The Three Dellortos
Hero member
Still love the mini Hot Rod creation that has been shown here !
I would like to see build on that sucker
supa doops
I would like to see build on that sucker
supa doops
Best Tube for making a frame
- Thread starter 81Lav
- Start date
GregT
Hero member
- Location
- Christchurch NZ
Bruce - DOM mild steel will do you just fine if you're not shaving the last ounce of weight off...
Due to the Speedway scene I'd guess we're the same here in NZ - plenty of chrome moly around but no aerospace T45.
Be wary of the Chrome moly as a lot is uncertified tube and can be in various tempers, some of which are simply dangerous.
All the isues raised are covered in great detail in Bradley's book - and it's up to date material specs too unlike a number of books on the market.
After seeing Roger Tichmarsh's work in the book I took a serious look at my own standard of bronze welding....I'm still trying to improve but the only way is to do it day in day out - and the NZ market won't support that.
The Diamante frame I'd guess is made from the lowest grade/cheapest material which would do the job - it's called "production engineering"
Due to the Speedway scene I'd guess we're the same here in NZ - plenty of chrome moly around but no aerospace T45.
Be wary of the Chrome moly as a lot is uncertified tube and can be in various tempers, some of which are simply dangerous.
All the isues raised are covered in great detail in Bradley's book - and it's up to date material specs too unlike a number of books on the market.
After seeing Roger Tichmarsh's work in the book I took a serious look at my own standard of bronze welding....I'm still trying to improve but the only way is to do it day in day out - and the NZ market won't support that.
The Diamante frame I'd guess is made from the lowest grade/cheapest material which would do the job - it's called "production engineering"
The Three Dellortos
Hero member
There is definatley the right tube as I said earlier 531 reynolds ..... Some people suggest mild drawn steel and that is quite cheap.. But you need to ask yourself are you cheap ?... the bloke i would ask is squigglly bob.He builds bikes for a living !. You should see his stuff ! FUCKING AMAZING !!
I ain't an arse licker .
Timbo the buttock of the Glen
I ain't an arse licker .
Timbo the buttock of the Glen
ScorchLaverda
Full member
- Location
- Brisbane
All I can say is that its a struggle to get the right tubing here in South Africa...
At the moment the only tubing I can get here is something similar to DOM SAE 1010... But you can still see the weld. They put it through a mandrel like they do with DOM tubing but only enough to "clean" the weld (CREW tubing). It all depends what type of frame you are build. For a Trellies type frame SAE 1010 is good enough. Its 310MPa, so its not too bad. I run a FEA on all my frames just to make sure its strong enough. I am busy looking at buying (importing) some SAE 1020 DOM tubing, because that it the right stuff to use for any type of frame. I want to get some 7020 Alloy tubing but min order is 250kg. Now do you guys know how much is 250kg of tubing!!
ALOT!
Just remember that DOM is not seamless. Seamless tubing is very expensive. 4130 is good but it cracks easily. My Moto Martin frame have a couple of cracks near the rear shock! I can also say that we have welded alot of KTM950 frames, because they also crack.
Also another thing... The biggest force will go through the pivot area of the swing arm. It all depends on the overall weight of the bike with you and your girl on it. Doesnt matter if you have a 1000 Hp engine in the bike. Its all about the weight.
Just build a frame. Its fun!
At the moment the only tubing I can get here is something similar to DOM SAE 1010... But you can still see the weld. They put it through a mandrel like they do with DOM tubing but only enough to "clean" the weld (CREW tubing). It all depends what type of frame you are build. For a Trellies type frame SAE 1010 is good enough. Its 310MPa, so its not too bad. I run a FEA on all my frames just to make sure its strong enough. I am busy looking at buying (importing) some SAE 1020 DOM tubing, because that it the right stuff to use for any type of frame. I want to get some 7020 Alloy tubing but min order is 250kg. Now do you guys know how much is 250kg of tubing!!
ALOT!Just remember that DOM is not seamless. Seamless tubing is very expensive. 4130 is good but it cracks easily. My Moto Martin frame have a couple of cracks near the rear shock! I can also say that we have welded alot of KTM950 frames, because they also crack.
Also another thing... The biggest force will go through the pivot area of the swing arm. It all depends on the overall weight of the bike with you and your girl on it. Doesnt matter if you have a 1000 Hp engine in the bike. Its all about the weight.
Just build a frame. Its fun!
bushman
Full member
- Location
- White Rock, BC
The Three Dellortos said:
I am using the original MV 20mm swingarm pivot bolt, with 32mmOD needle rollers bearings (2 on each side), with an oil seal. For the needle rollers I sourced the inner races 20x25x25 to bear on the spindle. More expensive than a bronze bush, but with 125HP I want to make sure all stays put for the long haul. Std bearings are cheap enough.
The pivot tube selected is 1.665" OD, .125 wall. I am machining a bearing carrier that will slip into the outer tube after welding up the swingarm. I am using the MV Magni design (see photo) with 1"x2" rectangular tube .100' thick swing arm legs with the 2" dia billet axle adjuster. I like this design, very simple and with the shaped sheet metal bracing ends up really strong.
JIM
Attachments
bushman
Full member
- Location
- White Rock, BC
ScorchLaverda
Full member
- Location
- Brisbane
bushman
Can you show me a pic of where the mandrel is mounted because I dont see it in the pic...? I LOVE old machines. We also have old school stuff in our workshop.
Your swingarm design sounds right. I just hate imperial...
Never see the point in that! Why? I am looking at that 1.665" OD dimension and think... "its like metric having sex with imperial and the babies are like 1.665 of an inch" WTF.. I had a laugh when I was living in London. It was just the time when they went over to metric... They just converted everything over from imperial to metric... On the Milk Carton it would be 1.898574638749556739335673456675673454 Liters - (1/2 Gal) or 4 Pints Funny
Can you show me a pic of where the mandrel is mounted because I dont see it in the pic...? I LOVE old machines. We also have old school stuff in our workshop.
Your swingarm design sounds right. I just hate imperial...
Never see the point in that! Why? I am looking at that 1.665" OD dimension and think... "its like metric having sex with imperial and the babies are like 1.665 of an inch" WTF.. I had a laugh when I was living in London. It was just the time when they went over to metric... They just converted everything over from imperial to metric... On the Milk Carton it would be 1.898574638749556739335673456675673454 Liters - (1/2 Gal) or 4 Pints Funny
bushman
Full member
- Location
- White Rock, BC
ScorchLaverda said:
Sorry nothing of the whole machine - it is just a big 600mm dia round plate on stand bolted to the floor. Here's a pic of the operator in middle of a bend. The piece that makes this unit work is the long piece of hardened straight bar, with a 1" dia channel running down the middle. Between the mandrel (or round die) in the centre and this bar, the tube is fully supported thru the bend, on both inside & outside. I tried all other types of benders, this does the best job by far.
JIM
