where can I get steel tubes tapered?

[zx9]

See attached. Weight difference between tapered bore and parallel bore is equivalent to 24p in coins.

Removing the loose change from your pockets or going to the toilet before riding will make more difference.

I am thinking they are part of the un sprung mass so not like emptying the rider or his/her pockets, I like the idea though.

 

[Matchless]

(47) chair leg reducing machine taper forming machine - YouTube

(47) J.A.P. NLG BIG TWIN 2714 cc - NEW PROJECT - YouTube

 

[Ali]

If you were really desperate...

3D Printing in Metal. Aluminium, Steel, Nickle Alloy, Titanium, Copper, Gold, Silver

Additive manufacturing service in a range of metals. Our service includes High Temperature solutions with Stainless 1.4859, Nickle Alloys, High conductivity with Copper and Silver and an range of Aluminium alloys. Large format options available.

www.3d-alchemy.co.uk

Not very 1920s though.
Bit of a laugh that most of the items on their page could be done pretty easy on a conventional milling machine or lathe, probably quicker too. You should ask them if they want a better example...

 

[Matchless]

Could you please clarify if the 3/4" and 1/2" dimensions are internal or external.

If we assume internal, then draw up a 1/2" parallel-sided hole, 6" long and surround it by the outside tapered profile (1/2" + 4mm at small end, 3/4" + 4mm at large). Work out the volume of steel in that. Also work out the volume of steel in the same profile with an internal taper and 2mm wall thickness. Calculate the difference in volume and multiply by density of steel to see difference in weight. Ponder whether that difference is really worth worrying about.

Work out the taper angle (1/4" in dia. over 6" i.e. 1:24 on diameter*) and see if that matches any standard taper. A tapered reamer could finish the inside (especially with careful step drilling) - and if a standard taper is not available, the next shallowest would help.

Morse tapers will be too short for your 6" length (you would need a 6 or 7 and then they are too girthy). Heating and spinning as pressbrake says is a good one but you will need some sort of back support or the spinning pressure will bend the mandrel.

* Standard imperial taper pins are 1:48. Jarno machine taper is 1:20. Browne & Sharpe is negligibly different to the one you want, but too short and obsolete.

The 3/4" down to 1/2" are external and are aproximate, as is the 6", and come to that the 2mm, I believe the originals are a bit thinner, if you look at the motorcycle picture at the top of the thread it is the tubes for the front forks, what happens internally is of little interest, the thick wall tube I have would make the whole assembly much too heavy, I always over engineer but it is easy to double the weight of a motorcycle that way and with only a few, 18-22 HP on offer that is important, also part of the joy of a veteran is the light weight, I will confirm all dimensions when I get a chance to measure the forks on my 1914,

 

[Shox Dr]

The 3/4" down to 1/2" are external and are aproximate, as is the 6", and come to that the 2mm, I believe the originals are a bit thinner, if you look at the motorcycle picture at the top of the thread it is the tubes for the front forks, what happens internally is of little interest, the thick wall tube I have would make the whole assembly much too heavy, I always over engineer but it is easy to double the weight of a motorcycle that way and with only a few, 18-22 HP on offer that is important, also part of the joy of a veteran is the light weight, I will confirm all dimensions when I get a chance to measure the forks on my 1914,

They say you can lead a Horse to water, but you cant make it drink. Who do you think were building motorcycles in 1914.

Seriously I would be calling a cycle manufacturer. Even chopping a set up and extending them. You can get straight and bent, in fact there's a jig to bend them.

 

[Matchless]

I would need to brush up on my Chinese to call a cycle manufacturer! does anyone know of a UK based small independant cycle manufacturer? not carbon fibre!

I used to get old cycles from the tip before they stopped anything leaving but there was not much I could use for my projects,

and yes my spell checker has gone missing! I can click on it in my browser but it no longer picks out misspelt words, not good for a dyslexic agnostic!

 

[Matchless]

Try these guys:

Elmill Ltd swaging and tube forming solutions

Only issue is specific sizes need a specific tool, but they may already have something suitable.

£3000 for tooling, not really interested in looking to see what they have on the shelf, they make taper tubes for cycle, table, chair etc. use, I said I can be flexible in my needs and adapt to suite std. tooling but ...............

 

[Seadog]

I know that Renolds had (may still have) the original tooling for making the tapered Manx swinging arm section. Probably a bit too chunky for your need, but it's possible that they have other tooling which may be for a smaller section. The only problem is that you need to find someone who's been there for long enough to know what is what.

 

[Shox Dr]

I would need to brush up on my Chinese to call a cycle manufacturer! does anyone know of a UK based small independant cycle manufacturer? not carbon fibre!

I used to get old cycles from the tip before they stopped anything leaving but there was not much I could use for my projects,

and yes my spell checker has gone missing! I can click on it in my browser but it no longer picks out misspelt words, not good for a dyslexic agnostic!

