Powermatch with fixed gear bike and Tacx Bushido Smart

Previously I’ve been using a dumb trainer, my geared road bike, and my P1 pedals connected to my android phone.
I’ve just started trying to use Powermatch with a Tacx Bushido, the same phone and pedals, and my fixed wheel TT bike in erg mode. The gearing was 48x17, but I can try different sprockets (up to 20, down to 14).
I’ve only done one ride so far, but I found that I couldn’t warm up or recover below about 150W without the resistance ramping right up, and it didn’t lock me into a power as much as I was expecting - it’s all over the place.

I didn’t do a calibration of the trainer as I wasn’t sure if a roll down made sense with a fixie. I don’t know if this is a problem with my expectations, my trainer, the combination of the trainer and the fixie, or an issue with the communication between the pedals, phone and trainer being too slow.
Does anyone else do TR with a fixie on a wheel-on trainer in erg mode? What changes should I try to make this work (I really want to use the fixie so I can spend time in my aero position)?

I know someone who uses their fixed gear for Zwift. I’ll see if I can get a hold of him to see how he handles calibration etc. I don’t think he uses PowerMatch though, just Zwift and a smart (TACX) trainer. Personally, I put my road bike on the trainer and use the track bike on the rollers.

Did you get the axle adapters to fit your bike on the trainer?

Thanks, I’d appreciate knowing how anyone else does this.
I’ve got the original Tacx bolts so my fixie fits on the trainer OK. I was hoping that I would be able to maintain a cadence and the Erg mode would just ramp up/down the effort required, but that wasn’t how it worked. It might just be that the time lag between the turbo and the pedals is just too great to keep everything consistent.
I’ll try not using PowerMatch tomorrow and see how that goes.

One of your issues may be the “wattage floor”. This is the lowest resistance level that can be provided by the trainer. It varies from trainer to trainer, and within gearing on a given trainer.

I suspect the somewhat fast/tall gearing you are using is preventing lower resistance levels. You should try a slower/lower gearing and see if that helps on the low end, without sacrificing on the high end.

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Thanks - I will try 48x20 tomorrow when I run without the pedals connecting. To go to a lower gear I need to get a new chainring and change the chain length.
The trainer is one that doesn’t need to be plugged in - I was hoping that the tallish gearing would mean I didn’t have a problem where I was going so slow that the generator was unable to run properly, but I guess I didn’t account for how low the braking effect would go.

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I set the bike up with the 48x20 gearing and MTB pedals, and I tried to loosen off the wheel roller so it wasn’t eating too much energy. Then I tried the spindown calibration (ride to 40kph, take feet off pedals), but that was done in 0 seconds!
The power would go down to ~120, but no lower and it wasn’t easy to ride at that level (cadence of around 60), but when it boosted up to over my FTP it felt like I was doing single leg squats (even with a cadence of 85 or so), so I gave up and did some single leg squats and stretching (no time to reset and then do something meaningful before going to work).

Saturday I want to do a ramp test - I think I’ll try it with the road bike, the P1 pedals, the Bushido smart and PowerMatch. That will at least give me gears to make life a bit easier at the low end. I’ll see how that goes and report back. /If it goes horribly wrong, I can always do another FTP test with the dumb trainer.

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Since you have the road bike, seems like some testing would be useful.

Play with gearing and low power stuff to see what, if any, effect that has on the power levels.

You might be able to determine a decent gear ratio that you can closely match on the single setup.

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I tried it with my road bike and P1 pedals on the weekend. It definitely worked better, though the gear ratio was ~ 34x25 or thereabouts, so I don’t think that’s going to be useful to keep as a single speed/fixed gear setup.
The plan called for a ramp test, so I did it, and I sucked! Not sure if this was down to eating/tiredness/motivation, (all of which were sub optimal) or whether it’s just harder on an erg trainer. I’ve been around 240 for a few months, but this ramp recommended 224 or something like that. :frowning: Then again, the last one I did to proper failure, this one I quit on, so maybe that’s the answer right there. I think I’ll be sticking to the road bike on the ergo for now.

