Why does my bike go faster without pedaling?

[Bobber]

So I am still getting used to my ebike conversion. It's a Specialized Crosstrail with Bafang 1000 watt mid drive. It will do about 38 mph on throttle alone. If I'm pedaling I can't seem to go quite that fast but if I stop pedaling and just use the throttle I can get some extra mph. I know the PAS is working but it's like it's slowing me down when I should be going faster.
On a different topic I got the gear sensor option and don't like it mainly because it cuts power and slows me down as I'm shifting down through the gears on hills. I live at the top of 2 really steep hills which were a strenuous first gear only on my manual bike. I am still pedaling coming home but the motor slowing me down forces me in a lower gear than I like.

 

[ElevenAD]

Just slowdown some and everything will work fine, 38mph is fast, your pushing the motor to its limit imo.

 

[Gionnirocket]

So I am still getting used to my ebike conversion. It's a Specialized Crosstrail with Bafang 1000 watt mid drive. It will do about 38 mph on throttle alone. If I'm pedaling I can't seem to go quite that fast but if I stop pedaling and just use the throttle I can get some extra mph. I know the PAS is working but it's like it's slowing me down when I should be going faster.
On a different topic I got the gear sensor option and don't like it mainly because it cuts power and slows me down as I'm shifting down through the gears on hills. I live at the top of 2 really steep hills which were a strenuous first gear only on my manual bike. I am still pedaling coming home but the motor slowing me down forces me in a lower gear than I like.

You'd have to take a look at the programming... But in PAS 9 you should be able to reach the same speed pedaling as with throttle.
As for the gear sensor you should be able to remove it as it is not necessary hardware for the motor to operate. That said you should be in a low gear going up a steep long hill so that you don't bog down the motor.
I'll add that 38mph is taking your life litely... a bicycle is not designed for that speed.

 

[ElevenAD]

I would strongly advise not removing the shift sensor on a BBSHD if your going to be riding at high levels of PAS.
Your chain and rear cassette will thank you!

 

[Gionnirocket]

I would strongly advise not removing the shift sensor on a BBSHD if your going to be riding at high levels of PAS.
Your chain and rear cassette will thank you!

There's definitely easier work arounds (for me :- )
I have my Start Degree set to 5 which allows for my initial quarter crank to be with no assistance... this is enough chain travel to switch gears under no motor load with only a very brief pedal pause.
Another approach that I don't find as useful is to set the Time of Stop to around 250ms... This allows a shift to complete as you briefly pause pedaling for a second. You need to time this more accurately and be more conscious of every shift you want to make.
You can actually implement both of these at the same time if desired.
Since both of these use very brief pedal pauses and it is how I've always obtained smooth shifting (motor or not) ... I have no need for the shift sensor.
Obviously you need to think ahead and attack the hill correctly.. gear and momentum wise. But that's how I roll

 

[Bobber]

Thanks everyone. I don't travel at 38 all the time but it is a buzz when I have the space which is not that often. Before the conversion I did some pretty steep and fast downhill grades and got above 40 mph regularly. There was a radar speed warning trailer and I went through there at 46 a few times. I did Hurricane Ridge Road in the Olympic National Park last summer which was 12 miles of continuous vertical. It was 3500' of vert and a bitch going up but did not have to pedal once going down for 12 frikkin miles. I know I was doing 40+ there! And I know what my brakes smell like.
I have this really steep grade about 2 blocks from my house. On my manual bike I would hit it as fast as I can and then shift down through the gears as the speed quickly bled off. That bike is now my converted ebike. As I'm shifting down now the motor depowering is actually slowing me down when I need all the speed I can get. FWIW my Ecotric Hammer doesn't have the gear sensor and it works fine there, actually better.

 

[ElevenAD]

Thanks everyone. I don't travel at 38 all the time but it is a buzz when I have the space which is not that often. Before the conversion I did some pretty steep and fast downhill grades and got above 40 mph regularly. There was a radar speed warning trailer and I went through there at 46 a few times. I did Hurricane Ridge Road in the Olympic National Park last summer which was 12 miles of continuous vertical. It was 3500' of vert and a bitch going up but did not have to pedal once going down for 12 frikkin miles. I know I was doing 40+ there! And I know what my brakes smell like.
I have this really steep grade about 2 blocks from my house. On my manual bike I would hit it as fast as I can and then shift down through the gears as the speed quickly bled off. That bike is now my converted ebike. As I'm shifting down now the motor depowering is actually slowing me down when I need all the speed I can get. FWIW my Ecotric Hammer doesn't have the gear sensor and it works fine there, actually better.

Your Ecotric hammer is a Hubmotor bike, the torque and power from your motor are not traveling through your bike chain at all, only the power from your legs so there is no need for a shift sensor on a Hammer.
A 1000watt middrive is a whole different game, maybe you should remove the gear sensor and see for yourself but by all means do tell us the results

 

[Bobber]

Actually Eleven, I think I will unplug it on my next ride just to see. Yes I noticed the smiley face emoji. Back at you.

 

[ExPatBrit]

Actually Eleven, I think I will unplug it on my next ride just to see. Yes I noticed the smiley face emoji. Back at you.

Probably a Normally Closed sensor, so if you unplug it will permanently cut power. If so you would need to jumper it out.

 

[Gionnirocket]

Probably a Normally Closed sensor, so if you unplug it will permanently cut power. If so you would need to jumper it out.

I don't think so as there are many that don't use it.. Self included.

