|internal and integrated headset...||joe mudd|
Feb 2, 2003 11:05 AM
|is this in the direction of frame set evolution or just another exotic gimmick?
i'm noticing more and more frame manufactorers instilling head tubes to receive either internal or integrated headsets, ya know, the ones where the headset is all inside the head tube .
[internal is with replacable seated bearing race and integrated is where the bearings seats right into the machined head tube!]
one advantage is that the total stack height is reduced, allowing a tri/trialist to go lower up front, thus taking full advantage of those frames specific angles, however, the diameter is increased significantly increasing overall wind drag and total weight.
apparently, there is no improvement nor reduction of handling,but i hear they are tricky to adjust, and can feel loose, rely on accurate assembly/milling, and can wear/ruin the frame if not properly adjusted(especially integrated), and maintained.
here's a link to what chris king has to say...
so what do ya think, and anyone have opinions to share from experience?
|re: internal and integrated headset...||Brad S|
Feb 2, 2003 12:06 PM
|This is my response to a headset debate in teh general discussion forum from a few days ago:
The biggest criticism leveled against the newer headset fads was the truly "intergrated" headset, where the bearings just pop into the frame, the frame provides the bearing race and cup at the same time. This is really stupid, because if the machined bearing races in the frame get pitted (easy with an aluminum frame)(or are machined wrong), the frame is toast. And as you stated, these are/were stupid, but unfortunately many manufacturers still use this design, it is not going away as you state.
Now "internal" headsets are a whole nother ball of wax. These are represented by the CC/FSA zero stack and Columbus style headsets were a cup is PRESSED into the frame. Pretty much the exact same design as a regular aheadset except the bearing size can be made large and the headtube can be made larger which looks better with fat aluminum main triangles and also allows for a large welding contact for the top and down tubes. You can knock out the internal cup and replace it if the bearing race ever gets damaged. Also the look is "cleaner" to some people, but that is really an aesthetic thing.
Now there are no mechanical advantages at all to the "internal" headset compared to a standard aheadset. This design doesn't do anything better or allow for any easier maintanence than a standard aheadset design would. I wouldn't really say there are any major downfalls either, except the selection of headsets isn't the best right now, and the standards aren't really agreed upon yet (CC standard, King has their new standard, Columbus standard is different again). So choice is very limited (at least for now). I actually have a Pegoretti GGM that uses this design, but again unfortunately my headset choices are limited. But I like the design for big frames because it allows the use of large top and down tubes and a better welding contact area at the headtube like I mentioned earlier.
Then there is a third new design that is in between the integrated and the internal. Some people call it an integrated design, but I will refer to it as semi-integrated. The difference is that the frame doesn't act as the bearing race, instead a cup (plastic or aluminum) is DROPPED in (not pressed in) the frame. A good example of this design is the Campy Record hiddenset. This design seems better than the true integrated, as the drop in cups should protect the headtube, but I would feel better using the pressed in cups of the internal headset personally. It's possible if riding with a loose headset the drop in cups could shift around and damage the headtube machining, thus trashing the frame. Also, since the cups are dropped in and not pressed in, the machining of the frame still has to be perfect and I have seen a lot of Italian aluminum frames where this is not the case. Also, the headtube is more easily damaged when shipping just the frame, as the metal is very thin at the end of the headtube (I had a frame ruined by UPS because of this, where if it had been a conventional design it wouldn't have been dinged as bad (thicker wall tube) and I could have cleaned it up with a headtube cutter).
Only time will tell how well the integrated and "semi"-intergrated designs holdup, but only 1-2 years is not sufficient time. Give the design 5-10 years and see how many frames with this design are still rideable at that point. I personally don't mind the internal design, but would never buy a bike with the integrated or semi-intergrated design.
And before you start ranting some more LazyWriter, I consider the Litespeed/Merlin design an internal headset and don't really have a problem with it except again you are limited to what headset you use. No cool upgrades to the Chris king.
|not entirely correct....||C-40|
Feb 2, 2003 3:13 PM
|There has never been a frame built where the head tube served as a bearing race. All intergrated headsets ever made have a hardened steel race that is inserted into the machined head tube. The race may be separate or part of a cartridge bearing, but either way the bearing balls don't contact the head tube directly. If the bearing balls were in direct contact with the frame, the frame would be toast after a vew rides. No manufacturer is that stupid.|
|not entirely correct....||Brad S|
Feb 3, 2003 1:45 PM
|you are correct that the ball bearing don't directly contact the headtube, that is not what I meant to say if it came across that way. But the headtube does serve as a bearing race when a cartridge bearing is laying in a headtube, still a shitty-ass design.|
Feb 3, 2003 2:04 PM
|Apparently you don't understand how a cartridge bearing works. It's a totally self-contained unit with two races, a set of bearing balls and seals to retain grease and keep out contaminants. The headtube is only a housing, not a race. Bearing balls ride against the races. Check out this site for info that will explain cartridge bearings.
|cartridge bearings...||Brad S|
Feb 3, 2003 4:25 PM
|I understand how a cartridge bearing works, but the headtube still has to be faced correctly, and if damaged, the headset will no longer be smooth. So though my terminology might have been technically incorrect, my points are valid.|
Feb 4, 2003 7:00 AM
|Regarding the original post, at this point it is likely the various "standards" are here to stay. It appears that each type is getting enough spec to survive. |
Regarding bearing alignment, this has been a problem on some frames. As a simple test, take the bearing and place it in the frame. Use your thumbs on either side of the bearing to rock is back and forth. Now do the same at a point 90-degrees from the first test. If the bearing rocks more in one orientation than the other, the frame can typically benifit from facing.
For professionals, the http://www.parktool.com/tools/756_S.shtml tool below is for the IS standard in the 1/-18" only (44mm size with 45-degree slope). The bearing contact is on this slope, not the inside edge or the top face.