Slowbee Posted June 18, 2010 Share Whats wrong with the square taper ones? I have one' date=' its done over 2000km and there are no problems, the BB's are R75 on CRC![/quote']Nothing and thats why I'm sticking to it. Done more than 3000km on mine and no problems.I understand its not easy to replace but considering the lifespan of it, who cares if it takes you an extra hour. WHAT?? Thats awesome. I hope with that mileage you are doing the longer race for Stellenbosch ? Are you going to enter the long route for Lourensford as well? When you going to do the 4 passes ride ? Link to comment Share on other sites More sharing options...
Bos Posted June 18, 2010 Share bit of a hi jack here..quick question: Are all shimano external BB's the same? I meen would the one on my XT crankset fit a Shimano 105 road crankset? Obviously theBB witdth's are different but thats just adding spacers etc ? thanks Link to comment Share on other sites More sharing options...
Zeps Posted June 18, 2010 Share Bos - a while ago we used an XT BB on a road bike (Ultegra but doesn't matter) by just using some extra spacers so ja it's fine Link to comment Share on other sites More sharing options...
Bos Posted June 18, 2010 Share Bos - a while ago we used an XT BB on a road bike (Ultegra but doesn't matter) by just using some extra spacers so ja it's fine Awsome! THANKS. Link to comment Share on other sites More sharing options...
SURFER Posted June 18, 2010 Share Hollowtech is not perfect and you'll find yourself facing a ruined left BB adapter more often than you'd like to but' date=' there's some new products on the market that makes a bearing swap cheap. [/quote'] Johan, why does the left BB goes first? Link to comment Share on other sites More sharing options...
Johan Bornman Posted June 18, 2010 Share Hollowtech is not perfect and you'll find yourself facing a ruined left BB adapter more often than you'd like to but' date=' there's some new products on the market that makes a bearing swap cheap. [/quote'] Johan, why does the left BB goes first? I wish I knew the answer to that one. Some say it is because the left side is more exposed to the elements but I'm not so sure. The right side is a bit protected by the chainring but that type of protection doesn't keep water out. Most BBs fail prematurely because the BB shell doesn't have a drainage hole. The BB then rots from the inside out, so to speak. But why the left one goes first is a mystery to me and I have not yet seen a plausible explanation. We do know that torque is only transmitted along the BB spindle from the left crank, not the right but if that has an effect, I dunno. Link to comment Share on other sites More sharing options...
Johan Bornman Posted June 18, 2010 Share Nothing wrong with square taper but eish what a mission to remove! I have just replaced square taper on my 2001 Cannondale hard tail' date=' which has not given any problems btw but fitted new Hope external BB and Hollowtech crankset hand-me-down from my Scalpel, so it became obvious how cranks and BB technology has evolved over the last decade. External BB and self-extracting screws are so much easier to work with. Even consider upgrading to used crankset with new rings and BB?[/quote'] It's not a mission if you have the right tool. It's a cheap little tool too and, used to remove both Octalink, ISIS and Square Taper BBs. These things are impossible to remove safely without the tool but with it, 30 seconds max. Square taper fell out of favour when the weight weenies started to weigh things. That's what started the Octalink madness. Link to comment Share on other sites More sharing options...
Thug Posted June 18, 2010 Share Whats wrong with the square taper ones? I have one' date=' its done over 2000km and there are no problems, the BB's are R75 on CRC![/quote'] The best BB on the market is a Phil Wood square taper and he has now started manufacturing external hollowtech type BB's. Link to comment Share on other sites More sharing options...
kosmonooit Posted June 18, 2010 Share Yes JB: if you have the right tool indeed. I went to LBS to buy such a Crank Extractor tool to do the job, was supplied one and told one size fits all, go home, the outer thread is right but the inner plunger doesnt clear the square hole to push against crank shaft to ease off crank, and since this whole project was seriasly behind schedule, I had to improvise with a spacer, that's what took the time. The square taper is a force fit, and later Shimano hollowtechs and Truvitiv self-extracting bolts are far more elegant solutions imhokosmonooit2010-06-18 07:44:58 Link to comment Share on other sites More sharing options...
River Rat Posted June 18, 2010 Share Trying to pull all of this together I have three options:1. Replace my sealed BB with another Shimano or similar and replace with Hollowtech compatiable crankset when the chainrings go. 2. Replace my crankset with a new Shimano XT including chainrings.3. Replace my crankset only and use my old chainrings. Any thoughts on which option? Link to comment Share on other sites More sharing options...
