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Posted

 

I have done some extensive research over the last year or so on building my own mtb.

 

 

 

I could not find anyone in SA that made custom frames. Morewood makes frames' date=' but their frames are all standard not custom made.

 

 

 

The whole process start at what want in a frame, your riding style etc. Then there are the 3 main materials used to build frames: carbon, aluminium and steel. All 3 have their strengths and weakness, the main thing to consider is weight vs durability.

 

 

 

Although alu would be the best bet, 7005 and 6061 are almost impossible to get in SA, and to expensive to order if you are not making 1000's of frames. Tubesets can be ordered online for rougly the same price as a good qaulity second hand frame. Not to mention the different types of heat treatment for alu. The welding process and equipmemt are very expensive.

 

 

 

Carbon are not hard to find but a fair knowledge of composites are needed for good qaulity and strong adhesion. Carbon is also expensive. Carbon frames are light and strong but, the builder have to be very precise in every process that are involved.[/quote']Lastly but surely not least are steel, I know we all have been told that steel are heavy and prone to rust etc. But steel are stronger than alu and there are new development in the steel industry that makes steel that are not only stronger than alu but also as light as alu. Steel are easier to work with and given a good anti rust agent and paint job will outlast any other frame. These steel can also be ordered online in various shapes and sizes, thereare no welding and the tubes are braized or silver soldered, like being used in copper plumbing.This is all a mouthfull but at the end of the day it is the rider of the frame that has to decide which material use. Above are only a couple of advantages and drawbacks. There are not a big weight differance between these 3 materials, altough carbon tend to be the lightest. I have read on the net that there are only a 14g differance between a cromolly steel frame and a alu frame sized meduim.There are also titanium, but this is a totally diffirent ball game.Please feel free to email me for more info or if you have any info that may be off help in regards to frame building. I am trying to get as much as possible info to put on my website for everybody that wants to feel the thrills and spills of riding their custom build dream machine.gawie@cyclebuzz.co.za

 

 

 

Thanks for the info! I'm interested in what you say about steel. It'd be good to see steel make a comeback, especially in MTB.

 

 

 

Let's just hope Jagwil doesn't see your post smiley18.gif

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Posted

@Johan

 

Regarding custom frame builders you are right, nearly all of them were/are brazed. Using lugs was more the "old" style, with the first mtb specific tubesets the many frame builders started brazing without lugs or just one lug for the BB shell. Looks very neat and is obviously lighter than using lugs.

 

The reason why they did not weld, was simply because the welding was very hard to control. The temperature is a lot higher, and if you don't get it right, you "burn" the tube.

 

The Taiwanese on the other hand saw that welding is a lot more cost efficient and practical for mass production. So they designed special welding machines and brought the welding process on bike frames to perfection. They mostly did not use any welding robots. In the 90's labour was still cheap in Taiwan and welding a frame with the right machines doesn't require high skills.

 

I would not say what the Taiwanese did and still do is cheap sh*t. Actually the best steel frames I have ever seen come from Taiwan.

 

So custom made steel frames are mostly brazed, frames from mass production (which is clearly the majority) are mostly welded.

 

 

 

@Mr. T

 

6061 tubes are impossible to get in SA. Even Morewood did not manage to get them here. They used some other 6-series alloy in the beginning and have started importing custom made 6061 hydroformed tubes now from somewhere overseas.

 

If you want to build a recumbent bike you better don't go for steel. The frame won't be stiff enough.

 

You will also need some very special tubes and cnc parts, so I think your only chance in fact is Morewood. They can weld aluminium, the have cnc machines, they can do heat treatments and have more experience in aluminium frame building than anybody else in the country.

 

 

 

 

Posted
@Johan
Regarding custom frame builders you are right' date=' nearly all of them were/are brazed. Using lugs was more the "old" style, with the first mtb specific tubesets the many frame builders started brazing without lugs or just one lug for the BB shell. Looks very neat and is obviously lighter than using lugs.
The reason why they did not weld, was simply because the welding was very hard to control. The temperature is a lot higher, and if you don't get it right, you "burn" the tube.
The Taiwanese on the other hand saw that welding is a lot more cost efficient and practical for mass production. So they designed special welding machines and brought the welding process on bike frames to perfection. They mostly did not use any welding robots. In the 90's labour was still cheap in Taiwan and welding a frame with the right machines doesn't require high skills.
I would not say what the Taiwanese did and still do is cheap sh*t. Actually the best steel frames I have ever seen come from Taiwan.
So custom made steel frames are mostly brazed, frames from mass production (which is clearly the majority) are mostly welded.

[/quote']

 

Two posts intonated that I don't like TIG welding or Taiwanese frames or both.

 

I just want to put in on record that I'm a HUGE fan of mass-produced Taiwanese frames that are TIG welded. I think these frames have done a lot for cycling by making it affordable and the frames reliable and neat looking.

 

What I tried to get across was that TIG welding has no place in custom framebuilding in SA and very little relevance in general unless the builders have equipment like we see on American chopper programs on TV.

 

Custom builders rely on lugs - a very desireable look and, fillet (don't say fee-lay, this is not a piece of meat) brazing, a look that went out of fashion for customer builds, yet remains in fashion on frames like Cannondale and Da Rosa.

 

The appeal in TIG welding is a nice neat weld bead that appears seamless but the start/finish is cleverly hidden. This is the domain of machines and robots, most of which live in Taiwan.

 

I am not a Made in Taiwan snob but a fan.

 

 
Johan Bornman2009-05-14 06:26:03
Posted

Its interesting how SA has never got involved in producing frames to the mass market.

 

I am not necessarily talking here about high end bikes, but just low end consumer and commuter bikes, which have a high demand value here.

 

I dont believe we dont have the technology to do so, I know of engineering companies who do TIG welding on a daily basis for very specialist operations - certainly a bicycle frame is well within their capabilities. Certainly, I know of engineering companies who manufacture highly specialised products here in high demand in Germany and the USA. 

   

Now, I understand all the cost / number production issues etc, but export freight from SA is cheap compared to import freight from Asia, so we have the possibility of still been competitive to a mass end user.

 
Posted
Its interesting how SA has never got involved in producing frames to the mass market.

 

I am not necessarily talking here about high end bikes' date=' but just low end consumer and commuter bikes, which have a high demand value here.

 

I dont believe we dont have the technology to do so, I know of engineering companies who do TIG welding on a daily basis for very specialist operations - certainly a bicycle frame is well within their capabilities. Certainly, I know of engineering companies who manufacture highly specialised products here in high demand in Germany and the USA. 

   

Now, I understand all the cost / number production issues etc, but export freight from SA is cheap compared to import freight from Asia, so we have the possibility of still been competitive to a mass end user.

 
[/quote']

 

Huge potential in SA alone for a cheap localy made bicycle that the masses can use, Taxi cartels would probably have a frothy about it tho...

 

 

 

 
Posted

Anyone hear of a "John Allen" Reynolds steel frame? Spotted one for sale recently. I think it may have been local many years ago?

Posted

Hey i am interested to know what bad experience you had with Produx?

 A local manufacturer of carbon frames? i did not even know there were such companies.

 

I had a look at his websit--seems more into moto bikes and cars though.

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