Adventures with Bike Trailers...
 

This thread is dedicated to DIY bike trailer stuff...

I've long been into bicycles and in high school put together a 2'x3' trailer out of copper pipes. The hitch arm could be extended a couple feet by screwing in an extra pipe. Used 20" wheels from Northern Hydraulics.

http://farm6.staticflickr.com/5230/5...ce198e87_z.jpg
Bike Trailer, top by Tyler Linner - now on Ipternity, on Flickr

The top was covered in very versatile (but dangerously sharp) expanded metal. It was fantastic for bungeeing stuff down. I had removable uprights on the four corners which helped the cargo from getting into the wheels.

http://farm4.staticflickr.com/3491/5...f99a901f_z.jpg
Bike trailer rear by Tyler Linner - now on Ipternity, on Flickr

With the extension in, I occasionally towed a 10' kayak to the nearby lake. With the extra torque it wobbled a bit with each pedal stroke, but ultimately worked fine.

So, recently I got my first "big boy job" very close to everything I need. Naturally, I got out the bikes and started doing errands on two wheels. This necessitated a bike trailer. I hopped on Craigslist and found this listed for $20. I got there and the lady only wanted $10. Score!

Hooked up to the Trek and took out the recycling, about a five mile ride total.

http://i44.tinypic.com/2s10nkp.jpg

So, that's fun and all but for cargo use it is horribly balanced. I went back home and looked at the stillborn project I'd been working on. The challenge was to build a trailer for $30 total. I hit $25 and had no hitch; that's what led me to CL.

Looking at them side by side, I decided to use parts from both and make one trailer to suit my needs.

http://i42.tinypic.com/v650ck.jpg

It's made from wooden pallet boards, a small amount of plywood, two $5-each wheels from Harbor Freight and a threaded rod axle. Once the hitch arm goes on, I'll be able to get a scrap sheet of thick-ish plastic for the top and try the thing out. The thing will have a completely flat top so I can hang stuff off the sides if need be, without worrying about hitting the wheels.

Until then, it's time to find a power screwdriver. When this thing's done it should be quite durable. The low load height means it will be able to hold a lot of stuff- anything from boxes of recycling to bags of groceries or Salvation Army furniture. Some eye hooks on the edges will help with tie-downs. I'm going to put a couple casters on the rear end so I can tip the thing upright and roll it through doorways.

Anyway, I will try to update this as the trailer progresses. I've been working on it on and off for a few weeks but would like to get it on the road sooner than later. Probably have about $40 into it now (not counting tool purchases which will last me many years).

Cheers! -Tyler

Cool.

Good job!

More threads on bicycle trailers:
How my home-built bicycle trailer lowers my MPG
I thought I needed the car to pull a boat...

How will the bike lean with the wooden trailer on?

I love my DIY bike trailer! (Piwoslaw linked to it, above.)

http://www.metrompg.com/posts/photos...r-tranny-z.jpg

I've done the kayak thing with this one as well.

Just yesterday I was thinking about making another bike trailer that would let me pull a ~140 lbs catamaran down to the river, instead of driving it down:

http://ecomodder.com/forum/attachmen...1&d=1285461394

If I take one hull off, lash it to the other, tip everything to stand upright on its side, it would only be about 2.5 ft wide, with most of the mass down low - appropriate for pulling behind a bike.

Probably won't do it this year though - too many projects.

Nice, guys! Someone mentioned a "throttle joint". It's also called a "heim joint" or "rod end". I wanted to use one of those but couldn't find one. You'd think Ace Hardware would sell them.

It will lean the same as any other one leans. I'm re-using the kiddie trailer's hitch, which just has a section of bendy rubber. It's not as sophisticated as my copper trailer's hitch, but it's cheaper and it works.

EDIT I think I see what you mean. The U shaped metal piece is just part of the kiddie trailer's hitch arm. It's designed so you can put a third wheel on it and push it while jogging. Obviously I'm not going to be doing much of that.

