Brake Sensors

[saneagle]

See if you agree. I think most of it is OK, but when these guys sell stuff, their comments are normally in relation to what they sell. and they only have limited experience of all the other stuff available. I don't have brake sensors on my cadence seensor bike, and I've been very happy with it for nearly 10 years. To me, the type of sensor doesn't matter. It's how the power algorithms in the controller and their response times are that makes the difference.

I like the idea of a gear sensor that reduces the power rather than cuts it completely. It seems obvious when you know about it.

Some of the comments underneath the video are interesting.

What I keep meaning to fit to my bike is a simple push-button cut-off switch to cut the motor temporarily when I need to, like cycling around pedestrians and to help balance on very tight zig-zags:

 

[guerney]

Initially, I used brake cutoff/ebrake before changing gear, but wanted automatic gear changes, because there's quite enough stuff to worry about on the road - it must depend on the bike and it's cables or something? Because my gear sensor works perfectly even when powering uphill. If you ignore the sounds of crazy people and listen to the video below, after the 20 second mark you can hear my powered snappy super smooth crunch-free uphill gear changes. The only time it ever annoyes me, is while powering up very steep hills in heavy rain (works when it isn't raining heavily; works in light rain), which is when the power off interval is ever so slightly not long enough. Sadly, there is no setting in the BBS01B firmware to adjust that.

Cables: Not at all sure if what type is fitted makes any difference, but I used brand new kevlar lined outer and smooth stainless steel inners for (allegedly) low friction. I also waterproofed the gear sensor ends with self-amalgamating rubber tape, to keep moisture and dust out. A straight cable run through the gear sensor helps, I think, rather than have it bouncing about elsewhere on the bike on a curved cable which changes it's curve as it bounces around. It also shuts off power when bumping over very deep potholes, because that moves the inner cable, therefore an integral accelerometer might be a good idea... or perhaps in the controller, to filter those irrelevancies out.

 

[Peter.Bridge]

I like the idea of touching the brake lever to activate the brake sensor to change gears on a mid drive going up hill. On my BBS02B (without gear sensor) I seem to able to change down gears on assist levels 1-5 (up to 50% power on my set up ) with the motor driving the chain with no (audible) problems, seems very smooth. Above 50% power it gets a bit crunchy.

 

[saneagle]

I like the idea of touching the brake lever to activate the brake sensor to change gears on a mid drive going up hill. On my BBS02B (without gear sensor) I seem to able to change down gears on assist levels 1-5 (up to 50% power on my set up ) with the motor driving the chain with no (audible) problems, seems very smooth. Above 50% power it gets a bit crunchy.

With derailleur gears, shifting is not a problem when you use low power. It's when you use high power that you need something to stop crunching the gears and chain, or when you have to do an emergency stop and get caught stationary in top gear on any setting other than the lowest power ones. Hub gears can be worse because they won't shift if there's too much tension in the chain. Most need a shift sensor power cut, but that's a pain when you need to shift when going up a steep hill.

I used a gear sensor on a BBSHD at 52v. It definitely helped, but I don't think I'd bother fitting one on a 36v 15A crank-drive. The more I think about it, the stronger the feeling I get that crank-drives are stupid.

 

[cyclebuddy]

It's when you use high power that you need something to stop crunching the gears and chain...

I know @guerney loves these gears sensors, but I hate mine (Bafang Maxdrive). It's too slow to react, and cuts power for too long in the scenario you describe, especially high power up a steep hill.

Simply back-pedaling 1/8-1/4 turn stops the over-run of the motor crunching gears by releasing the cassette/clutch. It sounds counter intuitive and thus takes a bit of practice, but it's the quickest/smoothest/crunch-free technique I've found. Works a breeze on both my mid-drive bikes (the other without a gear-sensor).

...or when you have to do an emergency stop and get caught stationary in top gear on any setting other than the lowest power ones.

Change gear, lift the rear-wheel clear of the road by the saddle/cross-bar, press "walk"? IMO it's better than stretching the chain/stressing the motor starting off in top gear.

 

[guerney]

Change gear, lift the rear-wheel clear of the road by the saddle/cross-bar, press "walk"? IMO it's better than stretching the chain/stressing the motor starting off in top gear.

Neat! I use the "walk" function so seldom, I forget it's there. A little lazy I know but... while the throttle was still attached to my bike, I used to enjoy quickly activating it to rapidly change to a lower gear ahead of stops - no crunches thanks to the gear sensor. I'll try the same using the walk function while in motion, although the 2 second delay could make it useless for that purpose, and "walk" might not be available while the bike is moving.

 

[PC2017]

I use mine all the time, the magnet fell off the other day & I was lost, even though I had the right hand sensor.

Speed reduction & smooth re-flow is my main function for the sensor now; When at cruising speed approaching a circle, for example, I can riding the brake just enough for motor disconnect, still allow for a speed roll, always prepared to stop in case there's a Citroen, however with the right motor disconnect-distance, I can allow for arrival at the circle after other traffic has entered & passed or cleared then release brake ride allowing for smooth non-stop flow with a decent speed to allow for observations.

