Easy hitch for upright bikes!

[xanda2260]

Hey guys, I'm a bit of a noob around here but I've been working on a cyclebully for a few weeks now and today I had a go at the hitch. After seeing RadBrad's awesome hub-cutting-and-welding business in the plans I decided I would probably screw it up as A) I only just figured out how a hub goes together B) I've only been welding a few weeks, and C) I can only find aluminium hubs. So, I started looking for another way.
After spending an hour hunting round my local hardware store, I left with panniers full of goodies I thought may make a suitable hitch mechanism. Of my 2-3 ideas, non worked out (largely due to my lack of welding skill). Anywhoo, I spent the enitre day in the garage welding and grinding and ended up with a really sturdy rear light mount!! Instead of a hitch...Arse.
Then, while poking around the interweb this evening I read a post about a guy who was doing something similar, and he gave me an idea. So I went back outside (9pm by now) and removed the handlebar clamp from an old BMX I bought at a car boot sale for £15. The bit that clamped the BMX stem fits over my seatpost (with quite a bit of room (rubber shims needed)) and the handlebar clamp can be used to hold a hub!!!! I clamped one of my hubs in it, slid seatpost through and - tada!!!! Now to weld up that funky arm bit and I'm done. Yay!!!
Hope this helps some one else bring a CB into the world...

P.S. Sorry for the essay!

[PeterT]

hi xanda,

my DF mountie tows a trailer
http://c4.ac-images.myspacecdn.com/images02/81/l_445463c329b545568e823752de56e7cf.jpg
http://c3.ac-images.myspacecdn.com/images02/90/l_4530bdbe3c2542808ca3f7b71fea33ae.jpg

the first hitch i made had an 8mm bolt drilled and tapped into the end of a 12mm mild steel bar that was a flexible gooseneck, but that wasn't able to support the loads without bending all the time, so then I weldedthis one together.

My simple solution for the pivot is to drill one hole through some nylon offcut, rotate 90deg and drill just beyond the first hole, then join a bolt with a pair of brackets at one end, through a sleeve with washers each end & place that sleeve into another housing that you can use as your carrier mounting. Giving the bolt 360deg movement saves lots of embarressment when your DF falls over and the contents fall out of the jack-knifed trailer. :cheesy:
Make another pair of brackets, attach them to the rear draw bar at 90deg to first brackets, and then bolt together for smooth 360deg rotational, +/-45deg vertical, 150-189deg horizontal towing.

PeterT

[xanda2260]

If I understand correctly, that hitch moves in all 3 dimensions? I take it your trailer has 2 wheels? If so, then I can't use it as the cyclebully is 1 wheel and would flop over. Nice solution though

[SirJoey]

That's a pretty slick u-joint, PT!
I need to make one like that! :)


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[PeterT]

Sir Joey,

I am honoured!

PeterT

[PeterT]

xanda,

the hitch would work fine for a mono wheeler if you DON"T mount it on a rotating pivot

PeterT

[badcheese]

The BMX handlebar clamp sounds like a great hack! Wish I'd thought of it. But I need to hitch my Cycle Bully to a High Roller, so I don't have a seat post to attach to.

Instead, I came up with a simple U-joint, very much like the one made by PeterT. Instead of a block of nylon (which would have been much easier), I drilled two pairs of holes in a short piece of square tube, offset from each other slightly along the length of the tube, so that the tube would hold two pieces of half-inch pipe perpendicular to each other. Those small pipes became my bushings, and through each one I ran a bolt to connect to a C-shaped piece of flatbar, just like PeterT's joint. I just tacked the pipes inside the square tube, since the welds only need to keep the pipes from sliding out of their holes and to keep them from turning, because I want the bearing surface to be the large contact area between the bolts and insides of the pipes. I capped the open ends of the square tube to make a closed block, much like PeterT's nylon block. I also had to drill out the half-inch pipe a little, because it was slightly too narrow for the 3/8-inch bolts and had a seam ridge inside it. I put nylon washers between the flatbar brackets and the block, to act as thrust bushings.

I haven't photographed the completed joint yet, but here are a couple photos of the assembly to give a better idea of what I'm talking about. The first is the pipes being tacked into the square tube:
http://rickert-digital.com/atomic_zombie/hitch-1.jpg

The second is the caps being tacked onto the open ends of the square tube:
http://rickert-digital.com/atomic_zombie/hitch-2.jpg

As I said, the BMX clamp or PeterT's way would have been easier, but it's been fun anyway.

[SirJoey]

Very kool, BC! Thanx for the pics!

I may have to make one like yours, cuz I
can't find the large block of nylon like PT used.


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[PeterT]

Would you like me to send you a square of nylon SJ? I could even pre-drill & shape it for you, and include the bolts and brackets if you want

I got my chunk of nylon from a bearing place, they have oodles of off cut sizes and shapes
PeterT

[SirJoey]

Would you like me to send you a square of nylon SJ? I could even pre-drill & shape it for you, and include the bolts and brackets if you want
I got my chunk of nylon from a bearing place, they have oodles of off cut sizes and shapes
PeterTUnbelievably kind offer, PT, & if you were here in the USA, I'd take you up on it,
but shipping costs from "the land down under" to here, would exceed the value of the parts, I'm sure.