Darin, please post pics when you get that catamaran behind a bike! I would love to see that. :D

Super bored today so I screwed it together by hand. Not fun, but more fun than sitting on the computer. Got it "done" and hooked up as it started raining. Still needs a top surface and some sealer/paint.

http://i43.tinypic.com/30l1lid.jpg

More images: ipernity: Bike Cargo Trailer by Tyler Linner

I should mention that the only power tool I've used on this is a hand-held electric drill. The only new parts are 4 sq ft of plywood, two wheels/tires, an axle and four nuts. The rest is recycled!

Up to this point if you did it smartly you could probably do it for $15-20 if you used the old wheels.

Holds at least 150 lbs.

Throttle joints for carb linkages are available at auto parts stores and came in sizes up to 1/2" diameter threads. I recommend at least 3/8" for light trailers: if you are hauling something more than 100lbs I suggest a steering tie rod end. A heim joint is slightly different in that it has a through hole rather than a male threaded stub.
The next level of sophistication would involve added brakes and suspension to the wheels. The axles can be truss supported for improved strength to weight ratio. Don't forget the aerodynamics especially when touring.

Not much touring happening here! Just bought a new bookshelf... how to get it home? :D

http://i40.tinypic.com/aw9j4z.jpg

Nice. I like hauling by bike.

Last few days, I moved on my trailer: half a dozen loads of mulch, plus a wheelbarrow.

No pics though, so I might just be making this up.

nice!

ive been thinking about the best way to do a trailer for a while now, theres only so much i can carry on my small rear carrier (makes more frequent shopping trips necessary which is both a pain and bad for economy on my motorised bike lol!)

i have a pair of wheels similar to yours laying around Sven7
http://i40.tinypic.com/aw9j4z.jpg

how do they do at speed? obviously my motorised bike will go a bit quicker than your pedal only one but do they show any signs of stress if your really moving like down a hill or something?

im thinking a simple 1"x1" steel frame and hitch for plenty of strength and durability and expanded aluminium mesh for the base to make tying stuff down super easy

Sounds like quite a load. Was the fish thiiiiiiiiiis big? :p

Yeah, those are just $5 wheels from harbor freight. Rated for 350lbs. or something. They wobble a bit and aren't completely smooth going down the road but I think the beads are just seated wrong. No other problems really. 1x1 would be my first choice if i had a welder and some more space. You could even do a simple swing arm rear suspension system!

I have & use trailers also. Most are converted yard sale kids trailers (1 Burley, a Rhode Gear, and a decent quality generic. All have aluminum tube frames & aluminum rims. Cheap too - the Burley was $25, but needed rubber. I usually modify the hitch (I ride recumbents) and use air couplings for the hitch - Bikefriday.com sells a similar hitch setup. It's wickedly fast to connect & disconnect, and you can buy the couplers cheap & Harbor Freight.

Air quick connectors are quick but not as strong as a solid connector such as a yoke and pin arrangement. If you are using air hose connectors, fill the male end with epoxy steel. The unit is much stronger in shear (right angle to the load) than relying on the unit holding together in tension. A safety strap or chain is a good addition.

Just how much shear load do you speculate is on the coupler? More specifically, how much shear is created pulling a 2 wheeled, 20 lb. trailer w/100 lb. payload? I'd wager far less than 15-20 lbs shear load. I would further estimate double that (40-50 lbs.) shear if the trailer catches a pot hole.

Here's the cad for one of mine.... (it regularly endures 150 lb. loads)...

http://i48.tinypic.com/2vj3nec.jpg

And I've been pulling it with this at 25-30 mph for the last 4 years...

http://i39.tinypic.com/24bt7xs.jpg

If it works, it works. Some of the trailers look like there are going to be some hefty loads. Just remember the material including the spring can wear over time and the load is supported solely by the balls in the groove. I am used to working around trailers for construction equipment as well as my two bike trailers. I tell my boys, "Careful, it's only made of metal." ;)

My trailers been up and running for a couple of weeks now, it holds plenty of weight but im having a few handling issues when its not loaded up it tends to get pretty bad sway at far lower speeds than id like, i want to strengthen and possibly redesign the hitch on the bike to fix the problem

http://i447.photobucket.com/albums/q...psbdd69db7.jpg

As much as I dislike the typical hitching off one of the bike's rear stays (usually the LH side), it's about the only acceptable method.

