Question about extending a recumbent bike boom

[Caden]

Hello Sector67 hive mind,

I've got an oldish Catrike recumbent trike I got on Craigslist 10 years ago and I'm still looking for ways to make it more fun and usable.

Because the biggest challenge with this bike is being safe when people don't see you when you're so low to the ground, I bought a Loud Bicycle horn (that's actually the brand, loudbicycle.com).  It's pretty good, but hard to mount when you don't have standard bike handlebars.  I've mocked up a prototype for how I'd like to attach it to the bike.  Basically, I'd like to extend a smaller pipe out from the bottom surface of the boom about 18 inches, with a T on the end where I can  mount things that would normally go on handlebars.  This position is also nice for lights, which if I mount them on my actual handlebars, mostly light up my feet.

I'm attaching some pictures of the prototype.  The biggest problem I'm having now is that, as you'd expect with two round surfaces strapped together, the attached PVC pipe travels around the boom.   The bottom of the boom is round so there's not much to prevent it.  I've searched for things like 'parallel pipe clamp' and various bike accessory attachments but I haven't found anything like this.  

Does anyone have any suggestions for a more stable way to extend the boom, and create a T for mounting horns and lights like this?  

Also, if someone is really into this sort of thing, I know there have been a lot of cool bike modification projects at Sector 67 in the past, I would really love to figure out how to mount a basket where the T is, so I could take my 15 pound dog on a few rides.  Maybe I could commission someone for a project.   It would be easy to strap a basket behind me on the cargo rack, but I want to keep an eye on the dog and how he's enjoying the ride.  I had a bad experience with my larger dog where I had her in an official doggie bike trailer and she was apparently panicked and tangling herself up in the safety leash and I didn't realize it for 2 miles.

Here's a link to the pictures of the prototype in case Google Groups strips the attached pictures:

https://photos.app.goo.gl/mXA48aBzgDgX45gs6

Thanks for any suggestions!

Caden

[Justin Meyer]

For a first attempt I would try replacing the zip ties that are holding the extension with hose clamps:

1. Remove the zip ties and foam insulation.

2. Where the zip ties will go, wrap the boom in a layer of electrical tape to add friction between the pipes (people also use a piece of old inner tube for this) and to protect the bike's paint.

3. Use one hose clamp like this where each of the zip ties used to be (I don't know what size, this is an example): https://www.homedepot.com/p/Everbilt-3-5-in-Stainless-Steel-Hose-Clamp-6772595/202309382 

Another idea would be to use two or three of these clamps (for mounting an antenna to a pole): https://www.amazon.com/Pole-Mount-EC-PTP-4-Brackets-Brand/dp/B011AGVLXM

Regarding mounting a dog basket to the extension, I'm a little concerned for the dog's safety if some part of the system failed. I'm also a little concerned about adding that much weight that far out front. The last bike I rode of this type was very prone to suddenly lifting the rear wheel off the ground under even light braking. I suppose the extension could be designed to also serve as a front-mounted wheelie bar to provide something to stop the rotation, though the dog might not appreciate the teeter totter effect. 😀

--
You received this message because you are subscribed to the Google Groups "Sector67 Public" group.
To unsubscribe from this group and stop receiving emails from it, send an email to sector67+u...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/sector67/3581cb46-8255-4cbf-8f1d-c70c8d05cbffn%40googlegroups.com.

[George Hartman]

Hi there.  Cut the boom PVC pipe where it crosses under the pedal crank housing on your existing frame.  Glue a cross fitting onto the shortened boom, then glue the cut-off piece into the cross fitting opposite the shortened boom.  Essentially, you're inserting a cross fitting into the current boom where it passes under the pedal crank housing on your existing frame.  Now you have the two empty cross fitting sockets sticking out on either side of the boom and you can use wire ties to strap each one to the crank housing above them.  This should keep the boom from rotating and give you a fairly solid mounting point.  One or two more wire ties farther back along the rear boom extension should finish the job.  Hope that helps, have fun!

To view this discussion on the web visit https://groups.google.com/d/msgid/sector67/CACV5zi2gFW4TgDD9y%2BN-E0-b0mHXAAm35COhtXGA0-H4bKft4Q%40mail.gmail.com.

