Hollowtech BB confusion
The confusion is from a couple of years ago when the last version of LX before it went Hollowtech II had an axle with longer splines, I believe it was ES51. I use the previous version of the LX cranks and also Hollowtech Deore, have used ES30, ES50 and ES71, all interchangeable. Now I need a new BB and see that ES51 seems to be sold as if it was the same as ES50. What gives? Thanks in advance.
Dont know specifics, but i would guess that it was a small change in materals/and or seals. Usually the differece from shimano like that is very minor. Like on a wheelset, one version will use a steel locknut, versus an alum. Small change, so they need to call it something different. R-550 vs. R-560 wheels - very similar, but not quite the same
Dont know if that helps or not.
Regardless of cranks, Shimano BB's went from Square Taper to Octalink (then to external).
There were 2 types of Octalink, one with a short spline (XTR & Dura-ace), and one with a longer spline (when they dicovered that people could destroy the spline in the crank arm by tightening the bolt when the splines were not properly meshed).
I believe all LX Octalink cranks used the long spline.
I think the only difference between the "0" and "1" (ie ES-50 and ES-51) is an anti-corrosion treatment on the inside of the axle, later cranks used a hollow bolt, so the inside of the hollow BB axle became exposed to the elements.
There are two specific crankset that requires the longer 118mm spindle.. that's the LX Hollowtech FC-M572 and the OEM Deore Hollowtech FC-M445. The reason being Shimano made the driveside a little deeper, thus forcing you to use the crappier ES-50/51 BBs. The ES-70/71 BBs don't seem to be available in 118mm but only at the standard 113mm. In theory you can use the 572 and 445 on the longer spindle but it just won't be safe (you won't be able to torque down the crank bolts, but they'll fit flush no problem tho).
Not dead yet, just playin
Cripes! 3 replies and not a single one has the correct info:
Originally Posted by sweathog
Heres a real easy way to deal with it:
LX-M571, XT-M751, and XT-M752 use ES70/ES71. 113mm and 118mm widths available for 47.5 or 50mm chainlines.
LX-M572 and Deore M445 use ES50/ES51. 121mm and 126mm widths available for 47.5 and 50mm chainlines.
I've seen the ES30 in 113, 118 and 121mm lengths. I assume theres a 126mm one as well, though I've never seen it. ES30s are mostly sold overseas and OEM.
If you try to mount M572 cranks on a ES71 bottom bracket you'll bottom out the granny ring's tabs on the drive-side BB cup. If you use a granny without tabs, your chainline will most likely be less than 47.5 (good or bad? thats a different discussion).
If you mount M571, M751, or M752 cranks on a ES51, you'll end up with a 52.5 or 55mm chainline, which will put your driveside crank way too far out from the frame to work.
If you get the correct length, you can mount any of the cranks to the correct ES30.
And to answer your question, there is no difference between ES70 and 71, nor any difference between 50 and 51.
right on possum, I've used the newer M572 crank with the ES71 118 and a tabless inner ring, good chainline but can be issues with clearance on full suspension pivots and or chainstays.
The 126 ES51 puts the chainline way out there, but it is good for getting a bit more tire clearance for bigger tires, our maybe paired up with 150mm rear axle.
Still waiting for a 121 ES51 so I can see if the inner ring tabs are an issue with that.
Originally Posted by ohpossum
Thanks guys. Based on your comments, my experience, and a search of the old discussion threads from when the LX change was made, my conclusion is that the only BB that is not the same as the others is the ES 51, because of the longer axles. My cranks are LX M571 and Deore M510, and I have used them both with 113mm ES 30, 50, 70 and 71. I have in front of me a 68x113 ES 50 and a 68x113 ES 70 - they appear exactly the same. The only visible difference among all of the models is that 70 and 71 have an aluminumretainer, the others plastic; I have had no problem with the plastic, but keep re-using the aluminum one for appearance. I haven´t found any difference between the bearings themselves; the only one which went bad on me was a 70. As for the 51, the old threads say that it was for the LX Hollowtech V2 cranks, which required the longer axle - the other Hollowtech crank models are V1. I asked my original question because almost none of the online stores seem to recognize the difference, I will guess because the V2 cranks only lasted a year or two before LX went to Hollowtech II. I ended up ordering three 73x113 ES 50s (one for a friend, a spare for me) from Nashbar for $10 each, less 20% with a coupon - hard to beat. Thanks all.