Why weren't ATBs a development of BMX?

[grey-beard]

Because...

Think back

riding off-road existed in various forms but not as a widespread sport or passtime

the great cycling parts bin comprised of road, tandem and BMX with a sprinkle of motorbike parts - sure , there was cyclocross but that evolved into lightweight bikes to be carried, not mudpluggers or fast off road

knobbly tires were not a 'thing' either

so, out of that you have to evolve an entirely new bike for you and your mates to hurl yourselves down Californian fire roads

and once you do start building your own frames after running out of 2nd hand ones, you are still limited to what is available. You have to adapt road and tandem again or go down the route of fabricating your own drop-outs, lugs and even rims

so there you go

read Charlie Kelly's books and you'll see why

That just explains what happened as opposed to what could've if they'd looked at BMX.
By the time mountain bikes were being produced BMX was already a pretty well established sport and bike type. With specific proven off road parts.
That's all.

 

[legrandefromage]

No, bmx was for racing over short circuits, frame tubes were way too skinny and, well, those bottom brackets still give me nightmares!

And again, fabricating a bicycle for off road use over long distance would need the already proven materials and components readily found in the touring and tandem world, not bmx

And here's your bmx inspired 26er, the Raleigh Bomber...

And what an utter shit show of a bicycle they were too

 

[legrandefromage]

And if some sort of easily accessible electronic pictorial communication's existed in the 1970s, things may have been different, but they weren't and bmx inspired beaxh cruisers, cruisers, came about instead and that was as far as you could go if your aim is to build a bicycle for all terrain based on the idea of a bmx

But...

Someone in the 1970s UK had been thinking about off roading and traversing all of the muddy terrain so they built their own 'atb'. Fabricating their own bits and utilising bmx and other bits...

Cleland!

 

[legrandefromage]

And and and

If the Internet had existed, you would have found out about 1970s hydraulic rim and disc brakes!

 

[legrandefromage]

Sooo, your bmx inspired atb

21.1mm stems, bmx bars, one piece cranksets

Bmx tubing? Are you sure? Designed specifically for small frames, not really suitable for the larger wheel size if going off road, bearings, headsets and seatposts

Gears: hub or derailleur? You're going to have to borrow from somewhere, there's only 2 and 3 pd hubs available, 4spd being too fernicketty

Hub or cantilever brakes? Hubs overheat and there's not much choice for decent rims

I think if you look at what was about in the 1970s, you'd end up with something very similar to what came about due to the impracticaliies of the parts bin of the day

Or, do a John Finlay Scott and build an 'mtb' in the 1950s when there were no bmx to look at

 

[grey-beard]

No, bmx was for racing over short circuits, frame tubes were way too skinny and, well, those bottom brackets still give me nightmares!

And again, fabricating a bicycle for off road use over long distance would need the already proven materials and components readily found in the touring and tandem world, not bmx

And here's your bmx inspired 26er, the Raleigh Bomber...

And what an utter shit show of a bicycle they were too

View attachment 785592

No, that's just a shit bike. An example of Raleigh's attempt at making a certain shape of bike.
Cruiser shaped.
There were proper race ready 26er BMX cruisers long before that poor excuse for a bike appeared.

 

[legrandefromage]

For racing, with a pit crew and support

Not out on your own in deepest darkest Surrey

 

[legrandefromage]

No, that's just a shit bike. An example of Raleigh's attempt at making a certain shape of bike.
Cruiser shaped.
There were proper race ready 26er BMX cruisers long before that poor excuse for a bike appeared.

But it's what you asked for! Bmx inspired off roader! Just because it was the Talbot Rancho of the day

Jeeez some people can be sooo picky!

 

[legrandefromage]

Looking at this 1977 Mongoose, I dunno, yes you could have upscaled to a bigger wheel size but there's a something missing that gave that secret ingredient to the earliest production mountain bikes

 

[legrandefromage]

And it could be argued that GT mountain bikes were bmx inspired but that was an 80s thing, not 1970s