Where's your headset gone?
The humble headset used to be very simple to understand. Firstly it was threaded to the top of your forks and came loose all of the time. It was a nightmare, for those of us that remember back that far, because of all of the different standards. You had 1" and 1-1/8", oh and lets not forget BMX 1" which was different again and Gary Fisher's 1-1/4" Evolution system. (He's always trying to make stuff bigger, now its wheels that are getting the oversize treatment. Hope he doesn't have a complex)
Then Cane Creek gave us the A-Headset or thread less system and put a stop to nearly all headset worries. Here was one simple industry standard that could be used across the board. Mountain Bikes, BMX and eventually Road bikes could all use the same headsets. Life was easy for bike mechanics the world over for quite some time.
But in recent years the headset wars have started up again and are more concerning than before with many differing factions vying for the venerable industry standard mantle. I'm talking about the the 1.5" standard and those shy little headsets that have hidden away inside the frame. The 0point5 standard as it has been called is fairly self explanatory. It simply consists of making the steerer column of the forks and the head tube of the frame bigger so that single crown suspension forks can take more abuse without having to go to dual crowns.
No, the real confusion comes from the current crop of internal type headsets. There seems to be loads of different standards which nobody really understands. I mean, as a product designer, I'm a proper techno-geek and I didn't fully understand the differences between all of the different systems before I did my research, so how are you guys out there supposed to know.
So how did we end up with all the variation. Well the first internal headsets were seen on Road bikes. The top Italian frame company Pinerello got together with Italian component manufacturer Campagnolo to produce an aluminium road frame with the headset hidden away inside the frame, which gave a really nice aesthetic look. Around the same sort of time Schwinn were producing their top XC frame frame with a similar system. I think that a lot of the different headset manufacturers saw these sort of designs start to trickle through and decided to jump in with an international standard to try and get a chunk of the pie that Cane creek got with the A-Headset system. Only problem is they all kinda arrived at the same time and none of them want to back down so we are left with around 5 or 6 different ways of hiding your headset.
The main division is INTERNAL or INTEGRATED types. Let's start with the latter as they came first.
The INTEGRATED headset is the type that does away with the conventional headset cups and instead cuts the bearing surfaces into the Head tube of the frame. (see pic A.)
Pic A.
This means that you have to weld a special head tube to the frame that after welding has to be precision reamed for the headset bearing to sit on. Now reamers are nowhere near as precise as a CNC mill or the like that make conventional headset cups so the bearings that sit in these type of assemblies are always described as self aligning. This is why the bearings just drop in and are described as "self aligning". This just means that the manufacturers can get away with slacker tolerances than with a normal headset. The biggest negative of this system is that if you damage the bearing surface in any way it's gonna mean a new frame rather than a new press-in cup.
There are two opposing teams in this field. You have Campagnolo Hiddenset (pic B.) on the left and Cane Creeks (IS) standard (pic C.) on the right.
Pic B.
Pic C.
They are practically identical but sadly not compatible. The main difference is bearing size. The Campag system uses a bearing with an outer diameter of 42mm and the (IS) system uses one with a 41mm outer diameter. Campag bearings have a reputation for being super tough. The (IS) system is open for any manufacturer so bearing quality can vary. The best ones are probably the FSA and Cane Creek ones.
The INTERNAL type of headset is also pretty self explanatory if you think literally. To combat worries about frame longevity some manufacturers have come up with a way to give a frame the appearance of the INTEGRATED system, by simply making the head tube bigger and putting the headset inside rather than outside as you would normally have. (see Pic D.)
Pic D.
This does away with the main worry about integrated systems by using replaceable cups just like a normal headset. This way if you come up short on a double, you may only crack a cup rather than the frame. The head tube has to be bigger than with the other setup but the bearings actually remain the same size so you are not getting a stronger bearing with this system.
As in the last section there are also two opposing teams in this field. Firstly you have the Cane Creek (again, they must have been really busy a couple of years ago to keep coming up with all these standards) ZERO STACK set up (see Pic E.) and the Chris King Perdido open standard (see Pic F.)
Pic E.
Pic F.
The main difference here is the way that the bearings fit into the cups. The Zero Stack system uses the exact same bearing size as (IS). The press-in cup effectively replicates the surfaces that are in the INTEGRATED system, so it works in the same way just with replaceable cups. The bearings are still a loose fit and have to be "self aligning".
The Perdido standard uses bearings that are pressed into the aluminium cups just like in the normal Chris King headsets. There are a couple of really good engineering terms why this is better but I think that I have bored you enough already. If you really want to know go to the Chris King website where there is a very in depth explanation.
Now officially these two are not compatible. The only real difference in the frame is the internal diameter of the head tube. Zero Stack has to have a 44mm head tube and Perdido uses a 44.4mm one. Now that is a difference of only 0.4mm which it may be possible to ream out of a quality frame with a thick head tube but there is obviously no going back once you have gone bigger. Oh and don't blame me if you cock it up and ruin your frame.
Zero Stack seems to have won the battle for the INTERNAL crown as very few companies have taken up the Chris King standard which is a shame as it is free just like his ISIS bottom bracket design and look how good that is.
Just to make things a little more confusing there is a fifth player which does not fall into either the INTERNAL or the INTEGRATED camp, which is made by Columbus. I haven't seen anyone actually using this one yet so I won't spend long talking about it. Hoorah I hear you cry. Basically they have designed a normal headset that once pressed into one of their head tubes blends together to make the frame look like it is integrated. It is essentially a normal headset in disguise.
Pros and Cons
Now what are the actual benefits of using one of these systems? Now this has been argued endlessly by mechanics and designers world wide. Most of the arguments against and the marketing hype for the products always talks about use for road bikes or XC bikes. So what are the real life pros and cons from a DH/BMX viewpoint?
CONS
PROS
So is it a good idea. I'm going to let you decide. I see no reason to force my views on you like some magazines. Just take a moment to think about it next time you want to buy a new frame.
