Yeah, that's what I perceived was happening too - I much prefer the realism of this, even if it is harder!Seemed to happen me when I gunned it coming into climbs. Bkool appeared to punish any attempts at slingshots by stripping my speed in an instant.If I kept the speed constant on approach or even accelerated fairly gently (more like real life) it didn't punish me. Just slowed down quicker than it used to, but definitely more realistic.
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bobinski
Legendary Member
- Location
- Tulse Hill
Sorry Bob.
.
That's alright Rick, I had only just got back from the pub and fancied a saunter on the turbo
gbrown
Geoff on Bkool
- Location
- South Somerset
Since vertical velocity is much lower than angular velocity on a 14% slope, I think you would come to a halt very quickly, but I haven't the time/ or ability to work it out exactly!
OK, vertical velocity appears to be calculated using the same sine function on the angle of the incline, which is logical!
Vvert = velocity * sin(8)
so at, say 50.4 kph velocity is 14 m/s and vertical velocity on a 14% slope (8 degrees) is 14 m/s * 0.139 so Vvert = 1.946 m/s
On a 8 degree (14%) slope, an initial velocity of 50 kph (14 m/s), or 1.946 m/s vertically, would decelerate at 1.365 m/s/s and come to a halt in 1.387 meters or about 4.5 feet!
Even at 80 kph it would only take 3.3 meters, or about 10.8 feet!
A brick wall!
Sounds like bkool have decided to go for a much more realistic model...
Geoff
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bobinski
Legendary Member
- Location
- Tulse Hill
OK, vertical velocity appears to be calculated using the same sine function on the angle of the incline, which is logical!
Vvert = velocity * sin(8)
so at, say 50.4 kmph velocity is 14 m/s and vertical velocity on a 14% slope (8 degrees) is 14 m/s * 0.139 so Vvert = 1.946 m/s
On a 8 degree (14%) slope, an initial velocity of 50 kph (14 m/s), or 1.946 m/s vertically, would decelerate at 1.365 m/s/s and come to a halt in 1.387 meters or about 4.5 feet!
Even at 80 kph it would only take 3.3 meters, or about 10.8 feet!
A brick wall!
Sounds like bkool have decided to go for a much more realistic model...
Geoff
Its good to know its more realistic and thanks Geoff for the explanation. I suppose, some niggles aside, the remaining issue is whether all turbo's are treated equally? FWIW if i choose to manually connect rather than auto connect the turbo my perception is its a little harder. Perhaps for the next ride we should all manually connect and see what happens? Perhaps the differences Kickr users perceive will be the same for all of us?
What's the difference between manually and automatically connecting the trainer that would mean it feels different?
bobinski
Legendary Member
- Location
- Tulse Hill
Bridgy, it may just be perception and therefore bollux
But if manual is designed to address non bkool turbos it might be more likely to make use of ant+ fec. I have been using manual for some months now because i ride zwift too and i need it in manual to use the ant+fec in zwift. Otherwise the resistance was all wrong. So, just wondering if it MIGHT have an impact in bkool too. probably boolux though...
AAAC 76C
Large Member
- Location
- LIVING THE DREAM
OK, vertical velocity appears to be calculated using the same sine function on the angle of the incline, which is logical!
Vvert = velocity * sin(8)
so at, say 50.4 kph velocity is 14 m/s and vertical velocity on a 14% slope (8 degrees) is 14 m/s * 0.139 so Vvert = 1.946 m/s
On a 8 degree (14%) slope, an initial velocity of 50 kph (14 m/s), or 1.946 m/s vertically, would decelerate at 1.365 m/s/s and come to a halt in 1.387 meters or about 4.5 feet!
Even at 80 kph it would only take 3.3 meters, or about 10.8 feet!
A brick wall!
Sounds like bkool have decided to go for a much more realistic model...
Geoff
Your right Geoff, I have go my % and degrees mixed up.
14% is 14 up for 100 along therefore 14/100 Tan slope
= 0.14
therefore slope = 8% as stated
Sin 8 degrees is 0.139 also as stated multiplied by 9.81 is 1.36359 (m/s/s) pretty much as stated
50 kph (30 mph ish) is 13.88 m/s (close enough to 14)
But think this is either the acceleration or deceleration of an item along the slope not in the vertical
i.e. as you approach the vertical your acceleration/deceleration approaches 9.81 m/s/s in the vertical
Using this simple rule and object dropped would reach 13.88 m/s in about 1.5 seconds, on an 8 degrees slope it will take considerably longer as would the opposite deceleration going up.
