new push trailer in the works!

Discussion in 'Push Trailers' started by rkbonds, Oct 13, 2008.

  1. rkbonds

    rkbonds Member

    Today a friend gave me his broken self propelled push mower. He ran over a brick and bent the end of the shaft. I'm not going to order a new shaft since I don't need the mower. I'm planning on building a push trailer out of it by cutting down the shaft which will allow it to run properly since it's just the tip end that's bent. I'm going to have to change the pulley's to get the proper ratio's but, I don't see any reason this won't work with the proper modification's (bearing's reinforcement's, and wheels. I'm going to take my time with this project and get it all right the first time. Speed isn't going to be top priority 20-25 is plenty fast enough. I have looked at the gear box and it is similiar to that of a riding mower. Any thoughts or ideas are welcome. I know there are simplier ways of building this but, are they as interesting? would they start as many conversations? Think about it "look at that guy pulling a lawnmower with his bike".:grin: :eek:

  2. s_beaudry

    s_beaudry Member

    Hey rkbonds...

    Greetings from a push trailer builder. Glad to see I am not the only one who sees the beauty in these things.

    I used a 6.5hp B&S horizontal shaft in mine. Very easy and very reliable setup it is.

    How are you going to incorporate a gearbox into your trailer?

    You are using a centrifugal clutch in some part of this, correct?

    What are your thoughts as to connecting it to the bicycle?

    Any ideas or thoughts you need, please ask me, I am glad to offer any help I can!
  3. s_beaudry

    s_beaudry Member

    Just to add this...

    Being a push trailer rider and a HT rider..... the push trailer definately turns more heads and gets people looking at it! Mainly because it is much more visible I am thinking.

    Show that trailer off with pride I say!
  4. rkbonds

    rkbonds Member

    I'm actually going to try and use the self propel unit. It seems to look like it will hold up to the task. It will of course need some bearings added to it as well as some different tires. It does have a 6 hp poulan engine so I should have plenty of power. I still have several things to figure out like trailer attachment because I still want to be able to use my other trailer to pull my kids. Then there is the cables and wires that need to be able to easily attach and detach. Is it possible to change over from the kill lever to a kill switch? I'm going to try and work on it some today if I have time.
  5. s_beaudry

    s_beaudry Member


    I would be very interested in to see this self propelled unit, do you have a picture to post here?

    How will you work gearing for this, the unit is set up for very low speeds I am sure, maybe ~4mph top end??

    If you check my picture galleries you will see how I connected mine to my seatpost with an aluminum tube from the trailer, very easily removed in 3 minutes or less!

    As for the cables, I gave some slack of course between the trailer and bike for turning (my seat post acted as a trailer hitch and pivoted) and zip tied the cables to the bike frame up to the handlebars.

    The kill switch on the engine can be easily routed up the the throttle cable to the handle bars for safety.

    I could start off from a dead stop going uphill without any pedaaling with that engine, it had incredible torque and power, and is not loud as you coast a lot with it and it idles quietly.

    Short story on my next trailer build...... thinking of doing a 5 or 6.5 horse horizontal shaft engine with electric start and connecting it to the rear axle studs. Thinking of enclosing the engine with a good sized 12 volt battery under sheet metal with venting and maybe a fan for air floww, as well for a serious night time headlight for safety reasons. Also, running a start and stop switch to the handlebars for convienence and safety.

    I am more into safety myself then top speed, my kids need me to work!

    Show some pics if you can to give us some ides what you are working with......

    Regards, Steve
  6. rkbonds

    rkbonds Member

    I should have taken some pics today when I had it apart. It just has small gear box like a riding mower but, without the gear selection. Works the same way with the pulley system and has a neutral just need to change the size of the pulleys and get a new belt now and finish the hitch and wiring and it'll be ready for the initial test on the bike. I will be doing some testing before I try it on the bike. I'll take some pics and post them tomorrow. After the initial testing I will be changing the wheels on it I'm thinking maybe a go cart wheel or lawn mower wheel? For the added traction and smoother ride.
  7. Motormaker

    Motormaker Member

    Many push mowers have aluminum flywheels that are not heavy enough. When it is used as a mower the blade acts as a flywheel. This can be overcome by using a cast iron or heavy steel pulley. If you have problems with kick back when starting or sheared flywheel keys a heavy pulley will almost all ways fix it.
  8. rkbonds

    rkbonds Member

    Ok here's what I've gotten done so far. I managed to remove and rebuild the drive set up, move the drive assembly from the front to the rear, and take some pics. I still have to figure out how to remove the bracket for the blade assembly from the shaft so I can change out the pulley. Until then here's some pics and what's going on. I don't know for sure if this will work the way I would like but, why not give it a try lawn mower engines are very easy to find.

