Sram boost / dub cranks - help needed

[DieselnDust]

then you need to change the offset of the direct mount ring. I'm not aware of 0mm offset from SRAm chainrings other than the spider mount versions. A 3mm offset is what you need if the crank you bought is non boost as the ring will be 6mm offset from the factory. the Boost 3mm offset ring should solve your problem

[Eddy Gordo]

OUCH!! I believe that could be your problem. Your chain ring might be too big. What size is it and is it oval?

[Yo-Yo]

then you need to change the offset of the direct mount ring. I'm not aware of 0mm offset from SRAm chainrings other than the spider mount versions. A 3mm offset is what you need if the crank you bought is non boost as the ring will be 6mm offset from the factory. the Boost 3mm offset ring should solve your problem

 

Thank you. That will save me a good R1000 by not buying a whole new crank. 

[Eddy Gordo]

As mentioned early its the chain ring that changes to boost offset

 

https://forums.mtbr.com/drivetrain-shifters-derailleurs-cranks/about-sram-boost-cranks-chanrings-1053669.html

 

https://community.bikehub.co.za/topic/178148-%E2%80%9Cboost%E2%80%9D-crank/

 

 

 

https://enduro-mtb.com/en/tech-talk-whats-the-boost-standard-all-about/

 

Paying more a crankset cause its "BOOST" is a no no

[Yo-Yo]

OUCH!! I believe that could be your problem. Your chain ring might be too big. What size is it and is it oval?

 

32 and it's round. Recommended max size is 36. 

[T-Bob]

As mentioned early its the chain ring that changes to boost offset

 

https://forums.mtbr.com/drivetrain-shifters-derailleurs-cranks/about-sram-boost-cranks-chanrings-1053669.html

 

https://community.bikehub.co.za/topic/178148-%E2%80%9Cboost%E2%80%9D-crank/

 

 

 

https://enduro-mtb.com/en/tech-talk-whats-the-boost-standard-all-about/

 

Paying more a crankset cause its "BOOST" is a no no

 

Here's a twist from my issue. Running a NX Eagle set up, non boost chainring, boost frame BUT I have non-boost Hope hubs with Hope convertors (which means they don't need redishing). Answers for 10.... Go!

[Eddy Gordo]

32 and it's round. Recommended max size is 36. 

6mm or 3mm offset chainring?

[DieselnDust]

Here's a twist from my issue. Running a NX Eagle set up, non boost chainring, boost frame BUT I have non-boost Hope hubs with Hope convertors (which means they don't need redishing). Answers for 10.... Go!

 

 

whats the question?

[Eddy Gordo]

Here's a twist from my issue. Running a NX Eagle set up, non boost chainring, boost frame BUT I have non-boost Hope hubs with Hope convertors (which means they don't need redishing). Answers for 10.... Go!

Wheels were not redished, so your cassette is inline, your disc is also inline cause if the spacers used.

[DieselnDust]

6mm or 3mm offset chainring?

 

 

He bought a non boost i.e. Std offset crank which means its a 6mm offset chainring

 

he needs the 3mm offset chainring

[Eddy Gordo]

He bought a non boost i.e. Std offset crank which means its a 6mm offset chainring

 

he needs the 3mm offset chainring

Agreed, I was not sure about the chainring, so yes def change to a 3mm offset. 

[MORNE]

Here's a twist from my issue. Running a NX Eagle set up, non boost chainring, boost frame BUT I have non-boost Hope hubs with Hope convertors (which means they don't need redishing). Answers for 10.... Go!

If it didnt need a re-dish it is because the spacers you used ad 3mm each side of the hub with plenty of bits. Wolftooth's Boostinator conversion for instance just replaces the non drive side's cup with a 6mm longer one than stock...leaving the cassette exactly where it was...but needing a wheel re-dish of 3mm. Easy 

 

EDIT: That also means your chain line is "sub optimal" according to the powers that be....but tonight go...with your non boost crank...and shift into the mid cog in the rear around 5 or 6 and you'll see your chainline will be near perfect with your non boost crank. As i already mentioned...Boost is foefie and was introduced to clear wider tires when cross chaining your great granny gear past your 2.8" tire.

[Eddy Gordo]

Thanks for the info everyone. That has helped alot but not 100% on if I need a dedicated SRAM boost crankset. I know that there are 6mm and 3mm offset chain rings for the Eagle GX but wasn't sure if the QFactor changes or if it's a combination of Spider and chainring.

 

I've found a cheap(ish) SRAM Boost chainset that I was considering buying but do you think It would be better to get the different offset chain ring rather. The GX was bought in January and at the time I thought I'd ordered the dub / boost version but apparently I didn't I got the Dub / standard version.

 

Shame Sram doesn't have more supporting documentation on this. Just frustrating as the bike shop that built the bike up from new didn't give any in diction that there was an issue and I took it back twice to say it was damaging the chain stays and each time they just added a random spacer. Most of the time it's fine but under power or climbing on the 50 it sounds like I've got a loose BB and that the barrings are grinding to dust. 

I had the same issue with my gx crank! Shop told me its a boost crank, which it is, but the 6mm offset chainring is not boost comaptible. However this didnt bother me as I needed a 0mm offset ring in any case.

[T-Bob]

whats the question?

 

I was wondering if there was any issue with running a boost chainringgoing to a non boost wheelset and the chainlink being 52. 

 

I originally had the set up described (non boost chainset with 32T ring) going to the non-boost wheels with spacers and the same issue happened as the OP. Markings on frame, too close and weird noises when in the top 3 gear ratio. That chainlink was 49 I think. 

 

Apologies if my case is confusing... I'm confused as hell about all of this! 

[DieselnDust]

I was wondering if there was any issue with running a boost chainringgoing to a non boost wheelset and the chainlink being 52. 

 

I originally had the set up described (non boost chainset with 32T ring) going to the non-boost wheels with spacers and the same issue happened as the OP. Markings on frame, too close and weird noises when in the top 3 gear ratio. That chainlink was 49 I think. 

 

Apologies if my case is confusing... I'm confused as hell about all of this!

 

There shouldn't be an issue. You may struggle with a little excessive chain noise in the granny sprocket and subsequent chain wear. But technically it's not an issue as xco racers using 38T chsinrings often have to opt for custom 0mm offset chsinrings to be able to fit anything bigger than a 34T ring on some bikes.

 

You will need to experiment to see if you can live with the few tradeoffs