1X crank options & Sram AXS BCD head-scratcher

[Wayne77]

Some background first: I need to optimize my gravel bike for a bikepacking event later this year with a significant amount of elevation gain. I need some really low gearing. My current drivetrain is Force 1X with a 38T ring. First idea was to use a Wolftooth or Absolute Black direct mount 34T ring (with an eThirteen 9-46 cassette or ratiotechnology 12 speed conversion to use an Eagle 10-50 cassette). But then I discovered my crank is one of those Quark "power meter ready" cranks that have an 8-bolt spider interface. The smallest direct mount rings for Sram 8-bolt are 40+ teeth. The smallest normal rings for the 110 BCD are 38T. After some more research I discovered Sram makes an 8-bolt spider for its new AXS cranks. You can get them in either a 94 BCD or 107 BCD (Aside: Huh?? I'm sure they have their reasons but 94 and 107 seems to be a really odd standard...unless they want you to stay with their proprietary AXS rings. None of which are nearly small enough). So weird.

Moving on...I then found out that Wolftooth and Garburuk make 94 BCD 1X rings. So I figured I'd get the Sram 94 BCD spider and one of those rings. Nope. The Sram AXS 94 BCD (or 107 BCD) standard is an _asymmetric_ 4 bolt design. I can't find any 1X rings that will fit an asymmetric 94 BCD 4 bolt design. Why Sram Why?? There are asymmetric 4 bolt Shimano rings but they are 96 BCD. So now I'm at a dead end and it looks like I'll have to sell what is otherwise a very nice crank and get something that will work with a small 34T 1X narrow-wide ring. So now on to my questions:

-Outside of buying a pricey Sram Force or Rival 1X crank (with 3 bolt interface), what other options are out there? I don't necessarily need cf crank arms, but would like to keep the weight reasonable.

-I need to stay as close to my current Q-factor as I can. A wide mtb crank Q-factor is terrible for my knees. Does that rule out all mtb cranks (even non-boost?)

-Or are there any 1X mtb cranks with a Q-factor closer to my current Sram Force cranks (I believe its a normal road standard, around 145mm)?

-Even if I can get my Q-factor right, how about chain line? A 1X mtb crank would mess that up wouldn't it? Looks like the rings are offset 3mm instead of 6mm and the chain line is closer to 150mm+.

-Can you get a narrower road-standard chain line with a non-boost mtb crank by swapping out the rings for a more traditional offset gravel 1X chainring?

-My BB shell is BB86. So even if I can find a mtb crank that would work, are the spindles too long for an 86mm BB shell?

...Maybe my only option is just to suck up the cost of a new BB86 compliant road or gravel 1X crankset like Force1, Apex1, etc.

Again...Why Sram why??

[yinzerniner]

Originally Posted by Wayne77

Some background first: I need to optimize my gravel bike for a bikepacking event later this year with a significant amount of elevation gain. I need some really low gearing. My current drivetrain is Force 1X with a 38T ring. First idea was to use a Wolftooth or Absolute Black direct mount 34T ring (with an eThirteen 9-46 cassette or ratiotechnology 12 speed conversion to use an Eagle 10-50 cassette). But then I discovered my crank is one of those Quark "power meter ready" cranks that have an 8-bolt spider interface. The smallest direct mount rings for Sram 8-bolt are 40+ teeth. The smallest normal rings for the 110 BCD are 38T. After some more research I discovered Sram makes an 8-bolt spider for its new AXS cranks. You can get them in either a 94 BCD or 107 BCD (Aside: Huh?? I'm sure they have their reasons but 94 and 107 seems to be a really odd standard...unless they want you to stay with their proprietary AXS rings. None of which are nearly small enough). So weird.

Moving on...I then found out that Wolftooth and Garburuk make 94 BCD 1X rings. So I figured I'd get the Sram 94 BCD spider and one of those rings. Nope. The Sram AXS 94 BCD (or 107 BCD) standard is an _asymmetric_ 4 bolt design. I can't find any 1X rings that will fit an asymmetric 94 BCD 4 bolt design. Why Sram Why?? There are asymmetric 4 bolt Shimano rings but they are 96 BCD. So now I'm at a dead end and it looks like I'll have to sell what is otherwise a very nice crank and get something that will work with a small 34T 1X narrow-wide ring. So now on to my questions:

-Outside of buying a pricey Sram Force or Rival 1X crank (with 3 bolt interface), what other options are out there? I don't necessarily need cf crank arms, but would like to keep the weight reasonable.

-I need to stay as close to my current Q-factor as I can. A wide mtb crank Q-factor is terrible for my knees. Does that rule out all mtb cranks (even non-boost?)

-Or are there any 1X mtb cranks with a Q-factor closer to my current Sram Force cranks (I believe its a normal road standard, around 145mm)?

-Even if I can get my Q-factor right, how about chain line? A 1X mtb crank would mess that up wouldn't it? Looks like the rings are offset 3mm instead of 6mm and the chain line is closer to 150mm+.

