How do I weld motor mount?

Discussion in 'Painting, Welding, Bending and Gas Tanks' started by m3h5l5, Jul 28, 2014.

  1. Essentially the idea with the V twins nobody has really an actual V-Twin on a bike and i haven't seen anything on YouTube so why not be the first

  2. FurryOnTheInside

    FurryOnTheInside Well-Known Member

  3. Heres where i know i would add hi tensile steel tubing to add extra support for the frame 20160814_000339.png
  4. Chris Duke

    Chris Duke New Member

    Not needed. A welded mount 'plate' would only strengthen the frame tubing. It would act as an extra part of the frame further increasing it's rigidity/strength. Not all frames are equal, and as such, some of them could have adverse effects to extra rigidity added to them. For example, Moly does not act the same as mild steel. One flexes more than the other, and the other is prone to breakage at the weld joint if not expertly welded. As in, a HF splatter box is not appropriate for welding moly tubing. It will break 1/8 to 1/4" away from weld joint.
    A welded mounting plate is 4 stroke application. In a 2 stroke application, any adverse effects would be minimum concerning rigidity due to the fact that the stresses are transferred threw the engine.

    That all being said, unless you are making some serious torque (150+cc engine), it shouldn't be much concern unless you are talking about a Huffy/cheap Wallyworld frame. I can't even imagine a China girl or 49cc 4 stroke causing any additional problems to a good welded frame from only one additional welded part/plate from the extra rigidity it would get from such an addition.

    Personally, I think the 4 stroke mounting plates, and the 2 stroke junk I see in these kits should be eliminated to create nice bikes. Welding on mounts and plates & tabs and brackets to frame will be the only way I'll ever consider a project complete. I had to sell my Miller Tig some time ago, would never consider my Lincoln Mig for the job, but can always outsource for such small jobs.

    In addition to that, what I'm thinking about doing, is to cut slightly larger tubing in 1/2, then welding it to frame contact points where the mounts/plates will be attached. This way, when you weld mounting plate/tabs to frame, you are spreading out the stress area on your (unknown strength/age/potentially brittle) tubing. Less chance of stress cracks at the welded mounting joints this way.
  5. Frankfort MB's

    Frankfort MB's Well-Known Member

    I'm pretty sure that bike is aluminum.... I had a buddy who put a HT on one of them and it help up a lot better than I was expecting
  6. Hey so im looking at some of these mig gas less electric welders on ebay for under $100.00, now my question is would any welder be good for welding supports or brakets?
    Do i need a specific type of welder?
    Does it need to be gas or can i use electric?
  7. Frankfort MB's

    Frankfort MB's Well-Known Member

    All Mig welders are electric....
    The best welder to start out on
    (and least expensive) is a flux core welder
    (aka gas less)

    A Mig will do everything you need to do, it might not be efficient in all circumstances but it will get the job done pretty clean
  8. Frankfort MB's

    Frankfort MB's Well-Known Member

    That's a TIG welder.... A lot different process, you have to be a really good welder before you can use one of them and be good:p

    All of the materials for Tig are a lot more expensive than Mig

    I recommend a Mig welder because it will do all you need to do (beware it won't weld aluminum w/o a special wire)
  9. Well first i never build anything on aluminum and second i appreciate your concern as far as being a novice when it comes to welding but what alot of people on different forums ive been reading say tig is the way to go for a bike frame welding. Although im a novice to welding i have my dad for one he knows how to use all the welding equipment and for 2 you can learn pretty much just about anything nowadays with youtube and thirdly im a very quick learner plus i had a different ideal for my bike build.

    So with my new ideal what im thinking is extending the bike by 6 inches to allow room for the 125cc engine

    So i plan on cutting top and bottom tube 3 inchs forward of the seat tube.

    Take a 10 inch long steel tubing with the O/D just small enough to fit 2 inches on each side of where it slip fits inside the frame.

    Next i will drill 2 small holes 1 inch in from slip fit on top going down and side going throug the frame through the slip fit tubing and once again through the frame on other side i will do this to all 4 connections. The point of this is to use the tig welder to put a tack on the inside part of the extension slip fit tubing.

    Next once i have one side done with the extension slip fit tubing i will also use a tubing thats the same diameter as the frame to cover the extension which would be cut at 5 7/8 inch so when i slide the 2 peices of the bike frame back together it would leave 1/8 inch exposed for to weld all 3 together.

