Opinions. Which is better, ISIS or Square Taper cranks. I would like to go to a 5 bolt compact crank. ISIS is expensive, but is it really better? A lot of guys in this forum seem to be happy with their square taper cranks. Any help would be appreciated.

It seems ISIS is doomed to begin with. The design uses small bearings which means after some riding and some wet you develop play in the BB and before you know it your servicing or replacing your BB.

Square taper is an old design that works, but may put more stress on your crankset because of the lack of splines taking up the force that is being applied on the arms. Square taper can also have issues with removing and replacing the cranks - afterall doing this a lot, the fit etc can get worse and I think stress can become an issue after long periods of usage (am i right?).

Personally, I wouldn't buy either because I don't like either design, but If I had to choose I probably would go square but then again there are good options out there (Read: Octalink)

Ciao
Trevor!

I have been mulling over this, and doing research for quite a while, and have decided to go with a new square taper crankset on my MTB - using octalink right now (the same that came on your Epic as did my Epic) - I'll be done with it sooon!!! But anyway - testing shows that Isis is anywhere from 5% to 25% stiffer depending on who you talk to, but almost no one under 160 lbs will be able to realize this difference!!! Most people over 160 will not realize it either -I have a cheap SquarT Tiagra crank on my Road bike....and I can't tell the difference in stiffness over the XT splined BB on my MTB......CAMPY IS STILL SQUARE TAPER!!! Jan Ullrich pushes Sqaure taper...among hundreds of other pros....regarding the "worn fit" problem with sqaure - mechanically speaking any alloy that rubs against another alloy will WEAR..it may take a "bit" longer with splined/isis but it will still wear... One way I will solve this (and what I've been doing with other parts) is to use AUTOMOTIVE BEARING GREASE. Slap this stuff on the sqaure taper, and the inside of the crank, and secure it nicely and this will go along way towards defending against wear..including heat, and water. But seriously folks - you can't expect a crank to last forever perfectly, and they wont. Along with the ISIS problems with bearings, and the cost - I see no reason that sqaure taper is inferior.. When people talk about stiffness they often forget that your frame goes along way in determining BB stiffness.

I dont' believe it's recommended to use grease on a press fit.

It seems ISIS is doomed to begin with. The design uses small bearings which means after some riding and some wet you develop play in the BB and before you know it your servicing or replacing your BB.
Trevor!

Large bearing surface between crank arms and bb, less room for bearing between bb and frame. The Octalink just has a head start and has better designed bearings. Eventually, ISIS will catch up.

If I were building to be light, and starting a new "project", I'd go square taper and run a light bb like the Action Tec or equal. My isis drive came with the blue nrs back on 02, so thats a no brainer. It is stiffer, but it is more $$ too, plus the problems of course. Action Tec's bearings are easy and cheap to replace, its light as hell, and its stiff enough. The cheaper std bearings that come with it are crap, so thats a good thing on the ease of maint. Then run a light compact set of cranks(my favs are next lps for this subject at hand) and live happily ever after. Cheap rings..cheap bearings..can run a 20t granny for the duraace in the back. End of story.

I DEFINITELY noticed an increase in stiffness at the pedals when I changed from square taper to ISIS. Yes, I've heard the horror stories about short bearing life, but I haven't had any problems myself. Maybe because I don't ride much in the wet. If I had it to do all over again, I would go ISIS without hesitation. By the way, I weigh about 160 lbs ready-to-ride, and my bike is a Klein Mantra Comp. My BB is one of the original Shook ISIS units, and my cranks are Truvativ Stylo Teams.

I kept the thread from a few weeks back that you put up on the old forum. I'm gunning for the Next LP's and Dura Ace cassette (with an 11 t/14t swap) . I'll have to check out the Action tec BB. Thanks.

..in the Classifieds here, at least he used too. He sells it less bearings but with ti crankbolts as well. Not quit as light, but much cheaper. The Action Tec can sometimes be found on sale, but its not very often. Think Cambria has them, but usually always at retail tho. Mine was the 112mm size at 140ish grams. Said 160gms last time, so I had to clear that little misqoute up. I'm vain like that ya know:).

Just got thru swapping out my too long 113 un73(hate that plastic cup deal for sure)for a 107 un72 and saved 20-30gms for Gods sake, all for $19.:) Coulda sworn that Moab needed a 113mm back last Spring. Been having to play the chainline more to the left up front then one would otherwise. Now the old 113mm un73 is my cheap backup for the race blue ride.

I don't think anyone is saying that ISIS is inferior to squaretaper by any stretch...but I think the CURRENT state or advantage is hard to put a finger on...like I said before professional roadies are putting thousands of miles, and generating way more wattage than most of us....and a lot of them are using campy square taper BB's etc.. When a racer gets to the level of Jan Ullrich - every facet of his game is analyzed by experts, and if someone thought that he was losing precious power with a square taper then I am sure he would use something else..then again maybe that's why he keeps coming in second - laugh -----

From an engineering standpoint, goign top a large bore thinwall tube is superior in torsiuonal strength to a small diamter more or less solid spindle....

