BB groupset confusion

[rick1127]

Ok guys im needing your help here.
Im rebuilding my 2006 santa cruz bullit its not being built to period its being built to use (im not a flat out racer) but that doesnt mean i want to lower the quality of components used.
My bb is past its sell buy date and the chain rings are very well used as is the 9 speed cassette .
id rather do this right and not have to do work on the bike in 6 months time because something has worn out already.
BB is shimano bb-es51 68 bc1.37x24 and 113 width and the crankset is shimano xtr
so here is the problem the bottom bracket is available but the quality is not as good as it could be and according to a few bike shops is now very low quality.
so talking to a very helpful guy at a local shop today he recommended going for a single ring crank setup with a 10 speed cassette .
If i can get NOS or as good as new or a single ring setup or what do you recommend.
To be Honest im now lost with all this
Any help is appreciated

 

[CassidyAce]

Unless you really fancy going 1x, buy a new BB-ES51 and make your own mind up about whether the quality has declined.

 

[stevet1]

What are you using it for? 1x with a narrow wide chainring and a 11-42T rear cassette is pretty good these days but will mean a bigger outlay than just a new BB. I'd probably get a new BB and 1x it by buying a N/W chainring to fit your cranks. Look at Works components, they do loads of different bolt configurations.

 

[rick1127]

mainly xc use
BB is there another model in the shimano range that will be a direct fit but better quality??

 

[greencat]

I would go with the BB available. IME even Shimano can't screw up cartridge BBs anymore. They are generally pretty reliable.

 

[rick1127]

this is looking like a new BB and get a new set of gears to replace the worn out ones.
as opposed to new crankset etc

 

[fettler]

Replacing 3 chain rings to fit your crank arms, rear sprockets and a chain will cost far more than a BB. You don't mention which model/year of cranks you have currently? Plenty of Bullits would have been single chain ring when new, albeit with a chain device to hold it on. Even low end Shimano stuff will last for a good few thousand miles with a bit of care/lube/wd40 when wet and a chain every 1000 miles or so at a push. Single ring set up can be done cheaply but depends on whether you want to keep it original or move into the modern age? With a single ring set up you will probably lose a bit of the extreme high/low gears but less things to worry about. Modern Alivio gears probably shift better than early XTR. Early XTR chain rings & cassettes will outlast modern Alivio/Deore.
Modern stuff is focused more on function rather any increases in longevity.

 

[benjabbi]

Hopefully not to confuse you even further but an ES-51 BB is not the correct one for an Octalink XTR crank. The ES-51 uses the V2 spline pattern (ES stands for extended spline) which was used on XT downwards. XTR used the V1 (short spine) pattern which was used on that and the road groupsets, the only easily available, relatively sensibly priced, new, V1 BB is the BB-5500 105 level which is decent but has slightly different axle lengths to the M950/952 brackets that aren't cheap in good/NOS condition.

 

[ishaw]

You beat me to it. If you have an xtr chainset with an octalink BB, it should be a v1 splined version, the es51 is V2. They aren't compatible, as the V2 spline is longer so the arms won't seat properly and may cause damage to the crank arm spline interface.

As your frame is 68mm BB shell (well assuming so, but as the wrong BB has been used, could be wrong), you can use the v1 splined road versions, 105, ultegra or Dura ace, though these come in 109.5bor 118 lengths where the xtr ones were 112.5 and 116.

Are you sure about the BB and crank, as 2006 is quite late for a bike running m95x which I'm assuming due to the BB you mention.

I think 2006 would be m960 xtr or possibly m970 (could be wrong on the latter as I think that's 2007 but memory of release dates isn't awesome), both run ht2 external bbs.

 

[Imlach]

Hopefully not to confuse you even further but an ES-51 BB is not the correct one for an Octalink XTR crank. The ES-51 uses the V2 spline pattern (ES stands for extended spline) which was used on XT downwards. XTR used the V1 (short spine) pattern which was used on that and the road groupsets, the only easily available, relatively sensibly priced V1 BB is the BB-5500 105 level which is decent but has slightly different axle lengths to the M950/952 brackets that aren't cheap in good/NOS condition.

If I had one that required V1 (bb's run for about 50 quid here) I'd just upgrade the whole lot to Deore 11 speed which cost me the equivalent of less than 100. Drowning money into an obsolete standard isn't worth it.