Indoor bike - buy new or new groupset?

Oreo speaketh the truth here. And on a related note to the original dilemma of ride quality and parts, etc., your self-selected cadence of 60 isn’t doing your groupset any favours. That’s a lot of constant high strain grinding that you could work on fixing to improve ride quality. I would wager the smoothness of the groupset would improve greatly with quicker cadence (this also impacts has well your bike shifts).

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I put a triple on my trainer bike, it saves having to use the trainer difficulty slider in zwift. That slider in zwift just scales the gradients so it won’t give you more top-end.

I also have tiagra 4703 on an outdoor bike that originally had 6703 on it and the tiagra 4703 is a huge improvement. You should be able to run pretty much any road triple with the 4703 and it’ll work. I’m running a 6603 crankset on mine. Lots of cheap triples out there I have a 12-30 cassette but you could probably keep your 11-34 with a triple and have an extra low gear for the alpe, as well as a good top-end, with more than enough choices in between. If you wanted to be safe with the rear derailleur you could buy one of those derailleur hanger extenders.

same here… in fact I use wax for everything but indoor trainer now

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This is something I just can’t fathom when it comes to the trainer. And perhaps the answer is in the settings for it, as I’ve changed nothing (everything is at defaults).
But I’m not a great cyclist, I’m 102kg and only ride in spring-autumn probably once or twice a week most of the time. Instead of 2 x 60-80km rides that I can get done outdoors, on trainer the intensity of the events means I generally just ride for about an hour or, tends to be 28-40km in total (some of the crits are only 20km).
My FTP is 260 estimate on Zwift, so I’m not at a high level.

I don’t ride that low a cadence on the roads. In fact since I got Sram AXS I’m spinning now more than I ever have, and I’m good with that especially noticing it better on climbs.

But in Zwift, if I’m going at 100rpm I am only putting out about 200 Watts and when you’re over 100kg, that’s obviously under 2.0 w/kg and you’re gone even on the 0% sections.
I feel I have to ride in higher gears, and hence lower cadence, to keep up.
If I try to pedal faster, in the higher gears - that’s when it feels like I’ll suffer knee issues because it feels like too much load on my knees.

If I spin, I don’t have cardiovascular issues first - I can ride like that for 30 minutes if need be, the problem is that whilst my legs are spinning at 100-110 rpm I’m losing the group.
So does that mean I need to somehow spin even faster (120 rpm), or does it mean I need to ride a harder gear but still spin at 100+?

I don’t have many gears to play with on this - in the 11 at the back it’s the hardest gear, if I drop 2 sprockets at the back I’m already getting dropped, definitely if I drop 3.

You’re probably going downhill. 50x11, I can get over 1200W on a flat sprint. Spinning out at 50x11 (even if it’s just 60rpm) has to be on a decline. I can probably load it up and give it a try, or someone else can comment. I can’t really recall, just that I know when I ride Tempus Fugit, 50x11 can get well over 500W.

I use 34x32 on my outdoor bike, as the lowest, but use 34x25 (would prefer 23 if it wasn’t more expensive than the 25) indoors.

The latter. The point is not to spin high cadence at a gear with no resistance. You don’t need to go 100+. You can spin faster, in a controlled and sustainable manner. Over time, you can increase your cadence. There’s a limit to it, though. My natural cadence is around 70rpm. I ride around 80-85rpm until I get fatigued. I can probably hold 90rpm for about an hour.

I use 9 speed on the trainer bike. It’s plenty fine for Zwift, just as it was for outdoors for the longest time. 11 speed would just give me 2 extra lower gears, but I don’t really need to go lower than 25 on the back for Zwift at the default 50% trainer resistance.

ditto. I think fixing what you have is the cheapest. It shouldn’t cost a whole ton, may the front and rear derailleur at the most.

Hmm, I remember something about this as well, but can’t recall what the specifics are, would have to look it up. Maybe you’re onto something here, I think OP mentioned Tiagra shifters.

Not downhill - I deliberately redid the flat stage of the Zwift Tour earlier to trial this out, and on the 0% I was consistently between 66 and 72 rpm.
And I was doing about 300 Watts.
I’ve never gotten anywhere close to 1200, ever, I think the most I’ve hit even for a second was 860 or something like that - I certainly don’t have strong legs when it comes to the pedal stroke (having played contact sports for years I was more trained for power lifts).

I genuinely can’t make my legs go faster in the 50-11 gear though, the muscles tire and tighten and as another poster suggested I even after a while feel it a bit in my right knee.
Hence I drop down at least one gear to spin, but usually to get close to 100 I have to move down 2 gears or 3. So by then I’m in either 50-26 or 50-23 (the 34 cassette being 34-30-26-23…). And whilst I can spin at 100 rpm there, it’s putting out about 200 Watts and I get dropped.

I have when I first got Zwift, mucked about with a 2nd fake profile to see how much difference weight makes. It really adds drag - I was 106kg at the time but I set up a 2nd user at 76kg to see the difference and its crazy how much it matters on the flat. I completely understand why it makes a huge difference on climbs, but in real life I’m riding and my mate (who is about 80-85kg) is clinging on even though his FTP is much higher than mine (he rides for a team in Cat B on Zwift year-round). So in real world I can hold my own on the flat, it’s as if Zwift overemphasises how much effect weight has when not on an incline.

Here is what I think is happening: you wrote earlier that your FTP is 260 W, i. e. 300 W is VO2max territory (115 % of your FTP). And with 100 kg you have strong legs (they have adapted to deal with your body weight), but your cardiovascular system isn’t very strong. So you lean on what is currently the strongest: your leg muscles. The lower the rpm, the more you shift the burden towards your muscles and away from your cardiovascular system.

But if you want to keep up, you need to improve your cardiovascular system.

The point is that you should sift down rather than just increase rpm in the same gear. It is highly unusual for someone (who is not a pro) to be in 50:11 on the flats.

100 rpm is too quick for most, the recommended cadence range for most is 85–95 rpm on the flats with some people being on the lower side (think 80 rpm) or on the higher side (100 rpm). If I were you, I’d try to shoot for 80–85 rpm. Spinning at 100 rpm feels quite unnatural if you haven’t trained for that. Most people tend to like to spin faster when they are moving faster: the rotational inertia of the wheel tends to keep things spinning, and you can get away with a more uneven, “stompy” pedal stroke. On an incline (or on a low gear on the trainer) you need to keep on the more for the entirety of the pedal stroke, so most people favor a lower cadence.

Overall, try to increase your cadence, but be reasonable. Extend the range of cadence where you feel comfortable over time. This has nothing to do with you weighing 100 kg, this is just training. You’ll get there eventually :slight_smile:

Thanks for the explanation.

To be honest what you have written ties in exactly with how I ride on the road. I’ve SRAM on my main road bike and I never really use the 46-10 other than when already going pretty fast. I am normally in the 80rpm average on the road (unless doing a particularly hilly/climbing route).

But this is where I don’t find Zwift quite so realistic - I absolutely have to put out more effort to ride in a group at 40km/h on Zwift than I do on the road. And of course you can’t coast either. Hence Zwift is always a much more intense ride, and why I only tend to do an hour on it whereas in real world I pretty much always ride about 3hr (at least 2, usually closer to 4hr total). I figured that’s fine for the purpose of getting quick training rides in over winter, and the events keep me motivated as competitiveness kicks in, as opposed to when I used Trainer Road which was instructive but I struggled more with motivation.

So basically you reckon I should ride in probably the 50-30 and try hit about 85rpm?

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