|   Please Tell Me the Difference between.............. | mtbagz
Apr 24, 2002 4:18 PM | | ..........a threadless, and threaded headset..........and how do i distinguish which one i have??
also..........wuts the difference between a splined, ISIS, and tapered BB and crank??? and what other kinds are there??
plz help....im lost
thanx |
| re: Please Tell Me the Difference between.............. | Eric Hoefer
Apr 24, 2002 4:43 PM | | i can answer the threadless threaded thing... go to http://www.parktool.com/repair_help/howfix_headtypes.shtml |
| re: Please Tell Me the Difference between.............. | næstep
Apr 24, 2002 4:52 PM | | Technically, this isn't the correct answer, but here's the easiest visual clue as to what kind of headset you have your stem.
If you have a threadless headset, you'll have a stem similar to this one that clamps onto the outside of the steerer tube (usually with two bolts), much like you'd grab onto a soda can with your hand:
If you have a threaded headset, you'll have a quill stem like this one, where the stem-to-steerer interface is inside the steerer tube and only a single bolt on top of the stem holds everything together. The "real" tip-off is the part of the headset at the base of the stem has two large hex nuts.
 
There are exceptions to identifying by stem type. A threadless stem can be (wrongly) clamped to a threaded steerer, and you may see a quill stem inserted in a threadless steerer (with additional hardware clamped around the steerer). But in general, these rules of thumb hold true.
A splined BB has a hollow pipe billet spindle with splines cut into it. ISIS is a competing standard to Shimano's 3 different spline systems:
A square taper is just a four-sided spindle:
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| Whoa...great post, dude (nm) | Retro
Apr 24, 2002 9:36 PM | | |
| re: Please Tell Me the Difference between.............. | Yeti_Rider
Apr 24, 2002 4:54 PM | | A threadless headset relies on a fork that has a threadless steerer tube. The stem clamps directly to the outside diameter of the steerer tube adn the top cap holds the stem onto the sterrer by using a nut that gets pressed into the sterrer tube. A threaded headset uses a fork that has threads on the tube. Then a nut screws onto the threads which holds the fork to the bike. The stem than uses a quill which is nothing more than a fancy name for an expanding wedge that goes inside the sterrer and as you tighten the nut, the wedge expands to clamp the inside of the sterrer.
On a threadless system, if you take the stem off, you can take the fork off without tools. On a threaded system, taking the stem off doesn't affect the fork at all. Threaded systems began to get phased out in the early to mid 90's if memory serves me correctly.
A tapered BB is the standard that has been around forever. The cranks slide over the tapered shaft which is nothing more than a square that tapers outward so that when the cranks are put on they wedge against the taper.
A splined BB is something Shimano came out with but at the time didn't license. IT's basically a stronger interface than a tapered BB. In a tapered BB, the rotational load is being distributed onto two or four surfaces of the BB and only on one area of each face. Imagine an open ended wrench on a bolt and you have the same thing happening only it happens on all four faces. The splined BB has a number of notches and the crank has a corresponding patter so they mesh together and are able to distribute the load over more (sorry, I don't know how many notches there are) points which in turn makes for a stronger part.
ISIS was a joint effort by RaceFace, TruVative, and (help me out, can't remember the third one) to develop a system similiar to Shimano's that didn't violate the Shimano patent. They wanted to be able to sell aftermarked parts so they joined forces, came up with a system that many people felt was superior, and released it into the public domain which means they pateneted it but let anybody use it for free.
Hope this helps.
Michael |
| Did Shimano really invent splined BB? | root locus
Apr 25, 2002 9:54 AM | | I don't think Shimano invented splined bottom brackets.
Remember the Redline Flight cranks? They came out about 20 years ago and they were splined. They are still considered some of the best cranks ever made, at least in the BMX community. I wish they made them for mountain bikes. They were heavy (chromoly) but indestructible. |
| THANX alot everyone.........and that was a sweet post! nm | bagz007
Apr 25, 2002 5:15 AM | | nm |
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