    Attached Files:

  9. s_beaudry

    s_beaudry Member

    Don't give up on it, you never know when something is going to work even better then you thought it would!

    Keep us updated here as you progress, many are interested in this working as vertical shafts are a dime a dozen...
  10. rkbonds

    rkbonds Member

    Not going to give up anytime soon. This is too much fun trying to figure out what has to be done to make it work.
  11. ZnsaneRyder

    ZnsaneRyder Member

    Keep us posted! The bike trailer thing is starting to catch on now, and it's nice to see what types of trailers are being built!

    6HP will have plenty of torque, and it would be nice to see someone finally getting a vertical shaft engine on a trailer!
  12. Mountainman

    Mountainman Active Member

    they sure do turn heads !!!

    turn more heads -- THAT'S FOR SURE

    an old friend down the mountain built a pusher many, many years ago
    I saw him again on it recently -- it's still up and running
    a pooolice person gave him a ticket for riding his pusher MB
    he went to court and took some pictures of MB to judge


    hard for anyone not to love a pusher
    they look so original -- old school

    ride that thing
  13. rkbonds

    rkbonds Member

    Can anyone help me figure out what size drive pulley I need? My driver pulley is 2" and my tires are 8" the engine rpm that I want to run is around 2200 what size drive pulley do I need? Estimated desirable top speed is 30 mph give or take a little as long as it's close I don't care that much. I don't know how to figure this stuff but, I can't afford to buy several belts and pulleys. All help will be much appreciated.

  14. Right away I see more speed by changing your wheels to larger ones. Even 20 inch BMX front wheels bolted in by the original axles somehow.
    If you change your drive pulley to 4 inch with the small wheels that would double your speed. So let's say high gear on a regular self propelled mower is about 4 mph. With the 4 inch your top speed may be 8 mph. Now add in your wheels. 8 inch wheels to 16 inch kiddie bike wheels should double it again to 16 mph. So a 20 inch wheel should bring that up another 8 mph or is it 4 mph?
    So top speed would be 20 or 24 mph.
    Remember though the larger the drive pulley the faster you will be asking your gearbox to spin.
    Changing your 2 inch drive pulley to 4 would double your gearbox speeds.
    So take away gear box speeds and just to say that it can handle it (it probably can anyway) I would go with a 6 inch drive pulley and 20 inch wheels.
    Last edited by a moderator: Oct 18, 2008
  15. rkbonds

    rkbonds Member

    Thanks for the help. My end results do involve changing of the wheels but, for now I want to stay with the small ones until I get all the bugs worked out to keep the center of gravity real low. So maybe an 8 inch drive pulley with the 8 inch wheels and when finished working out the bugs changing to the 16 or 20 inch wheels I have laying around? Would that give me enough speed to test with out of the smaller 8 inch wheels?
  16. s_beaudry

    s_beaudry Member

    Any pictures or progress on this you can share?
  17. rkbonds

    rkbonds Member

    No, not yet still trying to find a driver pulley all I've done since is remove the orignal handle and cables. :(
  18. s_beaudry

    s_beaudry Member

    Any updates or new ideas on this?
  19. rkbonds

    rkbonds Member

    Unfortunatley/fortunatley I've been too busy lately with work and the sickness going through my 5 kids to work on it. Then add on top of it no garage to work on it with our temps here being a little to cold to work on at night. I'm thinking though that I might try to add some 26 inch wheels to it, to try and keep the gear box spinning at a slower speed but, right now I'd just be happy to get it going at any speed to see how it's going to work out. Hopefully I'll get the chance to work on it over the next few days.