They do it because it keeps the hitch mount low (unlike yours), which not only improves towing, but is safer and more predictable during panic stops. Two suggestions...

1. Hitch off the bike's LH chain stay - if enough threads are exposed, you can mount to the rear axle.

2. remove your trailer's tongue at the bed, then reattach (weld?) it to the LH side of the bed with the arc pointing inward. Length looks about right. Now build your hitch.

Here's a couple of valuable links with many examples of DIY trailers..

Trailer Construction Tips

The post your trailer thread.

Here's just one example in the link above...


http://img580.imageshack.us/img580/5...0419122920.jpg

Yet another example in the same thread...

http://photos1.blogger.com/blogger/3.../TrailerB3.jpg

Thanks for the tips Kenny

I too disliked the idea of hitching off one of the rear stays but now that ive tried this way i know why they do it like that...

The only problem is my wheels have those quick release clamp on axles so i cant use the axle and nut to hold on the hitch very easily
My main idea to try next is a set of rear stays from a junk bike cut up and mounted backwards with the hitch where the seat tube normally would join on, Then i will brace it either with an old school round steel mudguard or up to the rear carrier so it doesnt move up or down, similar to how most big harley bike trailers are hitched and the same as car hitches (in the middle of the bike at or below axle line)

http://www.totalmotorcycle.com/submi...r-Damien-A.jpg

Similar to Surly Bikes hitches, except they retain the LH side hitch only.

Bill the Trailer | Bikes | Surly Bikes
http://surlybikes.com//uploads/downl...nstruction.pdf

But the Surly method still mounts off the bike's rear axle, so you'd need to replace the QR with a longer one, or replace the rear axle with a solid axle.

Disregarding the hitch location for a moment, please consider lengthening your trailer's tongue, whatever hitch location you employ. The longer the tongue, the less it negatively effects the bike's handling. Too long and it becomes awkward to navigate tight corners and complicates parking choices. About 18-25" (475-635mm) measured from the leading edge of the bed to the hitch. Also figure on 8-10% tongue weight. (example - if your gross (loaded) trailer weight is, say, 120 lbs, then shoot for approx. 10-12 lbs tongue weight (at the hitch).

Thanks for the advice once again Kenny

That Surly hitch looks great but I cant for the life of me figure out why the left hand axle mounted hitch is better than a hitch at the back of the bike in the middle like nearly every other vehicle trailer hitch has, the only benefit i can see is ease of attachment to any bike frame as they all have a rear axle to attach to but the surly mount had the bracket that goes all the way around the wheel anyway so wouldnt mounting the hitch in the middle be better?

The bikes handling hasnt been affected noticably with my current design, its the trailers handling that im worried about, will the longer hitch arm help prevent sway at higher speeds?

I know about loading from towing car trailers for quite a few years but thanks anyway :)

The hitch mount on the LH chain stay is typically preferred because it allows transferring the trailer to multiple bikes. The LH side because it doesn't interfere with the gearing (deraileur and IGH shifting mechs). It's also easier to install without permanent modifications to the bike.

Mountings with hitches that pivot at the center/rear place the tongue weight (and hitch pivot point) further aft of the rear tire's contact patch. This location gives the loaded trailer greater leverage to effect the bike's handling - most notably during emergency maneuvers w/heavy loads or when the trailer tire catches an obstruction such as a pot hole. Just think of the conventional automotive bumper hitch Vs. the bed mounted 5-wheel trailer, common with the longer & heavier travel trailers. Semi's too utilize hitches that place the hitch weight (and pivot) directly over the tractor's rear tire's contact patches.

