Cannondale MTB Ai Offset Decoded

[@That_Stealth_Guy]

As an owner of a 2020 Cannondale Habit and 5 other Cannondale MTB's of older generations, I am used to Cannondale quirks. However, this is a great video for those that couldn't figure it out the Ai offset quirks since there is hardly any information out there. Cannondale has always loved their mysteries, it only got worse once they got bought out and moved to Taiwan. Thankfully, Cannondale ditched the Ai offset on the 2023's when they FINALLY added the UDH.

[@AndyTSC1]

Thanks a lot for this, I finally find someone who explain this in a reasonable way. So technically if you need to replace only the chainring in the transmission you could as long as you get one with direct mount and 6mm offset right? Again, thanks for the video!

[@BBInfinite]

If the Transmission crank set is SB+, you can use it in an Ai MTB with a caveat; it's 2mm longer than the Ai Dub spindle. That means you're effectively decreasing the +6 chainring offset by 1mm, so now you'd be more like +5. This is not a major problem. We recommend reducing the Dub Offset spacer (all Dub systems have an DS offset, so don't be confused, this isn't the chainring offset we're talking about ) by 1mm on the DS and move that 1mm over to the NDS so the pre-load adjuster isn't stroked out. Once finished the chainline will be money and the crankset will have a slight 1mm offset from the frame centerline. You'd never notice this when riding.

[@bohous808]

@@BBInfinite Same question as @andyTCS1 but I'm not smart enough to completely keep up with your thorough explanation. For the dumb guys, if swapping out the chainring only can we simply go with a 6mm offset and be ok or do we still need a spacer? Is the current chainring on my Habit a 6mm offset?

[@joebikeguy6669]

You helped me before (I did not realize my CAAD 12 was asymmetric until you told me, so thanks!). Anyway, I just got it back from the painter and am planning to install a BB30A Outboard threaded together bottom bracket. I just noticed that the outer lip of the BB tube is painted which makes the OD 74.18mm. Should I use a stone to remove the paint from the outside surfaces, to get it down to bare metal and closer to 73mm? I remember you said the Shimano safety tab will not close if the dimensions are a bit off. Anyway, any advice is appreciated. Continued success with your channel and thanks in advance.

[@BBInfinite]

We don't make thread together bb's. Sorry. They are rubbish. We made some early one and we quickly saw how they: Did not align bearings properly. Always end up creaking because they loosen up with use. Make achieving the perfect chain line almost impossible because a thick flange on either cup is forced into the system. Thread together is dreadful. Go one piece or nothing.

[@joebikeguy6669]

@@BBInfinite thank you, regards,

[@alexberrypgt]

Great vid thanks! So i cant use my Dub Ai chainset on a non cannondale bike? Id planned to move the bits from my FSi world cup to a pipedream sirius but it sounds like ill need a new chainset

[@BBInfinite]

A DUB Ai MTB crank spindle length is 2mm longer than a standard SB+, so we see no reason why you can't run it in any place an SB+ crank would work. 2mm means 1mm shift in chain line, which is basically meaningless, especially considering a 1X system. Don't forget that the Ai 6mm offset ring isn't going to work on your new bike, you'll need something else.

[@BVAR16]

What's the difference between Wheelset SL 27 Ai and non Ai? Same 148 boost hub? I'm planning to buy a Scalpel carbon 3 (Ai specified, not 55mm like the Hi Mod), those wheels and also I actually have a dub XX SL crankset but 3mm boost chainring, I wanna know how it works, thanks

[@BBInfinite]

And Ai wheelset is laced so that the hub is offset in the hoop so the wheel is on the centerline of the bike frame whilst the hub is not.

[@christiangottlich6207]

Would it be possible to install my Sram Ai crank with a chainring with 6 mm offset on a Scalpel without an Ai triangle?

[@BBInfinite]

Are asking: My Scalpel is the older model (pre-2016, before Ai offsets were a thing) with standard 73mm wide MTB PF30 (46x73), and I would like to install an Ai crank set that I already have? If that's the question, then yes, treat the Sram DUB Ai crank like an SB+ as they are only 2mm different. You'd need a different ring because 6mm offset is not going to work in a symmetrical system.

[@christiangottlich6207]

@@BBInfinite I have a 2023 Cannondale Scapel frame with a UDH derailleur hanger. I still have the Sram XX1 Ai crank with a 6 mm offset chainring from an old Fsi. Which chainring should I use on the new Scapel, one with 3 mm offset?