Fluid Trainer Q
endonsmend
Posts: 7
I have an Elite Chrono Hydro-mag trainer from a few years ago now (?2012) which has both fluid and magnetic elements to its resistance. (http://www.wiggle.co.uk/elite-crono-hyd ... l-trainer/). It has five manual, magnetic, resistance settings.
I have a stages power meter on my turbo bike and also a garmin speed cadence sensor. I almost always have the manual resistance set on three. If i do any kind of interval session (e.g 3x20 mins at FTP) in the initial interval I have to start by riding a big gear in order to achieve the power I want. This gets the wheel spinning fast and I therefore get a high speed reading in kh/h from the speed sensor. After 5-10 mins i find i need to slowly change up through the gears in order to hold my cadence and maintain the same power for the rest that interval and the rest of my session. Once i've reached a steady state i'm then getting a lower speed as i'm spinning a smaller gear with the same power produced. So in short it seems that the resistance ramps up over the first 10-15 mins.
Does anyone know why this happens? Do the fluid type trainers like this take a wile to warm up and get to their proper resistance levels?
Thks - ES
I have a stages power meter on my turbo bike and also a garmin speed cadence sensor. I almost always have the manual resistance set on three. If i do any kind of interval session (e.g 3x20 mins at FTP) in the initial interval I have to start by riding a big gear in order to achieve the power I want. This gets the wheel spinning fast and I therefore get a high speed reading in kh/h from the speed sensor. After 5-10 mins i find i need to slowly change up through the gears in order to hold my cadence and maintain the same power for the rest that interval and the rest of my session. Once i've reached a steady state i'm then getting a lower speed as i'm spinning a smaller gear with the same power produced. So in short it seems that the resistance ramps up over the first 10-15 mins.
Does anyone know why this happens? Do the fluid type trainers like this take a wile to warm up and get to their proper resistance levels?
Thks - ES
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Comments
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endonsmend wrote:Do the fluid type trainers like this take a wile to warm up and get to their proper resistance levels?
Yep, this exactly. As the fluid warms its viscosity changes and so the resistance at a given speed will change until it is properly warmed up. As you're working with a PM though this shouldn't be a big deal as power is still power, irrespective of the wheel speed on the turbo0 -
Cheers - What I thought then. As you say not a problem when training to power, maybe just a slight psychological downer when you feel it getting harder and slower in the first few mins!0
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In general with indoor training you should never look at the speed of your rear wheel. It's really a useless metric especially when you are using power and leads to issues like this one.0
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endonsmend wrote:Cheers - What I thought then. As you say not a problem when training to power, maybe just a slight psychological downer when you feel it getting harder and slower in the first few mins!
only initially, once you have been riding for a while you discover that for the 1st 10 mins of a ride you cant produce anywhere near the power you are capable of without real effort.
when I ride in the morning it takes me at least 30 mins until I can comfortably cruise at 200w ... up until then I struggle to keep it above 160w
and you will discover that after 15-20 miles you are absolutely flying compared to what you were doing 5 miles in.
so in real terms the 1st 10 mins are a write off any way, use them to warm yourself up and your turbo ... finish with a few high cadence bursts and start proper0
