Diy crashbars

[Lancastermick]

had i quick look on the net and this website has all the pipe you could possibly need

http://www.metals4u.co.uk/products.asp?cat_id=56

Ha! You beat me to it John...you reckon the milder stuff would be ok then? I thought that might be the stuff they use for conduit?

[moto al]

hi give stu a email on walker ecosse. he has a dakar team.and i think he invented the wheel tell him .moto al sent you .cheers

[redbikejohn]

well it looks like conduit can be made out of any old metal asi can't find info on it yet but i did find this:

CRUSH STRENGTH
The crush resistance of a conduit depends on such things as strip materials and thickness, depth of conduit wall, shape of corrugations and so on. Crush is usually graded by pushing a 50mm wide steel block into the conduit, with various degrees of “push” or load between “very light” to “very heavy” as detailed in BS EN 61386 part 2. The conduit will be graded depending on what weight it will hold, without collapsing more than a quarter of its own diameter and returning to within 10% of its original shape, preventing damage to cables inside

[redbikejohn]

had i quick look on the net and this website has all the pipe you could possibly need

http://www.metals4u.co.uk/products.asp?cat_id=56

Ha! You beat me to it John...you reckon the milder stuff would be ok then? I thought that might be the stuff they use for conduit?

nope - the process of 'cold drawing' helps the strength of the metal i believe. far too expensive for conduit which is more than likely cast or poured somehow (not sure)

[redbikejohn]

These processes are known as cold working or cold forming processes. They are characterized by shaping the workpiece at a temperature below its recrystallization temperature, usually at the ambient temperature.[3] Cold forming techniques are usually classified into four major groups: squeezing, bending, drawing, and shearing.


ok i was going to post a whole load of info of the net ref conduit, but i stopped myself in time!

[CRAIGREVO]

Isn't conduit galvanized? if it is it would a pain to weld.

[redbikejohn]

Yes it is - but it can be done if you grind off the galvanized coating but it blow through easy. As a test frame it cheap and easy to bend so good for practice until you do the real one.

[mark1150]

Isn't conduit galvanized? if it is it would a pain to weld.

NO, not allways.
Sorry to contradict John, but the galvi stuff is for outdoor use, plain steel painted black is for indoor use.
As for useing the galvi in this application the galv is only microns thick, and can be filed away with a hand file, the use of a grinder is a bit excessive as it will remove too much material from what is quite thin guaged walled material in the first place.
If galvanized is used it is best to reapply the removed galv, with a paint on product such as Galvafloyd or similar, the only thing being it wont be as shiney as the factory finnish infact it's dull, and it's quite expensive when you'll only want a bit.
The other place to watch it's use is in flattening the fixing ends, as conduit will split when subjected to cruching by hammer or vice.
To avoid this I'd heat it, but then I couldn't vouch for the material becoming soft in the process and thus defeating the object.
Finaly if there is a kink in the bending process, the area of the kink will be weakened and could fail under load again defeating the object.
BTW, we stopped useing 3/4 inch in the 70's all conduit is sold in metric the equivalent being 20mm, best place to buy it being a local electrical wholesalers such as Edmundsons, not sure if you can buy less than a bundle though.
Hope this helps.

[redbikejohn]

true mark but then again i personally don't see much indoor stuff used. plus don't forget that he has decided to use proper steel tubing for the final product so the conduit is just for testing and mock up's.so painting and care is a bit of a moot point - otherwise it's good advice.

[Barnman]

Mick - have you seen this thread?
Homemade crash bars gs650