S40 Chainring - for lower gearing

[Robert Holler]

Hey all - I have been asked a few times about this so I thought I would post it here.

The S40 uses the Apex 1x - which has asymmetrical 110 BCD chainring bolt pattern - so just getting a smaller chainring won't do the trick.

Here though is a good source for one that will work - its also a narrow/wide which is critical IMHO for the wider 1x systems. It looks like they only have 42T in stock and an option for a 40T, not sure if anyone makes a 38T... but the key is that it has to be an asymmetric 110 BCD.

As with most components - companies are making the days of "mix and match" go away with these types of special setups - but thats an area we have no control over.

https://www.wolftoothcomponents.com/products/110-bcd-asymmetric-4-bolt-for-sram-cranks

 

[Shakey]

Thank you for this, I was just trying to figure out a way to get up hills when loaded for touring.
.... but after a bit of searching, there does not seem to be a easy/cheap solution.

I can find 36/38 tooth 110 BCD asymmetric chainrings for Shimano, but none for Sram.
It is looking like at minimum I will need new cranks & cassette.
Has anyone else found a better idea?
thanks

 

[McWheels]

Ray (@rfneep ) of this parish fitted his S40 with a Granny gear on the casette rather than a smaller chainring. I bought it off him a year and a half ago and it's very good. Specifically it's a Wolf Tooth GCX 46t which has replaced the stock 42. And in all honesty if I get to the bottom of that one it's so steep that walking's just as quick.

20200818_122742

• McWheels
• Aug 18, 2020

The final iteration with B&M light mounted to boom clamp and wired through the frame.

 

[rfneep]

In a similar approach, I changed my 1x11 drivetrain on my S30 to use the 10-48t 11-speed cassette from Garbaruk. This required the extended derailleur cage but works very well, better than the SRAM cassette with the 46t Wolf Tooth cog. If you choose the 10-46t cassette, you apparently do not need to make any changes to your derailleur.

These are nice options!

Ray

 

[cpml123]

In a similar approach, I changed my 1x11 drivetrain on my S30 to use the 10-48t 11-speed cassette from Garbaruk. This required the extended derailleur cage but works very well, better than the SRAM cassette with the 46t Wolf Tooth cog. If you choose the 10-46t cassette, you apparently do not need to make any changes to your derailleur.

These are nice options!

Ray

Did you need to change to XD driver for the hub?

 

[rfneep]

I had an XD hub already, but they also advertise a shimano freehub compatible cassette. I believe it is a 11-46t or 11-50t. The 11-50 would require a derailleur cage upgrade, I believe.

 

[ak-tux]

I use 11-speed Sunrace 11-46 Cassette with the stock SRAM Apex that came with my S40 and it works.

Below I changed my chain ring to 48T and added a couple of links but the stock 42T SRAM chainring and the stock chain would have not required an increase in the chainlength.

 

[jond]

I was once shocked by the sheer size of 10-11 speed 11-36 clusters.

Lol what was I thinking. ?

 

[bladderhead]

In bottom gear the tensioner is pulled out straight. You could ride on bottom gear without one. In top gear it is folded in almost as far as it can go. They must be approaching the limit of possible range of ratios. If you want more cogs in the same frame you have to make them and the chain thinner. Or start selling frames with wider drop-outs. Aargh, a new standard! In that case, what is the limit of cross-chaining? Or could they make a thing where the chainring slides sideways?

 

[rfneep]

Actually, the SRAM Eagle set supports a 12-speed 10-52t cassette without over-stressing the derailleur. It’s a pretty nice range…

 

[3bs]

On my new to me s40 (ex Rudy ex Casey) I just could not find my rhythm on the 1x apex even with a couple cassette swaps and chainring swaps.
so I stripped it all out and went obsolete 2x10 rival 50/34 and 11-36. No wolfs tooth. Much better. About max for the drive train. Might add the tooth back to carry one more inch of chain. Changed seat padding some and put on a set of obsolete Reynolds assaults with the crossed spokes for a little more strength, and 700x28 schwalbe

okay it’s a boring set up, and similar to my v, but it works.

parenthetically, I am totally amused by the constant “headwind” I have on the s40. Of course it’s not actually a headwind, it’s just the air resistance difference between the v and the s

 

[Merczak73]

3bs - agree with your assessment 100%. While I like the simplicity of the 1x, I could not find correct gears - was spinning to fast or too slow. I am loving my 2x force axs setup. Smooth, and no more searching. To each his/her own.

 

[jond]

2x obsolescence is a thing of the past. Tee hee.

 

[mpayne]

In my quest for lower gears to help with our hills around here and my not-so-young age anymore, I found that SRAM makes a 40 tooth asymmetrical Apex chainring which I just picked up today and added a Sunrace 11-46 cassette (per am-tux’s suggestion). Got them both installed this afternoon and very happy with the results. No need to alter any other components. Next up - 650b wheels and 38mm tires to help on some of the gravel roads/trails.

 

[bladderhead]

I have 40t chainwheel and 10-51 cassette and I like the wide range. If the Sunrace works for you you must be stronger than me or in the Netherlands. 650b and 38mm is a good idea. I speak from experience.

 

[RBW1938]

My problem is just the opposite here in flat central Florida. I purchased a 46 tooth chainring with the exact specs that Robert Holler listed. Asymmetric 110 bcd 4 bolt SRAM but it turned out to be made as a small chainring I guess in a two spd setup and it threw the chain off whenever I shifted into the higher gears. Thought it might be my problem so I took it to my bike shop and they had the same problem. So I am out $60 and still looking for a bigger chainring.

 

[ElyDave]

Thank you for this, I was just trying to figure out a way to get up hills when loaded for touring.
.... but after a bit of searching, there does not seem to be a easy/cheap solution.

I can find 36/38 tooth 110 BCD asymmetric chainrings for Shimano, but none for Sram.
It is looking like at minimum I will need new cranks & cassette.
Has anyone else found a better idea?
thanks

My older model S40 has a Shimano ultegra triple 52-39-30 and a 12-30 casette, I've been up 14%+ with touring load on that.

Not sure if the SHimano triple is still available

 

[cranky cyclist]

I have a ethirteen trs 12 speed cassette with a 9 to 52 cluster. This is paired with a SRAM go eagle derailleur and a 42 tooth chainring.

 

[tiltmaniac]

I have a ethirteen trs 12 speed cassette with a 9 to 52 cluster. This is paired with a SRAM go eagle derailleur and a 42 tooth chainring.

Same here, except I still have the 50t in the front too, because I was too lazy to remove it.
I did the "ratio" mod of my brifter so I could have 12 speeds on the rear.

 

[zahid7600]

Hi everyone. I am new here