SupiV Posted August 13, 2018 Share Hi All Can someone please explain to me what the difference between lets say a XX1 Eagle boost crank and a XX1 Eagle crank is? Is the type of crank determined by the chainring? 3mm for Boost and 6mm for non Boost? Thanks Link to comment Share on other sites More sharing options...
BaGearA Posted August 13, 2018 Share Hi All Can someone please explain to me what the difference between lets say a XX1 Eagle boost crank and a XX1 Eagle crank is? Is the type of crank determined by the chainring? 3mm for Boost and 6mm for non Boost? Thankscorrect Eddy Gordo 1 Link to comment Share on other sites More sharing options...
BikeisLife Posted August 13, 2018 Share Correct. It’s just a different chainring offset for boost frames so obtain a better chain line. Link to comment Share on other sites More sharing options...
SupiV Posted August 13, 2018 Share Thanks. That is what I thought. Lots of different opinions on the web. Edited August 13, 2018 by SupiV Link to comment Share on other sites More sharing options...
Grease_Monkey Posted August 13, 2018 Share Saying the same thing as above but maybe in a different way... There is no difference between the crankset on a boost and non boost bike, boost just uses a 3mm offset chainring, and non boost a 6mm offset. If a crankset is being advertised as boost it simply refers to the chainring attached to the crankset when you buy it. Link to comment Share on other sites More sharing options...
DieselnDust Posted August 13, 2018 Share Saying the same thing as above but maybe in a different way...There is no difference between the crankset on a boost and non boost bike, boost just uses a 3mm offset chainring, and non boost a 6mm offset. If a crankset is being advertised as boost it simply refers to the chainring attached to the crankset when you buy it. Well.... That's not entirely correct. A non boost bike may have a narrower Q factor crank than a boost bike. Boost cranks are generally >164mm q factor while non boost is generally >155mm. Then the chain ring offset is 6mm for conventional and 3mm for boost. boemelaar_bob 1 Link to comment Share on other sites More sharing options...
Grease_Monkey Posted August 13, 2018 Share Well.... That's not entirely correct. A non boost bike may have a narrower Q factor crank than a boost bike. Boost cranks are generally >164mm q factor while non boost is generally >155mm. Then the chain ring offset is 6mm for conventional and 3mm for boost.Yeah, true. Just referring to the general aftermarket sales of cranks - the majority of the ones I have seen differ only with the chainring offset. I've used cranksets from boost bikes on non boost frames and vice versa successfully by just changing chainrings. Personally I like a nice wide q-factor though, so having crank with a bigger q factor makes more sense for me. DieselnDust 1 Link to comment Share on other sites More sharing options...
GravelTime Posted June 11, 2019 Share I bought a boost Sram crank and would to fit it to my non-boost frame..should I use 3mm or 6mm offset?Thanks Link to comment Share on other sites More sharing options...
Captain Fastbastard Mayhem Posted June 11, 2019 Share I bought a boost Sram crank and would to fit it to my non-boost frame..should I use 3mm or 6mm offset?ThanksAnswer is in the post above, but 6mm. Link to comment Share on other sites More sharing options...
Wilhelm Landman Posted July 30, 2019 Share I currently ride a non boost mountainbike with a Quarq powermeter. I am looking to upgrade my bike, to what will be a boost bike. Will my Quarq be compatible, and if not, is there any way to do some sort of conversion? Link to comment Share on other sites More sharing options...
Mongoose! Posted July 30, 2019 Share I tried to put my Scalpel (first generation) crank on my new Scalpel Si. The spindle was too short. (Both BB30)Is the term "Boost crank" not referring to the spindle length of the crank? a Boost crank has a longer spindle as the BB shell is wider? My new Scalpel has a boost bb shell but a NON boost rear hub. If you think you know, please ad a link in support... Link to comment Share on other sites More sharing options...
BikeisLife Posted July 31, 2019 Share I currently ride a non boost mountainbike with a Quarq powermeter. I am looking to upgrade my bike, to what will be a boost bike. Will my Quarq be compatible, and if not, is there any way to do some sort of conversion?Nope, you get a boost specific quarq spider, you'll need to get one of those. There isn't a way to convert it. You could probably run the non-boost quarq on the bike but the chainline will be out. Best option will be to sell the unit and buy a Sram crank and then buy yourself a Power2Max unit. Link to comment Share on other sites More sharing options...
DieselnDust Posted July 31, 2019 Share I currently ride a non boost mountainbike with a Quarq powermeter. I am looking to upgrade my bike, to what will be a boost bike. Will my Quarq be compatible, and if not, is there any way to do some sort of conversion? Short answer is no because the non boost Quarq mounts the chainring on the frame facing side of the spider. In order to meet the boost chain line requirements the chaintring needs to a further 3mm outboard requiring you to take material away from the spider to mount the chainring in this position. If you have the 8 bolt mount spider (uses 8 bolts at the back to mount the spider instead of 3 bolts) then you can replace the Quarq spider with a Boost version. he other property to consider is the crank a 156mm q factor or a 168mm q-factor? if 168 then the crank arms are worth saving.If its 156mm then the crank will likely not fit but you will have to trial fit to be absolutely sure. If you crank is the old 3 bolt spider mount and 168mm then a Power2Max NGeco power meter spider is the alternative as Quarq is no longer available in 3 bolt mount Bike Mob 1 Link to comment Share on other sites More sharing options...
DieselnDust Posted July 31, 2019 Share I tried to put my Scalpel (first generation) crank on my new Scalpel Si. The spindle was too short. (Both BB30)Is the term "Boost crank" not referring to the spindle length of the crank? a Boost crank has a longer spindle as the BB shell is wider? My new Scalpel has a boost bb shell but a NON boost rear hub.If you think you know, please ad a link in support... the older Scalpel use a BB30 ID42 x73mm shell. The scalpel Si uses a PF30 ID 46mm x 83mm long BB shell so the axle will have to be a longer unit (137mm Ai axle). boost just refers to bikes that have a 148mm wide spacing between the dropouts for the rear hub, the Drivetrains are shifted outboard by 3mm. This may or may not affect the crank axle length depending on the bike and crank combo,In most case it has just resulted in wider q-factor cranks and not longer axles. e.g. Shimano Hollowtech cranks still use the same length axle but have a 6mm wider q-factor now.Cannondale uses the same Hollowgram SiSL crank arms but uses different length axles.SRAM BB30 and GXP uses the same lkength axles as they have in the past but have increased the width of the bearing seat to allow the bearings to be spaced differently in different BB shells. the exception is the SRAM Ai cranks used on Cannondale Scalpel Si bikes where the axle is longer by 10mm (PF30-83) Mongoose! 1 Link to comment Share on other sites More sharing options...
Bike Mob Posted July 31, 2019 Share I currently ride a non boost mountainbike with a Quarq powermeter. I am looking to upgrade my bike, to what will be a boost bike. Will my Quarq be compatible, and if not, is there any way to do some sort of conversion? Depending on the frame chainring clearance and what size chainring you use you may be able to use it, try it first and if you cannot get enough clearance then you would require the boost spider. DieselnDust 1 Link to comment Share on other sites More sharing options...
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