Oversized frame tubes, ugly bling or actually beneficial?

[Big Hammer]

One thing that seems to set apart old-school bikes from modern ones is the appearance of the frames and the size of the tubes. If you look at a late 80's or early-mid 90's rigid MTB frame in a fairly big size, they often don't actually look that different from a typical road frame of the same era, and whilst the tubes are usually slightly beefier, they aren't massive. Bung a rear rack, a set of mudguards and narrower tyres on such an MTB, and it just looks like a heavy duty utility bike - which is exactly what you've created.
Then someone decided it was a good idea to make the frame tubes half again or even twice the diameter of a road frame, and things started to get a bit silly. When did all this become common and who started it off? I'm guessing the mid to late 1990's was the time when the appearance of the MTB frame started to bear no relation to a road one and manufacturers vied with each other to see who could build the most ugly and chunky looking bikes.
I don't even see any point, as the modern oversized tube frames I've ridden have not been any better than the old-school ones. The cheap far-eastern variety seem to be heavier, so the theoretical weight reduction benefit from using larger, stiffer, tubes has been missed and it's just become a case of style over substance.

 

[mattr]

Pretty sure it was cannondale who started off with the oversize tubing, on their road bikes. At least for the mass market. MTB then followed.

And the cheap far eastern frames will be heavier, because they use cheap oversize tubes that don't feature thin walls......

 

[mattr]

I don't even see any point, as the modern oversized tube frames I've ridden have not been any better than the old-school ones.

TBH, the modern oversize aluminium frame is pretty much an evolutionary dead end. Carbon does everything better (for a given value of better). The development isn't there, the materials expertise isn't there so they just rehash the same old materials in very similar ways (mostly). Only time it's better to use aluminium is if you want a suspension frame in less than massive volumes.

Though it's been interesting watching the development of Bowman, as they are starting to use so new and quite interesting aluminium alloys which you can do some nice things with (only interesting to engineering geeks.)

 

[Big Hammer]

the cheap far eastern frames will be heavier, because they use cheap oversize tubes that don't feature thin walls......

That's my point, they are adding extra material that just adds weight, and such bikes usually have cheap wheels etc, so they can't even be treated hard enough to need a super-strong frame.
I pulled such an ugly brute out of a bin a few months ago, and took the damaged front mech & changer off so it runs as a six speed. It's OK as a knockabout pub bike, but it sure ain't pretty.

 

[mattr]

That's my point,

What? That cheap heavy frames are cheap and heavy, despite trying to look like expensive flashy bikes? Its all about the image. Nothing to do with anything else. And cheap heavy bikes were cheap and heavy before they were oversize!

Try a top end cannondale aluminium frame. (if they even make top end aluminium MTBs anymore?) it'll be night and day compared to anything steel and skinny. (Or cheap and heavy)

 

[catf]

aluminium alloy is a lot lighter than steel, aluminium being less dense. the downside is it cracks if you flex it, so you need to make the frame stiff. bigger tubes make teh frame stiffer.

generally having lighter frames is good, especially on the road, so light weight is associated with high end, better engineering etc. also newness is associated with progress, so the new technology of alloy frames was seen as better. i know i thought so when i was a kid. before i actually rode one.

 

[mattr]

i know i thought so when i was a kid. before i actually rode one.

I've ridden a lot of them. The only high end one i didn't much like was the zaskar.

 

[M-Power]

Re:

Interesting recent article about this in Pinkbike iirc. Personally im a fan of a stiff frame but with some flexibility for comfort. Old school top end steel and Ti rides nicer imo as a HT. There is defo an optimun tube diameter to fine tune handling. There also evidence that a bike thats too stiff is slower to ride and less popular with ‘experienced’ riders.

 

[T'boo Ted]

OP Do you mean the fat tubes due to being aluminium? as steel would vary in size but is still very small (and Ti) compared to aluminium. It's all due to the properties of the material, aluminium needs to be bigger (but thinner wall) tube so its not a noodle and fail

 

[Stick Legs]

There are a lot of myths about Aluminium (Aluminum?).

1) It work hardens... yes, but depending on heat treatment and alloying properties it can be more resilient than steel for a given weight of frame.
2) It won't flex... Look out the window next time you fly. The ponder point 1).
3) Its's brittle... See points 1) and 2).

In answer to the OP's question, the way OS Aluminium was worked by Klein & Cannondale it is hugely beneficial.
Something like a Barracuda BSO is not.

https://www.sheldonbrown.com/rinard/fra ... e_test.htm