Tadpole trike

  1. timmyfishfinger Member

    Hi all, new here so be gentle!
    I'm looking at building a tadpole trike from scrap cycle parts and steel tube but need some (a lot!) of guidance in which welder to purchase.
    Maximum steel thickness will be 1.5mm.
    I'll be working in the garage (probably setting fire to the nice pink carpet in there with the sparks) so gas will be the route i will probably take as it looks like nobody recommends gasless.
    What welder range should i be looking at 30-90, 25-130, and is mig okay?
    There wont be loads of welding but i can see me wanting to do more if i do a decent job hence the reason fo buying one.
    Does anyone want to be a mentor??......if you have a workshop and you are local to rochdale can i bring my parts and get help with what i'm doing?
    I haven't the time for college to learn so anyone who has some equipment they use who can be of assistance would be a godsend!
    Drop me a line if someone can help, cheers. Hope this post is legal here!!:whistle:
  2. dutchman

    dutchman t(r)igger happy

    Tig or brazing are the options, Mig is hopeless on biketubes.
  3. wellingtonrock wannabe welding wizard

    Dutchman's got a point. Cycle tubes are very thin wall. Even with good mitre-ing, it's very difficult not to blow holes. I've gotten better at it, but my homebuilt is quite ropy in the MIG welds department. I bit the bullet and got an oxygen-propane kit which makes brazing a breeze. It's far more controllable than the MIG. Search Flickr on 'homebuilt recumbent tricycle'. You'll find some photos of my MIG welding (on the front end) and brazing (on the boom, seat and rear triangle). I'll probably grind off the ugliest of the welds and prettify them with braze before I finally paint it.

  4. aero Member

    I would have thought a decent MIG would have been ideal on thin stuff?

    The portamig seems to make an excellent job on car panels.

    I'd hate to think what that stub tube on the sprocket carrier would do to you if you hit something at speed on that! I've seen first hand how the Dutch ride those things and how fast they can go. I worked out there for a number of years.
  5. chunkolini

    chunkolini celebrity artiste

    [I have mig welded bike frames when building freakbikes, it works fine if you are using the crap supermarket bikes. But if you start playing with better quailty frames it just melts to hell. I braze my better builds, and have built some brazed frames that have had awful things done to them and never had a frame collapse. Hers is an image of The Ratking, a quality build made of 13mm mild steel box section, a high quality tube set fillet brazed..

    No it didn't collapse when i got on board, or even when I did this on it, on one of our dodgy Rat Races, cider fueled off road expeditions.
    Copy (2) of RatRace 05 027.jpg

    It does have some interesting handling quirks, lock up the back wheel to get round a bend and it hops all the way round in a series of short skips, as he back end loads up and flexes.

    On a sensible note, if Timmyfishfinger is after tinkering and building a functional 'thing' using cheapo frames as donor carcases Mig would be fine, just avoid using decent carcases. The thing is to take time mitring the tubes, and I would recomend using the whole rear triangle off a bike to save a load of faffing around. Re welders, I used a 130amp Clarke welder for 6 years of merciless abuse before it croaked, it worked fine down to about 1mm sheet.

    be warned Timmy, this is not a game to take lightly, after a couple of builds you become twitchy around dodgy secondhand bikes, you se a dead derraileur and it becomes a piece of treasure, your family will avoid you.

    Good luck and dont get killed.


    or to use my formal title Bennitto Chunkolini Prince of Darkness, Pres RatpatrolUK. One evening I will get on the cider and put up a full portrait of our (dis)organisation.

    Note also dont think 'I'll give it a test drive' until you have installed at least on brake.

    Warning to all logical minded adults. Do Not Click on the following link, it might wreck your lives.


    When I was a senior care worker my manager threatened me with disciplinary action, as I was bad example of 'The Service' if I would not stop riding these crap bikes to work. I named The Poison Dwarf after her.
  6. wellingtonrock wannabe welding wizard

    Chunkolini, I >>LOVE<< that bowsprit! Is that handmade or salvage?
  7. timmyfishfinger Member

    Thanks guys for all the help, purchased my first lot of el cheapo bikes from fleabay, all heavy steel so hopefully if i go steady they will be fine. Whats the best setting to use, low and 0.6 wire? cheers
  8. twowheels Member

    I use a clark 90EN and use gasless. Cheap steel bikes, I got a few from the tip and some from people who were clearing out. Buy a flap disc for the grinder to get the metal clean and a good mitre as suggested is a must. Tack weld every so often and fill the gaps.

    Its my birthday in a few weeks time and I am buying £60 worth of tubing etc as a present, my wife just shook her head. Show some photos when you start welding it together.....

  9. chunkolini

    chunkolini celebrity artiste

    Probably a higher setting than you would expect. 0.6mm wire works a treat. Best option is to get a load of bits of tube and monkey about with them and make a load of test joints. Keeping an eye on the results. Boooring.

    Or you could just set too and build a crap chopper to ride to the shops and see if you die.

    So far we have had no fatalities or even injuries, and we have been trying quite hard. But the feeling of riding a bike you have kludged up yourself is great. 2 tips.

    Never ever butt weld your forks, always sleave one tube over another.
    never spend money on this nonsense, maybe buy cables and brake blocks, everything else scrounged, found or acquired.

    Go go go, Chop Kut, Kill Destroy, Chop That Bike and Bring Some Joy.

    Also think you are helping the world, one more crap steel mountain bike out of the gene pool, no poor sucker condemned, Sysephus like to heave that sorry tragic overweight pile of shite up hills and down dales.

    Just dont blame me when your family disown you. Interestingly the gobby obnoxious teenager love this stuff.

  10. timmyfishfinger Member

    I was looking at tubing as well to purchase with my christmas money!! yep, her indoors thought i was bonkers too!!!
    Pics when i get it started no problem.