Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Dec 13, 2016 20:58:11 GMT -5
New to the forum, I thought I say hi and see if anyone can share what size tubing they use for their frame.
|
|
|
Post by DaveJ98092 on Dec 13, 2016 22:44:59 GMT -5
Welcome to the forum.
A lot of builders use 1 1/2 inch diameter in 0.065" for most rails but step up to 0.095" for other places like engine mounts and suspension. Some one will come on soon.
|
|
2rike
Full Member
Posts: 184
|
Post by 2rike on Dec 14, 2016 1:42:02 GMT -5
Welcome to the forum, Dave is right 1.5 inch tube is about right and I would recommend a good quality cold drawn seamless tube with a wall section of 1/16th and 1 inch by 1/16 wall for the suspension In my case with the 2rike it only weighs 360kgs on the road so even the 1.5 diameter tube is over engineered
|
|
|
Post by Liteway on Dec 14, 2016 11:41:01 GMT -5
Sound Advise above. Most of us here are rather limited in our ability to design and carry out an optimal frame design, that gives the best rigidity and durability with the lightest weight, so we err on the side of caution and that generally results in heavy robust frames.
Wall thickness and tube diameter requirements very depending on how the tubes are placed and the material used. If the tube will only be subject to tension/compression and not bending loads, it can be much lighter. Sudden failure of a poor weld probably represents a far greater danger to us garage rats than a slightly undersized tube that usually results in flex, not failure, though flex over time can cause failure.
Overbuilding can mean substantial weight penalties. For example, the frame I made for my rather compact, single seat trike weighs in about 80 lbs. Compare that to some of the 2 seat racers Colin Chapman (Lotus) built using mid 1950s tech.
By using a limited number of thin stressed aluminum panels over them, he was able to make frames suitable for the rigors of racing weighing less than 50lbs.
The old AC Cobras used a frame based on a couple of thick wall 4 in. dia. tubes running front to back. The frame was notorious for both bending and torsional flex, demonstrating there is a lot more to frame design than how big and thick the tubes are.
Triangulation.
|
|
|
Post by DaveJ98092 on Dec 14, 2016 12:10:18 GMT -5
While there are many "Air Boats" that mount an engine in the rear with a propeller to push made out of EMT tubing, it is not recommended for a road trike. It is made of many different alloys from scrap metals mixed, rolled flat and the flat steel is rounded and seam welded.
When you buy DOM tubing it is made from a "SPEC" grade of steel alloy, rolled flat then rounded, seam welded and then it is drawn thru a rolling mandrel that rolls the weld seam flat so no stress risers can form.
2rike is in England so his steel will be graded a bit different, just like all over the world. His 1/16" is 0.0625 so USA spec 0.065 is good to go.
Most motorcycle frames made from steel are about 0.028" in main tubes and only thicker in like swingarms and the steering head areas. Overall lightness makes it not needing thicker walls.
|
|