Johan Bornman Posted June 18, 2010 Share Yes JB: if you have the right tool indeed. I went to LBS to buy such a Crank Extractor tool to do the job' date=' was supplied one and told one size fits all, go home, the outer thread is right but the inner plunger doesnt clear the square hole to push against crank shaft to ease off crank, and since this whoel project was seriasly behind schedule, I had to improvise with a spacer, thats what took the time. The square taper is a force fit, and later Shimano hollowtechs and Truvitiv self-extracting bolts are far more elegant solutions imho[/quote'] Happiness is: The right tool. They sold you one that only fits Octalink and ISIS. Are you sure the tip (plunger) is not removable. Nowadays the tip is either a magnetised cap or screws off to make the tool suitable for ST and ISIS/Octalink. As a matter of interest, ST, ISIS and Octalink are all press fit. Admittedly the ST is a very toit fit. I agree on the elegance of self-extracting and anything that uses standard tools such as allen keys are pure zen. We'll overlook the requirement for a pin-spanner to remove the self-extracting bolt though. Link to comment Share on other sites More sharing options...
greatwhite Posted June 18, 2010 Share Hollowtech is not perfect and you'll find yourself facing a ruined left BB adapter more often than you'd like to but' date=' there's some new products on the market that makes a bearing swap cheap. [/quote'] Johan, why does the left BB goes first? I wish I knew the answer to that one. Some say it is because the left side is more exposed to the elements but I'm not so sure. The right side is a bit protected by the chainring but that type of protection doesn't keep water out. Most BBs fail prematurely because the BB shell doesn't have a drainage hole. The BB then rots from the inside out, so to speak. But why the left one goes first is a mystery to me and I have not yet seen a plausible explanation. We do know that torque is only transmitted along the BB spindle from the left crank, not the right but if that has an effect, I dunno. I'll give you an answer and your going to laugh when you hear it: Most folks lie their bike to the left, so all the contaminent goes to the left. Why do we all lie the bike down that way? because the drivetrain is on the right and ironically we don't want to get that full of contaminent Don't believe me, go to a race - all the bikes lying on the ground with chain etc facing the sun (or rain) Link to comment Share on other sites More sharing options...
Bos Posted June 18, 2010 Share Hollowtech is not perfect and you'll find yourself facing a ruined left BB adapter more often than you'd like to but' date=' there's some new products on the market that makes a bearing swap cheap. [/quote'] Johan, why does the left BB goes first? I wish I knew the answer to that one. Some say it is because the left side is more exposed to the elements but I'm not so sure. The right side is a bit protected by the chainring but that type of protection doesn't keep water out. Most BBs fail prematurely because the BB shell doesn't have a drainage hole. The BB then rots from the inside out, so to speak. But why the left one goes first is a mystery to me and I have not yet seen a plausible explanation. We do know that torque is only transmitted along the BB spindle from the left crank, not the right but if that has an effect, I dunno. I'll give you an answer and your going to laugh when you hear it: Most folks lie their bike to the left, so all the contaminent goes to the left. Why do we all lie the bike down that way? because the drivetrain is on the right and ironically we don't want to get that full of contaminent Don't believe me, go to a race - all the bikes lying on the ground with chain etc facing the sun (or rain) But the BB dont touch? and dirt wont get in like that? the crank will first touch, then the opper part of the crank that sits in front of the BB and in the end, Its upside down, so sand has to be forced up against gravity... Greatwhite Im not convinced Link to comment Share on other sites More sharing options...
Johan Bornman Posted June 18, 2010 Share I'm also scratching my head here. Link to comment Share on other sites More sharing options...
River Rat Posted June 18, 2010 Share Erm, me too. The thread on the wear has been an interesting but any thoughts on my options? Link to comment Share on other sites More sharing options...
Johan Bornman Posted June 18, 2010 Share Trying to pull all of this together I have three options:1. Replace my sealed BB with another Shimano or similar and replace with Hollowtech compatiable crankset when the chainrings go. 2. Replace my crankset with a new Shimano XT including chainrings.3. Replace my crankset only and use my old chainrings. Any thoughts on which option? Option one. But with one edit. Replace with Shimano, since there are no compatibles for Octalink. Shimano didn't license it AFIK. Sometimes you have to stick with something less than optimal. My dog is ugly but I'll just have to hang in there for a while. Link to comment Share on other sites More sharing options...
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