The offer is much appreciated, though. Thanx anyway! :)


http://img384.imageshack.us/img384/7131/sirjoeysigmedij1.gif

[locolarry]

SJ,
How big a block do you need? I've got one 3"x3"x6"..
Will 1/2 of that work for you?
Loco

[SirJoey]

SJ,
How big a block do you need? I've got one 3"x3"x6"..
Will 1/2 of that work for you?Seriously? Hmmm... let's see...

Hey PT, this is YOUR baby... what do you recommend?


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[PeterT]

I was just using 40mm square by 50 deep
PeterT

[PeterT]

Unbelievably kind offer, PT, & if you were here in the USA, I'd take you up on it,
but shipping costs from "the land down under" to here, would exceed the value of the parts, I'm sure.

The offer is much appreciated, though. Thanx anyway! :)


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Sir Joey,
The shipping costs may very well exceeed the value of the parts, but that wouldn't even slightly dimish the joy at being able to bless someone with something built from the heart, that serves them as well as it has served you!

tremlett@emailaccount.com

PeterT

[SirJoey]

...but that wouldn't even slightly dimish the joy at being able to bless someone with something built from the heart, that serves them as well as it has served you!Well, you have a good point, mate, but I can't let you do it.
Think I'll get my buddy LocoLarry to hack off half of that piece he has.
That would make it roughly 3x3x3. Should work nicely, I would think, eh?

Again, thanx for the more-than-kind offer, though! :)


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[PeterT]

Money is only a problem when you let it worry you, I never worry about where my money is coming from, and I never worry about where it goes either, so money never worries me.

What is the difference between me buying most of my items from the USA and paying freight to get it downunder, and me sending you a gift from downunder?

PeterT

[PeterT]

3"x3"x3" would give you enough to make a u-joint to go on your car, for towing your trailer!

1.5"x1.5"x2" should be ample big enough for a bike hitch.

This is what I have based my design on
http://www.tregtrailers.com.au/poly_block_couplings.aspx

PeterT

[xanda2260]

The BMX handlebar clamp sounds like a great hack! Wish I'd thought of it. But I need to hitch my Cycle Bully to a High Roller, so I don't have a seat post to attach to.


Why thank you Mr Cheese Sir. I've just got the main frame finished and the bully is now towable!! Yay! Hitch works well, although a combination of my stubby legs and my luggage rack (trailer has to mount higher to clear it) means that when I execute a tight turn I get a dropin in the back of my thigh!! May have to limit motion or round the dropins off a bit!!

[PeterT]

Make a bracket that attaches to both sides of the rear wheel forks, and run your trailer joint off of that, with supports running up from the end of the forkmounted hitch to the seat support posts for triangulation. This lowers the trailer's tow point COG,(maximum height is only 14" of the ground!) and the supports also strengthen the seat tube

PeterT

[PeterT]

When I was walking though one of my local super rip-off chain stores, I happened to see this variant on the u-joint.

http://farm4.static.flickr.com/3528/3885666866_17734d6796.jpg

PeterT

[SirJoey]

Hey PT, that package I got from LocoLarry yesterday included that block of nylon he mentioned.

I figure it'll cut okay with my mitre saw, but was wondering if the high speed of the blade might melt that stuff.

Don't think I've ever tried machining a block of nylon before...


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[PeterT]

SJ,
I have found that the ol' hackie works best, fast enuff to cut, but slow enough to not stuff your blade with the molten plastic.

PeterT

[SirJoey]

Maybe I could put it in my mitre box, & cut it by hand, then.
If I use a hackie on something this thick, it's liable to come out triangular shaped!

...or worse! :eek:


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[PeterT]

SJ,

I have found that if I rough cut it, and then file it with a second file, it sorts itself out, and the nylon is quite forgiving if you take it slowly

PeterT

[PeterT]

Here is trailer hitch that I just made showing the amount of movement you can get out of this type hitch

http://farm3.static.flickr.com/2607/3964184081_eeab05af3e_m.jpg
http://farm3.static.flickr.com/2592/3964184067_305566385e_m.jpg
http://farm3.static.flickr.com/2470/3964184073_871f132bb5_m.jpg

PeterT

[SirJoey]

Here is trailer hitch that I just made showing the amount of movement you can get out of this type hitchOh, you're such a show-off! :jester:

Seriously, nice work, PT! :)


http://img384.imageshack.us/img384/7131/sirjoeysigmedij1.gif

[PeterT]

Well if I am such a show off for making it, how much of a show off will you be when you have it on your bike?

PeterT :wacky:

[SirJoey]

Well if I am such a show off for making it, how much of a show off will you be when you have it on your bike?I will display it PROUDLY! :D Think I'm joking?

...and why did I have a sneaking suspicion this was coming? :rolleyes:




A 3-axis hitch... hmmm...
:thinking2:

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