Shimano 5 arm crank question

[FluffyChicken]

Ignore the missing teeth, that's called ramp profiling and probably some other fangled name (hyerdrive-C-X-SG-X-II-...)

it's actual wear on the teeth at the chain contact points you need to consider and i'll let other decide as I to some that would be worn, others it would be good condition plenty of miles left.

 

[Tad]

As FC says, the teeth are supposed to be like that.

Shimano chainrings are notoriously made of cheese, new ones will end up looking as worn as that in no time.

 

[uphillcursing2]

Cheers guys. So the opinion seems to be there is life in those chain rings.

In that case I think a good clean and refitting is in order. Just been combing through the classifieds and I cant see a Shimano crank of late '90s for sale. Am I correct in thinking the XT ones had 4 arms rather than 5? Would that make obtaining replacements a less painless process?

Do they not come up very often?

Cheers for the time you guys are taking answering my bone headed questions.

 

[FluffyChicken]

The rings in both types are easily available as middleburns from CRC, though Modern 4-arms have a greater cheaper choice. The 4 arms would be a few years later but if you find MC40's they are a better choice than the M739/569's for 4 arm.

look for 737's and put some silver or coloured middleburn slickshift on them (about £60 for a set from CRC) or find the 739/569 with a 5 arm spider on them.

 

[Tad]

Chainrings to fit the higher end stuff like XT are easy enough to get whatever the age.

 

[Xesh]

......Is the middle ring you know of silver? .......

It is indeed. I'll see if I can get some pics if you want (and a price).

 

[uphillcursing2]

Xesh,

That would be very kind.....

 

[sam_white]

I'd say that middle ring and big ring are close to needing replacement. 1 of those teeth on the big ring looks quite chewed up.
You could keep the STX cranks and run a double ring setup, and forget about the granny ring. Or I'd probably ditch the STX and get an STX-RC chainset which uses standard rings. 94bcd mid and outer, 58bcd granny.