--

George A. Hartman

[John Hunt]

My first question is how heavy is the dog. A small diameter PVC pipe is prone to creep bending especially with a load (the dog) and hot days. The first issue is the dog's safety and it's a cantilever beam bending problem. If you want to use PVC then you might be able to cut a larger diameter PVC pipe, maybe 2 or 3 inch diameter and cut three "slots" large enough for either side of the pedal shaft and one for the handlebar shaft. Essentially you have three pieces extending back. You could then cut spacers to go between the PVC pipe and the extension tube. Then use a couple of worm clamps to secure the slotted pipe to the extension tube. I would then test the bending properties of the PVC pipe with about 3x the dog weight. You may also need to add ballast behind your seat to compensate for the weight of the dog times the distance. The ballast weight will need to satisfy  the equation Dog wt. x distance to the center of your two wheels = ballast weight x distance behind your seat from the center of your wheels. If you need a 3D model of the slotted PVC pipe let me know. 

Just some quick  thoughts

Best Regards,

John F. Hunt

3D Fiber Engineering, LLC

Seeking to be committed to doing the harder right, than the lesser wrong. 

(This is not a political statement.)

www.3dfiberengineering.com

Profile: www.researchgate.net/profile/John_Hunt3

LinkedIn: linkedin.com/in/john-hunt-a401b311

Cell: 608-332-2207

Email Disclaimer 
***************************************************************** 
The information contained in this communication may be confidential, is intended only for the use of the recipient(s) named above, and may be legally privileged. If the reader of this message is not the intended recipient, you are hereby notified that any dissemination, distribution, or copying of this communication, or any of its contents, is strictly prohibited. If you have received this communication in error, please return it to the sender immediately and delete the original message and any copy of it from your computer system. If you have any questions concerning this message, please contact the sender.

On Tue, Apr 20, 2021 at 5:30 PM Justin Meyer <meyerj...@gmail.com> wrote:

To view this discussion on the web visit https://groups.google.com/d/msgid/sector67/CACV5zi2gFW4TgDD9y%2BN-E0-b0mHXAAm35COhtXGA0-H4bKft4Q%40mail.gmail.com.

[Jim Rasmussen]

Nick Hein got a rear view camera with a small screen for his recumbent.  It was pretty cheap.  That might be an option for keeping an eye on the dog riding behind you, while keeping it in a safer location.

Jim

To view this discussion on the web visit https://groups.google.com/d/msgid/sector67/CA%2B6AjnanEBQTAo5n8m5NrmOgUqtOFsXh2y1dMZut%2BZRJBt2QUg%40mail.gmail.com.

[Nickolas Hein]

Thanks for the mention Jim,

If you want to see how this is done well, take a look at the Terracycles trike fairing mount.  That might give you some better ideas for how to construct the mount.  Also, if you want a windscreen, I have a spare (no hardware, just the lexan) that you can have.  I would go along with Jim's recommendation that you put the dog in the back or on a trailer with a camera or mirror to keep an eye on it.

https://www.youtube.com/watch?v=VBnXR3cCMYE

Nick

To view this discussion on the web visit https://groups.google.com/d/msgid/sector67/CABLNewmxx7cXMe9FboEzDFWF60odh9w30YqJ-HfUjudctwNmhQ%40mail.gmail.com.

--

Nick Hein
Madison, WI

[Nickolas Hein]

Caden,

On the recumbent homebuilder forums there is a guy building recumbents using 3d printed joints.  He prints them in the usual plastic, but then plates them on both sides to put the plastic in compression - clamping evenly without crimping the tubes underneath.  You can see pictures of it on facebook if you search for oleg tsyganov recumbent.

Nick

[Caden Howell]

Hey everyone,

Thanks for the suggestions.  I plan on combining Justin and George's suggestions next,  trying the PVC with the cross piece next. with some addiitional tape or an old bike tube for better friction. .  I did try to look up fairing attachments before I wrote you guys, as my boyfriend's bike came with a fairing and I remember it had a boom attachment, but I haven't been successful finding parts for just that part of the fairing setup.

Also thank you for being concerned for the safety of my dog. :D  He's 15 pounds.  I was thinking of the PVC being truly a prototype in that case, and putting together something welded for a doggie basket, maybe even with a wheel under it touching the ground.  But I don't know much about welding.  It would be really fun to make a sidecar for him, but then I think I'd be too wide on the bike paths unfortunately. 

BTW I can't remember if I ever got back to you years ago after I asked for advice about my treadmill continually tripping a breaker, and I did ask the landlord to just replace the breaker on that circuit.  It worked a treat!  So the breaker was just old and worn out.  Thank you for the advice.

Caden

To view this discussion on the web visit https://groups.google.com/d/msgid/sector67/104d2513-8700-429d-9e4c-e1e648710236n%40googlegroups.com.