Just purchased the kickr core to use for 2021 top fuel 12sp for rainy days.
The fop fuel IS compatible with the unit.
I’m using my old sram nx eagle cassette that originally came on bike and is mounted on the micro-spline drive that was pre-installed on kickr. I have the 148 boost adapter on non drive side and the drive side spin cap. shifting is fine except when shifting all the way to lowest range of shifter it jumps off the last sprocket. wahoo tech is telling me i need the xd driver which makes no sense? their also telling me i may need to adjust the derailleur? I would think the whole idea of have spacers is position the cassette exactly the way in needs to be centered between the axels and to not have to adjust anything. the bike is ridable, but i need to be aware of not shifting to shifters lowest range.
I can’t help on the SRAM side of things but it’s not unusual, in fact I’d expect to, to have the adjust the derailleur when you take off the wheel and put the bike on the trainer. A quarter turn or two of the barrel adjuster does the trick for me.
Check with SRAM if your 12 speed is XDR compatible. I have AXS which will NOT work with the KICKR unless I use one. If it doesn’t it may be a matter of adding or removing spacers to get the right fit. If all that happens is overshifting, you may just need to adjust the derailleur to not do so. Are you having issues with the chain hitting your frame when in the smallest cog? That means you need to adjust the low limit screw to keep this from happening. It’s not just a matter of adjusting the barrel or cable setting. If you are on a wireless system, you WILL have to set the low limiter.
@owenpga I think you are correct that NX is compatible with Shimano.
On the spacers, my experience has been mixed - sometimes they work perfectly and sometimes you need to make an adjustment. I think it has to do with how much torque you put on the cassette when installing along with variations in spacer width.
I think we all missed the original posters information:
SRAM 12 Speed shifter and system.
NX 11 Speed cassette.
I would check with SRAM but I think that SRAM has stated that 11 speed cassettes CANNOT be used with the 12 speed systems.
Not a KICKR issue at this point.
im using the 12sp sram nx cassette not the 11sp.
since i ride on the trails more than i do on the trainer i’m trying to avoid having to adjust the derailleur every time i use the damn thing. it’s an over-shifting issue nothing else. yes the chain falls between cog and frame. i’ve done every configuration of the adapters possible with the current one being the best. i guess i’ll just have to live with it.
- List item
There should be no difference on the distance on the small cog. Do you have the same issue with the small cog when you have the 12 speed cassette mounted? If so, the limit screws need to be adjusted and I highly recommend having this done at the LBS unless you are very familiar with this process (I have over 40 years of experience and unless this happens on the road, I’m at the shop having it done.)
I’m now completely confused and need some help here. Original post says that you have a 12 speed Top Fuel. You also state you are using the original 11 Speed NX cassette on the KICKR. So, here’s how to unconfuse me:
- What is the cassette installed on the bike for outdoor use?
- What is the cassette installed on the KICKR?
- Are you experiencing overrun on the inner most cog when you are outdoors?
One thing to check is if the KICKR has the same amount of space between the smallest cog as you do when you have the outdoor wheel installed.
The usual situation is that you will experience overrun on the biggest cog because you are now overshifting it. As a matter of compatibility, you should be using the same cassette and number of gears on both your outdoor and indoor bikes. If you are using a SRAM 12 speed cassette and it is AXS/XPLR compatible, you WILL need to use an XDR adaptor. I’m thinking of downgrading my wheels to use a AXIS compatible 11 speed hub and I will have to replace the freehub or it will not work properly.
I think you might have to either adjust the derailleur or learn to live with it. The core comes with an HG body so your NX cassette is compatible. XD driver is only for gx and up. There is no Shimano 12spd compatibility(without some work around). While I am on Shimano I do experience some shifting issues on the trainer, but I like to keep the derailleur set up for the outdoors and accept the shifting issues indoor. I’m mostly in erg mode anyways, so my shifting indoor is limited to only a few workouts.
i’ve only mentioned having a 12sp in original post? Yes i’m using my original 12sp nx cassette.
Adjusting the limit screws works but it doesn’t actually adjust the shifting so when i shift to the bottom sprocket i have to shift 2x to get it up the next sprocket. It does fix the chain dumping.
"1. What is the cassette installed on the bike for outdoor use? 12sp gx sram.
2. What is the cassette installed on the KICKR? 12sp nx sram
- Are you experiencing overrun on the inner most cog when you are outdoors? no
One thing to check is if the KICKR has the same amount of space between the smallest cog as you do when you have the outdoor wheel installed.
The usual situation is that you will experience overrun on the biggest cog because you are now overshifting it. As a matter of compatibility, you should be using the same cassette and number of gears on both your outdoor and indoor bikes. If you are using a SRAM 12 speed cassette and it is AXS/XPLR compatible, you WILL need to use an XDR adaptor. I’m thinking of downgrading my wheels to use a AXIS compatible 11 speed hub and I will have to replace the freehub or it will not work properly." as stated earlier i’m using the same spacing cassettes on both wahoo and top fuel 2021 thanks for your help. i’m just going to live with it until i get another bike that i can keep permanently hooked up.
Thank you for answering my questions. Yes, you WILL experience issues because the NX and SX are NOT the same type of cassette. You have a great idea. Getting a trainer only bicycle comes highly recommended and what I was doing for about 10 years. Unfortunately, I stopped doing this when I bought my now stolen Pinarello (I had a 2014 Roubaix S-Works on my trainer). It comes recommended that you get an aluminium bicycle for this purpose.
Best wishes on getting on with indoor training and improving on riding.