Buying Individual Chainrings

[Lovacott]

I assume this will be obvious to most on here, but is there a standard for individual chainrings?

My hybrid chain set is a Suntour XCT, 38/36/26t and I am looking to buy a set of replacement rings to put into my parts bank.

Can I buy any make of 9 speed chainring with the same number of teeth or do I have to buy Suntour?

 

[MontyVeda]

You can get them, but some cranks have four fixings, others have five, so you'll have to look at your type of crank first

I tend to replace only the middle ring, purchased off ebay for not much money. The last one supposedly fit my truvative crank, but i did have to file it a bit to get it to fit... but that's to be expected when buying cheap stuff off ebay

You might find though, that it's more cost effective to buy a crank and rings than just buying the three rings.

 

[Sharky]

38/36/26t

The big ring doesn't sound right - can you do a recount.

 

[rivers]

You will also need to check the BCD (bolt circle diameter). It should be labelled on the chainring itself. I just had to order a new chainring for my gravel bike. It will say something like 120/90 BCD on the chain ring.

 

[Lovacott]

The big ring doesn't sound right - can you do a recount.

It's actually a direct copy and paste from the bike spec PDF.

A two teeth difference between rings would be a bit pointless.

On counting, it's a 48T.

 

[Lovacott]

You might find though, that it's more cost effective to buy a crank and rings than just buying the three rings.

I've looked online for a full set but because the spec sheet is wrong (see above) I haven't been able to find a full set.

Now, when I paste in the correct spec (48t rather than 38t) I can find them easily.

 

[MontyVeda]

I've looked online for a full set but because the spec sheet is wrong (see above) I haven't been able to find a full set.

Now, when I paste in the correct spec (48t rather than 38t) I can find them easily.

it definitely looks like a typing error on the spec sheet; what's the point in having a two tooth difference between the big and middle ring?

The last time i priced up three replacement rings for my MTB, a complete crankset was cheaper so i bought that instead.

 

[Lovacott]

it definitely looks like a typing error on the spec sheet; what's the point in having a two tooth difference between the big and middle ring?

The last time i priced up three replacement rings for my MTB, a complete crankset was cheaper so i bought that instead.

My MTB crankset has got riveted rings so I have to replace the whole thing each time although it's really only the small ring which needs replacing.

First up for the Hybrid, I was going to buy a small 26t ring so I'd have a spare ready to fit rather than have to lay up the bike for a month due to supply issues.

I've got a pretty impressive box of new spare parts such as chains, cables, freewheels, cassettes, MTB crankset, pedals, tubes, bearings, disc calipers, pads and tyres. I learned my lesson after having to wait weeks for basic spares last year.

 

[MontyVeda]

I do the same... keep the parts in stock so when I need them I've got them to hand.

Bike repairs need to be done 'now', not after a trip to the bike shop, or after a parcel has been delivered

 

[Lovacott]

I do the same... keep the parts in stock so when I need them I've got them to hand.

Bike repairs need to be done 'now', not after a trip to the bike shop, or after a parcel has been delivered

I had a chronic case of chain suck last year which needed a new crankset to put it right. I had to wait four weeks for the replacement which meant I had to commute without using the small ring (hard work).

I also had problems getting hold of spare chains, disc pads and brake and gear cables.

It makes sense to keep a set of consumables at hand so that you can fix problems as they happen rather than trying to soldier on through waiting for parts to turn up.

Buying spares in advance also saves a fair bit of cash. When demand is high, I've seen parts online for 50% more than normal.

 

[Sharky]

what's the point in having a two tooth difference between the big and middle ring?

No point nowadays, but one of my early bikes had a double with 3 teeth difference. Something like a 52/49.

On the rear was a 5 speed block in 2 tooth jumps. 14,16,18,20,22

The idea being that you could go/up down at the rear and on the big ring and when you felt that you needed something in between, just move to the smaller of the chain rings. The three tooth difference gave a ratio mid way between the sprockets.

 

[TheDoctor]

Half-step gearing. One gets nostalgic...

 

[Sharky]

Half-step gearing. One gets nostalgic...

I'd forgotten what they were called, along with the steel Williams C34 and "clanger", the seat tube front changer.

They don't make bikes like that anymore.

 

[mustang1]

You will also need to check the BCD (bolt circle diameter). It should be labelled on the chainring itself. I just had to order a new chainring for my gravel bike. It will say something like 120/90 BCD on the chain ring.

+1 to what @rivers said about BCD. I believe sometimes they are also called PCD (no, IDK what that stands for and it was odd when I bought new chainrings a few months ago).

 

[Sharky]

Pitch Circle Diameter
The Pitch Circle Diameter (PCD) is the diameter of the circle which passes through the centre of all the studs, wheel bolts or wheel rim holes.