There are plenty of custom cycle builders in the UK. Start with Ribble Cycles.

 

[Morrisman]

I would need to brush up on my Chinese to call a cycle manufacturer! does anyone know of a UK based small independant cycle manufacturer? not carbon fibre!

I used to get old cycles from the tip before they stopped anything leaving but there was not much I could use for my projects,

and yes my spell checker has gone missing! I can click on it in my browser but it no longer picks out misspelt words, not good for a dyslexic agnostic!

A few years ago I located a company on line who supposed all the parts to build bicycle frames, the raw steel joints, junctions, swaying, pedal boxes etc etc, so one could simply braze together what they wanted. I had an idea to build a few wild ‘chopper’ or low rider staple bikes, just for fun, but never got around to it.

If you could find one of them they might supply suitable tapered tube sections. I have always been surprised how immensely strong bicycle front fork legs are, in 16g steel, simply welded to the fork top tube. Built into a 3 dimensional frame, as per board track racer type front ends, they would be indestructible.

If you do Facebook there is a group called Board Track Racer Builders that might be worth a look. I’m a member just out of curiosity, no plans to build one. Yet.....

 

[Guzrik]

I would need to brush up on my Chinese to call a cycle manufacturer! does anyone know of a UK based small independant cycle manufacturer? not carbon fibre!

I used to get old cycles from the tip before they stopped anything leaving but there was not much I could use for my projects,

and yes my spell checker has gone missing! I can click on it in my browser but it no longer picks out misspelt words, not good for a dyslexic agnostic!

My wife always watches househuntingshows, often with Kirsty Allsopp. On one of these shows they always show some local speciallity and I remember seeing a small local bicyclefactory once but I can't find that episode back.

 

[hazzabo]

£3000 for tooling, not really interested in looking to see what they have on the shelf, they make taper tubes for cycle, table, chair etc. use, I said I can be flexible in my needs and adapt to suite std. tooling but ...............

Thought that might be the case. The company I work for has two sizes of tube Swaged by them - let me dig out the drawings and see if the sizes are any good to you.

 

[Screwdriver]

With a gun to my head and I had to do it: I'd make up some swage blocks (turn a tapered hole, chop in half), probably make 3 pairs so manageable 2 inch sections at a time. Get the tube hot and forge a taper on the last six inches.

Nice thing about having 3 reducing swages is you can start off with the biggest, work down to the smallest for the end section, two for the middle and just the big one where the taper starts. Soon find out which end it's best to start from, my guess would be at the sharp end first but then, it's all guesswork so...

 

[Guzrik]

Did these a while ago, I guess if I had conical die set it could work, in multiple steps and it would need finishing.
It is 3/4 OD seamless staninless tube, and the smallest diameter is 13.5 mm due to the fact I don't have smaller dies yet.

 

[citizen kane]

This is a typical selection of tubes from Ceeways spare tube selection, they have some taper sections.

https://www.ceeway.com/Spare Tubes.htm

As you can see, bicycle frame tubes are quite thin wall.

Reynolds still draw their high end tube sets in house and they will provide catalogues on request but again its all thin wall stuff.

 

[Shox Dr]

This is a typical selection of tubes from Ceeways spare tube selection, they have some taper sections.

https://www.ceeway.com/Spare Tubes.htm

As you can see, bicycle frame tubes are quite thin wall.

Reynolds still draw their high end tube sets in house and they will provide catalogues on request but again its all thin wall stuff.

Good link. While thin wall, its all Cromoly/4130/t45 or similar High tensile strength

 

[hotponyshoes]

It's not something I have tried on anything of any size but could you not get a bit of solid bar, grind/turn it down to the taper that you want for the ID of the tube to use as a former.
Then get a bit of thick wall tube, heat it up and beat it onto the former?

You could then grind down the wall on the thin end if the weight was that critical

 

[Screwdriver]

It's not something I have tried on anything of any size but could you not get a bit of solid bar, grind/turn it down to the taper that you want for the ID of the tube to use as a former.
Then get a bit of thick wall tube, heat it up and beat it onto the former?

You could then grind down the wall on the thin end if the weight was that critical

That might work with V shape swages...

 

[hotponyshoes]

That might work with V shape swages...

Do you need a v shape swage?
I'm thinking if you had a hot bit of tube and just drove a tapered bar into it you'd end up with a tapered tube

Edit, you would wand to use a bit of seamless tube I expect but if it's for forks you probably would anyway

 

[Screwdriver]

Do you need a v shape swage?
I'm thinking if you had a hot bit of tube and just drove a tapered bar into it you'd end up with a tapered tube

Edit, you would wand to use a bit of seamless tube I expect but if it's for forks you probably would anyway

Oh you'd open it up to the larger diameter? Can't see that working easily for a home workshop on a long enough tube. I guess you would heat the tube in stages but wonder how such a long former would hold up remembering the expanded part is going to cool and shrink. I'm sure there's a trick to making that work but sounds difficult.