ISIS vs square taper question
#1
Lost in the Black Hills
Thread Starter
Join Date: May 2005
Posts: 5,725
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
ISIS vs square taper question
it is my understanding that the taper fit of square taper cranks "wear" out with with repeated cycles of assembly/disassembly...or any taper fit assembly for that matter.
are ISIS a form of taper as well but with the addition of splines? are they just as susceptible to "wear" as the square taper?
thanks
are ISIS a form of taper as well but with the addition of splines? are they just as susceptible to "wear" as the square taper?
thanks
__________________
Tomac Mountain Bikes | Light-Bikes l Magura USA | Industry Nine | Schwalbe Tires | Caffélatex
Tomac Mountain Bikes | Light-Bikes l Magura USA | Industry Nine | Schwalbe Tires | Caffélatex
#3
Dave
Join Date: Jan 2006
Location: Homestead FL
Posts: 685
Bikes: Nashbar X-Cross 29r wheels front disc brake
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
I don't think the spindle is going to be the wearing component. The aluminum crank arm is the part that will eventually suffer from improper installation and repeated removal.
#4
Senior Member
Join Date: May 2005
Location: Queanbeyan, Australia.
Posts: 4,135
Mentioned: 85 Post(s)
Tagged: 0 Thread(s)
Quoted: 3450 Post(s)
Liked 420 Times
in
289 Posts
Well with my old racing bike of 25 years ago I certainly DID cause the square taper interface to wear from repeated removal/assembly because I used the same frame and cranks for road and track so I was reguarly removing/refiting items.
I currently use an ISIS bottom bracket/cranks and I am happy with its performance and yes it is also a form of taper. I've removed/fitted them a few times now for various reasons and haven't noticed any wear or movement yet so they seem to be better but I haven't had them for as long as the square taper cranks.
Regards, Anthony
I currently use an ISIS bottom bracket/cranks and I am happy with its performance and yes it is also a form of taper. I've removed/fitted them a few times now for various reasons and haven't noticed any wear or movement yet so they seem to be better but I haven't had them for as long as the square taper cranks.
Regards, Anthony
#5
Senior Member
Join Date: Dec 2004
Location: Quahog, RI
Posts: 1,509
Bikes: Giant TCR Comps, Cdale R5000, Klein Q-Pro, Litespeed Siena, Piasano 105, Redline Conquest Pro, Voodoo Bizango, Fuji Aloha
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
ISIS ain't tapered.
#7
Senior Member
Join Date: Nov 2004
Posts: 550
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
The spindle is a constant outer diameter shaft with 10 evenly spaced flutes
machined or forged into each end. The flute cuts themselves are 6mm in
diameter and inclined at a 1° angle to the spindle axis. In addition to the
tapered flutes, a hard stop is positioned 16mm from the end of the spindle on
both sides of the bottom bracket.
From:
https://www.chrisking.com/pdfs/ISIS%2...%20Rev%20D.pdf
Isis has some taper to it.
machined or forged into each end. The flute cuts themselves are 6mm in
diameter and inclined at a 1° angle to the spindle axis. In addition to the
tapered flutes, a hard stop is positioned 16mm from the end of the spindle on
both sides of the bottom bracket.
From:
https://www.chrisking.com/pdfs/ISIS%2...%20Rev%20D.pdf
Isis has some taper to it.
#8
Lost in the Black Hills
Thread Starter
Join Date: May 2005
Posts: 5,725
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
thanks guys for those links...it kind of confirms what i thought. so i am guessing that because of the "positive" stops on the ISIS, even though there is a slight taper, they are probably not subjected to the same amount of wear as a square taper can be.
right?
right?
__________________
Tomac Mountain Bikes | Light-Bikes l Magura USA | Industry Nine | Schwalbe Tires | Caffélatex
Tomac Mountain Bikes | Light-Bikes l Magura USA | Industry Nine | Schwalbe Tires | Caffélatex
#9
Senior Member
Join Date: Oct 2005
Location: Fresno, CA
Posts: 4,454
Mentioned: 6 Post(s)
Tagged: 0 Thread(s)
Quoted: 128 Post(s)
Likes: 0
Liked 12 Times
in
10 Posts
Square-taper BB's function as a taper - it's the taper that stops the crank from going further onto the spindle. And they have a 2-degree taper.
ISIS Bb's have a stop, and therefore the main thing that keeps the crank from sliding further onto the spindle is the stop, not the taper, I think.
If installation is done properly, I think it's the aluminum crank that deforms (and then only slightly) when installed repeatedly on a square-taper. On a micro-level, the deformation of the aluminum is part of what keeps the crank firmly on the square taper.
But I don't think that a properly-installed square-taper crank has any real downside in the department that you seem to think. The issue comes if you're installing it and removing it a lot, but even then I don't think much long-term deformation is likely.
ISIS Bb's have a stop, and therefore the main thing that keeps the crank from sliding further onto the spindle is the stop, not the taper, I think.
If installation is done properly, I think it's the aluminum crank that deforms (and then only slightly) when installed repeatedly on a square-taper. On a micro-level, the deformation of the aluminum is part of what keeps the crank firmly on the square taper.
But I don't think that a properly-installed square-taper crank has any real downside in the department that you seem to think. The issue comes if you're installing it and removing it a lot, but even then I don't think much long-term deformation is likely.
__________________
"c" is not a unit that measures tire width
"c" is not a unit that measures tire width
#10
Senior Member
Join Date: Dec 2004
Location: Quahog, RI
Posts: 1,509
Bikes: Giant TCR Comps, Cdale R5000, Klein Q-Pro, Litespeed Siena, Piasano 105, Redline Conquest Pro, Voodoo Bizango, Fuji Aloha
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
Originally Posted by Soil_Sampler
#11
Senior Member
Join Date: May 2005
Location: Queanbeyan, Australia.
