Post it to me then
. I'm not allowed to buy one!Road Cycling
- Thread starter FrenchTart
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. I'm not allowed to buy one!
Soldato
I found when Im training its exactly what you need. Tells you the watts to hit, you can adjust to suit your goals/style. I agree though when racing in a RR its only there to log what you did lol.
Plenty people riding duals in the 1-5% region with every combo of source you can imagine so it's not crazy to think 5% or below is perfectly achievable. Even with the stated +/- % accuracy claims it's still more than doable.
Depending on your PWM and trainer you will have a +/- 1-5% accuracy..... So your PWM could be -1% and your trainer could be +4%. That's generalising, but you get the point.
Dual recordings is a calibration roulette. It's more about establishing a decent warmup and calibration routine which leads to closer duals than it being a proper test of accuracy or validation of legitimacy.
Sloping or scaling your PWM to match your trainer I would absolutely not advise if it's for racing/validation purposes!
Depending on your PWM and trainer you will have a +/- 1-5% accuracy..... So your PWM could be -1% and your trainer could be +4%. That's generalising, but you get the point.
Dual recordings is a calibration roulette. It's more about establishing a decent warmup and calibration routine which leads to closer duals than it being a proper test of accuracy or validation of legitimacy.
Sloping or scaling your PWM to match your trainer I would absolutely not advise if it's for racing/validation purposes!
Analysis from last nights TTT - https://www.zwiftpower.com/analysis.php?set_id=124353
Warmup in the Flux data, but some platform issues with Zwift last night meant it wasn't a particularly great one. Joined the pen and did a zero on the PWM before the ride/zwift data starts. While riding they seemed to track quite well.
My legs where a different matter, got dropped at 7.7km as we hit the lower ramps of the first KOM and had to surge through another team, when the real ramp hit a 5m gap quickly extended and I told them to leave me. I just couldn't recover. Equally me riding with a team expecting to average at least 3.5w/kg (who several last week finished at over 4.0w/kg avg) is my absolute maximum so I knew it was more of a case of hanging on as long as I could (usual team didn't ride). Now I'm hopefully getting some consistency I'll be arranging to ride with easier groups - at least until the couple of 'bad' data rides drop from my Zwiftpower averages (90 days...) to bring my numbers back down to normal...
The accuracy between the 2 power sources is just what I'm trying to pattern right now to get some consistency with the Flux as I've seen such variation with it. I'm using the comparison to a PWM for that, but now I have the Stages as my primary power source it's more of an interest to see how closely the Flux is tracking in various situations. I'm at the point now I don't trust it, but I do trust the 4iiii (and probably the Stages). I want to trust the Flux again but highly likely I won't until I can replace it (not happening any time soon)...
Not sure he did a massive power meter shootout - at least not recently, but all of his reviews you'll see him generally comparing them in his data. He seems to get them quite accurate and track but is probably one of the most experienced people in the world when it comes to that stuff, I'm just an amateur!
The Direto (or Elite trainers in general) have always had a good reputation for calibrating well and generally being accurate. Tacx far less so as I'm obviously finding. But I do think much of my inaccuracy I'm seeing now is due to the cold weather and not having enough time to do a proper 'warm up' and calibrate of Trainer & PWM before each ride/race. Lets be honest the recent Zwift bug where you get stuck in the pairing screen and have to re-launch the app hasn't helped matters... Although I've been lucky and not missed a race/ride due to it like many others... I have also avoided it those times I've not got enough time to re-join in the pen (if required), but that does mean I'm not calibrating as much as I should.
Although moving over to the PWM does mean it'll run a zero-calibration from my head unit in 30s while staying connected to Zwift, rather than the trainer which won't and takes 5+ minutes to do. I can do that before every ride. Interesting the Stages shows a 'temperature' in the calibration app, mine seems to always read around 2 degrees, but then garage temp has been around 2-5 degrees every time I've run it so far.
Think I'm finding the issues with cold weather probably more accurately linked to the calibration side of things. When the weather/temperatures improve a little it'll be interesting to see what happens.