I’ve used a fixie on a trainer for years – one note about coastdown calibrations (I used a Kinetic Inride for a couple of years before springing for a powertap fixed hub): a fixed gear won’t give you an accurate coastdown; if you can grab a bmx freewheel in the right cog, and you have a flip-flop hub, going with a single-speed freewheel will give you better, more consistent and accurate coastdowns (within the range of the Tackx).

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Fail again today (in a geared bike, using powermatch with my phone, the P1 pedals and the Bushido Smart.
Second interval of second set, the resistance just died off. I don’t know if it was the power meter, the trainer, or TR on my phone, but it was like I finished the interval. Resistance didn’t pick up for the third one, so I stopped and recalibrated the trainer, and suddenly I was having to do 400W instead of 300W! I then recalibrated my power meter, which jumped from 18 to 23, but made no difference. I then stopped the ride, turned off bluetooth, turned off TR, and booted everything back up. I rode 2 intervals at 400W, and then changed the intensity to 85% so that the resistance came down and I could do 400W. I turned it back up again for the last set, and resistance seemed a bit low, so I wasn’t able to get 300W unless I span at >110 rpm. I was short on time by that point, so I skipped ahead to the cool down.

I can see the advantages of erg mode, in forcing you to do the workout as specified, and not clunking up and down the cassette, but it’s really frustrating when this sort of thing happens.

Hi DuncanM23, I am experiencing exactly the same problems with my dad’s old Bushido Smart trainer (that I use because my own Tacx Vortex is broken, however up till last month this Vortex worked perfectly with TR), even up to the 0 seconds run down from 40kph.

did you already found a solution for your problem? As I also experienced issues with the Tacx Trainer app I subsequently used for comparison purpose, I suspect this may be faulty hardware issue?

Any tip / suggestion is warmly welcomed :slight_smile:

Stijn

Hi @strynw
I think there were a couple of issues happening. With the fixed gear bike I think the gearing was just too high, so it couldn’t adjust the resistance down low enough. I solved that by getting a 24 tooth cog for the wheel - it’s been great with 48x24 gearing.
The other issue of massive ramps in resistance may have been due to a couple of the workouts putting the trainer into resistance mode. Some workouts (eg the ramp test) put the trainer into resistance mode, and if you aren’t aware what’s happening, then it’s really weird.
Give it another go with a workout you know, see how that goes and report back. :wink: Good luck…

I’m primarily a fixed gear rider, full on roadie, I just prefer to ride fixed.

I’ve traditionally used my geared bike for all my TR training, since last spring. However in February I’ve moved to doing indoor rides on my fixed gear.

I’m riding a different setup that you. I use my Garmin Vector 3 pedals (fixed or geared) for all power and train on either a set of no resistance rollers (Tacx Antares - 20% of indoor riding) or a dumb trainer/roller (Feedback Sports Omnium Over-drive - 80% of indoor riding).

47x17 (73") is my go-to, all around, do anything gear and what I ride most of the time outside. I’ve found it also good for all workouts under Threshold with only slightly higher cadence than geared (100-105rpm, which is normal for me outside anyway). For Threshold and above I gear to 47x15 (83") or ever 53x15 (92") if I also want to focus on power at the same time (of steady state with some sprint pulls in it). I’ve found these gearing options are around where I’d shift into geared anyway (one the Omnium, for rollers I keep it to workouts like Baxter). The one drawback that I can see with training fixed is the rest valleys are not the same. Since I rarely ride geared outdoors anymore not being able to “rest” is more realistic for me but on the trainer it means cadences under 60rpm often, which is not for everyone.

Lastly, fixed on the road gives you momentum for your legs, since you can’t coast. On the trainer it’s a different feeling all together, a much more clear “stop” when I stop pedaling. Even my geared bike will coast a little.

I know this doesn’t answer you question directly but maybe it helps figure out gearing and what things should feel like for you. I’m happy to answer any other fixed questions.

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Thanks for the tips, I’m just getting started on a “serious” training plan other than just get out and ride.
If you dont mind, can I pm you with specific questions. I’m on fixed with rollers too.
Thx!

Post your questions here. I get alerts, but you’ll get good info from others too. :slight_smile:
I might not be able to help much with rollers - I only got my first set today and I’ve not ridden (i.e. fallen off) them yet.