1x - optimal chainring & cassette mix

[RossTopher]

my first foray into a 1x setup. Its a cyclocross bike which i intend to use primarily as my training/do-it-all road bike and casual adventurer. (i have dedicated road and mtb's so dont need to hit 500kph, or climb everest on this)

It has an APEX 40t up front with 11-36 at the back. so far its unfaultable, bar the odd spinning out (but thats good resting time). i am in no rush to change, but want to hear thoughts of more learned folks, as i do feel like both top and bottom end may get limited on that chainring.

i was initially looking at getting a SRAM/sunrace 11-42 (or shimano's slightly different ratios), but a bit of research has me set on Shimano 11-40, which has much better ratio jumps. obviously neither changes the top end. the Sram 11-42 is ostensibly the same as the 11-36, with my most used 12t sacrificed for a massive jump at 36 to 42.

the Apex BCD is bizarre, rings are like hens teeth, so while i can get a 42t, i think i should, as i cant find 44 anywhere. i want to future proof and make sure i get the right cassette and if the 2t gain is worth it. if i went 11-40, would there be any noticeable speed gain from up front, or does the downside of tougher climbing outweigh it by not having a 1:1 ratio?
 

I've done the Sheldon Brown stuff, but want some real world thoughts.

Long story short, whats the best combo:

40t with 11/40 or 11/42

42t with 11/42 or 11/40

PS: 2x is better!

 

PPS: not currently considering wheel changes to cater to 10/9t cassettes for top end. its just too costly, and seems those 9/10s dont last.

having said that, the rims are 19mm IW and cinturato gravel h 40's, so its pretty much the limit. so is a wheel change the only real answer?

Edited June 16, 2022 by RossTopher

[PeterF]

I converted my road bike to 1x using a 50 tooth Absolute Black oval chainring up front and a Shimano XT 11-40 cassette at the back with an Ultegra RX derailleur to handle the shifting.  It works beautifully and I have all the gears I need.  I don't use it for gravel riding though.

[Toasted marshmallows]

Chat to csixx.... they can produce a ring you need....

 

Honestly run a sram force 1x 50t with a 12 speed 11-50 sunrace cassette....

Only upgraded internals with a ratio 12speed kit.... kept the standard derailleur.....

Shifts great... Good climbing gear and enough top end to sit with roadies. Can eventually get a 12 speed road cassette and wheelset for road ride

[Wayne pudding Mol]

Have a look at garbaruk stuff - many options 

I run a 42 with a 10/50 and have everything I need 

for touring I change the front to a 38

[ACE Cycles]

5 hours ago, RossTopher said:

my first foray into a 1x setup. Its a cyclocross bike which i intend to use primarily as my training/do-it-all road bike and casual adventurer. (i have dedicated road and mtb's so dont need to hit 500kph, or climb everest on this)

It has an APEX 40t up front with 11-36 at the back. so far its unfaultable, bar the odd spinning out (but thats good resting time). i am in no rush to change, but want to hear thoughts of more learned folks, as i do feel like both top and bottom end may get limited on that chainring.

i was initially looking at getting a SRAM/sunrace 11-42 (or shimano's slightly different ratios), but a bit of research has me set on Shimano 11-40, which has much better ratio jumps. obviously neither changes the top end. the Sram 11-42 is ostensibly the same as the 11-36, with my most used 12t sacrificed for a massive jump at 36 to 42.

the Apex BCD is bizarre, rings are like hens teeth, so while i can get a 42t, i think i should, as i cant find 44 anywhere. i want to future proof and make sure i get the right cassette and if the 2t gain is worth it. if i went 11-40, would there be any noticeable speed gain from up front, or does the downside of tougher climbing outweigh it by not having a 1:1 ratio?
 

I've done the Sheldon Brown stuff, but want some real world thoughts.

Long story short, whats the best combo:

40t with 11/40 or 11/42

42t with 11/42 or 11/40

PS: 2x is better!

 

PPS: not currently considering wheel changes to cater to 10/9t cassettes for top end. its just too costly, and seems those 9/10s dont last.

having said that, the rims are 19mm IW and cinturato gravel h 40's, so its pretty much the limit. so is a wheel change the only real answer?

Running 1x12 on my Monstercross

36T with 9-50T

[JulienR]

i am assuming you want to stick to 11 speed?

I think the size of the chainring depends on how fast you want to go and the largest cog on the cassette depends on how much steep stuff you intend climbing

I think that a 42T up front on a gravel bike with a 11-42 at the back is probably best for most gravel riding. If you want a bit more top end i think a 44 chainring mated to the 11-42 would probably work but you would not be able to climb the really gnarly stuff

[RossTopher]

16 minutes ago, JulienR said:

i am assuming you want to stick to 11 speed?

I think the size of the chainring depends on how fast you want to go and the largest cog on the cassette depends on how much steep stuff you intend climbing

I think that a 42T up front on a gravel bike with a 11-42 at the back is probably best for most gravel riding. If you want a bit more top end i think a 44 chainring mated to the 11-42 would probably work but you would not be able to climb the really gnarly stuff

yip, i am looking for the most cost effective option, so no changing of shifters etc. its an 11 speed Apex1 hydro groupset, with Rival1 RD which i believe you can push to 46, but thats overkill for me.

sounds like 42t in the front is the way to go. bigger chainring is more efficient.

