how much faster by eBike.....???

shemozzle999

Esteemed Pedelecer
Sep 28, 2009
2,826
686
its not all about weight ;)

Danny is one of the lightest riders on the circuit and he seems to do ok.

this is worth a watch, if you've not see it before.


google danny hart champery if the link doesn't work.
Hi Colin,

I assume it is still Colin, I understood from your opening post that you posed a question how much faster a daily commute would be on an ebike I didn't realise you were talking off road.
 
Hi, yes sorry - still me.

my commute is on road. but I do have lots of offroad options, that I do when its dry.

I was just trying to make things a bit clearer on here, there is lots of take of numbers, but no one seemed to have actually done anything to show how much faster or easier things are with an eBike.

So we've set about planning a load of things over the coming few months to allow our dealers to actually put some sensible numbers together to give customers real world figures that are actually useful to them.

Col.
 

flecc

Member
Oct 25, 2006
53,163
30,581
thanks flecc. I'll have to have another look at how to post links.

Col

Here you are Col. Heading the reply box are icons, the rectangular 9th one across is shown as "Link" if you hover your mouse pointer over it. Highlight the text you want to be a link, click that icon and then paste the link into the URL box that appears. Click the "Insert" button that's under the URL box and then post the contribution.
 

shemozzle999

Esteemed Pedelecer
Sep 28, 2009
2,826
686
It depends what you are trying to achieve, if it is maximum speed on a journey then surely it just means applying maximum assist at times when the speed is below assist level but if you are looking at efficiency of using the stored energy available from the battery then you need to know what are the most efficient speeds in each gear, for that you would need to know the power curve of the motor.

I wouldn't have thought it would not be to difficult to program an extra processor output to illuminate an extra indicator on the display when you are hitting the sweet spot.
 
Last edited:

flecc

Member
Oct 25, 2006
53,163
30,581
if you are looking at efficiency of using the stored energy available from the battery then you need to know what are the most efficient speeds in each gear, for that you would need to know the power curve of the motor.
This is where systems like the legal speed Panasonic crank unit are at their best, the torque sensing and software combined enforcing optimisation for efficiency. Not ideal for the performance enthusiasts though.
 

Artstu

Esteemed Pedelecer
Aug 2, 2009
2,420
925
Whilst not commuting I had the chance to do a comparison last week with a local 24 year old club rider/ national road race rider on a training ride he did.

It was 36 miles with 2,900 feet of climbing, he did it in 2.42 hrs at an average speed of 13.5 mph, by his own admission he wasn't going for it and did the 6 climbs of a small loop in the big ring. His bike is a light carbon racing bike.

Because it was local and not like his usual 60 to 100 mile rides I thought I'd have a go and see how I compared. I packed my spare 300 w/h battery in the pannier and set off with a full 400 w/h battery, I also disabled the speed restrictor. Bear in mind I'm twice his age and not in good health. I doubt very much I was getting any where near his power output.

Anyway I did the 36 miles in 1.52 hrs at an average speed of 19.3 mph ! have to say I was quite chuffed with my performance. It would have been a little quicker had my second battery not expired 1 mile before the finishing line. I have a feeling he'll be back out one day to try and beat it and put me back in my place.
 

trex

Esteemed Pedelecer
May 15, 2011
7,703
2,671
ok, just been thought the stats on my Garmin, and here are the results.

Bike used was a 2014 KTM Macina Action mountain bike - 29er with Bosch Active drive. It had standard mountain bike tyres.

Conditions were similar to the previous day when I'd ridden a standard road race bike home.

Homeward bound.

Normal Bike: 55.13 minutes. Average Speed of 17.3mph and average heart rate of 152

looks like I had a bit more of a headwind when I rode home on Sunday, because last night with the eBike I did.

45.25 minutes. Average Speed of 20.8mph, but I had to work harder for it, average heart rate was 163

For the ride into work.

Normal bike takes 1 hour 13 minutes. average speed of 12.5mph average heart rate of 156

eBike took 1 hour exactly, average speed of 14.9 mph with an average heart rate of 158

---------------------------
so basically it knocks 10 minutes off each way, using a similar amount of energy. I went pretty hard, keeping my heart rate at about the level I'd normally commute to see the effect.

its was only a bit quicker on the climbs... 2 minutes on a 13 minute climb. Because I normally go pretty hard on the climbs. So it looks like most of the time was made up on the slow speed sections where I'm accelerating away from lights etc etc.

Personally its made me realise there is little point in road legal e Road Bikes, ie 700c wheels with drop handlebars and skinny tyres. They simple roll to fast that I'd be over the speed for support for so much of the time that it wouldn't be worth having.

Having a mountain bike means the riding is more comfortable and more fun and actually a bit safer in traffic. I'm sure if my commute was more stoppy starty, there would be even more advantages.

