Bosch Gen 5 efficiency?

[nickf]

Like already said, I would also point my finger to the Schwalbe radials. U already ride the Maxxis non-radials at extremely low pressures.

The Schwalbe radials are by some tests supposed to have cca 20% higer drag, have seen reports by other users on other online forums of extremely increased consuption on the radials.
In your case combine this, your extra low pressures, bit lower temperatures and a bit smaller battery, let's say all ads to cca 25% higher battery consumption overall

45km - 25% = 33,75km which is very near your number.

Also you can't realy equate access road km to uphill km, a better base value for emtb is altitude gain, distance should be second.

This guy on yt did quite some tests in Turbo mode on all the new batterys on the new Bosch Gen5 all on the same trail.

I asked about his trail, the area he does the tests has an average incline of cca 9 to 10%.

Altitude test in Turbo on the 600Wh



Distance test in Turbo on the 600Wh

These are all valid points, and you may well be correct that running the MM radials at low pressures does indeed add a significant amount of extra drag (although remember I run the Maxxis at very low pressures too). I can't comment on your 20% figure, but clearly if it could be as much as that then the tyres might be well be the main culprit for the low autonomy.

BTW I agree that you can't equate access road km with uphill off-road km, but in my case the Rail and the Vala did exactly the same steep, rocky off-road circuit, but the Rail then did - in addition - another 15km on the road. Even if this only equates to say 10km of trail riding it's still a noticeable difference and hence my enquiry into the autonomy of the Gen 5 motor/battery compared to the Gen 4. However, I would be quite happy to see that my single poor autonomy experience is just a statistical outlier - possibly explained by accumulated small factors - and that other Gen 5 riders get an equivalent performance+autonomy to the older Gen 4s. Hence this thread and everyone's useful comments so far

Sadly I don't understand German, so I can't follow the conclusions in the two YT videos. Can anyone summarise?

 

[emtbeast]

These are all valid points, and you may well be correct that running the MM radials at low pressures does indeed add a significant amount of extra drag (although remember I run the Maxxis at very low pressures too). I can't comment on your 20% figure, but clearly if it could be as much as that then the tyres might be well be the main culprit for the low autonomy.

BTW I agree that you can't equate access road km with uphill off-road km, but in my case the Rail and the Vala did exactly the same steep, rocky off-road circuit, but the Rail then did - in addition - another 15km on the road. Even if this only equates to say 10km of trail riding it's still a noticeable difference and hence my enquiry into the autonomy of the Gen 5 motor/battery compared to the Gen 4. However, I would be quite happy to see that my single poor autonomy experience is just a statistical outlier - possibly explained by accumulated small factors - and that other Gen 5 riders get an equivalent performance+autonomy to the older Gen 4s. Hence this thread and everyone's useful comments so far

Sadly I don't understand German, so I can't follow the conclusions in the two YT videos. Can anyone summarise?

The 20% higher drag claim is from different tests done on yt where testers talked about significant higer drag at the same pressure numbers, also on this forum

Schwalbe radial tyres

Look interesting, any information other than what's on the Schwalbe Web site? https://www.schwalbe.com/en/radialtires-mtb

www.emtbforums.com

there is a thread about them, on a another forum there was a user asking specifically of increased battery consumption with the radials(will try to find it later).

The conclusions of the two tests in the videos are:

On the 1st test he rides the same hill in Turbo mode until the battery is at flat 0%. The goal is max possible altitude gain. On the way down the motor is aways off.

The first video test results:
Altitude gain 1605m
Distance uphill 20,7km
Average cadence 90rpm
Average speed 18,9kmh

The second test is the same in Turbo mode until flat 0% battery but the goal here is distance, not altitude gain.

The second video test results:
Distance 79,3km
Altitude gain 396m
Average cadence 76rpm
Average speed 23,7kmh

Note: in both tests he is using the Bosch factory settings.

I am not ruling out a faulty battery in your case, but am pretty sure the main culprit here were the Schwalbe radials at really low pressure. As all the tests I have seen, the users had a tendency to over inflate compared to ther previous normal pressures.

Update: forgot to also mention that the Schwalbe radials are avaliable only in soft or ultra soft compound and they are quite heavy, could also be up to 1,5kg(depending on the casing), all of of course kills efficiency.