Yes. The longer the tongue, the greater the leverage because the bulk of the trailer's weight is placed further aft of the hitch pivot point, which reduces lateral dynamic loads on both the hitch and the rear of the bike. The downside to longer tongues is the minor inconvenience of greater overall length (parking) and reduced maneuverability around tight corners.

There's also yet another dynamic in-play when hooking a trailer to a bike (any two-wheeled single-track vehicle).

Bikes are not 'steered' (in the conventional sense) to navigate. We steer primarily to control the bike's CoM (center of mass). We do this by steering the tire's contact patches left & right beneath the bike's CoM. When the bike starts leaning to one side, we steer in the leaned direction to stop or slow the leaning. Ultimately, the bike is continuously zig-zagging left & right as we ride, but the faster we go the less it's noticed to the rider. So how does this affect trailer towing?

The bike's left & right 'leaning' pivots at the tire's contact patches on the riding surface, and intensifies vertically. So the higher you place the hitch on the bike's frame, the greater the lateral movement of the trailer hitch (not good). Conversely, the lower you place the hitch location, the less lateral movement occurs in the trailer (preferred). Make sense?

Thanks a lot Kenny, you sure do know your stuff about trailers!

All of your points make a lot of sense. I think i might see if i can get a normal rear axle instead of a quick release to allow me to build a side mount hitch after all, i think it will be easier to do a RHS on mine though as it has a disk brake on the LHS which would get in the way

Thanks again

Yur certainly welcome bobo. One last suggestion....

I'm using a telescoping tongue on one of my trailers so I can vary its length with a single cross pin. All I use is compatible OD & ID round tubing, then cross drilled about 4 holes spaced about 4". It's also handy when want to experiment with different hitches 'cause you needn't butcher or remove the whole tongue.

Another reason for the left side mount was the ability to lay the bicycle down without tipping the trailer. People were concerned about the bike falling over with children in the trailer.

If you haven't already altered the trailer tongue, in this set-up it's going to sheer off where the vertical post meets the trailer frame.
Rather sooner than later.

The high-hitched bike trailer we have at work failed in a similar spot in a short time.


As suggested, put the hitch as low as possible on the bike.
I have yet to see a motorcycle trailer with a high hitch position ;)

Bigger wheels would help, too.

I did a few mods to the rear carrier yesterday as it was coming loose a bit and swayed side to side, some triangulation when looking from the top fixed that as well as bigger bolts holding it on...

but in the process i removed the trailer hitch mount at the back so now i need to redo that

Side mount is looking like the best option so that will be done when i get some spare time to nut it out

Brought the good trailer home... used it to haul a project bike to the shop lol.

http://u1.ipernity.com/37/30/01/2671...807.500.jpg?r1
Varsity Towing par Tyler Linner, on ipernity

Turns out I haven't updated this in forever. The wood trailer didn't really work out. It was too heavy to carry up and down stairs and didn't offer the smoothest ride in the world.

After that I tried to make a trailer out of a 66" (1.67m) long plastic toboggan that was on sale. I figured that it was long enough to fit big items, but perfectly fit my plastic bins side to side. Mounting some angle iron underneath it, I put the allthread axle through and bolted my white 20" wheels on. I had a friend weld up a hitch arm and bolted in the hitch from the blue trailer. It didn't work very well. The whole thing twisted really badly and it was too long to carry up the stairs to my apartment.

I salvaged the good parts off of it and took a look at my friend's trailer. He used a Kmart In-Step kid-hauling trailer as a basis for a big flatbed. Removing the fabric canopy, he added an X-frame over it with a piece of plywood on top. It was tall enough to clear the top of the tires, acting as both fenders and a way to carry really wide items without hitting the tires. Buying a ready-made trailer took over the work of building a sturdy frame- all he had to do was adapt it to his liking.

