Step 4: Fabricate the Pulling Arm

The pulling arm attaches the trailer to your bicycle rack.  The arm is made from 1"x1" steel tubing and 1"x3/16" steel flat bar .  The pulling arm attaches to the upright tube on the frame with two pinch bolts.  The top pinch bolt goes through the two clamping plates with the 3/8" holes and around the upright tube.  This clamps firming on to the upright tube.  The bottom pinch bolt tightens against the upright tube and uses the tapped hole. This keeps the arm from twisting on the upright tube.  I chose to attach the pulling arm in this way because wanted to be able to adjust the height of the arm in order to keep the trailer platform level.  By moving the arm up and down I can adjust for different bike rack heights, so the trailer can always be level on any bike its attached to.  

<p>You know, the main part of a TrailGator would make a handy replacement for the towing arm - it's designed for towing a child's bike so allows a good range of movement and mounts to the seat post for good strength and stability. It's bolt right onto the front of your trailer and would give you a stronger mount point- only mention it because sometimes those racks aren't as strong as you'd like and it'd give more clearance when you go over a bump or a mound. Plus as a bonus they can telescope out if out need more distance </p>
<p>I might make something like that, except longer and more like a mini artic trailer instead of the normal design. Just for fun but could be quite useful for stuff like shopping or something. You could try it.</p>
Have you considered a safety chain? What about lights? <br> <br>And depending on your location there may be maximum dimensions for something to be classed as a bicycle. <br> <br>Whats your top speed compared to the untrailered speed? Half ?
Oh, who cares about the bike dimensions, no cop is going to do anything if he sees your bike tailor 3 inches over-sized.
Probably not, but I see you're in litigation-happy USA so think what would happen if you did clip someone.
Alright I don't know about you but, I live in Amish Lancaster county, and the roads there are very biker, and buggy friendly. I'm just saying that dbc1218 did a good job.
Never thought about saftey chains but I think a simple cable bike lock would work well, just connect it between the pulling arm and the rack. I would recommend lights, I used standard blinking bike lights attached to the trailer when I towed the grill. <br> <br>I didn't check any of the laws around here for limitations, but I never heard of size limits. <br> <br>When towing your more worried about making sure you don't hit to many pot holes and that the cargo stays on the trailer, than speed. Don't expect to be able to ride very fast. When I towed the grill 10mph felt like a safe speed but I did do 15mph and that felt like the max. Another important thing is your brakes. Make sure their in good working order, front and rear, you will need more space to stop. As far as top speed with out a trailer, I have gone 46mph on a steep down hill in the rocky mountians with the bike in the pictures. thats the fastest I've ever been on a bike.
I really like that design. I more prefer the hitch that goes to the side bottom of your bike, but the toolbox strapped to the front is great.
This is a sick trailer !! Thanks for posting!
You must have some huge legs to be pulling a barbecue and a full size trailer with a steel bike!
dude that is so cool but is it lugit! <br>
Looks great. You may inspire me to finish the trailer I have partially built that has been sitting around. I got spoiled when I got my long tail bike. I have one trailer on instructables too. <br> <br>The only suggestion I have would be to move the pivot ball up a bit from the rack deck. Or get some off set in your trailer tongue. It appears from the picture going over a hump it could bind up on you. I learned the hard way to anticipate these things in my designs (usually after the fact). <br> <br>Keep up the good work.
Your right, I have scratched up the back of the rack because the ball is a to low on the rack. The second nut on the stud was used to make it a little higher but its not enough. I think mounting the ball about 2&quot; above the rack would work pretty well, I have not decided on the best way to do that yet.
I would suggest cutting the hitch off your tongue and putting the offset there. If you get the pivot too high off the deck of your rack, it may overload the engineering of the rack itself. Your slick adjustable part will more than compensate for the offset. Think 5th wheel trailer in design. <br> <br>Keep up the good work. I have a box full of failed trailer idea concepts before I settled on the one I built. <br> <br>https://www.instructables.com/id/Fast-Handling-Bike-Trailer/ <br> <br>
Good Idea, I didn't think about changing the pulling arm. That may just be what I do.
i heard that the axle or the rear trailing arm mounts can tweek the frame. thats why i thought about putting it on the seat post <br>
only problem i see is that alot of bike racks have a 20 pound limit. i might modify this to attatch to the seat post.
Your right most racks are fairly light duty, but another important thing to consider with this trailer is how and where the cargo is loaded. If you can center the weight of the cargo right in the middle of the trailer, directly above the axles then the weight will be carried by the trailer not the rack. <br> <br>What you want is to load the trailer with the weight centered just slightly forward of the axles, this will put some down force on the ball which will help it stay attached. Once loaded, but not attached to the bike, the trailer should be tipped forward, then you should be able to lift it by hand with the pulling arm to attach it the the bike.
A lot of the commercial bike trailers attach to the rear axle or some point near there.
Yeah I considered mounting the trailer to the axle, like a BOB trailer, but that type of mounting is more complex and I don't think its the best for large/heavy/bulky loads.
It's a great project!! I would add holes in the bottom leg so that you could lift it out of the way and slide a bolt through it to keep it there. Also 3/8&quot; plywood would be lighter too. If you are going to keep the tool box ( great idea) on the trailer, you could bolt it down through the bottom. <br> <br>Again, Great project. The quick release and the ball joint was a great idea in case the bike should tip over.
I have considered making some sort of jack, like a screw jack used on most car trailers, to hold deck level when not attached to the bike. I think this would make loading and unloading a lot easier, because the bike is not in the way.
You could do some simple flip down legs like on the old bikes.
I made something similar but it used wheelchair hubs, that way you don't need the outside support?
great looking trailer ! I think using eyebolts to secure the platform would have given you secure attachment points for securing your load but then they my have occasionally gotten in the way.. thank you for sharing
The eye bolts are attached through holes in the front and back sides of the frame and do not obstruct the deck surface. the 1/4&quot; -20 bolts in the pockets hold the deck to the frame not the eye bolts
I'm sorry, I missed the eye bolts you used, however what I was suggesting was using eye bolts instead of hex headed bolts to attach the deck, killing 2 birds with 1 stone so to speak. I should have looked closer at your design before commenting

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Bio: I enjoy building things more than actually using them.
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