 

[nickf]

The 20% higher drag claim is from different tests done on yt where testers talked about significant higer drag at the same pressure numbers, also on this forum

Schwalbe radial tyres

Look interesting, any information other than what's on the Schwalbe Web site? https://www.schwalbe.com/en/radialtires-mtb

www.emtbforums.com

there is a thread about them, on a another forum there was a user asking specifically of increased battery consumption with the radials(will try to find it later).

The conclusions of the two tests in the videos are:

On the 1st test he rides the same hill in Turbo mode until the battery is at flat 0%. The goal is max possible altitude gain. On the way down the motor is aways off.

The first video test results:
Altitude gain 1605m
Distance uphill 20,7km
Average cadence 90rpm
Average speed 18,9kmh

The second test is the same in Turbo mode until flat 0% battery but the goal here is distance, not altitude gain.

The second video test results:
Distance 79,3km
Altitude gain 396m
Average cadence 76rpm
Average speed 23,7kmh

Note: in both tests he is using the Bosch factory settings.

I am not ruling out a faulty battery in your case, but am pretty sure the main culprit here. were the Schwalbe radials at really low pressure. As all the tests I have seen, the users had a tendency to over inflate compared to ther previous normal pressures.

Very interesting. Thanks for this useful info. I wouldn't disagree with your conclusion

 

[Rando_12345]

On the 1st test he rides the same hill in Turbo mode until the battery is at flat 0%. The goal is max possible altitude gain. On the way down the motor is aways off.

The first video test results:
Altitude gain 1605m
Distance uphill 20,7km
Average cadence 90rpm
Average speed 18,9kmh

I just want to point out, in case some people get the wrong idea, that those numbers are an absolute best case scenario. The rider is 70kg, on a lightish (but not extreme) 21kg ebike with fairly light and fast rolling tyres (rear hans dampf supertrail). His numbers for the Bosch gen5 are:
600Wh -> 1600m
800Wh -> 2130m

Knowing a bunch of riders on Bosch 4th gen and myself on 5th gen motor, all around 70-80kg range, we have always gotten around 25% less climbing than in those videos. I don't really know how he manages to get the altitude gains in his videos, I'm guessing the route he is using is very hardpacked and allows for very consistent, uninterrupted high RPM, also notice the very short distance numbers. But definitely don't expect to climb that much in any kind of real eMTB ride.


Anecdotally, I havn't found a rear albert radial to have any meaningful impact on my range, but I run it fairly high pressure and it replaced a much knobblier tyre.

 

[emtbeast]

I just want to point out, in case some pople get the wrong idea, that those numbers are an absolute best case scenario. The rider is 70kg, on a lightish (but not extreme) 21kg ebike with fairly light and fast rolling tyres (rear hans dampf supertrail). His numbers for the Bosch gen5 are:
600Wh -> 1600m
800Wh -> 2130m

Knowing a bunch of riders on Bosch 4th gen and myself on 5th gen motor, all around 70-80kg range, we have always gotten around 25% less climbing than in those videos. I don't really know how he manages to get the altitude gains in his videos, I'm guessing the route he is using is very hardpacked and allows for very consistent, uninterrupted high RPM, also notice the very short distance numbers. But definitely don't expect to climb that much in any kind of real eMTB ride.


Anecdotally, I havn't found a rear albert radial to have any meaningful impact on my range, but I run it fairly high pressure and it replaced a much knobblier tyre.

Good points, that I can completely agree with, imo the biggest factor for his numbers is hardpacked terrain and consistent rpm, the rest u mentioned just slightly adding to it.
A huge hit on system/battery efficiency is a lot of stop and go in blocked terrain when climbing, a lot of tests/ers miss this point or don't do tests of this kind.

The radials are not supposed to be taken as a bad tyre.

A radial tyre with a reasonably light casing(comparable with a Maxxis EXO+ or DD) and a good rolling thread(Schwalbe Albert Radial) has imo one significant advantage. If you want to increase your efficiency u can still increase your pressure to a higher number and still benefit from better rollover, grip and damping properties of the radial tyre.
This is not possible with a non radial tyre.

Maybe the first try unintentional mistakes by testers were using the same pressures they were used to and so a lot of reports of high drag etc...