Yet Another Cycling Forum

General Category => The Knowledge => Further and Faster => Topic started by: rob on 30 October, 2016, 06:59:48 pm

Title: Turbo Run Down
Post by: rob on 30 October, 2016, 06:59:48 pm
Just rigged up my new turbo.   On the old one the tyre resistance was set by body weight but on this one you have to manually adjust the braking.   It says to set so it's just touching.

I did a run down test on the lightest resistance setting and it went from 25mph to zero in 16 seconds.   I now have a benchmark, but was wondering what everyone else gets as a norm.


Ta


Rob
Title: Re: Turbo Run Down
Post by: chrisbainbridge on 30 October, 2016, 08:21:10 pm
I think it is quite turbo specific and resistance specific.
Title: Re: Turbo Run Down
Post by: Chris S on 30 October, 2016, 09:11:35 pm
No doubt it's the same for other manufacturers, but Tacx have an app that includes a calibration mode for checking resistance.
Title: Re: Turbo Run Down
Post by: rob on 30 October, 2016, 10:08:55 pm
Mine is a Tacx, but it's a basic model - blue matic.  It has 10 resistance settings and I found number 1 pretty hard and 10 impossible, before I adjusted the brake.   I was wondering if I had set it too easy but, I suppose, as long as it's constant then I can compare sessions.
Title: Re: Turbo Run Down
Post by: offcumden on 30 October, 2016, 10:14:18 pm
I find it surprising that the instructions say that the tyre should be just touching the roller. On mine (KK Road Machine) you are advised to tighten it sufficiently to eliminate slipping between tyre and roller under load. If there's much slipping you risk shredding your tyre. Of course increasing pressure will increase resistance, and decrease run-down time. The KK app has a calibration mode to allow for this.

--- just read your latest post, which makes me wonder whether I may have misunderstood just what it is you were tightening?
Title: Re: Turbo Run Down
Post by: rob on 31 October, 2016, 08:53:27 am
I probably didn't explain properly.

When you drop the back wheel into the turbo you then push a lever down that moves that roller up onto the tyre.    You can vary the pressure at this point using a small dial.   The user guide says 'adjust the pressure on the brake', but provides no further guidance.    I wound it up tight to start off with but the resistance even on setting 1 was pretty tough.   A bit of googling said the brake should touch the tyre enough to avoid slippage under effort.   I have slackened the brake off to its lowest setting and then did the run-down test on the lowest resistance.   It felt OK, but was just trying to benchmark my results.