[RossTopher]

@Wayne pudding Mol and @ACE Cycles . thanks, it does seem like the ideal "money no object" solution. I have looked at garbaruk and e13 and while the prices are high, my reading says they'll run forever, and a lot more resilient than the sram 10t cassettes.

my bike has 105 hubs though, so i dont think i can just replace the freebody with an XD, so it will be new wheels + the 3-4k cassette... which is a bit dear

[RossTopher]

5 hours ago, PeterF said:

I converted my road bike to 1x using a 50 tooth Absolute Black oval chainring up front and a Shimano XT 11-40 cassette at the back with an Ultegra RX derailleur to handle the shifting.  It works beautifully and I have all the gears I need.  I don't use it for gravel riding though.

thats the cassette!!!! if it works on your road bike, i should be good with those ratios. i may not get the 50t up front, but i must just up the rpm. bonus points for that entire setup being so easy on the eye. gorgeous.

 

[ACE Cycles]

6 minutes ago, RossTopher said:

@Wayne pudding Mol and @ACE Cycles . thanks, it does seem like the ideal "money no object" solution. I have looked at garbaruk and e13 and while the prices are high, my reading says they'll run forever, and a lot more resilient than the sram 10t cassettes.

my bike has 105 hubs though, so i dont think i can just replace the freebody with an XD, so it will be new wheels + the 3-4k cassette... which is a bit dear

I had a Titan Switch with 2x11, really enjoyed the range. Used it mostly for training on the road

[RossTopher]

2 hours ago, Toasted marshmallows said:

Chat to csixx.... they can produce a ring you need....

 

Honestly run a sram force 1x 50t with a 12 speed 11-50 sunrace cassette....

Only upgraded internals with a ratio 12speed kit.... kept the standard derailleur.....

Shifts great... Good climbing gear and enough top end to sit with roadies. Can eventually get a 12 speed road cassette and wheelset for road ride

thanks, i'll give them a shout. its a 110BCD 4 bolt assymetric, so not the same as the 4 bolt 110 shimano setup, nor the 5 bolt 110's.

the only place i can find the 42 is Bike Addict, and thats only online, so the only way to find out about its existence is to "order" and wait.

i think a 46 or 50 may be overkill for my needs, i run a 11-42 on my MTB with 26/36 up front a and find the 42 so inefficient. i prefer to grind than spin

[RossTopher]

1 minute ago, ACE Cycles said:

I had a Titan Switch with 2x11, really enjoyed the range. Used it mostly for training on the road

that is a lovely bike. i swore i'd never go 1x, but the bike i got was too nice, and the 1x11 has been fine. i have 2x10 on the MTB and a hybrid gravel build so if i go somewhere that needs the options, they offer that. so this is really going to be about 90% tar, mainly for the paintwork

[Sid the Sloth]

What wheels are you running? In my opinion it is definitely worth seeing if you can find a xd freehub body to get the 10t. 

I would say I am not bad at climbing and I was very happy with my setup on my gravel bike with 38f 10-42 rear... Lots of training around Knysna with steep climbs over 15% in z2 power. 

I also did PLENTY of road rides and was not getting dropped on the descents or false flat downhill. Now that I have gone back to 11t I basically have the same ratio as 34 / 10 and it is not as nice, the 10t was a lot better. Remember juniors race with elites here on a 3.7 ratio... so 38/10 on gravel wheel diameter should definitely be manageable. 

[Sid the Sloth]

Conversely I am hoping for 56 11-34 for the tt. Should be fun. 

Edited June 16, 2022 by Sid the Sloth

[RossTopher]

59 minutes ago, Sid the Sloth said:

What wheels are you running? In my opinion it is definitely worth seeing if you can find a xd freehub body to get the 10t. 

I would say I am not bad at climbing and I was very happy with my setup on my gravel bike with 38f 10-42 rear... Lots of training around Knysna with steep climbs over 15% in z2 power. 

I also did PLENTY of road rides and was not getting dropped on the descents or false flat downhill. Now that I have gone back to 11t I basically have the same ratio as 34 / 10 and it is not as nice, the 10t was a lot better. Remember juniors race with elites here on a 3.7 ratio... so 38/10 on gravel wheel diameter should definitely be manageable. 

thanks for the info. food for thought from everyone. 

checking the ratios on Sheldon Brown, it seems i dot get much change between the 4 options, a half kph here and there, so if i want real impact, consensus appears to be the 9t/10t cassettes.

I have WTB TCS i19, on shimano 105 hubs.

my rear hub is 142mm, so is it as simple as buying an MTB/gravel wheel built with an XD driver?

 

Edited June 16, 2022 by RossTopher
figured out XD vs XDR

[Sid the Sloth]

18 minutes ago, RossTopher said:

thanks for the info. food for thought from everyone. 

checking the ratios on Sheldon Brown, it seems i dot get much change between the 4 options, a half kph here and there, so if i want real impact, consensus appears to be the 9t/10t cassettes.

I have WTB TCS i19, on shimano 105 hubs.

my rear hub is 142mm, so is it as simple as buying an MTB/gravel wheel built with an XD driver? i understand road disc wheels have a different width or something?

 

You have options, cheapest would probably be freehub body and sram xg 11spd 10-42 cassette, not sure how easy that is though. Second it new hub and rebuild, most 142x12 (non-boost) rear hubs should do the job with the right spoke count and pull orientation, but maybe I am wrong. Or just an mtb non-boost rear wheel with a gravel tyre slapped on. I would keep an eye out in the classifiieds for a 10-42 cassette in decent condition as that will definitely be required.