shimano hollowtech II

[02GF74]

won myself off ebay a shimano xtr hm960 hollowtech chainset - the type that uses external bearings and has a hollow tube fited to the RH crank but need to get bearing for it,.

I am only seeing hollowtech II bearings .... - so will these be compatible?

i.e. the chainset is described as hollowtech but is that same as hollowtech II?

thanks.



... and would XTR chainset work with XT bottom bracket cups?

 

[PpPete]

IIRC the original Hollowtech was what is now generally called Octalink (ie splined BB - not external bearings at all)

 

[potsy]

As an additional question-are all H2 BB's the same size? ie-will a Sora crankset work with a Tiagra bottom bracket(HII)?

Currently have an Octalink which comes in all sorts of lengths as I found out when I ordered the wrong one

 

[2Loose]

Potsy, H2 doesn't have a bottom bracket at all!

Bearing cups on each end of the shell, with the chainset axle going all the way through the shell for the left hand crank to attach to.
Very clever really. So any H2 chainset effectively includes the BB.

 

[chriswoody]

If you buy second hand chainsets, then they won't come with a bb. If as you say the rh side is welded to a hollow axle,, then yes you need hollowtech II external bb. Any mountain bike specific will do. Check out the park tools website for specific instructions on fittings as they have a series of washers which fit in a multitude of ways. You will also need a specific tool to fit them, ah the joys of upgrading!

 

[RecordAceFromNew]

As PpPete and ChrisWoody said, regarding your last question it should work with other bb bits and pieces in this diagram from a Hollowtech 2 XT chainset. Official fitting instruction is here.

 

[zacklaws]

Another thing to watch out for is, Hollowttech 2 BB comes in 2 different threads, British and Italian. I know because I need to replace mine, and have not worked out what mine is. Despite gettting the part number off the BB, and searching online, I get pointed to both of the threads and nothing to indicate the difference. One website even has the same picture on both the different threads along with the same part number in view to make it confusing.

End of day it is no major problem as my LBS where I bought it from would know when I go to buy one.

 

[fossyant]

Another thing to watch out for is, Hollowttech 2 BB comes in 2 different threads, British and Italian.

Shsssh....all BB's come in two thread types................

 

[RecordAceFromNew]

Another thing to watch out for is, Hollowttech 2 BB comes in 2 different threads, British and Italian. I know because I need to replace mine, and have not worked out what mine is.

I don't know if you have taken them off in the past, if you have and if both cups are right hand threaded then it isn't English/ISO. It can be French, but only if it is ancient, otherwise it is Italian. That's why one has to take extra care in securing an Italian left cup - it can work itself loose through use otherwise.

Another clue - an Italian bb shell is usually 70mm wide (rather than the common 68mm or 73mm).

 

[potsy]

Potsy, H2 doesn't have a bottom bracket at all!

Bearing cups on each end of the shell, with the chainset axle going all the way through the shell for the left hand crank to attach to.
Very clever really. So any H2 chainset effectively includes the BB.

Ahh very clever,wondered how it worked,cheers.
So if I see a crankset for sale I just buy the 'cups' to go with it?

 

[02GF74]

Ahh very clever,wondered how it worked,cheers.
So if I see a crankset for sale I just buy the 'cups' to go with it?

yes - is why I ask the question.

anyways thanks to those that have replied - it confirms what I thought.

I am familiar with octalink (aka hollow tech I) - hollwotech is the tube type axle with the RH crank permanently fixed.

I also have seen instructions on how to take the cups apart and inside they use a standard size bearing so it would be weird for Shimano to re-invent a bearing when you can get an off-the-shelf part.... hence it was my guessing that the cups will fit bottom bracket. note that replacement bearings are maybe a fiver but replacement cups cost £ 40 so quitea bit of profit into Mr Shimanos pocket, plus it should be possible to get the new fangle ceramic bearings for these cups.

The RH use LH thread and I thik I have the notched spanner to fit the cups.

One thing to watch out for is that the bottom bracket on the bicycle needs to have parallel sides otherwise the cups and bearing will not sit square and this leads to bearing failure - LBS should be able to reface them ... but when I buy my cups, I will fit them and see how it goes.

 

[zacklaws]

Shsssh....all BB's come in two thread types................

I know, I was tired from a long crap stressful day at work, and what I wanted to do was put the message over that if you buy online be sure you get the right type as from my experience some websites confuse the issue. Just done a search again today for my BB and most websites have made it a lot clearer thankfully.

For instance look at the Chain Reaction Cycles website at the SM FC5600 BC 1.37 x 24, unless you know what thread you need, you are stumped as the picture itself (which is Italian) does not indicate which thread it is, but if in the details they published BC 1.37 x 24, then you know exactly it is the British one you need.

http://www.chainreactioncycles.com/Models.aspx?ModelID=11726

Think I'm still tired if I'm rattling on, but I want to get a ride in as soon as the frost goes and before the snow comes later today.

 

[chriswoody]

Ok now I'm a little confused by some of these replies so please forgive me if I've got the wrong end of the stick.

A little while ago shimano came up with a way of making crank arms hollow, this were hollowtech I and were fitted to standard square taper bottom bracket. Octalink had passed away years before. (my partners bike uses these cranks)

then the cunnng folks thought if we moved the bearings outside the small bb shell on the frame then we can make the bearings much larger, then as a direct result we can make a hollow axle because the bearings are now closer to were they need to be and much larger. So know the chainset has the axle permantly attached. When you purchase a new chainset they come in a box often, but not always, with a bottom bracket. The new bottom brackets all look like the one linked to in the previous post, and as with most things bike related come in various flavours from £10 replacements to several hundred pound uber materials. The bottom brackets are similiar to the old square taper in one regard, they are designed as sealed disposable units, so when it's worn you whip the cranks of and throw away the whole BB unit and buy a new one.

 

[e-rider]

I didn't read all the replies but to answer the question:

the BB cups (bearings) and not all interchangable/compatible. I'm fairly certain the XTR cranks require XTR bearings - ie. XT ones wont fit.

 

[chriswoody]

the BB cups (bearings) and not all interchangable/compatible. I'm fairly certain the XTR cranks require XTR bearings - ie. XT ones wont fit.

No they are all interchangeble, so all MTB specific BB cups will fit. So you could use Deore bottom bracket cups on an XT chainset. The BB units are sealed, just like the old Square taper ones and screw into the bottom bracket shell, so as a previous post said, you just need to know if you have italian or british threads and the width of your shell. Then you screw in the new cups, one either side, before poping the chainset on. The difference between deore and XT is just in the materials and quality of construction as with everything else in the groupsets.