Is chain ring on correct way around?

[Smythe]

You're spot on markfh!

I looked at the back of the cranks and observed a sticker on both.

One states: "FC-M430/431" and the other "FC-M431".

I'll have a look at both the links now and check back later.

[Brucey]

this is how it is meant to look;



cheers

[Smythe]

Further to my last post I have found a picture of the FC-M430 crankset on a Shimano website (http://bike.shimano.com/content/sac-bike/en/home/mtb1/drivetrain/crankset/fc-m430-l.html) This shows both the black and silver versions of the crankset. If you look at the picture of the silver version the position of the outer chainring on top of the spider is clearer due to the contrast between the silver crankarm and spider and the black chainrings.

I've had a look at the links. I'm reasonably sure the setup shown in my original photo is the same as shown in your links. That is, the large ring is on the outside of the spider.

Maybe it's a poor photo which I've posted.

[markfh]

As I see it, unfortunately, the picture you posted is clear and shows the outer chainring behind, not in front of, the spider. If you look at the picture Brucey posted there is only a single (slightly curved) line adjacent to the chain fixing bolts between the fixing bolt and the centre part of the spider. In your picture there are three four lines, the curved one one between the fixing bolt and the centre of the spider and three others forming a truncated pyramid which represent the edges of the spider overlaying the outer chainring. If the outer chainring was in front of the spider these edges would not be visible.

[Smythe]

three others forming a truncated pyramid

Is this the truncated pyramid which you refer to (in red)?

[MikeF]

three others forming a truncated pyramid

Is this the truncated pyramid which you refer to (in red)?

Yes. That should not be visible in your picture. The large chain ring needs to be on the outside of that hiding it from view, ie nearer the crank arm, which will be further away from the bottom bracket.

[Smythe]

Ah, okay - thank you.

I know where my error has occurred now.

Thanks very much for all help!

[MikeF]

You gave a link, but did you also follow the link from that to the exploded view?. Here you will see exactly how the parts should be assembled. The outer chainwheel and middle chainwheel are clamped together with the spider arms between them ie chainwheel spider arm chainwheel. Note that the drawing shows an outward facing peg on the large chainring. As others have said, this needs to be positioned adjacent to the crank. Its purpose is to prevent the chain falling down between the large chainwheel and crank should it come off the chainwheel.

[Smythe]

You gave a link, but did you also follow the link from that to the exploded view?.

I've had a look at that. Yes, was very helpful. Thank you.

[delap]

Coincidentally I fitted the almost the exact same set of chainrings (only 48/36/26) to a similar chainset this afternoon and fussed about the same questions. I think the right answers have already been covered and the only point I would add is that when you refit the rings, Brucey mentioned that all three have a correct rotational position as well as the other changes mentioned. You already spotted the chain catching pin on the outer ring but the inner two rings also have a tab (part of the ring itself, not a pin as on the big ring) which should line up with the pin on the outer ring. Coincidentally you have the inner ring 180°out so the tab is visible in your photo. The middle ring has a similar tab (I think the big ring may have one as well). The tabs on the inner two should line up with the chain catcher pin on the big ring and all three should be behind the drive side crank arm.

hth

[MikeF]

You can't beat practical experience.
If the exploded view is looked at closely, the tabs you mention are quite visible on the small and large rings, but less so on the middle one. Also the large ring for chainguard use does not have a pin, but still has the alignment tab.
It pays to study diagrams in detail - at least from a good manufacturer.

[delap]

Quite right MikeF, I changed from a guarded ring to an unguarded ring (which happened to be quite a bit cheaper). The pin on the big ring is not big enough to catch the chain (I discovered, when adjusting the front derailleur) but it is big enough to stop the chain from being picked back up by the derailleur after over-shifting outwards so whilst the chain I wasn't fussed about the chain guard as a trouser protector it seems it was more use as a chain guide. Maybe I will try drilling and tapping the new ring to take the old guard