Smaller diameter ball sin a bearing cage are not a liability if they are engineered properly which means more balls and appropriate seals, wether shileded or contact style.

To say that old fashioend square spindles are superior in design to ISIS just doesn't hold engineerigng water.

I dont' believe it's recommended to use grease on a press fit.

The reason to lube the tapers is to prevent galling and fretting from occurring
during installation. Basically, what this IS is that while the machined tapers
of the Ti (or CrMo) spindle appear smooth to the naked eye or to the touch of your
fingers, when viewed under high magnifaction (like 1000x), they are actually
quite rough with peaks and valleys and sharp edges. When you're pressing the cranks on,
which are almost always aluminium and softer than the Titanium spindle,
the BB tapers are acting like minature files and removing small flakes
of aluminium from the crank tapers. These flakes then become trapped between
the crank & BB tapers, leading to an imperfect press-fit and are the MAIN source
of creaking noises.

For many decades, there has been an old wives tale unique to the bicycle
industry about greasing the spindle tapers being a major no-no and sure fire way
to over-install the cranks. This is a myth, pure and simple. Its only now that
crank & BB makers are doing their own R&D and correcting their manuals and
informing consumers and bike mechanics to lubricate the tapers. RaceFace manuals
state to do this now when originally they said not to do it, Shimano's master
bible for installing their parts say to do it (and they even ship the BB spindles now with
grease on the tapers already, ready to install), and the latest edition of the
Sutherlands manual says to lube the tapers.

Square taper is an old design that works, but may put more stress on your crankset because of the lack of splines taking up the force that is being applied on the arms. Square taper can also have issues with removing and replacing the cranks - afterall doing this a lot, the fit etc can get worse and I think stress can become an issue after long periods of usage (am i right?).

You're not right.

Square-Taper was used on track bikes for decades and track racers put a lot more stress into a crankset than any mountain biker does. Also if the cranks are properly installed in the first place (which means cleaning and then lubricating the tapers and using a torque wrench)
you can remove them and reinstall them hundreds of times.

I dont' believe it's recommended to use grease on a press fit.

It is. Any machinist could tell you when joining metal parts together to lubricate the interfaces, especially when the principal holding it together is elastic deformation of metal. Its the softer aluminium of the crankarms deforming against the harder spindle material (ti or steel) under pressure. When the pressure is relieved (using the crank extractor), the metal returns to its previous state. Its NOT surface friction that holds the parts together and in fact, surface friction during assembly is exactly what you don't want a lot of, as this leads to galling and fretting. Pretty much every crank maker today advises to lubricate the tapers (including shimano, hell, they package their BB's with grease on the tapers already) as do most of the leading bicycle mechanics manuals (sutherlands, park, haynes) that weren't written by old fart bicycling magazine editors.

The reason to lube the tapers is to prevent galling and fretting from occurring
during installation. Basically, what this IS is that while the machined tapers
of the Ti (or CrMo) spindle appear smooth to the naked eye or to the touch of your
fingers, when viewed under high magnifaction (like 1000x), they are actually
quite rough with peaks and valleys and sharp edges. When you're pressing the cranks on,
which are almost always aluminium and softer than the Titanium spindle,
the BB tapers are acting like minature files and removing small flakes
of aluminium from the crank tapers. These flakes then become trapped between
the crank & BB tapers, leading to an imperfect press-fit and are the MAIN source
of creaking noises.

For many decades, there has been an old wives tale unique to the bicycle
industry about greasing the spindle tapers being a major no-no and sure fire way
to over-install the cranks. This is a myth, pure and simple. Its only now that
crank & BB makers are doing their own R&D and correcting their manuals and
informing consumers and bike mechanics to lubricate the tapers. RaceFace manuals
state to do this now when originally they said not to do it, Shimano's master
bible for installing their parts say to do it (and they even ship the BB spindles now with
grease on the tapers already, ready to install), and the latest edition of the
Sutherlands manual says to lube the tapers.

That looks like it was copied word for word from one of my earlier posts on the subject.

The Campagnolo manual specifically stresses not to grease the tapers...I realize it sounds wrong...I think the idea behind it is to prevent people from chasing the crank up the BB spindle until it splits. When there's no grease you're less likely to split the crank before you bust the mounting bolt.

The Campagnolo manual specifically stresses not to grease the tapers...I realize it sounds wrong...I think the idea behind it is to prevent people from chasing the crank up the BB spindle until it splits. When there's no grease you're less likely to split the crank before you bust the mounting bolt.
Using a torque wrench should solve any problems with that...they've done tests at Stanford on this stuff man.

i used to ride square tapper for at least seven years, from bmx to dh, back in 96 when i decided to race xc i bought a xtr crankset and bb (octalink) i was really impressed by the stiffness gain. its really noticiable. im currently riding 2002 xtr cranks/m950 bb and couldnt be any happier.

