I sent an email to the Bosch help desk asking about optimum cadence. I noticed the motor did not increase its power contribution above 105 revs of the pedals per minute. Generally they recommend a cadence of between 60 and 90 which is fine for me.
I have other queries which I will send to them in due course. One is to do with the maximum watts the motor can deliver. It is stated as 250 watts and I assume this puts a limit on what it can contribute at any particular moment for maximum efficiency for my and the motor’s power output.. Whatever I produce and whatever the percentage increment is theoretically, if the motor’s contribution reaches 250 then it can’t give me any more.
For instance if 40% = 250 then I would have to generate 625 watts myself to get the motor to provide its max 250. If this was possible, then our combined output would be 625+250=875. This would be eco mode.
If 100% (tourist mode) = 250 then I would generate 250 myself, a total of 500 watts.
If 180% (sport mode) = 250 then I would have to generate 139 watts, a total of 399.
If 270% (turbo) = 250 then I would have to generate 92 watts myself, a total of 342 watts.
To get the full 250 watts assistance realistically I could only do this in sport and turbo modes. According to Zwift my FTP is 170 .In addition I’m sure these figures would be complicated due to each mode offering different levels of torque in Nms.
So using real world figures, let’s say I can produce and sustain 120 watts.
In eco mode the increment would be 48 and the combined total 168 watts.
In tourist mode the increment would be another 120 and the combined total 240 watts.
In sport mode the increment would be 216 watts making 336 watts in all.
In turbo mode the increment would be 324 but the motor is not capable of this so would give me the max of 250 and a total of 370 watts. In fact I could produce as little as 92 watts in turbo mode to take the motor up ti its full 250 watts contribution.
I assume in practice the variable Nms of torque available in each mode would also put a limit on the power available.
It would also be interesting to know how different power figures from me impact on battery life. I assume that in any given mode if my power level is lower and requires less power from the motor, below its max of 250, then there is less demand on the battery. However this may not make much difference to the available range, only the overall average speed.
I picked it up the new e-bike last Saturday morning and road home from Saltaire via a combination of Hollin Hill, Escholt, Old Hollin Hill and Guisley. I still worked fairly hard but went up the hills at about 10 mph rather than my usual 4 mph on the steeper sections. I assume if I had used a lower gear and gone at my normal slow speed up these hills I would hardly have raised a sweat. As I had hoped, it also meant I got away from junctions and traffic lights quicker and smoother and therefore safer. I’m not able to get out of the saddle for faster acceleration or to get up steep sections of hills because of a knee injury I got many years ago from a motorcycling accident but the electric assist, especially on the sport and turbo modes does the same job for me. According to the control display if I ride it like I have so far (only a hilly 9 mile sample of course) the battery range will be 75 miles. This is better than I expected and means for less demanding terrain when I can stay in eco mode for most of the time I may even be able to get 100 miles, more than enough.
I’ve done two more rides since, a short one to friends Susie and Peter Saturday evening for a BBQ, about 3 miles and arrived fresh as a daisy despite the significant inclines on the way, and to the squash club Monday morning for a regular racketball session. I was very pleased with this as again there were significant hills and using only the eco mode and a touch of tourist mode on a steeper section I arrived in good shape to play.
My bike has the Active Line Plus motor which produces 50 Newton metre torque which I think is something under 2 horse power. The maximum power it an produce is 250 watts and this is used to increase the power I am producing by pedalling. This is provided as a percentage so in eco mode I get a 40% boost, tourist a 100% boost, sport 180% and turbo 270%. The maximum torque provided varies in each mode as well – 35, 40, 45 and 50 respectively. The maximum pedal revs the motor can operate at are 105 per minute which is plenty. However, there is a question about which is the optimum cadence for the motor to produce maximum torque.
So, if I’m producing 100 watts at the pedals (pretty comfortable for me) then in eco mode this is increased to 140 watts, tourist mode 200 watts, sport 280 watts and in turbo mode 370 watts. This is why riding the e-bike makes you feel, in my case, 45 years younger!
