Gary Brower

I tried to search for this, but had no luck . . .

I've got a 105 Triple (52-42-30), and I need to replace the middle ring. They're difficult to find, although I see Harris Cyclery has them for $70. My question whether it's "wiser" to go ahead and replace that middle ring, or to replace the whole set? The bike's about 11 years old, but still a good steed!

Thanks!

Gary

dr_lha

Shouldn't be too hard to find a replacement 42T chainring for it. You don't say what model/speed your crank is, but I would guess it would be easier for you to find a third party brand chainring, rather than a Shimano one.

Gary Brower

Well, it's a 9spd Shimano 105 42t middle chainring. A Google search yields very little, other than older posts wondering where to find one. Of the two "stores" I've found online, one is out-of-stock (and doesn't know when/if they'll ever get more), and the other has no phone number (BikeParts360.com).

dr_lha

I'm guessing what you want is a 42T chainring with a 130mm BCD.

Something like this will likely work fine:

https://www.amazon.com/Vuelta-8689903...=42T+chainring

(select the 130x42T)

Gary Brower

Thanks for the pointer. I'll give it a try.

JerrySTL

How about a 39 instead?

patrickgm60

To answer OP's question: look closely at the teeth on all 3 chain rings. Once the shape of any of the teeth includes a sharp break, rather than a smooth/wave shape, it is time to replace the ring. If you've done a majority of your riding on the 42, you may be able to replace just the one.

Clem von Jones

Except the Shimano Hyperglide crank rings all have sculpted teeth - every one of them is a different shape and some deliberately have no peaks to help facilitate shifting. I find it difficult to judge when they're worn out because even new teeth seem to have a shark-fin like profile.

Ebay is sometimes a good place to find new chainrings.

patrickgm60

True, it's not as simple as that, if he has the Hyperglide rings. Still, I had a mechanic walk me through it, once and it became pretty evident to me (in my case, the 39 and 52 needed replacement, the 30 did not.)

osiris419

Those Vuelta rings will probably not work if they aren't ramped and pinned for a triple. Best bet is to replace the entire crankset.

Soody

wiggle.com | Shimano Tiagra 4603 Hollowtech II 10 Spd Triple Chainset | Road Chainsets

Stronglight Impact JIS Triple Chainset Road, Chainsets, CHAINSETS ROAD

Shimano 105 Silver Triple 5703 10 Spd Chainset, Chainsets, CHAINSETS ROAD

You could also go for a Campy or Sugino triple for a bit of bling.

Just stay away from 11 speed

Gary Brower

Thanks for all the suggestions!

And, to be clear, this is a 9-spd. So even the 10's are problematic

I'll check on the Vuelta.

I also received a PM about a triple crank. I couldn't reply to the message because "I've not posted enough". If "bykemike" would PM me again with an email address, I'll follow up on that as well.

Again, thanks!

Gary

Gary Brower

Okay, folks,

The Vuelta arrived today, and doesn't have the same configuration as the Shimano: the Vuelta is simply a mostly flat piece of metal with the teeth cut out, and the Shimano I have has bevels and other additions -- probably to aid the shifting).

So, I can't really find a "reasonable" on-line replacement for the ring. Should I go with Harris Cyclery (@ $70) or replace the crankset. And, if so, will a 10 spd set work with my overall 9 spd set up?

JohnDThompson 

Triple cranks don't require ramped and pinned rings, they just shift a little better with them.

osiris419

The bevels are the ramps and the other additions are the pins. They are there to help get the chain on the ring from the smaller chainring. If the ramps and pins are not there it will be very difficult to shift into that ring unless you have friction shifters, which you don't. The only ring that does not need ramps and pins are inner rings. Middle and outer rings need them.
From my experience non-ramped and pinned middle rings do not work. I've tried it for people at work a few times because they want to save a buck. We usually end up selling them the correct middle ring or a new crankset.
You can try the Vuelta ring on there but you probably won't be happy with the shifting performance. At $70 for a middle ring you could probably find an entire crankset on eBay or something and a 10 speed crank will work.

Gary Brower

Thanks for all the help, folks. The Vuelta DOES work, but, as some have noted, it doesn't easily shift up from the small ring. The shifting is fine to and from the large ring, and down to the small ring. I can coax the chain back up from the small to the middle ring. It's not a big deal, as I'm rarely on the small sign any more, but I will look for a new crankset. Thanks for letting me know that the 10-spd will work.

Gary