# Standard (39/53) chainrings in compact (110BCD) spacing?



## jared_j (Jun 11, 2009)

I would like to occasionally be able to swap cranksets between standard (39/53) and compact (34/50) - I live in the flatlands but sometimes ride steep mountainous areas.

I'd like to find standard size chainrings (39/53) that come in 1110BCD diameter for use with compact Shimano / SRAM compatible cranks. My thinking is to own one crankset that is compact that can fit the compact as well as standard (my understanding is that you can't get any smaller than 39 inner ring for 135BCD cranks).

My thinking is that I'd have a separate chain for use with the alternate chainrings since swapping SRAM chains is pretty simple with the masterlink.

Do such size rings exist? I haven't had luck finding them on the internet.

Second question: Could I keep the front derailleur set up for the 'standard' size, then swap in compact rings without having to move it? Seems like the 50 ring isn't that much smaller than a 53.


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## LandShark'n (Jan 10, 2011)

I don't know if what you're seeking exists, but I have had similar thoughts back when I ran a 50 x 38 on a standard crankset.


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## Drew Eckhardt (Nov 11, 2009)

jared_j said:


> I would like to occasionally be able to swap cranksets between standard (39/53) and compact (34/50) - I live in the flatlands but sometimes ride steep mountainous areas.
> 
> I'd like to find standard size chainrings (39/53) that come in 1110BCD diameter for use with compact Shimano / SRAM compatible cranks. My thinking is to own one crankset that is compact that can fit the compact as well as standard (my understanding is that you can't get any smaller than 39 inner ring for 135BCD cranks).
> 
> ...


Specialites TA makes 40 - 61T outer and 33-46T inner (some pinned on the inside for triple crank use) 110mm BCD rings. Peter White stocks them in the US, although you'll do better financially importing them yourself from Europe.


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## aaric (Mar 10, 2011)

IMO, you'd do better to use 110BCD rings in a 36/52T combo. (these rings are readily available - the 36T is ~$20, and the 52T is ~$70 for SRAM Red) of course depending on what cassette you use. Rumor has it that running larger than a 52T on 110BCD is too flexy.

You could go with an 11-21 or 11-23 cassette for the flatlands, and drop to a 11-25 or lower for the mountains, and not have to mess with your FD, or cable adjustments...but this depends on how much time you are spending in either place, and what pace you normally ride: some people would be annoyed topping out in their lower ring at ~21mph @100 RPM.

You can keep your front derailleur set high for swapping cranksets/rings, but shifting will suffer, and going to a larger tooth gap (compact) in the front generally reduces shifting performance slightly.


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## Peanya (Jun 12, 2008)

Since you'd have to take off the cranks to swap out rings, why not just have a second crankset? If they're external bearings, then all you need to do is swap the cranks. Less time anyway.


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## Kerry Irons (Feb 25, 2002)

*Say what?*



Peanya said:


> Since you'd have to take off the cranks to swap out rings, why not just have a second crankset? If they're external bearings, then all you need to do is swap the cranks. Less time anyway.


I don't think I've ever encountered this issue. Every crankset I have ever worked on has allowed the removal of the chainrings without taking the crankset off the bike. Are you talking about a specific brand that doesn't allow this? The OP did not mention the brand/model of his crankset.


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## cxwrench (Nov 9, 2004)

^ what Kerry said^...i never have to remove the crank to swap rings. that would wreak havoc w/ track racers! i change rings on the girls tt bikes all the time (sram red) and never have had to remove a crank arm to do so.


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## m_s (Nov 20, 2007)

I've run 38 x 48 on a standard crankset and it was pretty nice with an 11 tooth cog. Made the big ring much more useable for me. I would consider keeping your 50 and just swapping the inner ring.


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## Ventruck (Mar 9, 2009)

Does exist, as someone already mentioned Specialties TA. Doing a Google search, so doesIRD as well as Fulcrum and Stronglight. How are you having no luck?


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## thebikingcello (Feb 3, 2011)

just get another crankset. the Tiagra level is not to bad, and its about 80 bucks online. you can most likely just change the drive side crank.

by the way, you will have to adjust the FD every time you do this... so maybe you can get the best of both worlds and get a 38/52 rings or crank and get a wider cassette like a 11-27 so you still have the high and the low.

and I would say you can't adjust the FD to standard and use a compact on it because in my mind the chain would rub. 

btw, this is one of the reasons some people have 2 road bikes, one climber and one aero flat lander 

I don't know everything, but I do know your LBS knows TONS more then me if you ask them


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## jared_j (Jun 11, 2009)

Thanks everyone for the links, looks like there are good options that I wasn't finding. The cassette swapping thing to avoid swapping chains also is a great point.


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## Mark Kelly (Oct 27, 2009)

dupe.


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## Mark Kelly (Oct 27, 2009)

For ultimate flexibility you could look at the new reproduction Rene Herse crankset, which promises to be able to mount any combination of 1 to 3 rings from 24 teeth up.

It will probably cost as much as three normal cranksets....


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## Peanya (Jun 12, 2008)

Kerry Irons said:


> I don't think I've ever encountered this issue. Every crankset I have ever worked on has allowed the removal of the chainrings without taking the crankset off the bike. Are you talking about a specific brand that doesn't allow this? The OP did not mention the brand/model of his crankset.


My mistake. I have never taken off the rings by themselves. Still, it seems easier just to swap out a crank on an external bearing BB.


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## Drew Eckhardt (Nov 11, 2009)

thebikingcello said:


> just get another crankset. the Tiagra level is not to bad, and its about 80 bucks online. you can most likely just change the drive side crank.
> 
> by the way, you will have to adjust the FD every time you do this... so maybe you can get the best of both worlds and get a 38/52 rings or crank and get a wider cassette like a 11-27 so you still have the high and the low.
> 
> ...


If you need wide range and want narrow spacing just ride a triple.

52 - 38 x 11,12,13,14,15,17,19,21,24,27
53 - 39 - 30 x 11,12,13,14,15,16,17,18,19,21

No need for two bikes, no need to change cassettes depending on whether your riding buddies want to head west to the mountains or east on the plains, no compromises on gear spacing.


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## wim (Feb 28, 2005)

jared_j said:


> I live in the flatlands but sometimes ride steep mountainous areas.


Concur with Drew: the perfect setup for this is the triple. There's simply no need to be screwing around with different chainrings and chains, plus fiddle with FD height and readjustment every time your riding venue changes from flat to steep and back.


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## CleavesF (Dec 31, 2007)

FSA and SRAM makes 52/38 rings in 110bcd

I upgraded one of my compacts to this setup.


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