So, new bike will have a boost back end and I’ll be using my existing Cinch cranks but I fancy trying an oval ring. Just can’t work out if the boost version is the way to go or not. While it seems like the obvious choice, there is plenty written that suggests boost works well enough with a more conventional chain line.

I have a conventional triple chainset with single ring in the middle position on my boost
frame. Works perfectly

I have a Cotic Flare with boost rear end 1 x 11 but running non boost cinch cranks and standard AB oval and don’t have any chainline problems

Ok!

I’ve just had a Boost Oval from AbsoluteBlack….. and a non boost too.

On a YT Jeffsy, Boost frame, Turbine crankset…

Long story short:

On my frame the 6mmm non boost chainring gave a better chain line. Pretty much spot on the middle sprocket on the 11 speed sram cassette.

But…. Only about 2mm clearance between teeth and frame. 30T ring btw.

To be honest I think it would have been fine but I’m a picky sod so went for the Boost version…. chaining not so good but more clearance. Boost version has 3mm offset.

Hope that info has helped a bit.

You just missed the non Boost, cinch, Absolute Black chainring I sold earlier today on here. 😉

Thanks for the info , especially Poopscoop. I guess it might be more of a clearance consideration than I chain line one in the end.

Yup, a mate’s just had to return a DM ring for his Jeffsy for the same reason as above. Way to close to the chainstay. It seems that the chainline is vaguely doable, but clearance is the main issue.

submarined – Member
Yup, a mate’s just had to return a DM ring for his Jeffsy for the same reason as above. Way to close to the chainstay. It seems that the chainline is vaguely doable, but clearance is the main issue.

Guessing he has the carbon Jeffsy 29er?

The alloy one has more clearance.

That said I know that some people are running the non boost AB Oval with only the 2mm clearance.

Bit too close for me though…

The 3mm difference doesn’t seem to be a showstopper in either direction. Use Boost if you’re tight on clearance. You might also find that using Boost cranks and some spacers to move the chainline back inboard 1 or 2mm will give a good compromise.

Similar to above. Non boost RF turbines on my Flaremax. 32T Oval *just* fits. Was a bit worried it would clog up with mud and foul chainstay but seems okay. On my Mojo 3 (same setup), no way to get a 32T on there. Don’t want to run a 30T.

Did consider the WolfTooth new Cinch system which basically turns it into a spider so you’re going to get the clearance that way. Decided it wasn’t worth $100!

Nt seen the Boost Ovals so far. Will take a look. Problem is chainline is very good and I’m not missing the oval as much as I expected.

Oh those boost ovals look pretty good. Going to try a standard one the wrong way round to give me an idea if it’s going to badly compromise chain line. Will do some pics and report back.

When it’s reversed it’s setup for fast bike use, the chain line will be massively out I would think?

Sorry wasn’t clear. I’ll reverse a standard one as that will be pretty similar to buying the boost version. I did run that config on my fat bike and it was pretty good.

Doesn’t the standard one offset inwards 6mm and the boost 3mm? If so, when you reverse a standard one, don’t you add 12mm to the chain line? Reversing a boost one would add 6mm, which sounds about right for a fat bike.