Picking up his new bike at the UPS center
http://ecomodder.com/forum/member-sv...3-trailer2.jpg

I decided I liked the basic premise, but wanted to undersling the cargo bay and make use of the trailer's design. I bought an almost identical In-Step trailer for about $125 (I thought it was going to be on sale), obnoxiously hauled it home by bike and promptly stripped it down. After a bit of work and some eye rolling from the girlfriend, I ended up with this.

http://ecomodder.com/forum/member-sv...2-trailer1.jpg

Supported by 2x4's scavenged from a discarded pallet, and topped with a sheet of luan plywood. I positioned it to balance fairly well over the axle and screwed it on through the metal frame.

http://ecomodder.com/forum/member-sv...4-trailer3.jpg


It got a coat of primer, then Rustoleum to protect against bad weather, since I am quite hardcore about this and will not bat an eye at cargo biking in the rain or snow. I noticed, though, that my cargo kept sliding over and rubbing the wheels. This was especially problematic when hauling bikes. I was just barely able to carry a Schwinn Varsity to a flea market.

I was also having a hard time finding places to strap things down, and, worshiping the Bungee Gods, needed to add some hook points.

http://ecomodder.com/forum/member-sv...5-trailer4.jpg

Some side plates just barely fit on the inside of the frame rails, so I drilled some 1" holes and bolted them on. They're not yet fully painted.

The local bike junk shop (I say that lovingly) had a random axle block sitting around, so I picked that up and mounted it on the front. I can now haul most bikes upright on the trailer with no issues at all. The whole thing is about the length of a bicycle wheelbase, so they barely fit. I picked up my fatbike in December by towing the trailer to the bike shop, attaching it to the new fatbike, and towing home my "old" commuter. It worked alright.

I made some small aluminum L-brackets and attached coroplast fenders with splash guards to keep my cargo dry. Then I added a few reflectors for visibility and continued to beat the crap out of it. I actually used this trailer and my fatbike to move a good deal of stuff from my old apartment to my new house. It performed quite well. Six paper boxes full of random junk did not stress the trailer, but they were a bit heavy for my taste.

http://ecomodder.com/forum/member-sv...7-trailer6.jpg

It even takes longer things, if I'm very careful.

http://ecomodder.com/forum/member-sv...6-trailer5.jpg

That's about where I'm at with this whole trailer thing today, but I'm not done. A few things that need fixing are:

-Hitch is too high, so I'm planning on transplanting the 20" wheels onto this to level it out.

-Trailer is too short on the front, and I can't balance really long items on it without hitting the bike tire. I am planning on building a longer hitch arm and extending the cargo area.

-2x4 structure is heavier duty than the luan, so I want to build a new top using 2x2's topped by 1/2" OSB.

-The side plates are great, but a little weak at the frame attachment point, and I wish there were more of them. I'll figure something out...

And so continues the DIY bike trailer saga; I am forever building the perfect trailer. It should be said that all the above was done with hand tools and a DeWalt corded drill in a second floor apartment. Nothing fancy (you can do it)! If anyone has questions about trailer construction or whatnot, feel free to PM me. I've got ten years and five trailers of experience! :)

It's a great saga. Nice to watch the new ideas coming from lessons learned. Using it to move is even better.

:)

A couple more notes-

-Trailers like this almost always come with a little 'safety strap' that you're supposed to string around your chainstay in case the hitch fails. DO NOT TRUST THESE! I saw firsthand when my friend's custom hitch came loose- without a strap, the trailer simply spiraled to a stop. If it would have had a strap there, the hitch likely would have fallen straight into the wheel, likely breaking spokes, locking up the wheel, or similarly giving him a really bad day. Remove the strap and throw it in the trash.*

-The bike side of the hitch sometimes is a bit of a hassle to mount. Mine is currently clamped into my quick release 170mm rear axle. Getting the axle over both dropouts and keeping the hitch plate on the outside is a real chore. Above friend has come up with a novel solution- mounting the hitch plate to the rear disc brake mount! I am planning on doing this in time because it is just so slick. The brake mount is an integral part of the frame, and a solid mounting point for anything- after all, it has to stop 200lbs of rider and bike on a 9" lever. The hitch mount extends diagonally rear and downward from the brake mount, so the trailer hooks on just aft of the rear axle.

