Why did headsets change from 1"to 1 1/8"?

[Blue Hills]

Still a lot of 1 inch headsets blasting around the streets of London as well for that period of bike has gone through something of a reputation revival.

I'd be willing to bet that the majority of those bikes still have the original headset in them.

ps, yellow saddle - would still be interested in your views on lowrider pannier mounts on a fork with such a headset.

 

[hoopdriver]

Still a lot of 1 inch headsets blasting around the streets of London as well for that period of bike has gone through something of a reputation revival.

I'd be willing to bet that the majority of those bikes still have the original headset in them.

I'd bet that too.

 

[FishFright]

Some of you may need to google* the difference between primary failure mode and still working, you may be in for a pleasant learning experience.

*Once up a time i would have said research but progress and all that .

 

[Ajax Bay]

I, along with a number of other people on this thread

I suggest that those reading this thread and being bothered to comment are not a representative sample of 1" steerer /headset users (perhaps they are better at keeping their headsets serviced, for example). So drawing the conclusions you do cannot be usefully relied on by using the various comments being positive about 1" steerers. And I too have been blessed by good 1" steerer/headset experience on all the bikes I've had (or have) with them.
OP asked 'why' and answers have been offered. Not much point in saying 'not in my experience', is it?

 

[hoopdriver]

Yes, there is a point if in your experience what is being described and given as a possible reason for change has never occurred.

Sorry if the real world experiences of people with many years in the saddle and many thousands of miles behind them does not fit with your received wisdom, but there we are.

 

[tyred]

[QUOTE 4852536, member: 45"]What's a plain bearing?[/QUOTE]

A plain bearing is one without balls or rollers - a typical bronze or brass bushing type bearing.

 

[Dan B]

I've never had my house flooded, but my many years of personal experience still don't add up to a good reason to eschew contents insurance

 

[hoopdriver]

I've never had my house flooded, but my many years of personal experience still don't add up to a good reason to eschew contents insurance

That is irrelevant.

It is not even logical within the context of this discussion

 

[Vegan1]

It was because finally we could see the back of Quill Stems.

 

[Yellow Saddle]

If you've read my posts you'll see that I did not propose any means of failure. I merely commented on the fact that I, along with a number of other people on this thread, have not suffered problems with 1" steerers, despite collectively speaking, decades of use and many, many thousands of miles.

This reminds me of discussions I see on some photography forums. I am a professional photographer but on these forums I see a great many posts by people who possess great technical knowledge and are obsessed by resolution charts and the minutiae of sensor technology. They lose sight of the fact that for the overwhelming number of photographers, pros included, a camera is a tool and that the practice of photography in the real world is far more than resolution charts or pixel size. Yes a given sensor or lens might outperform another in a lab or resolve a level of detail that will never be visible anyway even on a double page spread in a high quality magazine, but what of it?

To these technology obsessed types it is technology itself that is the end-all and that is fair enough - for them. But to read their dismissals of what in truth are excellent cameras or lenses you would think they were describing Box Brownies, and that no photograph taken before, say, 2010, could possibly have the clarity or colour rendition or resolution to be worth the paper to print it.

I prefer to step back - look at the forest.

People got along fine with 1" steerers for many years.

Thanks for explaining. I now understand, you are a photographer, not a bike mechanic.

 

[hoopdriver]

Thanks for explaining. I now understand, you are a photographer, not a bike mechanic.

And you're a theoretician.

Oh, and by the way, in addition to being a photographer I have a City & Guilds certificate as a bicycle mechanic.

 

[Vegan1]

And I've had a bike license for over 10 years, being seeing as I've never really ridden one since passing my test does not mean that I'm good at riding a motorbike.

 

[hoopdriver]

It was because finally we could see the back of Quill Stems.

Yeah, I guess Eddie Merckx was never really strong enough on the bike to need a modern headset. We're all so much stronger and fitter now.

 

[hoopdriver]

And I've had a bike license for over 10 years, being seeing as I've never really ridden one since passing my test does not mean that I'm good at riding a motorbike.

Speak for yourself.

I guess you have

 

[dan_bo]

Anyone who has used 1" steerers and headsets extensively will know about their primary mode of failure - bearing indentation or so-called false brineleling. This is where the front and rear balls in the lower headset bearing fret away and indent the races and the headset becomes notchy to the point where riding straight ahead becomes a problem. With a notched headset the bike always feels like it fishtails or also as if the rear wheel is flat and the rear kinda sways as you pedal.

This type of bearing is unique to headsets because a ball bearing is not the ideal bearing for steering a bicycle that primarily rides straight ahead. The bearing never gets an opportunity to rotate and replenish its grease. The small sideways handlebar movements cause the balls to just move slightly, but never rotate completely. This causes them to push the grease out at the ball/race interface and make them run dry - steel on steel.

In addition, the flexible 1" steerer flexes a lot at the bottom bearing where the unsupported fork exits the head tube. It vibrates forwards and backwards from road shock and loading, forcing the bearings to move fore/aft and against the grain, so to speak. In other words, this movement is against the natural circular movement the bearing makes when the steering is turned. The combination of these two fretting forces causes micro-weld and breaks. The ball welds against the race over a few molecules and the very next bump breaks the weld and so on and so on. This causes dimpling of the races. These dimples are not impact dimples, but fretting erosion dimples.

One inch steerers are just too weak in bending to prevent this type of movement, hence the thicker and stronger 1 1/8th inch steerer. Although 1/8th of an inch more doesn't seem lime much, it is a lot more, since tube strength (in flexion) is proportional to the square of the diameter (Pi R Squared and all that). This extra thickness makes it stronger and headsets last much much longer.

The Aheadset is not related to the move to 1 1/8th steerers, but also contributes in its own way. This is because the beaings are loosely seated in the cups and can move when the steerer bends, thus protecting the balls inside.

I very much doubt that mountain biking is the primary contributing factor but the increased strength certainly helped mountain biking.

One inch aluminium steerers were the worst of all evils but in 1 1/8th they are fine.

It's like seeing the face of god.