Bolton controller on RR ST1

[Avg_Joe]

I installed the Bolton 35a controller on my Rad Rover Step Through 1. In order to use the stock controller location and minimize the ghettofabulousness:

• I used the stock lower mounting location + steel strap to secure the Bolton controller. This did require use of the longer bolts Bolton provides in the kit.
• For the upper mount, I took the other stock steel strap and slightly flattened it.
• I had to file the inside of the tab where one of the zip ties secures the taillight cable to get the strap to slide through (see picture below).
• Using some Delrin sheet I had laying around, I cut 2 strips of Delrin about 1", drilled 5/32" holes, and bolted these strips to the steel strap and the controller using 4mm hardware + nylock nuts.
• There's some light usage of double-sided 3M automotive trim tape to keep the controller off the downtube paint.

The speed sensor cable was a very tight fit, not quite enough length; I would like to get a very, very short extension to ease this a bit.

My initial impressions using Bolton recommended settings:

• The power is crazy.
• The noise from the controller is crazy.
• The noise from the motor is unwelcome.
• Power delivery is anything but smooth. It's either on - like, full on! - or off.
• Initially, I was thinking: I liked the stock controller behavior and silence much better, but appreciate the power on tap.
• In our typical suburban area with very slight hills, I remained in PAS1 and oftentimes turned off PAS altogether. For the steepest hills, PAS2 was plenty.
  • I enjoy actually pedaling and putting in work. On flat ground or slight grades, this does not happen w/ the Bolton controller.

I really need to fiddle with the settings. The refined stock rideability is completely gone, this thing is like an unruly muscle car now. Hopefully I can smooth it out, turn down the power some, and enjoy riding again.

This is where a zip tie was, and where I filed inside to get the strap through:

Closer shot of top mount:

Decent clearance to fender:

 

[Avg_Joe]

Thanks for an informative post!

Did you just get the controller? Did you get the real 750W motor as well?

I did not (yet) get the upgraded motor. Might just go with what I have until it dies. I'm not a power addict, I like to get work in - but there are times the power is definitely needed, such as on some multi-use trails I'll ride this weekend w/ very steep hills.

 

[AHicks]

Nice install! Pretty cool seeing the craftsmanship that goes in to some of these bikes.

DO spend some time on your parameter settings! You'll find the controller is WAY more refined than the RAD when you start getting close. Holler if you need a hand there. I can't share an entire set of parameters that will work best for you, but I may be able to help you figure out a problem area you're having. Like the jumpiness at low speeds. Try cutting back the available power using C5 by a couple of steps. For great low speed handling, I would recommend something around 100 watts when in PAS1.

Regarding the noise you're talking about, I have to wonder if this kit from Bolton themselves, or a wannabee? The 3 letters after the 48 in the model number are (KT48***)?

 

[Avg_Joe]

@AHicks I was hoping you'd chime in at some point - I really appreciate your posts and knowledge.

The kit is definitely from Bolton - I bought it directly from them and have interacted with them about it. The controller is KT-LCD8H.

I'll adjust the C5, thanks for that. I would like power to come on smoothly and ramp up as I pedal faster.

 

[AHicks]

The DISPLAY is a KT-LCD8H. The CONTROLLER model # will start with KT48. Need the 3 letters after the 48. -Al

 

[Avg_Joe]

Derp, sorry for that (wish I had an excuse). The controller is KT48SVPRL-SPS3 and what looks like an R as the final character (SPS3R?).

 

[Avg_Joe]

Disclaimer: I hate watching videos.

Fact: I just watched Bolton's videos and have a much better understanding of the options. I am going to play with it this morning and if I get stumped, I'll admit it.

 

[AHicks]

The reason I was asking about the 3 letters following 48-
ZWS is square wave
SVP is sine wave

The square wave controllers are generally NOT sold by Bolton, but I wanted to confirm. The square wave are notorious for being noisy at low speed, especially accelerating from a stop. KT makes both for some reason, but people in the know will seldom select the square wave controllers (out of experience).

Point being, I have no idea why you might be getting noise from the controller or the motor - unless the motor is not wired correctly - but in that case the motor likely would not be running?

I should have asked if you had watched that video. After seeing it you do have a much better idea of the KT potential. Best of luck! -Al

 

[Avg_Joe]

The reason I was asking about the 3 letters following 48-
ZWS is square wave
SVP is sine wave

The square wave controllers are generally NOT sold by Bolton, but I wanted to confirm. The square wave are notorious for being noisy at low speed, especially accelerating from a stop. KT makes both for some reason, but people in the know will seldom select the square wave controllers (out of experience).

Point being, I have no idea why you might be getting noise from the controller or the motor - unless the motor is not wired correctly - but in that case the motor likely would not be running?

I should have asked if you had watched that video. After seeing it you do have a much better idea of the KT potential. Best of luck! -Al

I just returned from a 15 mi ride and have to say - it's close to being dialed in now. Don't know if it was the Kenda Juggernauts, the incessant wind, ambient noise, or the settings but the controller was quieter today. Motor was slightly quieter as well. I did stop maybe 3 times to adjust things.

