Motorcycle frame tube section.

[Fazed]

Can any tube bending wizards help me out, pleeease?
I need a length of 22mm o.d. CDS seamless tube, 1.6mm wall, bent 180 degrees to form a rear frame loop a la cafe racer style. Like this:

I'm led to believe I would need access to a mandrel bender, which I don't have. I've spoken to a few local fabrication shops and they're not interested. Surely it's no mammoth task?
Could any folks on here sort me out? I'll cover the steel cost, postage, beer tokens, sekshual favours , bed bath yer granny, etc.
I'll do proper measurements and everything .

 

[busa]

You don't need a mandrel bender to form a 180 in that material. Get in touch with Blackjack on here, he will be able to bend that for you if he has the correct radius die.

 

[Sam]

I have 22mm x 3mm wall but cant find the former. p.s. if you are using the twin leading (comical) conical hub the same as in the picture extend the two arms by 1 1/2 in length it will give you better stopping power.

 

[Fazed]

I have 22mm x 3mm wall but cant find the former. p.s. if you are using the twin leading (comical) conical hub the same as in the picture extend the two arms by 1 1/2 in length it will give you better stopping power.

Thats just a random google pic to illustrate what I'm after, not my bike (unfortunately), but it is rather horny looking, isn't it?
I was given a little Suzuki GS125 that had been rotting in a shed for 4 years, so I've decided to 'bob' it, in the style of a Gravel Crew/Bratstyle/Heiwa creation.
Google the above... some amazing looking bikes can be created from polishing a turd!

Here's what it looked like:

This is where I'm at now:

 

[pedrobedro]

I've bent some 16g tube successfully with a plumbing bender in the vice but you may need a specific radius on your bend to meet up to the subframe rails.

 

[graffian]

I use a plumbers bender for frame tubing, you can bend up to 1-1/4 10swg OK with them, I park me landrover on one leg of the bender and use a bit of scaffold on the bender. You could sand bend it.

 

[chunkolini]

Fazed.
Respect is due. You are building a GS125 cafe racer, quality stuff.
You will get nowhere fast acting like this, You will get there in the end though.
You wont win the willy waving contest that often goes with bike building, you know 'Mine has more BHP than yours'. But you will win the moral battle.
Love the idea.

Chunko'.

 

[Fazed]

Fazed.
Respect is due. You are building a GS125 cafe racer, quality stuff.
You will get nowhere fast acting like this, You will get there in the end though.
You wont win the willy waving contest that often goes with bike building, you know 'Mine has more BHP than yours'. But you will win the moral battle.
Love the idea.

Chunko'.

I'm only building it for a laugh! It was free, hell... why not, what do I have to lose?
It's not as if it owes me £££'s.
It'll be the 'shizzle' or whatever term the young folk are using this week , but I still need that bit of bent tube

I save the 'willy waving' for when I'm out on either of these:

 

[chunkolini]

is that some Japanese four cylinder thing?
I can see why you are after a 125 single, a proper motorcycle.
Chunko'.

 

[brightspark]

I'm only building it for a laugh! It was free, hell... why not, what do I have to lose?
It's not as if it owes me £££'s.
It'll be the 'shizzle' or whatever term the young folk are using this week , but I still need that bit of bent tube

I save the 'willy waving' for when I'm out on either of these:

[/QUOTEit must be magic being out on both bikes at once hmmm photobucket pictures

 

[Blackjack]

I can probably bend that for you.

What's the gap between the rails?

If you're in a rush, e-mail me.

black.jack(at thingy goes here)blueyonder.co.uk

 

[Fazed]

I can probably bend that for you.

What's the gap between the rails?

If you're in a rush, e-mail me.

black.jack(at thingy goes here)blueyonder.co.uk

You're a star, sir! There is 170mm between the rails.
What I could do with is a few inches of 'straight' left on both ends as I'm not sure yet whether to cut more off the frame rails, or mount the loop in a flat plane, or mitre the tails to mount the loop kicking up slightly at the rear.
It depends on where I decide the mudguard/rear light/indicators/battery box, etc. will mount.
Too many variables.... makes my head hurt....

 

[Blackjack]

OK.