I'm continuing with the Stages as my 'primary' with the dual recording of the Flux just for interest purposes. But does mean I'm back to around a 250-260W FTP. It was fun with it up towards 270-280W so that really has to be my aim/target. Doesn't look like my 77kg is going any lower (not that I've really tried and am actually 78kg these days). Hopefully some more consistency with riding, a bit more volume and the nicer weather/longer days helping I'll trim a kg (or two) and gain a few watts! 
Warmup in the Flux data, but some platform issues with Zwift last night meant it wasn't a particularly great one. Joined the pen and did a zero on the PWM before the ride/zwift data starts. While riding they seemed to track quite well.
My legs where a different matter, got dropped at 7.7km as we hit the lower ramps of the first KOM and had to surge through another team, when the real ramp hit a 5m gap quickly extended and I told them to leave me. I just couldn't recover. Equally me riding with a team expecting to average at least 3.5w/kg (who several last week finished at over 4.0w/kg avg) is my absolute maximum so I knew it was more of a case of hanging on as long as I could (usual team didn't ride). Now I'm hopefully getting some consistency I'll be arranging to ride with easier groups - at least until the couple of 'bad' data rides drop from my Zwiftpower averages (90 days...) to bring my numbers back down to normal...
Oh I know the numbers don't specifically matter, especially for me as I don't train to power (or even train much at all, I just ride!) the power side of things is just all monitoring and 'data interest' than any specific tool I need accuracy for.
The accuracy between the 2 power sources is just what I'm trying to pattern right now to get some consistency with the Flux as I've seen such variation with it. I'm using the comparison to a PWM for that, but now I have the Stages as my primary power source it's more of an interest to see how closely the Flux is tracking in various situations. I'm at the point now I don't trust it, but I do trust the 4iiii (and probably the Stages). I want to trust the Flux again but highly likely I won't until I can replace it (not happening any time soon)...
Yeah there's no 'smoothing' you can run on the data streams in the ZP tool. Unfortunately. But there's enough in there (being able to offset the data so it matches up) which is stopping me from using something else with a subscription for it...
Yeah 5% is well within 'margins' and consistently out like yours wouldn't be anything to worry about. Just the inconsistency of mine is what I'm looking at and why I'm comparing.
Not sure he did a massive power meter shootout - at least not recently, but all of his reviews you'll see him generally comparing them in his data. He seems to get them quite accurate and track but is probably one of the most experienced people in the world when it comes to that stuff, I'm just an amateur!
The Direto (or Elite trainers in general) have always had a good reputation for calibrating well and generally being accurate. Tacx far less so as I'm obviously finding. But I do think much of my inaccuracy I'm seeing now is due to the cold weather and not having enough time to do a proper 'warm up' and calibrate of Trainer & PWM before each ride/race. Lets be honest the recent Zwift bug where you get stuck in the pairing screen and have to re-launch the app hasn't helped matters... Although I've been lucky and not missed a race/ride due to it like many others... I have also avoided it those times I've not got enough time to re-join in the pen (if required), but that does mean I'm not calibrating as much as I should.
Although moving over to the PWM does mean it'll run a zero-calibration from my head unit in 30s while staying connected to Zwift, rather than the trainer which won't and takes 5+ minutes to do. I can do that before every ride. Interesting the Stages shows a 'temperature' in the calibration app, mine seems to always read around 2 degrees, but then garage temp has been around 2-5 degrees every time I've run it so far.
Haha, then Sufferfest really isn't a good shout! Just wonder if there's something similar to the Peloton lead spin rides without buying into an expensive setup like theirs, something you can do with 'standard' equipment. There must be someone offering similar.Nah she hates the pro cycling vids
Oh I know, I'm not worrying about anything less than 5%. To be fair anything less than 10% isn't any concern, but I'd just like some consistency at this point and that's why I'm doing dual recordings! I'm not Pro enough to need it for validation!
Think I'm finding the issues with cold weather probably more accurately linked to the calibration side of things. When the weather/temperatures improve a little it'll be interesting to see what happens.
