Hi gents.

I am new to this forum. I have a question for you.

I have a frame that says:

Cr-Mo Tubing
Tange 5
P.G Tubes

what does it means?

The frame you've got was made with Tange No.5 plain gauge tubing. That's a Japanese low-end cro-moly tube set.

Thanks for your reply. :-)

I am from Denmark, and I have a hard time understanding certain words.

- what does it mean?

Does it mean, that the frame quality is bad?


I have a little project about making my own bike. But if the frame quality is bad, maybe i should get another frame?

"plain guage" means that the thickness of the steel stays the same all over, on 'better' bikes the thickness of the steel changes to make the bike both lighter and stronger

yes, he means the frame quality is not very good... does not mean it wont be a fun bike though.

Plain gauge means the tubing wall thickness is consistent along its entire length. It's not butted - or thinned in the middle - like a lighter and more expensive tube would be.
Tange is a quality tubing manufacturer, so even their low-end product is very decent, in my opinion. The No.5 tubing isn't bad, but it's not great either. It's very solid, but a bit heavy. I wouldn't spend a lot of money to build it up with racing-level componentry if I were you, but it's worth keeping, I think.

Bad is the wrong word. It means that the tubing isn't butted (which means that you can use thinner tube diameters and save weight). It really means that your frame is a bit heavier than one of the higher grades of tange tubing. If by bad you mean it will fall apart, or that it's poorly made, it's not bad. It should be a very durable and comfortable ride...it's just not as light as some other pricier and fancier tube designs.

It would be a very good platform to make an effective low price commuter with. Torchy is right...don't try to make it something it isn't (an expensive high end road bike). Put decent mid-range Japanese parts on it...like lower level suntour, dia-compme, sugino and shimano...and you'll have a dependable and inexpensive bike.

Thank you for all the answers.
Very informative and great answers :-)

One thing does not make sence to me:

if the thickness of the steel changes to be a bit thinner, then how could it be stronger?

It is the other way around:

A steel that is made to be stronger by the way it is manufactured, can be thinner (and thus lighter) than steel that is less strong to result in at least equal frame strength.

Does this make sense?

Let's say that you have to have a certain amount of strength (call it "x") for the tubing on a bicycle frame to be functional. The higher grade the tubing, the thinner walls and lighter weight is possible and still be able to reach that minimum "x" amount of strength. Tange 5 will reach that level of strength at a certain wall thickness, therefore a certain weight. Tange 4, 3, etc. will be able to meet or go beyond that "x" factor with thinner walls because the steel is stronger. Thus the "butted" tubing, aka, double butted tubing (which you don't have) - the tube walls are thinned out in the middle because the steel is strong enough to make the strength requirement without using as much material. The ends are kept thick for brazing purposes, and to handle the stresses at the joined parts.

Bottom line, you've got a decent frame - I've never seen a bad Tange frame yet, be it the cheapest (Tange 5) or the most expensive (Tange 1). Build it up, ride and enjoy.

It makes sence :-)
And thank you..

Thank you :-)

I might post some pictures when itīs build up.

I am going to use it as a city-bike here in Copenhagen (Denmark)

Thanks for all the replies.
You guys know a lot about bikes :-)

This is incorrect. Tange #1 though Tange #5 all use the same grade of CrMo with the same tensile strength. As the tubesets get progressively lighter (i.e thinner) they are rated for lower loads and less strenuous applications.

A frame made from Tange 5 tubing should be a great start for a city bike. I would apply a rust-preventative on the inside of the frame-tubes. J.P. Weigle's bicycle frame saver rust inhibitor is a well proven product.

https://www.amazon.com/Weigles-bicycl.../dp/B0012GO58Y

Michael

I have been to Karup, and I used to hear a lot of jokes about Arhus.

Plain guage means the thickness of the metal is the same end to end.
Chr-Mo tubing is an alloy of steel, commonly grouped into a classification once known as HSLA, or High Strength Low Alloy. It's good stuff.
Tange 5 is the level of tubing, I had a great bike made with Tange 5, a Shogun.
The frames are light, well-made, and generally have excellent paint.

I'd say, in words you can understand, "cool."