Build questions--drivetrain issues?

[kondilemma]

Hey there,







I have some questions about fitting newer Octalink style Shimano cranks/ bottom bracket to my 857 frame, size small.  The info I have states the original BB spec was a Shimano LX 68x110, but the closest I can find in the Sh'mano line is a 68x113. Will this work?   Am considering using the XT line for shifters/deraillers.  Will be going Avid for V-brakes







And what about 9speed vs. 8speed?  Is there an issue with the closer tolerances of a 9speed drivetrain in a full susp setup?  Greater chance for ghostshifting, fitting problems, etc? [smiley=worry.gif]







Specifically, I'm looking at the M760 crankset and rear cassette, with a ES-71 BB.   Probably the matching from and rear changers from the 760 series.   Comments?  







Thanks,



--brrrrrrrrrrrrt [smiley=beer.gif]

[kneedowndean]

It would help if I gave you an explanation of what these figures mean with regards to your bb. The first bit "68" is the width of the actual bottom bracket shell. This is important as no other one will fit. The next bit 113, this is the width of the axle in mm(ie 113mm wide). The width of the axle you need will depend on the crankset you use. For instance, on my beast I had a 68x115 or something, but I changed my cranks to middleburn and this meant that the cranks where far from the frame due to their design. So I changed to a 68x107, which bought the crank arms closer to the frame and meant it shifted correctly.

As for the 8 or 9 sp debate, I personally use 8 speed. I think that 9 speed is much less tolerant of mud and badly lubed gears. I could see no real advantage of using 9 speed on my bike

Why not try other makes of gears and cranksets? Its cheaper and other stuff like middleburn and fsa look alot nicer in my opinion. SRAM do nice gears, although personally I use XTR mechs and SRAM gripshift shifters. Check out my gallery for my setup. Hope this helps! Steve

[kondilemma]

 Thanks, KDDean,



There is only one motivation for considering the XT drivetrain--the budget.  I may be able to purchase them thru a Shimano sales rep at a deep discount, but I need to know exactly what I need, down to model #s and the like.  I need to be clear, after all, the rep is from the FISHING division... [smiley=laughing.gif]







As for other products, I'd be willling to try anything, as long as I didn't have to sell a kidney to finance the purchase!  After all, the 'chilluns' need shoes on their feet and food in their bellies.







I agree with the 9/8 speed debate.  Simplicity seems to be the logical choice, and since I currently run a 7speed on my hardtail. the 8 would seem to be the logical step up.  







my project frame is in the gallery also--just stuck them in today.  nothing fancy, but a start.  I plan to be riding it this summer.







--brrrrrrrrt

[shovelon]

All my bikes require a 113 spindle length. One is a 957 large that takes 68x113. Another is a 4000 that takes a 73x113. The third is OzM that also takes a 73x113. Beyond 1998 K2 changed the BB length to 73mm on their existing strut bikes in an effort to streamline assembly.

I reckon that 68x113 is correct for your x57 series small. I assume you are putting a 170 length BB on the small frame? No difference in 8 speed or 9 speed.

One nice thing about  the Octallink bb, is that FSA made carbon pro cranks to fit shimano splined BBs. It would be a direct fit and nice upgrade later. There are several 170mm length on ebay right now to look at. The FSAs are about  75 lighter than shimano hollowtechs.

Personally I am moved away from shimano in an atempt to loose grams. My Hollowtechs have a date with a dremel for shaveing.

Have fun, Terry

[kondilemma]

I assume you are putting a 170 length BB on the small frame? No difference in 8 speed or 9 speed.

Yeah, I'll be using the 170 mm cranks.  Those FSA carbon cranks are beautiful,and the perfect compliment to the 857's swingarm, but will probably have to wait on a $$ winfall before that happened.  I'm not so concerned about wieght at this moment--just would like to get this thing in a rideable condition without breaking the bank.



Thanks for the advice--keep it coming

[shovelon]

Yeah, I'll be using the 170 mm cranks.  Those FSA carbon cranks are beautiful,and the perfect compliment to the 857's swingarm, but will probably have to wait on a $$ winfall before that happened.  I'm not so concerned about wieght at this moment--just would like to get this thing in a rideable condition without breaking the bank.

My Hollowtechs have been pretty good. the only problems I have had is creaking at the chainring bolts. finally blue loctited them on all surfaces. Have not creaked in a year.

[Simon]

Simple go with the 9 speed Octalink,
I'm a big fan of 8 speed and have been running it
for years BUT, this is now becoming a problem,getting
replacement parts for 8 speed is getting more difficult
and as not all 9 speed and 8 speed parts are compatible it makes things even harder,
I'm running 9 speed now and its not given me any issues and I appriciate the extra spread of gears,
can't speak for its longevity as of yet though.

Simon.

[kondilemma]

Hmmm... perhaps I should do my homework before placing a post.  It occurred to me that the  XT

Hollowtech model # I quoted might not need a separate bb.  Checked out the Shimano site and it would seem that the FC-M760 model has an integrated BB, which is adaptable to either a 68 or 73 mm BB shell.  Just move the included spacers around and viola!--off to the races.  I still think old-school where ever crankset needs a separate BB--a square tapered BB that is.



Looks like I may have to enlist the services of my LBS for installation. And my old Park Tools crank puller won't be much use, anymore...



As for 9 speed--looks like Shimano has forced me into getting a 9-ganger if I want the latest series, at least according to their Compatability chart for drivetrains.  How nice of them :-/

[shovelon]

Hey, you are right. FC-M760 is integrated. That is a great crankset. Sounds like a no-brainer

Terry