But I was impressed, I've saved essentially 20 minutes off my commute per day, using the same amount of energy. So if I used this bike every day, that would give me 1 hour 40 extra per week of my life at home to do something better then commuting.

Or equally I could ease off a bit on the effort I put in, so the ride takes the same amount of time, but I'll be using loads less effort which will mean I'm fresher in the evenings or weekends to go on actual rides.
For a quick estimate how much faster on e-bike, this is my calculation:
distance: 15.9 miles (25.59km), elevation: 1165ft (355.1m), total energy required on a crank drive at optimal gear selection: 25.59*6.3 + 355.1*0.465=326.32WH
These are WH at battery (burn) level, transfer yield at 0.8 is built in.
A good cyclist burns 132W, your cycling ability is much higher than this, at nearly double a good cyclist, so I leave your case for later, I just calculate with normal cyclist profile, the Bosch motor burns 511W, on a derestricted Bosch bike, in ideal conditions (no stoppage), your combined power is 643W, it would take you just 30 minutes to complete the journey.
Without GPS information, assuming 10% average gradient on the hills, 3.5km and 22 km flat roads, the climb will take 15 minutes.
On a restricted bike, the flat section takes 52 minutes at 25km/h. On an unrestricted bike, you can do the same flat section in half the time, 30 minutes.
You should be home in 1 hour 7 minutes with a legal bike, 45 minutes with a derestricted Bosch bike.
With a derestricted 8-Fun BPM and a throttle, you can get home in about 45 minutes without pedalling.
In view that most commutes are within 30 minutes and most of it is flat anyway, good cyclists won't benefit from motorisation unless the bike is derestricted.
The main benefit is to arrive fresh, pink and not hot.
 
Last edited:
D

Deleted member 4366

Guest
Can you do the calculation for a Kudos Tornado with BPM restricted to 26.5mph? Lets say 700W from the battery during slow hill-climing.
 

trex

Esteemed Pedelecer
May 15, 2011
7,703
2,671
The BPM case:
flat section: 22km, maximum speed: 42.4km/h: 31 minutes 10 seconds, no pedalling.
3.5km 10% hill section: motor running at 700W + cyclist 132W = 832W, climb speed: 13.1km/h * 832/711=14.14km/h: 15 minutes 15 seconds
Total in ideal condition: 46 minutes 25 seconds
To get the best of the BPM, you'll need 48V 20A continuous discharge. For the best result, I reckon the BBS01 at 48V would win the race.
 

trex

Esteemed Pedelecer
May 15, 2011
7,703
2,671
22km @ 26.5km/h=49 minutes 48 seconds no pedalling
The hill climb remains as it was (15 minutes 15 seconds)
Total time 1 hour 5 minutes
The flat portion can be done more quickly than that but Iif the motor cuts out, then you are effectively limited by legalisation.
 

Joneser

Pedelecer
Oct 13, 2013
83
2
"Or equally I could ease off a bit on the effort I put in, so the ride takes the same amount of time, but I'll be using loads less effort which will mean I'm fresher in the evenings or weekends to go on actual rides."

The beauty for me is the flexibility. My commute is 10 miles with big long hills which I was doing on a hybrid (pre conversion) taking about an hour each way. It was OK when I was feeling up for it but 5 days a week, all conditions (weather and personal health) it was a bit gruelling. My fastest time was 50 minutes pre conversion. Now with my little Q75 and 2.3Ah battery I do it in about 50 minutes as a matter of course. I also find that I get still get a seriously good workout as its fun going really fast up steep hills, especially flying past lycra cyclists. And its been a godsend in the recent gales.
 
Using the numbers to predict savings is great and very interesting, certainly something that I think could be used to generate a nice simple webpage that gives people an indication of the times / effort they could save if they plug in their distance / fitness level / bike details etc etc and then it could work out the numbers.

Does this already exist somewhere? Perhaps this site could have a page that does this?

However it doesn't really take account of the slow speed sections where most time and effort gains happen. My commute isn't really that typical as there are hardly any corners or lights, its just one straight road - so I don't really stop at all, so didn't benefit from these gains.

Most commutes for most people will involve lots of stopping and starting, and its these 0 - 20mph accelerations where most of the time gains happen.

The other benefit of eBikes that I think aren't talked about often enough is the fact that you get away from lights really quickly meaning you are much safer and also the support at these low speeds really helps people who arent so confident getting up to speed on a bike.

My results really show improvements in time, when I actually wasn't expecting any, due to the nature of my commute and the fact that I thought I'd be able to go above the assist speed for most of it. The fact its a benefit for me, means it should benefit lots of others a LOT more.

The second thing about the graphs I've shown so far is that my commute home is more downhill than uphill, so again I didn't expect the impact of the eBike to save as much time.

Cheers
Col