-Can you get a narrower road-standard chain line with a non-boost mtb crank by swapping out the rings for a more traditional offset gravel 1X chainring?

-My BB shell is BB86. So even if I can find a mtb crank that would work, are the spindles too long for an 86mm BB shell?

...Maybe my only option is just to suck up the cost of a new BB86 compliant road or gravel 1X crankset like Force1, Apex1, etc.

Again...Why Sram why??

First
-If your crank Force AXS with DUB spindle? Pretty sure the previous-gen Force cranks only came with 3 bolt spiders

If it is indeed a Force AXS 8 bolt spider, then:
-Why not just get an older 8 bolt 110 BCD spider and mount the 34t Wolftooth 5x110BCD chainring on it? Pretty sure the DUB 8 bolt cranks work with older 110BCD spiders.
-If you need power, then I know for a fact that the DUB cranks work with the Quarq Dzero PMs in 8 bolt 5x110 config.

[Wayne77]

It's actually a Sram "Quark Prime power meter ready" crankset. Looks very similar to the normal Sram Force1 crankset, but has an 8-bolt interface. Marketed as a crankset making it easy to install a Quark PM spider. Anyway, I don't need power...just want the ability to install a 34T or even 32T ring.

Not sure how I missed that Wolftooth has a 110 BCD 34T ring. I had read somewhere that the smallest 1X ring you could use was a 38T. Maybe that was meant to be "smallest Sram 1X ring".

Still interested in hearing about other crank options...I'll snag that ring but I may even want a 32T ring. This event has 85,000 of climbing over 10 days. With a loaded bike, I need all the low gear I can get.

Originally Posted by yinzerniner

First
-If your crank Force AXS with DUB spindle? Pretty sure the previous-gen Force cranks only came with 3 bolt spiders

If it is indeed a Force AXS 8 bolt spider, then:
-Why not just get an older 8 bolt 110 BCD spider and mount the 34t Wolftooth 5x110BCD chainring on it? Pretty sure the DUB 8 bolt cranks work with older 110BCD spiders.
-If you need power, then I know for a fact that the DUB cranks work with the Quarq Dzero PMs in 8 bolt 5x110 config.

[dr.dre]

Looks like wolf tooth makes sram direct mount compatible chainrings for SRAM cranks, as small as 26t even: https://www.wolftoothcomponents.com/...or-sram-cranks

Looks like it will work with the cranks you have, and provide plenty low gearing.

[djg21]

Especially with a 10-50 cassette. If you need that small of a gear, you might be faster and better getting off the bike. I use a 44 on my new gravel bike with a 10-50 and I have a lot of gearing.

But, the Eagle cassette also is available with a 10-52. I haven’t look at a gearing chart, but it may make sense just to get the bigger cog set.

[yinzerniner]

Originally Posted by Wayne77

It's actually a Sram "Quark Prime power meter ready" crankset. Looks very similar to the normal Sram Force1 crankset, but has an 8-bolt interface. Marketed as a crankset making it easy to install a Quark PM spider. Anyway, I don't need power...just want the ability to install a 34T or even 32T ring.

Not sure how I missed that Wolftooth has a 110 BCD 34T ring. I had read somewhere that the smallest 1X ring you could use was a 38T. Maybe that was meant to be "smallest Sram 1X ring".

Still interested in hearing about other crank options...I'll snag that ring but I may even want a 32T ring. This event has 85,000 of climbing over 10 days. With a loaded bike, I need all the low gear I can get.

Ahh, got yah. The "Quarq Prime power meter ready" arms were the same as the previous-gen Red power meter arms, not the Force arms due to the bolt interface change.

If you're going down below 34t you're better off just getting another crankset since there's no real option for the 8 bolt 5x110 interface and that low a chainring. Even with a 10-52 cassette you'd still be some ways off.

Otherwise you'd have to get the Quarq 4x104 which is even more expensive than the Quarq 5x110.

As for the 94t AXS wide spider, won't work with your arms unless you want to dremel off some of the carbon around the DS arm where it sits flush at the outside of the spider. And even then you might have some chainline issues since it pushes the chainline out 2.5mm

32/50 gear is really low though, basically climbing the side of a building.

[Wayne77]

Those are for the standard Sram 3-bolt interface, not the less common 8-bolt interface on their Quark powermeter ready 1X cranks and now the AXS cranks. They do make 8 bolt direct mount but nothing smaller than 40T

Originally Posted by dr.dre

Looks like wolf tooth makes sram direct mount compatible chainrings for SRAM cranks, as small as 26t even: https://www.wolftoothcomponents.com/...or-sram-cranks

Looks like it will work with the cranks you have, and provide plenty low gearing.

