IMHO the welded mounts are the way to go as long as the welding is done by someone who is skilled on aluminum and has a good machine. Those broken frames were most likely the result of stresses from a poor fitup and/or cold welds. Of course I'm a welder so I am biased.
Craigus
No weld front mounts
I know this may sound insulting, But: Cardboard Is Your Friend!
Seriously, cardboard from a Cornflakes (well, name your poison, about once a year, I go on a "Fruit Loop Sugar Frenzy"
) pack, is great for doing mock ups. You can cut it to fit in the available space and, make it Big, initially, as you can then see it in and out of position, and think clearly about the final, perfect shape. And, you can get very accurate hole location indicators, from just putting the dummy plates in, and then using something like a slightly convex ratchet end to press against the cardboard and mount / hole faces.
Infinitely easier than f***ing about with 'precious' 4130, and you don't waste material. I'm a big one for using my materials to their utmost, and having bugger-all unusable scrap. I assume you got a 300 x 300 square or two?
Seriously, cardboard from a Cornflakes (well, name your poison, about once a year, I go on a "Fruit Loop Sugar Frenzy"
) pack, is great for doing mock ups. You can cut it to fit in the available space and, make it Big, initially, as you can then see it in and out of position, and think clearly about the final, perfect shape. And, you can get very accurate hole location indicators, from just putting the dummy plates in, and then using something like a slightly convex ratchet end to press against the cardboard and mount / hole faces.Infinitely easier than f***ing about with 'precious' 4130, and you don't waste material. I'm a big one for using my materials to their utmost, and having bugger-all unusable scrap. I assume you got a 300 x 300 square or two?
Appreciate it , already planned to use a thin cardboard that comes in engine gasket sets. I a got an 18"x 12" piece that I'm planning to incorporate into a skid plate/ front mount. The "bend" is done between the 2 motor mounts front & lower center. I'm thinking I can add a little strength back in by tying the front mount & the lower middle together. It should work out to where I can tune the firmness of support as well. My initial plan was more of a box but it struck me you could easily make something much stronger than the rest of the frame.I know this may sound insulting, But: Cardboard Is Your Friend!
The steel framed bikes use .100 plate for the mounts so I'm gonna assume .100 of 4130 should be good . Where I'm spreading the frame to wedge in-between the stock mount & motor I went with .050 plate but it will be double on the front mount creating more of a box with the front bit of ear I had left.
I'm not pushing the frame to the point it doesnt spring back to stock location, so I will have to load it to where it needs to be before I weld the skid plate
you can see here where I'm intending to anchor into the frame by actually drilling & tapping the thickest part of the mounting plate
I'm not pushing the frame to the point it doesnt spring back to stock location, so I will have to load it to where it needs to be before I weld the skid plate
you can see here where I'm intending to anchor into the frame by actually drilling & tapping the thickest part of the mounting plate
Last edited by 81cr450 on July 6th, 2013, 1:30 pm, edited 1 time in total.