    Once the frame is done i will take a 1/2 thick steel plate that would have a c < cut out on both sides so it will wrap the frame tubing which would then get welded to the frame as well

    I was also considering welding a steel tube under the motor plate from the seat tube to the bottom tube

    So with something like this i think i would want the precision that a tig welder gives you over a mig from what ive been reading.

    Or can this project be done with a mig i plan on taking extra care and want it to look as professional as possible.
  10. Frankfort MB's

    Frankfort MB's Well-Known Member

    I was just informing you that Tig welding can be a pain if you don't get used to it, I'm not saying it's impossible to be good your first time.

    They can be very precise but you have to have very clean metal, a good grinder, and a lot of practice

    A Tig welder, if you didn't know, they use tungsten rods (what the electricity comes out of:p) and the rod will eventually dull flat.... I've always had best luck with making the rod as sharp as you can possibly can:D
  11. Yeah i knew you weren't discrediting me on what skills i have or dont have was just making my opinion on stuff ive read about tig and mig.

    And yes i heard about the making the tungsten tip pointed i have plenty of power tools and air tools as well which does include a grinder or theres even the craftsman grinder i have as well either will get the job done now its just a matter of saving up the money for this build with tools and material im looking probably at $1500.00 right now
  12. SLUGO-SS-MBK-RD_03.jpg
    So here is the plan layed out getting really excited too bad i still have to wait i want to build this bike now :( oh well so let me know what you guys think the plan is to stretch the frame 6 inches and add extra support let me know if i missed something or if im good to go with this plan as its laid out
  13. FurryOnTheInside

    FurryOnTheInside Well-Known Member

    Yeah you might have missed something..
    The frame in the picture has a very tapered top tube. A piece of ordinary tubing will not fit snugly 2" into ether side.
    The two tubes, top and down tubes, are at an angle, not parallel, so that a straight piece of tubing cannot fit into both. Somewhere there has to be a bend or angled, butted joint.

    If you do have the tools to create the parts and a jig to hold them in place, but you don't have a welder, or mask, or gas, wire or welding skills, why not just pay a professional welder to do the dangerous bit? Then you don't have to buy a welder or materials, or practice for ages, or risk burning a big hole in the frame that you spent ages making parts specifically for. :)
    Last edited: Aug 18, 2016
    Frankfort MB's likes this.

  14. Yeah and you might have missed the part where i told the other guy im fast learner, and you might have also missed the part where i said my father knows how to use all the welding equipment. You also missed the part where youtube in todays era is another form of education i cant tell you how many countless videos there are on youtube as far as basic to medium to harder difficulties of welding

    So whats gonna cost more paying a welder to to do some custome work or buying the equipment and having a lifetime of learning experiences, and further more why am i gonna pay someone to do my hobby for me whats the fun in that.

    Im the guy that likes to get his hands dirty and do the whole tinkering thing, so paying someone to do it for me takes the fun out of it

    You do make a good point on the angles in the frame i had noticed that and ive done pipe bending before with my exhaust pipe. On my original 29 mountain bike the pipe was hitting the pedals so it had to be bent inward by a hair. Yes i know it would require a specific bend. You pointed one good thing out that i had missed, but next time try not to be so much of a pr*ck
  15. Oh and yeah i noticed the tube diameter is larger closer to the handle bars but near the seat post its at its straightest as well as closest in size, and to compensate for any wiggle is why i will be adding 2 holes one vertical and the other horizontal at each of the joints to be able to tack the internal part of the joint these holes would be very small in diameter basically just big enough to get a tack in
  16. FurryOnTheInside

    FurryOnTheInside Well-Known Member

    Bit strong, mate. You did ask for people's thoughts. :(

    You asked if it is "good to go as its laid out". The plan as laid out will not work. I was supposed to say it will?

    If you want to make it yourself I have no objection to that. It was merely a suggestion. Try to read things in the spirit they were written. :rolleyes:
  17. Yes im asking if it can be done, no really im asking the best approch of what i have in my ideal in my head? asking what i left out? I know this kinda thing can be done ive seen it on youtube.

    However my friend i was not asking you to criticize on my skill level or tools that i plan on purchasing
  18. What if instead of cuting the tube and adding a peice to make it longer. How bout i cut them off completely and replace with longer steel tubing and just weld them back together at the seat tube and neck not sure if thats right but the part of the frame where the handlebar and fork assembly go?