I'll be in my workshop on tuesday, Ill try and remember to have a look at the 7/8" former and see what radius it is, and how that works out with 170mm between the rails

 

[Fazed]

OK.

I'll be in my workshop on tuesday, Ill try and remember to have a look at the 7/8" former and see what radius it is, and how that works out with 170mm between the rails

Brilliant Blackjack! It would be much appreciated, thanks.

 

[Blackjack]

Formers 3 3/8", but I forgot to write down whether that was RR or CLR,

Most of my formers are marked in RR.

If it is RR that gives a bend which in theory is 171.45mm between tubes on a 180.

Only it wont be, because it'll spring back and that changes the radius of the bend. But if I bend it through 180, let it spring out, and then tweak it back off the former, it ought to come out somewhere close.

I've got some 22mm dia, 12 gauge (2.5mm wall) ERW on the shelf, and some 22mm 14 gauge (2mm wall) ERW too (not much of that though).

Could probably get a length of 22mm dia 16gauge ERW, but seamless might be a problem as buying a length is a bit steep, though John at JT tubes in Poole, or Robbie at Wasp Motorcycles near Salisbury might have some and would sell (and post) a metre or so.

I have to leave enough straight tube to locate on the stop on the bender anyway, so it'd be a "U" and not a "C".

How's that sound?

 

[Fazed]

Formers 3 3/8", but I forgot to write down whether that was RR or CLR,

Most of my formers are marked in RR.

If it is RR that gives a bend which in theory is 171.45mm between tubes on a 180.

Only it wont be, because it'll spring back and that changes the radius of the bend. But if I bend it through 180, let it spring out, and then tweak it back off the former, it ought to come out somewhere close.

I've got some 22mm dia, 12 gauge (2.5mm wall) ERW on the shelf, and some 22mm 14 gauge (2mm wall) ERW too (not much of that though).

Could probably get a length of 22mm dia 16gauge ERW, but seamless might be a problem as buying a length is a bit steep, though John at JT tubes in Poole, or Robbie at Wasp Motorcycles near Salisbury might have some and would sell (and post) a metre or so.

I have to leave enough straight tube to locate on the stop on the bender anyway, so it'd be a "U" and not a "C".

How's that sound?

That sounds absolutely cock-on to me fella!
14 gauge would be better if that's the closest you've got, as the standard frame tubing is 1.6mm wall I don't want to be blowing it away by migging thick to thin, IYSWIM.
Also, seamless tube isn't absolutely essential, I don't think it would compromise the integrity of the frame.

 

[G Jones]

That sounds absolutely cock-on to me fella!
14 gauge would be better if that's the closest you've got, as the standard frame tubing is 1.6mm wall I don't want to be blowing it away by migging thick to thin, IYSWIM.
Also, seamless tube isn't absolutely essential, I don't think it would compromise the integrity of the frame.

Hi - are you intending to "sleeve" the 2 tubes ? - or just butt weld ?
I you've got access to Tig - might be better - or even bronze welded...

 

[Blackjack]

That sounds absolutely cock-on to me fella!
14 gauge would be better if that's the closest you've got, as the standard frame tubing is 1.6mm wall I don't want to be blowing it away by migging thick to thin, IYSWIM.
Also, seamless tube isn't absolutely essential, I don't think it would compromise the integrity of the frame.

I don't think it would be a problem there either, and motorcycle frames is sort of my day job....

If this is a butt join, which it pretty much has to be, you do know it ought to be sleeved?

I can knock you up some stepped internal sleeves too if you need them.

 

[Fazed]

Thanks fella's. I think sleeves would be the way to go. BTW Blackjack, the I.D. of the existing frame tubes is 19mm if this is of any use to you (I've PM'ed you).
G Jones, I have a Tig at work but I'll get away with using my little Clarke on this. I have patience and plenty of linishing discs if needs be .

 

[Pete.]

I'm only building it for a laugh! It was free, hell... why not, what do I have to lose?
It's not as if it owes me £££'s.
It'll be the 'shizzle' or whatever term the young folk are using this week , but I still need that bit of bent tube

I save the 'willy waving' for when I'm out on either of these:

[/QUOTEit must be magic being out on both bikes at once hmmm photobucket pictures

You've waved your willy too hard - your purple helmet has dropped off