I have a Trek hardtail frame set up permanently on my Kickr Core, but have been using the flat bar shifter and an old 11-34 11 speed cassette. I’m trying to expand my horizons beyond erg mode since I got a deal on 11 speed 105 shifters and derailleur I’ll be using this set up with TrainerRoad (year round) and maybe Zwift over the winter.
Do you think it makes sense to go with a cassette with really tight spacing like 12-25, so it’ll be easier to fine tune power/cadence in resistance mode? Or is it better to have more range (use 11-32 on the road for example)?
I’m not an erg mode user, and would go as tight as possible for dialing in cadence to a given power. I have 11-28 on my trainer bike and will be moving down to 11-23 or 11-25 when the time comes for a new cassette.
If it’s exclusively for trainer use, I’d probably go with something with tighter spacing so you can really dial in your cadence. No need for the super easy gears when you’re indoors on the turbo!
If you plan on using the trainer to simulate climbs, then get a wide range cassette just like you would for outdoors. No sense getting an 11-28 and trying to climb simulated 12% with it … Otherwise, listen to above suggestions!
Hadn’t thought about climbs but thats a good point. I could see really close spacing being useful for endurance and steady state intervals, but wonder if more range would be useful for VO2/ Zwift climbs
I would try it on Zwift before buying. I had a 11-23 on my trainer, but found my natural cadence for endurance riding on Zwift had me cross chained (always on the big-big or small-small combinations) on the flat.
After years of having my trainer difficulty set to 0%, I ramped it to 50-100% for some training rides as I wanted to break the boredom and have a feel closer to the outdoors. I found my 52/36T combined with an 11-30T cassette was just not enough to do proper climbs comfortably, so swapped to an 11-34T cassette.
If you are on desktop for TR (with access to mouse or keyboard), using the percentage adjustment of Resistance mode is a relatively easy. I do this via the Left/Right Arrow keys and you can really dial in your cadence/power without touching your actual shifting.
That may be a better option while maintaining your existing cassette for wider use in Zwift and such.
Let me mention one factor: low cadence drills and sprints. How many do you do of those? If the answer is non-zero, I’d get the biggest range that fits (e. g. a SRAM 11-speed 11–36 cassette). If you don’t do those, you can stick to tighter gearing.
For reference: I have a 10–36 cassette with a 42-tooth chainring on my trainer and I regularly use the first 8 gears (i. e. 1x). I have adjusted the difficulty so that I am doing my rest interval in the easiest gear.
Great points! I found a killer deal on a 12-25, and currently have an 11-34. I think I’m going to try both!
I got stuck in the erg spiral of death on a recent threshold interval, so I can see the benefit of having tight spacing for those kind of intervals in resistance mode. But I see the flip side too…your point is well taken about cadence drills and sprints.
Trying new things is always a good thing, especially if it is for cheap. I vastly prefer resistance mode for anything except perhaps endurance rides on the trainer where I want to relax a bit.
And just to mention it since things like cadence and sprint stuff was mentioned, it’s worth a look to see if your trainer offers Standard mode too. This is like Resistance but STD has a more progressive wheel speed to power curve that is more like older fluid trainers. STD has a 0-9 scale and works well for stuff like sprints and such because the power ramps up more quickly with wheel speed vs the very linear way RES does. Each may be preferred for a number of reasons, but it’s good to test both if you have them as options.
I use an old road bike with 9 spd Campag for my trainer bike…pretty sure I have a 12-25 cassette (with a 53 / 39 crank)
Absolutely zero issues with it for TR and ERG mode…but can quickly run out of gears when riding on Zwift with sustained climbs. As a result, I have my resistance setting for Zwift set to ~65%, IIRC. With that setting, I can do all the climbs and keep a reasonable cadence at all times.
Living in the dead-flat Chicago area, I would absolutely kill for a 11-23 12 spd cassette. I probably only use 6-8 cogs on my existing cassettes (road or gravel).
Not to mention straight-block cassettes just look bad ass.
Slightly off topic, but on the general topic of cassettes for trainers: I wish someone would make an all steel cassette prioritizing longevity & shifting / rigidity (who cares about weight) for use on trainers.
Most cassette are steel, unless you are taking the more modern super-wide range stuff like AXS, MTB and such that utilize aluminum for larger cogs. Just about any “budget” level cassette is steel, even from the main makers and certainly most of the 2nd tier brands is too with the exception noted initially.
AFAIK, TR’s Standard mode is available on all Wahoo trainers (not sure about the bikes) when connected via Bluetooth, DirectConnect or WiFi. I don’t think it’s there via ANT+.
I’ll be using this set up with TrainerRoad (year round) and maybe Zwift over the winter.