I did mostly road, but did find an area on dirt that allowed me to do several miles - mostly hardpack, some very light mud, great hills - think clearcutting several hundred acres for a new subdivision with dirt "roads" freshly cut and packed (and the incessant bumps from the tracked vehicles they used). Overall, I had to do slightly more work than I expected, which is a Very Good Thing.

Bolton's video was actually quite good and very helpful. Current settings, but they will be changed a bit (apologies in advance for the crappy photo):

 

[Avg_Joe]

I have been fiddling with the settings constantly, and am at the point that I'm struggling to find anything I like about this controller - aside from the color screen.

I simply cannot find any combo of settings that produce smooth, linear power. I find power delivery is just... awful? For example, at slow speeds in 1st or 2nd gear, I start pedaling hard, there's little assist then whoosh - assist comes on hard.

The noise from my motor is very disconcerting. When coasting or in PAS0 and pedaling, it's not there, which makes me think it's not the gears but rather something in the controller itself?

Battery usage is abysmal. Went from 53.9v to 45.9v in less than 40 miles, largely using PAS1, PAS2 on occasion. And no throttle at all. On the stock controller, I'd easily have another 40 mi range for my riding style.

I'm going to put the stock controller back on in the next day or 2, and see if this is my imagination. I am not busting on Bolton at all, what they do is very admirable - but it just may not be for me.

 

[AHicks]

How many watts are you pulling in PAS1?

 

[Avg_Joe]

How many watts are you pulling in PAS1?

I'll reply with details a bit later, when I have time to take a quick spin; and will include current settings.

 

[Mitchb]

I dont know much about your bike or the controller you are trying but Im wondering how your bike would feel if you switched your candence sensor to a torque sensor? I think that may give you the feel you are looking for and they're not expensive.

 

[Avg_Joe]

@Mitchb I would be thrilled to fit a torque sensor, however I have no idea if it is even possible. Is retrofitting one to a cadence sensor system something you've done? If so, I'd love details!

@AHicks sorry for the delay, but I've not been able to get out the past 2 days. I have found out I can mostly smooth things out and reduce the noise from the motor by setting my Bolton controller as follows. Note, I have not been able to get in an extended ride to see how this works overall, but may be on to a solution:
These are all variations on the generic Bolton-recommended settings:
P2: set to 5. This seems to affect the wheel speed sensor?
C5: set to 02. This is max current.
C14: set to 1. This is the "weakest" PAS setting.

I can post my full settings if needed.

It seems to me the motor noise is most impacted by C5, by lowering that I no longer have the incessant buzzing. And a very quick ride indicates I'm getting to close to my ideal settings. A longer ride this weekend will tell me more, and I'll follow up. BTW I was seeing +200 watts in PAS 1 while shifting through the gears, which seems kind of nuts to me.

 

[AHicks]

You're making me wonder if you may not have an issue with this controller. To start with, there should be NO buzzing, and further, C5 settings should not affect buzzing vs. no buzzing. Suggest you get an email in to Bolton in this regard.

I wouldn't put too much weight in settings you get unless you're underway. The 200w is high for sure (for most of us I think). Something in the range of 75-150 is more normal, and to get there you would adjust C5 to get close, then trim using C14. That's what NORMAL would be like anyway. Not clear what you have going on at all.... That controller should be silent under ALL conditions. -Al

 

[Avg_Joe]

My controller stopped buzzing after my first round of adjustments; after yesterday's round, that's when the motor quieted down (granted it was only several hundred feet of riding). I'll fiddle more. Bolton did not respond to my last query.

The +200W was while riding as well. I'll continue fussing with C5 and C14.

I wish they had just a simple sheet for what each setting actually does. I watched another video where a guy described it better than Bolton, but it still feels - very nebulous?

 

[Mitchb]

@Mitchb I would be thrilled to fit a torque sensor, however I have no idea if it is even possible. Is retrofitting one to a cadence sensor system something you've done?

 

[Mitchb]

Installing a bottom bracket torque sensor is as easy as replacing your bottom bracket, plugging it in, and disconnecting your cadence sensor. Just do a search for torque sensors for the motor you have, Im guessing its a Bafang. I have a Bafang hub drive motor with a bottom bracket torque sensor on my bike, it feels similar to a mid drive motor, meaning no surging. Im sure Bolton may be able to advise you on compatibility.

 

[JTK77]

Torque sensor on Bolton (KT) controller is not going to happen in any meaningful way.

 

[AHicks]

Installing a bottom bracket torque sensor is as easy as replacing your bottom bracket, plugging it in, and disconnecting your cadence sensor. Just do a search for torque sensors for the motor you have, Im guessing its a Bafang. I have a Bafang hub drive motor with a bottom bracket torque sensor on my bike, it feels similar to a mid drive motor, meaning no surging. Im sure Bolton may be able to advise you on compatibility.

Installing a torque sensor of ANY type is pretty easy. It doesn't get tricky until you try to get it to communicate with the controller. Which leads me to wonder if you have done something like this successfully, or is it something that SHOULD work? If you were successfull in adding a torque sensor to a bike that didn't have one previously, I'd like more detail if you wouldn't mind, starting with the information on the controller that you used. Maybe a link to it?