I'm continuing with the Stages as my 'primary' with the dual recording of the Flux just for interest purposes. But does mean I'm back to around a 250-260W FTP. It was fun with it up towards 270-280W so that really has to be my aim/target. Doesn't look like my 77kg is going any lower (not that I've really tried and am actually 78kg these days). Hopefully some more consistency with riding, a bit more volume and the nicer weather/longer days helping I'll trim a kg (or two) and gain a few watts!
Soldato
I was lead to believe a clean drivetrain would give ~3% lower power at the rear axle turbo power meter compared to a crank power meter. A big unknown for many of us with single sided power meters compared to turbo readings is any leg power imbalance.
I've not been overly confident in my Direto's readings for over a year, but I use the figures it generates to set training zones in ERG workouts. If they are inflated and I use the Direto data to set my estimated FTP, it does make a mess of fitness/fatigue/form trends from rides outdoors with the 4iiii on the road bike (plus what I'm capable of holding for any given interval duration) and my rides on the hybrid with estimated power.
Supposedly, I did my best ever 20mins in a Zwift TT ~2.5 weeks ago, according to the Direto. I was certainly at my limits on the day, but did I really average 319W? I'm ~6Kg heavier after almost a year of long Covid, my bars were at their highest setup instead of 30mm of spacers above the spacer, but I feel nothing like as fit as I was in Feb 2020.
Now the "outdoor season" is almost upon us, although temps have taken a tumble these last few days, now my cold/flu appears to be gone I'll be ditching the Direto as a power source and switching to the 4iiii while setting slope feel in Zwift to 100%... In theory giving me a better idea of what I can try and do on the local hills this spring/summer without trying to get too depressed about what I did 2017-20!
I've not been overly confident in my Direto's readings for over a year, but I use the figures it generates to set training zones in ERG workouts. If they are inflated and I use the Direto data to set my estimated FTP, it does make a mess of fitness/fatigue/form trends from rides outdoors with the 4iiii on the road bike (plus what I'm capable of holding for any given interval duration) and my rides on the hybrid with estimated power.
Supposedly, I did my best ever 20mins in a Zwift TT ~2.5 weeks ago, according to the Direto. I was certainly at my limits on the day, but did I really average 319W? I'm ~6Kg heavier after almost a year of long Covid, my bars were at their highest setup instead of 30mm of spacers above the spacer, but I feel nothing like as fit as I was in Feb 2020.
Now the "outdoor season" is almost upon us, although temps have taken a tumble these last few days, now my cold/flu appears to be gone I'll be ditching the Direto as a power source and switching to the 4iiii while setting slope feel in Zwift to 100%... In theory giving me a better idea of what I can try and do on the local hills this spring/summer without trying to get too depressed about what I did 2017-20!
I wouldn't think a turbo drivechain loss was really that much. They don't tend to get filthy like road ones! I'd heard a similar figures mentioned about drivechains on Pro's bikes but always took it as marketing, with those of us not on pro level or pro maintained equipment even (if that figure was accurate) I'd say unlikely we would see more than a couple of percent from the most filthy to the most clean outdoors. So less on a turbo. A bad chainline/indexing/chain rub and worn cleats probably accounts for far more.
Why have you found the Direto that 'bad'? Just the 'feel' of it's readings compared to crank arm? That is another reason why I switched my 4iiii over to the Turbo bike. Power has always felt quite different inside & outside for me so I've not really compared or measured them against each other as know that's a slippery slope/rabbit hole to go down. I know I'm getting into it now, but at least they're both in the same situation and 'source' (me on the turbo!) to get some baselines from.
Good to hear you're over your illness, but still shaking off that long covid? I've a friend who still has some symptoms from July last year. He lost his sense of taste/smell several weeks after a positive test when over the other symptoms. Although he felt fine just overly fatigued and reduced lung capacity for many many months. Like he almost couldn't shake it off fully. He didn't get his taste/smell back properly until nearly Christmas time and even now says he's not back fully to 100%.