Using a torque wrench should solve any problems with that...they've done tests at Stanford on this stuff man.

If you had used a Campy crank you'd know that during the first few rides the crank will squirm up the taper due to pedaling forces, resulting in the mounting bolts feeling loose. The user then thinks his crank has loosened and proceeds with tighten them down again. When greased there might be a higher risk of this process continuing until the crank splits.

(This is just my personal theory to their reasoning. I've never actually split a crank)

If you had used a Campy crank you'd know that during the first few rides the crank will squirm up the taper due to pedaling forces, resulting in the mounting bolts feeling loose. The user then thinks his crank has loosened and proceeds with tighten them down again. When greased there might be a higher risk of this process continuing until the crank splits.

(This is just my personal theory to their reasoning. I've never actually split a crank)

Hmmmm so is this just campy related?? Because I have Shimano square taper on my road bike and it's as stiff as can be and never broken loose. My wife runs XT square taper on her MTB....and it's ridiculously stiff...so I guess I just don't understand... I think we have definitely left the weight forum on this topic.......... I guess I just cant relate to flex period because I'm a 150lb XC epert racer..and I don't think I've experienced any "noticeable" flex on any of my lighweight part...(but I like to think that I have a really refined and smooth riding style) :-)...but yea, I have a buddy who races 190 lb, and he breaks everything......he even has a set of isis cranks that are "cockeyed" now at the bottom bracket .....so I don't know.....one things for sure is you can get square taper BB's that are light and cheap, and probably more reliable for an almost "imperceptible to most people" difference in stiffness...

I think you quoted the wrong post.....personally I don't perceive any difference in crank stiffness either. I've got SI Hollowgram, DA, and Record.

campy's tapers have always been, whats a good word.... different.

Basically you only use campy cranks with campy BBs and vice versa because they don't work well with any BB comforming to the JIS 2degree taper (which is what, shimano, suntour, sachs, and almost everybody else uses). They're a shorter taper for starters so you have less room for error on your installations. On top of which, campy is one of those old roadie companies that doesn't actually do research into old wives tales of the bike industry so of course, they're going to keep on repeating the no-grease myth.

Even with grease, you'd need to FAR exceed the recommended bolt torque to install an Al crankarm far enough up a square-taper spindle to actually split the arm open (like over a hundred foot pounds, when correct torque is usually 30-40 ft-ibs).

The taper Campy uses is ISO.

...doesn't do research. Is that the reason they make components for the aerospace industry and Ferrari.

making stuff for ford doesn't mean they've done the basic research into how a crank taper works. For years raceface made cranks and said not to grease the tapers, THEN they did the research and about faced on their instructions for assembly of the cranks when it comes to greasing the tapers.

The benefit if Octalink & ISIS is for the OEM not the consumer.

They are easy to install (cartridge B.B.), and the crank arm sits in the same spot on the spindle from bike to bike. This facilitates front derailleur setup/ installation (reduces fine tuning).

The OEM sees a reduction in assembly costs. That is the same reason for the use of : cassettes over free wheels, threadless (aheadset type) vs. threadless headsets, cartridge B.B. vs. cup & cone, cartridge headset vs. cup & cone, v-brakes vs. fiddly old cantis (remember mid '80's XT: aagggh!), pre-assembled wheel sets.

I am not saying WE don't benefit. Bikes are way less hassle now, but , think like an industrial engineer & you will see the rationale behind all these changes & choices. Henry Ford would be impressed.

As far a lubing tapered crank spindles: From my machinist/millwright days, an interference fit is NEVER greased. Both surfaces should be clean and dry. The grease prevents proper "intereference" between the two parts allowing for some movement, creeping etc. I could be mistaken tho...

As for Campy vs. Race Face engineeering savvy, while the cats at Race Face are awesome dudes, (specially R.H.) I bet they would agree that Campy have a little more engineering muscle. R.F.'s advice to lube the tapers is prolly predicated on their material choices/forging specs. :rolleyes:

I just ordered a Race Face Next LP crankset in square taper. It was literally half the cost of the ISIS, and wasn't so expensive that I couldn't switch if I ended up really hating it. And my guess is that its much better than my stock Specialized crankset. I'm also on the verge of ordering an Action Tec BB, just looking for the right source.

I came from Bontrager Cranks/Square taper to Race Face XC ISIS and I definitely think ISIS is much stiffer. I am sure the Bonty is a bad example of square taper, but the stiffness of the RF XC cranks and the ISIS drive have been kickin but for me in XC and some freeride conditions for the past two years. And, it is still going strong. But, I only weight 155 so that ight make a difference.