Back from another lovely holiday in France and back to reality. It took seven hours of driving for the last leg yesterday from Brighton to Bradford (about the same total time from Dieppe to the Dordogne) and this morning we woke to heavy rain. At least I’m not sweating.
The plan to use the holiday and daily rides round our Laveysierre circuit did not work out due to me arriving with a heavy head cold. It was not too bad on the Saturday afternoon we arrived so I did a circuit steadily straight away as we had had 2 days of driving, eating and drinking with practically no exercise. The cold got worst for a couple of days so I only managed to go round the circuit a couple more times towards the end of the week. My best time this year was 22 minutes 03 seconds compared with my all time best of 19 minutes 38 seconds. My best time this year up the 1.2 mile climb was 9 minutes 38 seconds compared with 8 minutes 15 seconds. So not too bad considering my cold and the fact that I’m about a stone heavier than when the best times were set.
I’m now 32nd out of 46 on the leader board for the Strava segment I set up. The current leader is a young local man who has done it in 4 minutes 17 seconds, about twice as fast as me! Strava has a facility where you can compare your stats with any other rider. In 2017 so far this young man (I shall call him Pascal since that’s his name) has ridden 4,767 miles compared to my 256. I’m guessing he is a pro bike racer but he may just be an unemployed enthusiast. He also rides a full carbon bike worth about £6000. My rides are on a near 30 year old heavy steel hybrid with heavy duty wheels and tyres, not to mention a bell and a carrier. Pascal must be praying I never bring my carbon bike over! On the plus side I’m second on the 65 and over leader board and Daniel is only 1 minute 17 seconds faster than me, also on a race bike. He has done a mere 1,927 miles this year so far and I bet he’s only just 65, so a youngster. I think 6 minutes 58 seconds might be doable if I can lose the stone and get on a race bike. I will be petitioning Strava to introduce a 70+ leader board. 65 is so yesterday.
Another plus is that I didn’t put any weight on while in France this year. This, I think, qualifies as a miracle and I am expecting pilgrims at my door any day.
Went to Lavaysierre in France again this year with my bike and did quite a lot of cycling, some every day. I rode with Matt to the Bastille Day brunch at the Domaine De Coutancie brunch, about a 14 mile round trip. I rode to Bergerac and back for the first time, about 18 miles in all. And about 6 laps of the Lavaysierre circuit that Matt, Judy and I compete over. The following is my last ride round the circuit when I set a PB for it and also for the Strava climb segment. This is the first time under 20 minutes with and average speed of 14.2 mph and the 8 mins 15 seconds for the 1.2 mile climb represents 9.4 mph.
I have posted this here retrospectively (May 28th 2015) as I forgot to do it at the time. This is copied from the post I did on Facebook at the time.
Went out with the Airedale Olympic Cycling Club on an 11 mile mountain bike ride today. There were 6 of us altogether with me bringing up the rear. I’d not met them before but they invited me to join them via Facebook. They were very friendly and made me very welcome. I was amused when I found the young woman that accompanied me most of the time was the club Welfare Officer! I thanked her for her pains by accidentally knocking her off when I hit a large boulder and stalled right in front of her. The pace was brisk at times, especially as it was quite windy. I was last through obstacles and crossing roads so spent a fair bit of time catching up but someone always hung back if necessary to make sure I could see where the route changed. I was familiar with most of it as I’ve been walking these tracks for several years now so there was never any fear of getting lost. I dealt with the slippery and muddy conditions OK and only opted out of one rather technical detour more through tiredness than being particularly concerned about the difficulty. Two of us stayed on the bottom track while the rest took to the hills in Jerrison Wood and we all met up again at Esholt. I got home feeling quite shattered but pleased I had managed OK. I’ve not done as much cycling this last year as I’d hoped (more walking and racketball) but I will start doing a it more now, probably mostly mountain biking through the winter but in the new year I may start going on the club’s social rides on Saturday mornings on the roads. These are between 30 and 40 miles so I’ll need to check on each route before I decide. Then later in the year I hope to go on the Leeds Cycling Campaign’s Sunday intermediate rides as these are about the same length I think. By picking appropriate rides from these two schedules I hope to able to do one decent ride every weekend.