 

[m@Robertson]

BBSHD cutoffs are NO (Normally Open). So the brake levers are Closers. I use MT5e brakes and they are sold as Openers or Closers. I buy the Closers (which in the USA at least is the one that is normally for sale). If you are buying from a German site, look for the word 'Schliesser' or 'schließer'.

@Bobber as noted above pretty much all of your issues can be addressed by familiarizing yourself with the BBSxx programming, and tinkering with it. In fact I would say that owning a BBSxx motor should involve awareness of and access to the settings interface, because the factory settings are a far cry from the best that motor can be. Just for starters the factory settings waste a ton of power overclocking the pedal assist stuff.

Also, as to whether you need or do not need a gear sensor - you don't need one. You can easily learn to shift without one and avoid the mechanical interference of the shifter. No need to uninstall it. Just unplug it and put a weatherproof cover (silicone tape) over the plug.

...But before you do, read this first.

BBS02 and BBSHD: Do I want a gear sensor?

This is a common question on BBSHD and BBS02 motors, so I thought I would write up a quick post and describe what can be done, and what I do.

talesontwowheels.com

 

[ExPatBrit]

I don't think so as there are many that don't use it.. Self included.

From a "protect the drivetrain" POV , NC would seem prudent, but ??

I have a Bafang Ultra powered bike, I will take a look at the interlock

 

[john peck]

So I am still getting used to my ebike conversion. It's a Specialized Crosstrail with Bafang 1000 watt mid drive. It will do about 38 mph on throttle alone. If I'm pedaling I can't seem to go quite that fast but if I stop pedaling and just use the throttle I can get some extra mph. I know the PAS is working but it's like it's slowing me down when I should be going faster.
On a different topic I got the gear sensor option and don't like it mainly because it cuts power and slows me down as I'm shifting down through the gears on hills. I live at the top of 2 really steep hills which were a strenuous first gear only on my manual bike. I am still pedaling coming home but the motor slowing me down forces me in a lower gear than I like.

I´ve been considering the bafang 1000w mid conversion on a trike since most are front wheel drive. Itś good
to know that the gear sensor is not really a needful addition. 38 mph? I really don´t need that on a trike; I
have serious reservation about cornering above 15 mph. The idea was to create a cheap tractor for
light agricultural use. So far I´ve made a shallow plow & a rake for my bike, but that just scratches the surface.
There´s a free push mower out on the street on one of my routes. That might make an interesting jury-rig.

 

[Gionnirocket]

From a "protect the drivetrain" POV , NC would seem prudent, but ??

I have a Bafang Ultra powered bike, I will take a look at the interlock

I agree a supervised NC contact makes sense, especially with the brake levers. But it's not and I guess it makes them more versatile being easier to bypass for different applications.

 

[m@Robertson]

I agree a supervised NC contact makes sense, especially with the brake levers. But it's not and I guess it makes them more versatile being easier to bypass for different applications.

I think thats it right there. Bafang is for sure NO across all their motors. From their point of view, they want one standard so all of their parts can be shared across the entire product line.

 

[Bobber]

I unplugged the gear sensor today and that's all you have to do to cancel the function.. I was experimenting with stopping pedaling for a sec while shifting. Of course you have to pedal to shift so it can certainly clank in there sometimes and when it's clanking it's really clanking. I didn't like it so the GS was plugged back in mid-ride and everything is lovey-dovey. Eleven you were right.
Still experimenting with that dang steep hill next to my house. I haven't got it dialed in yet but will let you know. I have a digital level that measures roof pitch, degrees and percent of grade. I'm going to get a measurement on that hill. I think it's over 10%.
Accidentally did 36 mph today. Actually I accidentally did that a few times.

 

[Gionnirocket]

I unplugged the gear sensor today and that's all you have to do to cancel the function.. I was experimenting with stopping pedaling for a sec while shifting. Of course you have to pedal to shift so it can certainly clank in there sometimes and when it's clanking it's really clanking. I didn't like it so the GS was plugged back in mid-ride and everything is lovey-dovey. Eleven you were right.
Still experimenting with that dang steep hill next to my house. I haven't got it dialed in yet but will let you know. I have a digital level that measures roof pitch, degrees and percent of grade. I'm going to get a measurement on that hill. I think it's over 10%.
Accidentally did 36 mph today. Actually I accidentally did that a few times.

Well if you didn't make the programming changes suggested then yes you will get clanking with the pause pedal method.
And that accidental 36mph does happen to all of us

 

[m@Robertson]

Yeah just unplugging the sensor isn't going to get you anywhere.

 

[Gionnirocket]

Also keep in mind that you may need to increase the Start Degree an additional 1 or 2 depending on your derailleur smoothness and your abilities.
That said if the shift sensor works well for you... There's no need to fix what ain't broke.

 

[Bobber]

I measured the steep pitch with a digital level on one of the hills near my house. It was about 18.5% which is about 10.5° at the steepest part. Most of the grade was 14%+. It's the only way to my house. For reference they start putting the runaway truck ramps on the highways when it gets to 5 or 6%. The hill at the bottom is steep for a longer distance but I haven't measured it yet.
I did 32.5 miles last Sunday with about 8 miles of that being a really rough gravel road and some singletrack. The display said I had about half of my battery left with 28 miles range still possible. I pedal most times. I did have a few long downhills and the speedo got to 42 mph there with no motor because I was coasting. There was some controversy about me doing 36 mph on the motor but actually most of us have probably gone faster on our non ebikes but we didn't have speedos to verify.