E-bike range

[stodd]

For a start it's wrong to assume that everyone has the ability to increase the effort they put in, or that they'll reach the same speed in a lower assistance level, that won't be true for everyone.

That is true for people who can't put the effort in to reach a steady 26kph unassisted speed. However, if you can put in the effort to maintain that speed (and most of these posts are discussing that case) you will reach that speed eventually by putting in that same effort whether in tour, eco or unassisted; it will just take longer to reach it with less assistance.

I don't think anybody has suggested you can get higher range on tour than eco while riding assisted 100% of the time?

[RichardPH]

Bosch have a Range assistant that you can play with, adjust the variables - Rider, Bike, Environment - and it tells you the likely range. I've found it to be fairly accurate. It's Bosch specific, but I'd be surprised if there was a huge variation between makes with similar specification.
https://www.bosch-ebike.com/en/service/range-assistant

Come to this thread a bit late, but have plenty of experience with Tongsheng TSDZ2 powered bikes. Presently have two, I've run these to battery cut out in the #2 or normal rating.

#1 aluminium mountain bike with TSDZ2/Hailong 10s4p 10.2A-hr battery. Real world range 52miles.
Bosch prediction based upon 106kg- upright rider - slightly hilly - mediocre road surface - not windy - '400' battery - town tyres - 75rpm cadence, 50miles range predicted

#2 aluminium road drop handlebar bike with TSDZ2/Hailong 10s4p 10.2A-hr battery. Real world range 72miles.
Bosch prediction based upon 101kg- rider on hoods - slightly hilly - mediocre road surface - not windy - '400' battery - 25mm tyres - 75rpm cadence, 70miles range predicted

Hence Bosch predictor is really very accurate, impressed.

Regarding the selected power level and range resulting. This I think depends greatly on rider power to weight. In a lot of instances I will be riding at the threshold of the speed limiter cut-in, which appears to operate over about a 2kph taper zone. Thus it depends purely how much the rider needs to dip into full assistance and therefore battery drain as to the range achieved. Plus of course if you're a cyclist you'll be used to putting in your best effort for a given situation, which will contribute more or less dependent upon ability. In my case I can run pretty continuous 130W on an exercise bike, given the accuracy of the Bosch prediction I must be Mr Average for them. On the road bike conversion my average speed is usually in the 24kph band, on an equivalent road bike without motor 21kph.

Word of warning about 'running out' of battery. The TSDZ2 uses the sprag clutch freewheel as the chainset side bearing. As such it has a small amount of radial play that manifests as a once per rev clonk when riding with a dead battery. Annoying but I suspect not damaging. The TSDZ2 is otherwise really nice to ride, the torque sensing works really well giving it a totally natural feel.

Has anyone got range experience with a Fazua system? I'd be interested since I've just bought one and will be using it for touring. I have acquired a spare battery so in theory it should be better, especially since it has tubeless 25mm tyres and has carbon frame making it 3kg lighter than my TSDZ2 road bike.

[richtea99]

Has anyone got range experience with a Fazua system? I'd be interested since I've just bought one and will be using it for touring. I have acquired a spare battery so in theory it should be better, especially since it has tubeless 25mm tyres and has carbon frame making it 3kg lighter than my TSDZ2 road bike.

It's very dependent on terrain, speed, level of assistance selected, weight of rider, and so on.
We have a Fazua (Boardman) and an ebikemotion (Orbea), and this is roughly what we get:

- Fazua: About 30-40 miles with it enabled all the time, depending on terrain, speed, level of assistance selected. It's regularly on more than the lowest assistance which probably accounts for the low 30 figure.

- ebikemotion: About 80-100 miles BUT it's only used on demand - up hills and against the occasional headwind. If it was on permanently, I suspect they'd both come out around 30-40 miles.

We live in a gently undulating area with one or two big hills, so if you're in the Pennines, Wales, Scotland, etc you're likely to get less miles.

Neither battery is large, so don't expect miracles - both are aimed at partial assistance and not a 'throttle-like' free ride.

[RichardPH]

- Fazua: About 30-40 miles with it enabled all the time, depending on terrain, speed, level of assistance selected. It's regularly on more than the lowest assistance which probably accounts for the low 30 figure.

