Are these two the same?

blablablacksheep

Sinse i got to replace my chainrings i was looking around and came across this in CRC

http://www.chainreactioncycles.com/Mode ... elID=30986

Then this is what my bike spec says i have

hainset:
Shimano FC-MM442-8. Replaceable rings with alloy outer and Octalink spline.
Chainrings:
44/32/22 teeth.
Bottom Bracket:
Shimano BB-ES25 Octalink spline. Cartridge bearing. 68x118mm for 50mm chainline.

I was going to buy 32+44T from merlin cycles
http://www.merlincycles.co.uk/Bike+Shop ... gs_285.htm

But after seeing that from CRC it doesnt make sense considering the costs. :?:

RevellRider

For the price of the chainset, buy it use the rings and then sell the arms on ebay or here.

blablablacksheep

cheers for reply

tbh cant see the point in buying new chainrings from merlin given the cost, and mainly given the fact the CRC crankset costs less than new chainrings :shock:

I also looking into ebay for maybe a upgrade to LX or depending on cost SLX crankset+BB

I believe that is possible as my BB size is 73mm so a upgrade from octlink to LX hollowtech/SLX shouldnt be a issue i think?

nicklouse

so what are you asking?

the crank will not fit on your BB.

the rings on either will fit on your cranks.

if you go for an HT11 set up you will need your BB shell faced.

blablablacksheep

nicklouse wrote:

so what are you asking?

the crank will not fit on your BB.

the rings on either will fit on your cranks.

if you go for an HT11 set up you will need your BB shell faced.

The CRC will fit my BB as it the old style crank, unless mistaken?.Also it a cheaper option it seems than buying chainrings from merlin.

The LX wont ofc fit my BB but the one i looking into comes with BB included, so just means i need to change it.

You say HT11 setup will need my BB shell to be faced, what do you mean by this? I not sure why this would need to be done for hallowtech setup, and how much it cost(i remember hearing £10 quoted from MTBUK , but was a while back)

cooldad

Facing=machining the BB shell so the sides are square, as the sides of the shell line the bearings up. If not square the bearings will wear rapidly.
This is obviously not an issue with a cartridge BB.

blablablacksheep

i searched around about facing and seems to have rather different opinions to weather it is needed or not.

A lot of people and "experts" claim that if you have what i got ie a octalink crankset then it doesnt realy need facing as it just wears down the metal from inside the frame and if anything can weaken the bike.

then ofc the other side says that you need to face the frame every time you replace a BB.

no one argument seems to be the consensus,

By the way this is what i got, so i guess i right in saying the CRC crankset is the exact same?

http://img195.imageshack.us/g/dscf0586l.jpg/
http://img14.imageshack.us/i/dscf0588r.jpg/
http://img824.imageshack.us/i/dscf0590ch.jpg/
http://img225.imageshack.us/i/dscf0591vn.jpg/

nicklouse

blablablacksheep wrote:

nicklouse wrote:

so what are you asking?

the crank will not fit on your BB.

the rings on either will fit on your cranks.

if you go for an HT11 set up you will need your BB shell faced.

The CRC will fit my BB as it the old style crank, unless mistaken?.Also it a cheaper option it seems than buying chainrings from merlin.

The LX wont ofc fit my BB but the one i looking into comes with BB included, so just means i need to change it.

You say HT11 setup will need my BB shell to be faced, what do you mean by this? I not sure why this would need to be done for hallowtech setup, and how much it cost(i remember hearing £10 quoted from MTBUK , but was a while back)

you state

Then this is what my bike spec says i have

Quote:

Shimano FC-MM442-8.

which is octalink.

your pics provide no info. take a bolt out and look.

and yes BB sheels need facing for use with external BBs. No they dont need doing every time you change a BB.

Often internal BB can be helped with having the face the has a BB flange butt up to faced.

so check what you have fitted to your bike.

blablablacksheep

Often internal BB can be helped with having the face the has a BB flange butt up to faced.

Dont quite understand what you saying there

I spoke to LBS and they said that i could replace my crankset with a Shimano M590 Deore 2 Piece Design Chainset 9-speed.

He said

"external bottom bracket is supplied with the cranks and is a universal fit.and so be compatible with the octalink system."

so it sounded like i didnt need to face the bike from the gist of things.

If that the case would be a good upgrade instead of just getting the old octalink replacement.

piker

If you fit an external bottom bracket to a frame that has only had a cartridge type fitted before,you will need to get the frame faced.Have a read:-
http://www.parktool.com/blog/repair-hel ... ng-bts-bfs
http://www.parktool.com/blog/repair-hel ... tra-torque

supersonic

External bottom brackets are completely different from Octalink. Your frame can take both systems, but they are not cross compatible except the chainrings, and even then they may need filing a little.

As as above, the frame will require facing for an external system.

blablablacksheep

k cheers for help

comes down to weather any of them have a octalink in stock, if not seems like a external upgrade will be in order.

Quick question on that, Shimano Deore M590 how good is it? will it be as good as the old octalink,

cooldad

Very good and yes.