Edit for picture:
http://ecomodder.com/forum/member-sv...6769-hitch.jpg

-The trailer I currently use is steel, and is rusting from the inside. I don't know how long it will last, but I may need to get it powder coated if I'm going to keep it long-term. This is something to consider if you're going to be out in the salt.

-I'm still battling road spray from the rear bike tire going onto the middle of the cargo. I tried doing a makeshift fender on the bike but it didn't stay put. The best I've come up with as yet is to cover my cargo with a tarp. Not exactly high-tech. One option would be to make a canvas cargo topper like a military truck. I'm open to ideas, but once I get a rear rack it the modular fender may become more plausible.

*This is assuming you are not hauling humans on the trailer. At that point it is up to you- would you rather sacrifice your wheel and safety, possibly crashing in the process, or take the chance that the trailer will spin out in the right direction, away from traffic? The best option is always to overbuild your hitch. There aren't many good options available on the market, so it's up to your ingenuity and possibly your proficiency with modding caster wheels!

Give your GF +1 :thumbup: for patience!

One of the morals of your story is: If you had a ground floor apartment, then you probably would have stuck with a less efficient design.

How about a front wall on the trailer? It would not only block spray, but also keep any cargo from shifting forward into the bike's rear wheel. You could make it removable, for any really unshapely cargo that won't fit otherwise, or when it's dry.
I made one for my son's Croozer trailer, as he was always covered in sand, even with the bug screen down. I got the idea from a picture of a Croozer on a Czech webpage.

Well, I think I would have continued the design anyway, partly because of that awful hitch that clamped onto the rear triangle. But yes, the progress may have been slower!

That is one thing I considered, and I actually cut out a flat piece of plastic to extend horizontally forward from the trailer within probably 5mm of the rear tire. That lessened the spray, but did not eliminate it. A vertical wall could work in the right circumstance, I think, but I already have the axle block there to keep my bins from sliding forward. It might prevent me from hauling odd sized stuff for half the year, though, because winter.

Soon I'll be taking my truck's (rusty) wheels to the powder coater, then to the tire place to get new tires mounted, so I'll try to remember to get a picture of that. Last time I hauled wheels/tires it was quite a big job! :)

I use a 1 qt rectangular oil bottle to make a fender extension to reduce road spray.

Great thread, heres two of my trailers, both built using old kids strollers. The short one has had way more use... the sides are newer addition... lawn mower fits nice as does wheelbarrow and a bunch of tools. Also did recycling trips with it before we got roadside bins. The long one has wood frame ontop of metal base, and is 8 foot long plus hitch! They pull real nice.

Awesome! I assume the wheels are stock for the kid trailer?

Surprise! You can't haul things in a truck with no tires. I took them two miles down and back to get the tires dismounted. The gf wants the old tires for a flower planter project so I ended up having to find a way to get all the stuff back on the trailer. It wasn't easy.

http://ecomodder.com/forum/member-sv...-182947497.jpg

Tomorrow, the ten mile ride to deliver the wheels and other bits to the powder coating place. Wish me luck!

:D

HOLY! now thats a good load sven7... i hope you live in a flat town!
Yes the wheels are stock 20 inch, but they are old steel rims, so fairly strong. And they polish up nice.
This thread got me pumped to fix my hitch on the smaller one. I broke the big plastic nut a while back, but i found a metric wingnut that fit yesterday.
Its fun riding round round town with a big load, hopefully it opens eyes to what is possible on a bike
nice front rack sven, it looks bomber. And did you make those mudguards?

:)

Yeah, all drained swampland so I only had a couple landscaped knolls.

Good luck on the hitch; it seems like all stock hitches have one issue or another. I too love hauling big loads with the bike- it's such a feeling of accomplishment!

The front rack is an Old Man Mountain Phat Sherpa. Works pretty well. I did make the fenders, and they work well! :thumbup:

An issue is the strength of the ball and socket joint on the low mount hitches. A tie rod end from a garden tractor or small car would be super duty strong and a grease fitting may be included.

Does anyone have brakes on their trailer?