Thanks for that feedback

I've done some more experiments with my Tongsheng driven road bike. It has 4 power settings, I've recently run the 10.2A-hr battery to cut out on level 3, it achieved 54 miles on the same routes as level 2 achieved 72 miles. It does feel like it's delivering significantly more oomph, therefore draining the battery faster. I'll probably not bother with level 4, it crushes any concept of a manual ride.

I've started to assess level 1, usually known as 'eco'. It's a very low assistance level and I may be riding for some time to get a flat battery. It's also only marginally c.5% better than a non e-bike of the same type.

I'll report back when it's done.

Measuring battery voltage, it's 40.8V when fully charged, 34.8V when it's cut out.

[Slowtwitch]

Re: the 72 miles on a road bike vs the other bike, is the main difference in expected mileage down to the weight of the bike or wheel size, or what? Thanks

How could this range be extended, without spending too much money?

I'd like to try ebike touring, so a real world 70-80 mile range would be a minimum.

[stodd]

Many of the variables you mention are covered in https://www.bosch-ebike.com/en/service/range-assistant (mentioned a couple of times above). Good for bikes other than Bosch as well; it gives a very good idea of variations, and interpreted carefully gives pretty good idea of absolute range.
As said in different ways above: Weight of the bike is relatively unimportant; your weight more so. Tyre type and pressure is quite significant. The most important are level of assist, riding style, and conditions (hilliness, wind, road surface etc).

Bigger battery (or second battery) is the only guaranteed way. Not cheap; people's ideas of 'too much money' vary quite a bit.

[RichardPH]

Re: the 72 miles on a road bike vs the other bike, is the main difference in expected mileage down to the weight of the bike or wheel size, or what? Thanks

The 'other bike' is a mid 90's Trek non-suspension MB with 32mm Schwalbe town tyres, as ridden it weighs about 21kg. My test on that bike included boosting the assistance setting towards the end of the ride because it was getting weaker presumably because the battery voltage was dropping. It was a first look-see at range limitations because I too plan to tour on an ebike, The result was still remarkably close to the Bosch calculator results.

My more recent assessments have been with 'other things equal'. That is..
same 17kg bike and battery
same 85kg rider [me]
very similar route that has about 450m of climbing over 72miles, [the River Severn has occasionally got in the way of late]
same reasonable weather, I don't like high wind and rain.
level 2 72miles, level 3 54 miles, level 1 TBA

The battery starts fully charged and I ride it to cut out, hence the last few miles are inevitably in town to avoid a shock to the system riding an unassisted bike for miles

I've got a Hailong 10.2A-hr battery on both my bikes. These are 10s4p units [40 cells, 10 in series, 4 sets in parallel] to yield nominal 36V battery. Larger 10s5p batteries are available, I don't need this level, so didn't go that way. Weight goes up obv, but so long as it's positioned on the down tube it's not noticeable. I've attached a bottle cage to the top of the battery case since that's the easiest to reach when riding. Larger batteries than a 10s4p may make this tricky. depending on frame size.

Rear rack mounted batteries upset the balance of the bike IMO.

Hope this helps..

[RichardPH]

Now completed the test on TSDZ2/10.2A-hr battery in the 'eco' setting #1. Rather like Prince Phillip it expired just short of 100. 99.8 miles to be precise.

I was pleasantly surprised at the range, but assistance level is quite limited. The number of 100 mile rides I've done is minimal, whereas 72 miles is much more common and the boost from #2 level is more rewarding.

[RichardPH]

For completeness, and little curiosity, I've done the same test at level 4, the highest.
Thus for an all-up mass of 102kg, road tyres, road bike with drops, ridden almost entirely on the hoods and on undulating roads with about 500m total climbing/descending on circular routes, these are the numbers

level 1 160km @21.5kph
level 2 115km @23.5kph
level 3 87km @24.5kph
level 4 70km @26.3kph

Without a doubt level 2 is the most useful.

Eco is barely there, I can and have averaged that speed on a very similar manual bicycle, there's maybe 5% in it.

Levels 3 and 4 flip your normal routes on their head so to speak. The flat bits that were an opportunity for a rest become frustrating because one is forever exceeding that very obvious assistance threshold and having to work hard to keep the pace that the motor was largely responsible for achieving. They are both a bit of a hoot though, if slightly risky because you keep arriving at corners that are very familiar at rather greater speeds.