Reading back at old data really is hard isn't it! When we where younger and more powerful! To be fair my riding is hugely more consistent now than it was then with far less massive spikes of fatigue from monster rides digging myself into holes. But really I'm not massively off the same 'level' when looking at times and such. Hopefully this year will see some return to normality with more club rides and maybe some sportives to really see. I'd like to think I've made some good steady progress the last 3 years after the little guy came along, but I really did drop off quite a cliff for several months just before his arrival and post. Kidding myself I'll get back to the fitness I had in 2017/18 as I do realise will never really get the same amount of time to ride as much as I did back then. Sigh!
Soldato
I wouldn't think a turbo drivechain loss was really that much. They don't tend to get filthy like road ones! I'd heard a similar figures mentioned about drivechains on Pro's bikes but always took it as marketing, with those of us not on pro level or pro maintained equipment even (if that figure was accurate) I'd say unlikely we would see more than a couple of percent from the most filthy to the most clean outdoors. So less on a turbo. A bad chainline/indexing/chain rub and worn cleats probably accounts for far more.
Why have you found the Direto that 'bad'? Just the 'feel' of it's readings compared to crank arm? That is another reason why I switched my 4iiii over to the Turbo bike. Power has always felt quite different inside & outside for me so I've not really compared or measured them against each other as know that's a slippery slope/rabbit hole to go down. I know I'm getting into it now, but at least they're both in the same situation and 'source' (me on the turbo!) to get some baselines from.
Good to hear you're over your illness, but still shaking off that long covid? I've a friend who still has some symptoms from July last year. He lost his sense of taste/smell several weeks after a positive test when over the other symptoms. Although he felt fine just overly fatigued and reduced lung capacity for many many months. Like he almost couldn't shake it off fully. He didn't get his taste/smell back properly until nearly Christmas time and even now says he's not back fully to 100%.
Reading back at old data really is hard isn't it! When we where younger and more powerful! To be fair my riding is hugely more consistent now than it was then with far less massive spikes of fatigue from monster rides digging myself into holes. But really I'm not massively off the same 'level' when looking at times and such. Hopefully this year will see some return to normality with more club rides and maybe some sportives to really see. I'd like to think I've made some good steady progress the last 3 years after the little guy came along, but I really did drop off quite a cliff for several months just before his arrival and post. Kidding myself I'll get back to the fitness I had in 2017/18 as I do realise will never really get the same amount of time to ride as much as I did back then. Sigh!
I don't have a dedicated turbo bike, it's my road bike, which just happens to rarely visit the great outdoors from around November to March unless the weather is exceptional. But I don't meticulously clean and relube my draintrain frequently, no sign of corrosion thanks to the C3 Ceramic Wet, but it does turn into a gasty thick black sludge. There's definitely scope for losses through various means including the ones you listed between power readings at the crank and at the rear hub, but how much, I couldn't say.
To begin with, but without any dual recordings, readings around April '18 looked remarkably similar between my Direto and 4iiii. But at some point, the belt slackened and the "calibration" value went upto ~8 points below the slicker on the unit. Some time later, the belt snapped and I got a replacement, which got the discrepancy down to 1 point around autumn '19 iirc after calibration using the tension adjuster. But from around that point on, I discovered the dual recording analyzer on ZP, did the odd comparison every now and again and got similar variance to Lethal of the Direto being ~5/6% higher than the 4iiii. But then sometimes the variance dropped to ~2%.
There weren't many power interval "highlights" for me last year between the bouts of long Covid fatigue and not being allowed to do much for the whole of August following the dramatic back abscess surgery, but I did manage some 300W+ 20min efforts on the 4iiii in July (Zwift TT and local rolling route) and September (up Cheddar Gorge https://www.strava.com/activities/4063545832/analysis/3261/4465) before another health setback in October. After a "fake Festive 500" on the turbo I joined the STW league, which pushed me to me limits doing up to ~75min races, but I could feel my fitness improving a bit and just had to increase rest/recovery days to account for the extra fatigue I feel now compared to pre-Covid. However, as much as I could see my Direto power numbers improving, it was a shock to see a 319W 20min effort on 15th Feb https://www.strava.com/activities/4792440035/analysis even though I'd had surprisingly good numbers on 7th Jan https://www.strava.com/activities/4583079620/analysis . In hindsight, I wish I'd dual-recorded both those events, so I'll never know how real those power numbers are.
