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I'm building another kids bike.
Its a boost frame and I've torn off the boat anchor Sram SX cranks and putting a set of 'non-boost' 152mm Samox cranks on that have a Sram DM chainring mount.
If you can see the photo, I need to push the chain ring outboard by 3mm to get it centered in the chain guide.
According to Oneups site, they make a switch dm carrier in 0, +3mm and +6mm offsets, but this is driven by non/boost/superboost spindles and I'm unsure if this 'offset' is measured away from the chainring mount face (towards the bike center-line) of if is exactly as I need and is increased chain line outboard?
Can anyone advise how I increase my chanline by 3mm on this chainset (without just adding a 3mm spacer to the spindle as I don't have spindle penetration to NDS to allow for this)
https://photos.app.goo.gl/3MpnJ3f5EZXirnkz6
Ta
I'm not quite sure what you are asking but IIRC only Shimano (out of the main players at least) have Boost / No Boost etc cranks. Sram certainly just have one crank and then the offset is provided by the chain ring. Looks like you have a 6mm offset (non Boost) ring on that crank, and just need a 3mm offset (Boost) ring to move the ring further out. 0mm is for BB30 cranks, although may have other applications.
Here is a bit of related reading:
https://www.wolftoothcomponents.com/pages/boost-chainline-and-chainrings
Sounds like you need a 6 mm offset. Full explanation of how to measure offsets is available on our on our item pages. Basically zero offset is 4 mm thick chain ring Is completely flat. Hope that helps
Neil SuperstarComponents
What offset chain ring have you got fitted at the moment. My understanding of the different offsets available for a SRAM direct mount is that the bigger the offset is the nearer to the chain stay it gets. Looking at your photo are you wanting to move the teeth further from the chain stay
Yes, further from the chainstay to be centered in the chain guide
I think Will had it right off the bat, it has a 6, I need a 3.
0 would put the teeth on the opposite side (rhs) of the chain guide.
That's what I figured looking at the photo. If that's the case then the 3mm offset should do it. Depending on how many teeth the chain ring has you should be able to easily sort one.
Will has it correct, you want a boost ring
Here's another suggestion, do you really need the chain guide on a kids bike? Chain retention these days is pretty good with narrow wide rings and clutch mechs. Your cheapest option is to leave off the guide.
Here’s another suggestion, do you really need the chain guide on a kids bike?
Fair comment but we are talking about West Coast Canadian kids and we're saving a fortune with them not playing hockey 😉