your local garage or tire vendor can also offer advice. – andy256 May 28 '15 at 8:08
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    I think this is actually a fairly good suggestion. Most tires wear out long before the rubber begins to dry out and crack. Not sure of the best way to cut a tire with steel belts, but I'm thinking the sidewalls would not be steel, and should cut relatively easily. – Daniel R Hicks Jul 27 '15 at 13:19

Yes, you can replace it. Although you might have to goto another brands system, and a little hacking.

Personally, every trailer I have I use the Burley Flex Connector system (http://www.amazon.com/Burley-Design-Connector-Round-Black/dp/B001GSQXUG/ref=sr_1_1?ie=UTF8&qid=1438004399&sr=8-1&keywords=burley+flex+connector). What ever you go with though you may have to get a few other parts for it to all work. In the Burley case, the hitch for your bike (http://www.amazon.com/Burley-Design-Forged-Standard-Trailer/dp/B00VSOQN8K/ref=sr_1_3?ie=UTF8&qid=1438004399&sr=8-3&keywords=burley+flex+connector).

Here is the similar piece for the Burley flex connector system, and how it works on my bike:

flex connector Flex connector at work


What is your basis for not trusting it? That bolt has rust do you not trust it? Really how do you know that surface cracking is a structural integrity problem? Stand on it and see if it breaks.

If it breaks try a tire and frame dealer.

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    Good question. I believe its not reliable because when I twist it the cracks seem deep and it is simply too flexible. I believe I can break it off in a few seconds with my hands if I want to. – Mads Skjern May 28 '15 at 7:20

You could use a steel spring like the ones in old bedframes or around trampolins; it should be possible to get one from the nearest scrapyard or recycling centre. My trailer has such a spring by design and it works just fine.

In my experience the forces on the coupling are not enormous. The largest forces happen when you brake, but these are compression forces and shouldn't tear it apart. The pulling forces are normally not that large.

I would also add a safety rope from the trailer to the bike. Fix it to the bolt on the right side of your photo, and tie the other end to the bike frame, with just enough slack so that it doesn't stretch when the trailer moves in all directions and doesn't get caught in the wheel. If the coupling fails for whatever reason, then your trailer doesn't get out of control.

  • Yeah, a safety rope/chain/cable is a good idea. (I'd use a cable.) – Daniel R Hicks Jul 27 '15 at 11:35
  • I find the spring systems to be rather unpleasant riding. They tend to do a lot of tugging, jaring, and jerking that it was rather tiring. – BPugh Jul 27 '15 at 13:48

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