Posts: 4,135
Mentioned: 85 Post(s)
Tagged: 0 Thread(s)
Quoted: 3450 Post(s)
Liked 420 Times
in
289 Posts
A taper is a taper even if its a slow one. Even the old cotter-pins worked on the taper principle. Thinking about it the long, slow taper in the ISIS cranks is what makes them better as well as there being more contact but the problem of long slow tapers is that they keep on going so they put in a stop in the design.
Regards, Anthony
Regards, Anthony
#12
Lost in the Black Hills
Thread Starter
Join Date: May 2005
Posts: 5,725
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
cool....thanks guys
__________________
Tomac Mountain Bikes | Light-Bikes l Magura USA | Industry Nine | Schwalbe Tires | Caffélatex
Tomac Mountain Bikes | Light-Bikes l Magura USA | Industry Nine | Schwalbe Tires | Caffélatex
#13
Senior Member
Join Date: Apr 2006
Location: Kansas City, MO
Posts: 56
Bikes: 29"ers, fixies, and 29"er fixies
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
For what it's worth, I have never had a square-taper crank wear out from installation/removal. When I was in college, I used to rebuild the bb of my mountain bike about once a week b/c we rode in mud all the time (at the time, we thought it was "cool"). As long as you install it properly, you'll have a hard time wearing out a set of square-taper cranks.
I don't have any personal experience with ISIS, but I do know that most of the mountain bikers I know (including several experienced shop mechanics) refuse to use ISIS on their own bikes. It's either old-skool square-taper or the new hollow spindle stuff. The comments I remember basically sounded like it just creaked all the time. They got tired of having to pull the cranks off all the time to clean it out, so they quit using it. I also seem to remember some issues with the bb's too (wearing out/breaking).
Like I said, I don't have any personal experience with ISIS. Everything I have is either the new XT or old square-taper stuff. The square taper is really bulletproof, and it's easy to get replacements for.
I don't have any personal experience with ISIS, but I do know that most of the mountain bikers I know (including several experienced shop mechanics) refuse to use ISIS on their own bikes. It's either old-skool square-taper or the new hollow spindle stuff. The comments I remember basically sounded like it just creaked all the time. They got tired of having to pull the cranks off all the time to clean it out, so they quit using it. I also seem to remember some issues with the bb's too (wearing out/breaking).
Like I said, I don't have any personal experience with ISIS. Everything I have is either the new XT or old square-taper stuff. The square taper is really bulletproof, and it's easy to get replacements for.
#14
You need a new bike
Join Date: Aug 2002
Posts: 5,433
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
Likes: 0
Liked 4 Times
in
3 Posts
With the advent of the cartridge BB, crank arms rarely need to be removed. Wear on the taper should be negligable unless the cranks are improperly torqued.
#15
Listen to me
Join Date: Nov 2004
Location: Lexus Texas
Posts: 2,788
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
The bb spindle should never wear as it is hardened tool steel.
The Al cranks can expand or crack if overtouqued.
Since there should be no relative motion between the two there is no "wear".
Octalink and ISIS are solutions in search of a problem.
Enjoy
The Al cranks can expand or crack if overtouqued.
Since there should be no relative motion between the two there is no "wear".
Octalink and ISIS are solutions in search of a problem.
Enjoy
#16
Senior Member
Join Date: Sep 2001
Location: Montreal
Posts: 6,521
Bikes: Peugeot Hybrid, Minelli Hybrid
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Likes: 0
Liked 2 Times
in
2 Posts
If the bolt on a sq taper crank comes undone and the crank comes loose, riding the bike in that condition can destroy the crank fast. Repeated removal and reinstallation doesnt wear the interface. If the crank stretches so the mounting bolt cant tighten it onto the taper, before the bolt bottoms on the end of the spindle, the crank has to be replaced.
#17
Senior Member
Join Date: Oct 2005
Location: Fresno, CA
Posts: 4,454
Mentioned: 6 Post(s)
Tagged: 0 Thread(s)
Quoted: 128 Post(s)
Likes: 0
Liked 12 Times
in
10 Posts
Originally Posted by AndrewP
If the bolt on a sq taper crank comes undone and the crank comes loose, riding the bike in that condition can destroy the crank fast. Repeated removal and reinstallation doesnt wear the interface. If the crank stretches so the mounting bolt cant tighten it onto the taper, before the bolt bottoms on the end of the spindle, the crank has to be replaced.
#18
Listen to me
Join Date: Nov 2004
Location: Lexus Texas
Posts: 2,788
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
Originally Posted by AndrewP
If the bolt on a sq taper crank comes undone and the crank comes loose, riding the bike in that condition can destroy the crank fast. Repeated removal and reinstallation doesnt wear the interface. If the crank stretches so the mounting bolt cant tighten it onto the taper, before the bolt bottoms on the end of the spindle, the crank has to be replaced.
It’s a ghetto fix but it works great.
My winter FG has been going strong for two seasons.
Enjoy
#19
Senior Member
Join Date: Mar 2003
Location: Beaufort, South Carolina, USA and surrounding islands.
Posts: 8,521
Bikes: Cannondale R500, Motobecane Messenger
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 11 Post(s)
Likes: 0
Liked 1 Time
in
1 Post
You'll wear out the multiple crank arms before wearing the BB spindle out. Most of them are hardened cro-moly steel.