I would also recommend Ashley Neal's new cycling channel.
Just Cycling Ashley Neal

 

[guerney]

I know @guerney loves these gears sensors

I only love it because the gear sensor works great on my particular bike - do you know if during gear changes, the same unit of cable is moved by Shimano gear shifters as by SRAM's? Perhaps more cable moved within the same interval of time could lead to faster response by the controller?

 

[guerney]

magnet fell off

BTW Western Digital are now rubbish, it's not just me who's noticed:

Western Digital sued over claims of data-trashing SanDisk, My Passport SSDs
Drives are anything but solid, allegedly

Western Digital sued over SanDisk SSD data-loss claims

Drives are anything but solid, allegedly

www.theregister.com

Even the previously very reliable and long-lived Black edition spinners I usually buy turned out to be crap... so I'm presently torturing a Samsung 1TB 870 EVO which I bought in a moment of madness, when it was knocked down to £45 in one of Amazon's fleeting flash sales. I may get another to RAID mirror. The 2 year long torture test of a Kingston SSD went well, and it's still not dead.

GRC | Never10

Never10 - Disable Windows 10 Automatic Upgrade

www.grc.com

 

[portals]

On-premise storage RAID etc. is yesterday's news, spend a few $$ and sync to the Cloud provider of your choice.

 

[guerney]

On-premise storage RAID etc. is yesterday's news, spend a few $$ and sync to the Cloud provider of your choice.

Provide multiple points of entry for hackers and pay for the privilege? Never! I have RAID mirrored hard drives on several PCs, much rather trust those. I'd prefer a bank vault to cloud for offsite storage.

 

[cyclebuddy]

...do you know if during gear changes, the same unit of cable is moved by Shimano gear shifters as by SRAM's?

I have no idea. The gear-sensor was already fitted when the bike was new, Shimano 9-speed Rapid-Fire shifter, and Shimano hydraulic brakes without cut-off switches, so you can't use the "dab the brake" method.

 

[guerney]

I have no idea. The gear-sensor was already fitted when the bike was new, Shimano 9-speed Rapid-Fire shifter, and Shimano hydraulic brakes without cut-off switches, so you can't use the "dab the brake" method.

I wonder why the gear sensor is so hit and miss? When I eventually get around to sorting out the Espresso, and if I'm motivated by curiousity enough by then, I could take cable measurements to compare it's Tourney setup to the SRAM on the Helios. If different, I could install the gear sensor to the Espresso to see if it's gear changes work as well as they do on the Helios to cut motor power, without transferring the BBS01B kit over. Moving the kit over to the Espresso was the plan, but the Helios works so well I can't do it. Planning to use the Espresso as a manual/acoustic bike to get actual exercise instead, which the Helios is set up specifically to not provide in any shape or form, is responsible for the total lack of enthusisam I have for getting it back on the road. I also worry it's haunted.

 

[portals]

Provide multiple points of entry for hackers and pay for the privilege? Never! I have RAID mirrored hard drives on several PCs, much rather trust those. I'd prefer a bank vault to cloud for offsite storage.

Eventually you will see the error of your ways...back to Teletext now to get the latest news...

 

[portals]

Cloud storage has security baked in...it's the most sophisticated security that exists. If you look at the big players, SAP, MS Azure, AWS etc. rarely are they hacked...on-prem dinosaurs are hacked daily.

If I wanted your data (not the mucky films... ;-) ), then it wouldn't be hard to work out where you live by your many posts here. Then I just have to watch you cycle away then steal your PCs/laptops.

What then for your data? How do you get it back?

 

[portals]

Or you get burgled or your house catches fire or there is a gas explosion or there is a large meteor on course to wipe the planet out.

Stay safe...Cloud.

Musk has got servers in space...that might be an option, pricey mind...and what if he's using Western Digital....?

 

[guerney]

Eventually you will see the error of your ways...back to Teletext now to get the latest news...

Data I can't afford to lose exists heavily encrypted at home on mirrored drives, at the office, and USB drives on my person. That person being me.

 

[soundwave]

i have enterprise class encrypted data its worthless without my passwords ect unifi cams next

 

[cyclebuddy]

I wonder why the gear sensor is so hit and miss?

Variables I can think of are that my gear-sensor is an early "original" design Czech-made one (IIRC about £50-60 at the time), and I got the impression yours was a later Chinese copy version (did you say it cost £18?). Like most things, maybe the Chinese copied and improved it! Also, your motor is Cadence based and mine Torque driven.

I don't see why there couldn't be a variable in the App to at least adjust the cut-off time: It's workable on the flat with moderate power applied, but uphill under power where you're losing momentum anyway I find the length of delay more of a hindrance.

 

[guerney]

I got the impression yours was a later Chinese copy version (did you say it cost £18?

Yep. Was a punt which worked out.

I don't see why there couldn't be a variable in the App to at least adjust the cut-off time: It's workable on the flat with moderate power applied, but uphill under power where you're losing momentum anyway I find the length of delay more of a hindrance.

I expect all manner of things are possible with the BBS02/HD open source firmware now available for intrepid tinkerers. I doubt sufficient interest exists developing OSF for the lowly 250W BBS01B; may take a lot of time for your Maxdrive.