Most importantly, each and every rating wasn't a reason to shirk rider workload, once you're pressing the pedals at all, instinct takes you to putting in as much effort as on an unassisted ride. Time on the bike does get shorter of course..

The performance of lithium cells at varying discharge rates is explained in this link https://www.richtek.com/Design%20Suppor ... ment/AN025

[Jdsk]

Thus for an all-up mass of 102kg, road tyres, road bike with drops, ridden almost entirely on the hoods and on undulating roads with about 500m total climbing/descending on circular routes, these are the numbers

level 1 160km @21.5kph
level 2 115km @23.5kph
level 3 87km @24.5kph
level 4 70km @26.3kph

Mmmmm... data!

: - )

Jonathan

[stodd]

level 1 160km @21.5kph
level 2 115km @23.5kph
level 3 87km @24.5kph
level 4 70km @26.3kph

Without a doubt level 2 is the most useful.

Interesting. That was on the 36v 10.2ah battery above, 367wh?
Figures with Bosch assistant predicts for a 400wh battery with your setup (approx)
165/116/100/89 for 400w
151/106/92/82 compensated for 367w

Broadly similar to your real world results.
Of course there will be different relative assist in each of the four levels on the different systems.

I agree level 2 is best for many; it is what we use on a Motus hub bike. Very different bike, and a little hillier, so (real and predicted) figures for us are less than half yours at 48km, 30 miles in 2/tour

[RichardPH]

Minor confession here.. the 10.2A-hr battery is in fact a 10.4A-hr, or at least that's what's moulded into the casing, so slightly closer to Bosch figures. Also the average voltage is (40.5+34.5)/2 = 37.5 and at 10.4A-hr that makes 390W-hr.

Oddly, the hardest rating was probably level 4 because the effort required from me was so variable. Without a speed limiter it would just be a blast, and probably quite dangerous too..

[Biffo1262]

I have read these posts with some interest and not a little surprise as my 300W 7 year Motus has returned well over 100 mile range. Not on the same day but over a period of days over generally flat but some undulating terrain. I use the battery mainly on ECO WHENI need to use and thereby lies the method to long range. Once rolling and wind conditions are favourable try 5urning the power OFF and thereby saving it for when you do need it. I weigh 19 stone, am disabled and walking is very difficult yet riding the Motus is a breeze. Accuracy failure into the mix and you can see why opted for an ebike. However after a few weeks,now some three years ago, I found I could reduce the use of the battery by a massive amount and even ride with the power off about 50% of the time. It was then I decided to see just how far the 300w battery could take under these circumstances. The answer came as a surprise and a delight. I did 112 miles over four days and got down to my last full bar and the projected remaining range was 26 miles obviously based on my style of riding. I put in no undue effort but I did want some physical benefit. After all, that was the reason for purchase. Just under 140 mile range I think isn't exceptional with this method and a younger, fitter and lighter person will eleven better. The upside is I am fitter at 74 years age and my battery now in its 4th year is still in peak condition 3.5k miles from new. I would say it is absolutely certain the 400w battery could top 170 miles and the 500w could make it to 200 miles. Of course over a single journey of greater distance you will come across some hill but for every slope up there is a slope down. My journies were 45 mile max but generally 20/25 miles in rolling Cheshire plains and even flatter Lancashire and Greater Manchester canal towpaths which are excellent for switching off the battery. If you use it with range in mind the you will be very pleasantly surprised and don't believe those low range figures on the clock as they are simply based on the last bit of you previous journey so if that was uphill and you used a high battery setting it will give you a false projection. I was going to buy a 500w battery about a moth after I bought the Motus but I'm glad I didn't. BTW I changed those rather flimsy OEM tyres to something a bit more substantial tread pattern wise but they still had the centre rib for road use whilst giving me a deeper edge tread for the dust and grass towpaths. It was shod with those tyres on my 'economy' run. I have to say the Motus is a delightful touring bike and I would recommend it wholeheartedly though if I were to buy it again I would opt for the 400w 9 gear derailleur Tour model.

[Jdsk]

Thanks for that.

Great to hear how the eBike helps.

Jonathan

[peterb]

Another post proving that the less assistance used the better the range you get - who'd have thought it