Long Covid has hit our household hard, my better half worse than myself, she's been signed off work since Xmas and I have literally just about managed to continue working bar the recent cold/flu that started to make me feel not quite right the day after that 15th Feb Zwift TT effort. I can't do multiple z4+ intervals/races/TTs on the same day or even single events on the second day now without a massive fatigue crash, generally I now need three days between events instead of typically 24-48 hours before Covid. There's been other stuff as well, but not directly related to cycling.
At some point, we all realistically expect for our numbers to decline and at 47, I didn't expect to have many years where I'd keep improving having joined this Strava game very late on... I've not completely written myself off yet, but at several points in the last ~12 months I've started to question if it's realistic to try and get a 300W+ FTP estimate off the 4iiii hopefully in combination with getting my weight back down to ~75Kg, after the latest ~2.5 week setback that challenge has got that little bit harder.
so... this didn’t work out and sold it for similar on eBay. With some strong man maths, I’ve ordered a Dolan GXA frameset. Planning to move my sora groupset from my other bike other and slowly upgrade to a gravel groupset over time.
Cor blimey it was cold again this morning. Out by 8 with 3 layers on top half, thought after 20 mins I'd have overheated but it never really warmed up a great amount. Had to come home as had an issue with my gravel tyres slowly going down, swapped the wheels out and pushed round for 100km total and 5000ft climbing. Sun was nice for the last 45 mins.
Soldato
We were up Beeley Moor today and yep it was pretty chilly. Still had the legs out though
Ok well, I ordered black...Yep. Hope should be decent and bonus is it's probably some fancy anodised colour?
Soldato
- Joined
- 23 Nov 2004
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Went out with the same guys as last week to aim for 22mph averaged, just made it in the last half a mile.
Good run but my legs are nippy now
New shoes feel good too.
https://www.strava.com/activities/4905979095
Good run but my legs are nippy now
New shoes feel good too.
https://www.strava.com/activities/4905979095
Soldato
- Joined
- 23 Nov 2004
- Posts
- 10,647
It's chosen for a bunch route in Saturday's for that reason really.
Twisty A road, into a quite lumpy B road that goes quite high, into a bigger A road which generally has a westerly wind at your back and a mix of a few back roads in-between. 3 sets of lights on the whole thing really.
Twisty A road, into a quite lumpy B road that goes quite high, into a bigger A road which generally has a westerly wind at your back and a mix of a few back roads in-between. 3 sets of lights on the whole thing really.
A nice 3 hours this morning. Cold and grey but nice and dry.
Did a few roads I haven’t been down before, bit too narrow for my liking, nowhere to pass if you came up against a car.
Threw a little more elevation in there but still building distance and elevation. Went out with just a bottle of water and front loaded the ride with the climbing save for a steep hill at the end, so it was a little Ralph Wiggum, I’m in danger! Half expected to run out of gas but had enough to get over and home.
Did a few roads I haven’t been down before, bit too narrow for my liking, nowhere to pass if you came up against a car.
Threw a little more elevation in there but still building distance and elevation. Went out with just a bottle of water and front loaded the ride with the climbing save for a steep hill at the end, so it was a little Ralph Wiggum, I’m in danger! Half expected to run out of gas but had enough to get over and home.
The dream as I struggle round at 17mph off 220w constanlty speeding up slowing down!
You have issues here man. That's a wild dataset, I don't even know where to start! I think there is more going on here than temperature skews.
That Stages is more wild than most sketchy single sided 4iii files I have seen. And that was the source you DID calibrate? You be better off training to RPE than the numbers that Stages is throwing out bud. A 1.5% difference at 5 & 20 but a 7% at 10mins... Like, I don't even know what to say about that haha.