[Wayne77]

I hear ya. Plenty low when I use this current 38T x 42T low gear for gravel events. But the factor here is I will be dealing with a fully loaded bikepacking setup for an event that will probably take me 10 days to complete...with 85,000 of very steep climbs in the mountains (Utah Mixed Epic 1000 mile bikepacking race). So 38T isn't nearly low enough. The event director even said riders will ideally need a gear ratio between .65 and .70. As you probably know, an Eagle 32T with 50T cog is .64. This is basically an ultra-distance mountain bike race....lots of technical climbs.

So to get there, I already have an eThirteen 9-46 cassette. A 32T ring results in a .70 ratio. To get lower, in the range of an Eagle drivetrain, a 30T ring results in a .65 ratio.

Originally Posted by djg21

Especially with a 10-50 cassette. If you need that small of a gear, you might be faster and better getting off the bike. I use a 44 on my new gravel bike with a 10-50 and I have a lot of gearing.

But, the Eagle cassette also is available with a 10-52. I haven’t look at a gearing chart, but it may make sense just to get the bigger cog set.

[Wayne77]

Thanks for the additional info...much appreciated! Yeah, agree about how low that range is.

Two more options I've found:

- I didn't know a regular Force 22 crank has a removable spider. So I might be able to find an older used Force22 crank

- The Praxis Turn Zayante crankset also has a removable 3 bolt spider. Several used options on eBay

...Regardless, I'm probably going to be posting my Force1 Quark power meter ready crank in the classifieds soon.

Originally Posted by yinzerniner

Ahh, got yah. The "Quarq Prime power meter ready" arms were the same as the previous-gen Red power meter arms, not the Force arms due to the bolt interface change.

If you're going down below 34t you're better off just getting another crankset since there's no real option for the 8 bolt 5x110 interface and that low a chainring. Even with a 10-52 cassette you'd still be some ways off.

Otherwise you'd have to get the Quarq 4x104 which is even more expensive than the Quarq 5x110.

As for the 94t AXS wide spider, won't work with your arms unless you want to dremel off some of the carbon around the DS arm where it sits flush at the outside of the spider. And even then you might have some chainline issues since it pushes the chainline out 2.5mm

32/50 gear is really low though, basically climbing the side of a building.

[glepore]

Sram GX1400 1x? Hollow forged arms, direct mount rings as low as 32 t, reasonable q and price.

[joevers]

I'd rather just get mtb cranks and get shorter spindle mtb pedals like they make for XTR.

[yinzerniner]

Originally Posted by Wayne77

Thanks for the additional info...much appreciated! Yeah, agree about how low that range is.

Two more options I've found:

- I didn't know a regular Force 22 crank has a removable spider. So I might be able to find an older used Force22 crank

- The Praxis Turn Zayante crankset also has a removable 3 bolt spider. Several used options on eBay

...Regardless, I'm probably going to be posting my Force1 Quark power meter ready crank in the classifieds soon.

-Force 22 crank will need to be GXP to work with your BB86 - bb30/pf30 model is too large
-Praxis has their own BBs for their M30 crank arm standard.
-Last gen Quarq Prime shouldn't be confused with Force 1 since they use different bolt standards. Again, it was analogous to the Red model, not Force.

Prob your best bet is to go for a Force GXP model as outlined above. Will be a bit heavier than the current arms but you'll get the lowest gear imaginable.

[Wayne77]

Extremely helpful, thanks!

Originally Posted by yinzerniner

-Force 22 crank will need to be GXP to work with your BB86 - bb30/pf30 model is too large
-Praxis has their own BBs for their M30 crank arm standard.
-Last gen Quarq Prime shouldn't be confused with Force 1 since they use different bolt standards. Again, it was analogous to the Red model, not Force.

Prob your best bet is to go for a Force GXP model as outlined above. Will be a bit heavier than the current arms but you'll get the lowest gear imaginable.

[Mark McM]

Originally Posted by yinzerniner

-Force 22 crank will need to be GXP to work with your BB86 - bb30/pf30 model is too large

I don't believe that's correct. Force 22 "bb30" cranks use a long spindle, and with the proper spacers should work with most 'road' bottom bracket shells that can fit a 30mm spindle (including BB86)

[yinzerniner]

Originally Posted by Mark McM

I don't believe that's correct. Force 22 "bb30" cranks use a long spindle, and with the proper spacers should work with most 'road' bottom bracket shells that can fit a 30mm spindle (including BB86)

Since the OP's current crankset is GXP to work with the current BB they'll need a replacement GXP crankset. But if they're looking to do a complete BB and crankset change you're correct Mark it will "work;" whether it's advisable is another question, especially if the OP has the choice of buying something other than the currently held item.

A long spindle BB30/PF30 crank will fit in a BB86 BB but it'll require bearings with very small balls in a double config which isn't ideal.
https://wheelsmfg.com/bottom-bracket...-for-30mm.html
https://www.hambini.com/bb86-bottom-...-dub-crankset/

If the OP finds a great deal on a BB30/PF30 long spindle crank and is willing to spend the extra on double row bearings then by all means yes. However, if they want to keep the existing BB then they're better off trying to find a gxp crankset. Or go with a new BB and a shimano hollowtech model