spider Posted October 23, 2006 Report Share Posted October 23, 2006 Been wondering.. i know isis are shit (my friend's SKF looks nice) but isn't square bb's are worse? Quote Link to comment Share on other sites More sharing options...
Fishy Posted October 23, 2006 Report Share Posted October 23, 2006 Cheaper to run, and bearings don't die as much. Quote Link to comment Share on other sites More sharing options...
Ash-Kennard Posted October 23, 2006 Report Share Posted October 23, 2006 bigger bearings, smoother, strongerim an isis boy now though Quote Link to comment Share on other sites More sharing options...
TomR Posted October 23, 2006 Report Share Posted October 23, 2006 I ride ISIS. I always had square taper cranks that rounded off (cheap ones) so when i bought my 'burns i didnt dare get square tapered ones. Now i buy ISIS stuff outta habit. Quote Link to comment Share on other sites More sharing options...
Nick Garland Posted October 23, 2006 Report Share Posted October 23, 2006 They dont do decent ISIS bb's at 127.5. By decent I meant, the bearing dont shatter after 3 months (aka 2 of my FSA Platiums) nor should the cups break, which happened on all 3 of mine. So far 1 sq taper, lasting a long time. Quote Link to comment Share on other sites More sharing options...
RobinJI Posted October 23, 2006 Report Share Posted October 23, 2006 Pros: Longer bearing life, Much cheeper, probably lighter, easily strong enough for lightish people like me.Cons: Weeker axles, Need regular Tightening, round off if you dont tighten them, or if there cheep cranks. Quote Link to comment Share on other sites More sharing options...
THE trials commentator Posted October 23, 2006 Report Share Posted October 23, 2006 im too lazy to buy isis.plus the fact ive had the same square taper bb for 5 years and its still fine.if it aint broke,dont fix it.to be honest,ive ridden bikes with isis,and it doesnt feel any different to me.just gotta keep the cranks tight with square taper,thats all.Carl Quote Link to comment Share on other sites More sharing options...
GTF Posted October 24, 2006 Report Share Posted October 24, 2006 I´ve never used Square, but my mate had some square´s one time. They wasent near as good as my ISIS Quote Link to comment Share on other sites More sharing options...
MadChikken Posted October 24, 2006 Report Share Posted October 24, 2006 (edited) I´ve never used Square, but my mate had some square´s one time. They wasent near as good as my ISISThe only difference as long as you keep the bolts tight on a square taper is that it has much stronger and longer lasting bearings than on an ISIS bb. How can that not make it nearly as good? As for axle strength, ISIS bb axles are hollow down the centre as far as Im aware (though I always run square taper so...), so how can they be stronger than a solid single axle as used in a square taper bb.....? I thought common sense would put that the other way round personally!If any companies made them suitable for trials, we'd all be using Hollowtech II / Type-X BB/crank assemblies anyway, as they are a damn sight stiffer than both ISIS and square taper, and the external bearing races make them much easier to fit and replace!Shimano Saint or RF Diabolus would be sweet for trials if they made them the right width to be used, which Im not aware they do (feel free to correct me please). Shame really, they're both stupidly strong!M@ Edited October 24, 2006 by MadChikken Quote Link to comment Share on other sites More sharing options...
nmt_oli Posted October 24, 2006 Report Share Posted October 24, 2006 The ISIS interface is inherently stiffer, and allows for the use of a larger diameter axle to increase strength. Unfortunately however, the larger axle means there is less room for bearings, so in most situations the load capacity of the BBs are reduced, or they don't last as long, or both. Various methods have been devised to prevent this, such as the external bearing BBs, although the mentioned SKFs seem the best on the market at the moment.You are right about the actual taper causing problems over time. Square taper cranks work on a fully tapered interface, you can just keep going if the crank becomes slightly loose, wheres the ISIS taper has a much shallower angle, and actually has a stop, so unlike square tapers which you can keep forcing when the taper wears a little, the isis cranks push on and stop at a set point. If any play develops, which it can after a lot of use (accelerated by multiple removal of cranks) then there is no way of getting rid of it, the taper is permanently damaged. I've seen this happen to a few cranks, including middleburns. you undo the crank bolt and you can just slide the crank off, no need for an extractor.Square has been around almost forever, and i think it will have its place for a long time to come yet, its simple, cheap, universally known and easy to maintain.ISIS is a great solution for the more extreme ends of biking nowadays, which inherently have shorter lifespans on high stress parts such as cranks any way, so you may be able to justify the reduced longevity for the extra strength.ISIS are more expensive as the Tapers profile is harder to manufacture, it is a more complicated shape and has to be made to a higher tolerance than square taper cranks.As for axle strength, ISIS bb axles are hollow down the centre as far as Im aware (though I always run square taper so...), so how can they be stronger than a solid single axle as used in a square taper bb.....? I thought common sense would put that the other way round personally!M@the thicker axle gives the strength, yes they are hollow to save weight. this tube structure is equally strong, if not stronger than the thin solid axle of a square taper- put a torque through a pringles tube and feel how stiff it is, now do the same with a smarties tube, as its thinner, its will twist more easily and colapse.some manufactureres are however making the walls of the axles too thin. Also lx and xt squre taper BBs have hollow axles, so a deore or lower un52/53 is better specced for trials. Quote Link to comment Share on other sites More sharing options...
Brian Bleech Posted October 24, 2006 Report Share Posted October 24, 2006 I have never used square since I saw one snap and go and a cm deep in a friends leg! Trials need to use spanish/mid size bb's - i am sure i have said that before Quote Link to comment Share on other sites More sharing options...
Jamie_Neal Posted October 25, 2006 Report Share Posted October 25, 2006 the thicker axle gives the strength, yes they are hollow to save weight. this tube structure is equally strong, if not stronger than the thin solid axle of a square taper- put a torque through a pringles tube and feel how stiff it is, now do the same with a smarties tube, as its thinner, its will twist more easily and colapse.Good way of getting the point across only you'd need a solid smarties tube to see the comparison between ISIS/square.Personally I've used square for years but I am getting more tempted by ISIS mainly as I do see them as being stronger. But then again one snapped axle in over 10 years of riding isn't bad.I think at the moment the best option is an Echo external bearing bb as it seems like the best/longest lasting option over other ISIS bbs.Although if Middleburn started making Type x/Hollowtech II cranks I think they'd be onto a winner. Or if frame designers switched to Spanish size bbs. Quote Link to comment Share on other sites More sharing options...
nmt_oli Posted October 25, 2006 Report Share Posted October 25, 2006 Yeah, i know. im just trying to ge the point across that an axle need not be solid to retain strength! the central part really does very little, especially the larger you go. As a square taper axle is so thin, it beifits form being solid. An ISIS axle is twice the diameter, would just be silly if it was solid. Quote Link to comment Share on other sites More sharing options...
nafan Posted October 25, 2006 Report Share Posted October 25, 2006 Just better and stronger I think...Cheaper and easier too - cheaper for sq. taper cranks tooDown side is, all the new cranks (echo, zoo etc) are isis Nathan Quote Link to comment Share on other sites More sharing options...
Jez Posted October 25, 2006 Report Share Posted October 25, 2006 Square.Cheap and easy, if treated right will last forever.Can mash up your cranks if misused or if said cranks are shit. Even then, they're bodgeable, but you can forget bodging an isis. Quote Link to comment Share on other sites More sharing options...
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