That isn't taking into account what these trainers are programmed to do though in terms of power correction.
To my knowledge, it is not published nor stated what correction these devices are doing via coding/software to correct for DT loss to the trainer. I have seen many arguments mostly based on assumption either way on what these trainers are trying to cleverly do in the name of reliability/accuracy.
The biggest argument I see is that pedals/cranks/BB PWM's should ALWAYS read higher than trainers. Purely because they are higher in the chain of applied power with no/minimal loss in the drive train. But it's easy to see on any top Zwift race many different makes/models/variants of trainer reading higher than various pedal/crank based PWM's.
It's not ALL bad calibration. I genuinely believe the trainers are programmed to minimise DT loss on reported power.
I just bought a second hand but essentially brand new Gen4 2018 Kickr. This replaces my 2016 Gen2 Kickr.
Kickr 18 dualled with my Vector 3 pedals - https://www.zwiftpower.com/analysis.php?set_id=124463
Kickr 16 dualled with my Vector 3 pedals - https://www.zwiftpower.com/analysis.php?set_id=122621
I have gone from my Kickr16 reading 2-4% over the pedals to the Kickr18 (thus far but early days) reading 1-2% below the pedals. Is that because my Kickr16 was over reading? Is the Vector 3 pedals under reading? Or are the Vector 3 pedals great and I now have an under reading 2018 Kickr?
I don't know the answer to all that. It's impossible to know to tiny details specifically. The crazy thing of it all is that the new 18 Kickr is like a dream. It's insanely smooth, more efficient, spools quicker and reacts quicker. So I have effectively lost 2-3% power output from the trainer raw numbers wise but I think I will perform nigh on exactly the same and that's confirmed by me already seeing higher numbers on the Vector pedals than I was on the old trainer.... Purely because pedalling and power is way more fluid on the newer improved trainer. The old trainer was holding me back as it was in efficient.
THEN we apply the logic of these trainers trying to calculate DT losses and using firmware algorithm to compensate based on power output for assumed DT inefficiencies. This is a total rabbit hole guys. One I'd avoid if you don't need to bother with it like I do because it is a total ever evolving PITA.
Good work. Tyres got old sealant in them, or all Omlooped out?!
lol, well you did moan they only had black in stock!
Good stuff, strong riding as that looks lumpy as f*! Although elevation for the ride seems to be really cheating you!Went out with the same guys as last week to aim for 22mph averaged, just made it in the last half a mile.
Good run but my legs are nippy now
New shoes feel good too.
https://www.strava.com/activities/4905979095
I'm crap at the moment. Couple of poor Zwift sessions, but at least consistently low power now rather than the massive hike in performance which came from nowhere. It's probably just the lack of base miles (almost no commuting now) and me trying too hard! Need to get back to basics a little!
Maybe that's just it, simialr to me get a few 'off' readings so you calibrate a few more times and it just makes things worse. You then find faults (or experience as you did), 'fix' them and the units just never seem to settle down again afterwards to a stable state.
I've changed belt and tension arm on mine amongst other troubleshooting. I'm just praying the really cold weather is hampering my unit, as they are known for getting too hot/cold.
Even with all the health and illness issues there you've got some solid numbers. But you are right, it's the ever evolving 'chase of fitness' which is further hampered this time of year. We aim ourselves too high and are constantly nit-picking our performances and comparing them against better ones... Hardly ever do we look at poorer performances!
Haha I know it's still very wild, but it is getting 'better' than some of the earlier ones!
This saturdays is even better... Maybe it is a gradual process for me - Stages is new and the amount the Trainer has been through recently (combined with cold starts) are just hampering the otherwise bedding in process with wild skews in the data to match.
https://www.zwiftpower.com/analysis.php?set_id=124845
Your two at least are consistently out, that's what I'm aiming towards, just to 'know' that things have settled down (and are therefore likely to be a little more accurate).
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