Utility Cycling - Homemade surge brake trailer?

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View Full Version : Homemade surge brake trailer?


bengreen79
08-03-08, 04:05 PM
To preface this, I neither have the tools to make this nor any practical use for this idea but I had been thinking about how someone could make their own surge brake trailer. I didn't really see any threads on here so I thought this could help someone.

I was at a rummage sale and I saw a beat up Huffy mountain bike with a broken chain, missing derailleurs, etc. It did however have a suspension fork which seemed to have a fairly long travel and wasn't too hard to push down however still firm enough. It seemed to me that you could use the movement in the suspension fork to make a simple surge brake.

This is how I envision it. Feel free to make it, steal it, sell it, tell me why it won't work, improve on it, etc.

1. Cut off the ends of the fork just as they start to bend. I picked ugly green because that was the color of that garage sale junker.
2. Make a simple rectangle frame with two cross members near the edges (big enough to mount wheels in between). Length/width would depend on your needs however there needs to be a spot to put the break behind the wheels.
3. Weld the fork to frame in the center (parallel of the cross members).
4. Mount the wheels in between the cross members and the outside edge.
5. Attach a side pull break to the end of the frame between the cross member and outside edge. The cable connecting part points to the inside of the trailer.
6. Repeat on other wheel.
7. Attach a pipe or stiff rod above the shocks/springs on the fork. This would be on the same side as the brakes are on. This rod would need to NOT move.
8. Attach lightweight yet stiff rods from the rod you just mounted to the cable anchor screw on the side pull brake. Probably would want to drill holes in the pipe above the fork to allow for some flexibility.

If I were building this, I'd put all of the rods, brakes, etc on the bottom of the frame.

Now when you started to slow down your bike, the fork would compress, pushing in the sidepull breaks and helping you slow down.

Here's why I think this would work - I don't think it would provide TOO much braking. It would also be more prominent under load when you'd really want it.

A couple of things to consider:
1. Would a cheap fork you'd be willing to hack up handle the tongue weight (are they horizontally strong?)
2. You would need a hitch that allowed left to right movement but not too much up and down since you'd wouldn't want the hitch to buckle up or down (defeating the purpose of the brake).

What does everyone think? I've attached a crude drawing made with MSPaint (sidepull brake images ganked).

http://webpages.charter.net/redranger/surge_brake_trailer_frame.JPG


StephenH
08-03-08, 08:56 PM
I think the biggest problem is that it's just more trouble that it's worth.

In actual operation, I see two potential problems. One is that the actual braking force wouldn't be very large, so it'd be hard to get a lot of braking going with the trailer. Second thing is that I don't know how hard it is to operate side-by-side wheels with brakes like that. If one brake contacted first, you might get some good side-to-side oscillation going on.

Maxwell
08-03-08, 09:59 PM
yeah, as long as your trailer put's some tongue load on the bike, it greatly helps your braking power. The rear wheel is less apt to skid, and your front brake can't make you endo. Probably not necessary, but if you're in to building it just for fun, it could be an interesting project.


HandsomeRyan
08-08-08, 12:45 PM
Awesome idea. I'm thinking you'd need to have pretty exacting tollerances to make it work in real life but it's still a neat thing to discuss. Nice pics too.