So at a deceleration of 1.36369 m/s/s with an entry velocity of 13.88 m/s you would come to a halt in 10.18 seconds
Some 4 seconds more than I calculated for a 14 degree slope which is pretty much in proportion
Coming to a halt in 4.5 feet is less than a bike length which would throw you over your handlebars.
Also I think if this was the case skate-borders would never get up the other side of the ramp/tube whatever they are called.
The distance traveled in this time is = v1t+1/2at squared
=13.88x10.18+(1/2x-1.36369x10.18x10.18) meters
=141.3 - 70.66
=70.5 meters roughly
Probably didn't need to do all that because it was always going to be half of the area of the entry speed x time assuming a straight line deceleration to zero
Now if I go 70.5 meters along and 8% climb, how much have I climbed vertically = sin 8 degrees (= 0.139) x hypotenuse (= 70.5) = 9 .8 meters vertical
The general stopping distance for a car using brakes from 30 mph, not including thinking distance is 14m
Hmmm sounds like a scientific experiment is required!Bridgy, it may just be perception and therefore bollux
berty bassett
Legendary Member
- Location
- I'boro
Does anyone use erg mode ? how does it work ? and next silly question - how do you enable it ? thanks -if you point me to what page - ish its been talked about , i'll shut up and read in the background again 
i know absolutely nothing about it and dont understand in the slightest , i dont know what erg means except i last said it when i stepped in cat crep in my socks so any help will be apreciated ------ but please no algorythyms !
i know absolutely nothing about it and dont understand in the slightest , i dont know what erg means except i last said it when i stepped in cat crep in my socks so any help will be apreciated ------ but please no algorythyms !
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AAAC 76C
Large Member
- Location
- LIVING THE DREAM
Not overly scientific but I switched on my turbo and selected my down/up/down/up test session which goes down at 8% for 500m the up at 6% for 500m then down and up again but I only used the first down up.
Using my hand on one pedal gently I 'pushed' myself into the climb at a steady 7 watts just to stop the session crashing.
By the bottom of the 500m at 8% I had accelerated steadily to 67.6 kph
Using the online Bike Calculator my speed for 7 watts down an 8% on the drops would be 67.92 kph (not bad then BSim)
The 6%, 3.43 degrees, slope slowed me down in about 15 seconds which seemed about right to me but the real problem is that even though I was just twirling the pedals with my hands gently as I hit the incline BKool almost doubled my power thus slowing my deceleration.
To me the old Firmware was not far off apart from using your entry speed to suddenly calculate more power and then gift you speed as a result.
Just to note that 6% is only 3.43 degrees as the percentage of the slope is 100x(rise/run) re:
https://en.wikipedia.org/wiki/Grade_(slope)
6% = 3.43 degrees
8% = 4.47 degrees
10% = 5.71 degrees
12% = 6.84 degrees
14% = 7.97 degrees (as used previously)
15% = 8.53 degrees
20% = 11.31 degrees
25% = 14.04 degrees or 1 in 4
30% = 16.70 degrees
35% = 19.29 degrees or just above 1 in 3 (18.43 degrees)
The rest we will agree to walk up or use a rope.
Does anyone use erg mode ? how does it work ? and next silly question - how do you enable it ? thanks -if you point me to what page - ish its been talked about , i'll shut up and read in the background again
I have just used it on my kickr It does away with gear changes. To activate it, cycle at a certain power you want to achieve at a certain cadence, press `p` (awkward bit). Then the software takes over. Doesn't matter what the inclination is, the speed is adjusted and you just keep trying to my hold the set power level.
Problems, it drops out of Erg mode after 20 mins or so(maybe pre planned)
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Well done Wales too 
bobinski
Legendary Member
- Location
- Tulse Hill
Not being too much of a footy fan I did this instead;
https://www.strava.com/activities/615488844
I rode for distance rather than power or speed and as my distance increased beyond 40km I began to get a number of kudos and messages from other riders urging me on. More so when I passed 70km. This is easy with the integration of phone app and PC/Mac Sim. It really would be great to have this in Bkool. We could use it to goad, sorry, I mean encourage and support each after
https://www.strava.com/activities/615488844
I rode for distance rather than power or speed and as my distance increased beyond 40km I began to get a number of kudos and messages from other riders urging me on. More so when I passed 70km. This is easy with the integration of phone app and PC/Mac Sim. It really would be great to have this in Bkool. We could use it to goad, sorry, I mean encourage and support each after
gbrown
Geoff on Bkool
- Location
- South Somerset
Plan was to have another go at Haytor, but as you say, with the change in firmware mucking things up I think it would be better to run a clean session. Stage 3 - Rundlestone (again) is available and has not so far been run, so I suggest we give that a try.
Cheers,
Geoff
