Trek Marlin 5 w/ BBSHD and 52V Shark /// Best chainring size?

[Van-Isle-Rider]

Hi everyone.

Came across this active community this am and wish I had discovered it prior to doing a build. I enjoyed reading some posts and the Tales on Two Wheels blog this am that I'm certain would have helped me as I converted both my wife's and my mountain bikes to e-bikes. I have a question that I'm hoping I can get some advice on.

Gear

- Bike​

- 2019 Trek Marlin 5​

- Cassette - Shimano HG200, 12-32, 7 speed​

- E-bike Conversion​

- Bafang BBSHD 1000W mid drive kit​

- 52V x 20ah Battery​

- 42T BBSHD Lekkie Bling Ring​

Experience

- We've done about 75km over the past few days doing mostly paved path riding on level 2 and 3 on the controller. I'm finding that I'm on my smallest cog and really only require any sort of shifting when we are climbing the hills near our house, whereas everything else relatively flat for the most part. I end up basically running on the motor, spinning like a clown, when I would like to maintain a high rate of speed by contributing through pedal power. I would also like to better utilize the cassette since I really only use the bottom 3 which I believe are 12-14-16-18 with heavier use on the bottom 2.​

​

Question

- Would it be advisable to get the 46t or 52t BBSHD Lekkie Blingring, or similar in order to give myself both a higher top speed, as well as creating a combination of gears that I'm more likely to use through pedal power?​

​

I'm a very new builder but competent rider so please ELI5 if you have advice you're able to share. I'm not sure how many more tabs I can open on my computer looking at all the info from this forum, and other websites.

Much appreciated all. Happy riding.

 

[A-DamW]

Not a direct answer to your question, but here is a well written article on tuning your BBSHD for pedaling:
Sully's BBSHD Programming (for people that like pedaling)

For gearing, it is fairly well known the BBSHD likes to spin fast, ~180 rpm @52V IIRC, about twice what most
people prefer to spin at.
For the front chainring, whatever gets you the straightest chainline, and cadence for the range of speeds you are at.

For the rear cluster, some people re-stack the cassette so the 3-4 most used gears are centered
around a straight chainline.

 

[rudivb]

Yeah, one of the reason I run a 52t is so I'm not spinning like a maniac and you stay more in the middle gears, I top out at around 50 - 55kmph. If your chain line is straight you won't need a lekkie, you can get way cheaper chain rings from AliExpress or similar places, as long as it's 130bcd.

Shorter crank arms can also help, although I don't have experience with it.

 

[Van-Isle-Rider]

Not a direct answer to your question, but here is a well written article on tuning your BBSHD for pedaling:
Sully's BBSHD Programming (for people that like pedaling)

For gearing, it is fairly well known the BBSHD likes to spin fast, ~180 rpm @52V IIRC, about twice what most
people prefer to spin at.
For the front chainring, whatever gets you the straightest chainline, and cadence for the range of speeds you are at.

For the rear cluster, some people re-stack the cassette so the 3-4 most used gears are centered
around a straight chainline.

Thanks A-DamW. Appreciate the link and info!

 

[Van-Isle-Rider]

Yeah, one of the reason I run a 52t is so I'm not spinning like a maniac and you stay more in the middle gears, I top out at around 50 - 55kmph. If your chain line is straight you won't need a lekkie, you can get way cheaper chain rings from AliExpress or similar places, as long as it's 130bcd.

Shorter crank arms can also help, although I don't have experience with it.

Thanks Rud! I think I'm going to order a 52 but with my chain line I do need some sort of offset so will need to go with the Lekkie, or another brand off of AliExp. Not that cruising at 30-35 is so bad, I'd just like go a little faster.

 

[Kottbullar]

VanIsle:

Keep us updated, and send some pics too ...

I'm scoping out a conversion right now, and am looking at a similar mid-drive rig for mine. Would love to learn from your learning curve ... One reason I am big on the BBSHD is the configurability (you may want to explore an EggRider display as well).

Can you share where you sourced your kit? (esp. the 52V x 20ah Battery) and your experience with the supplier ....

 

[Diggs]

I run a 52-tooth Lekkie Ring with my BBSHD as I'm a country cruiser and like to keep my cadence down. In fact, I'm on my third Lekkie. I cracked a few by running too much power in 1st gear where the chain line was at its most misaligned. I had a discussion about it with Lekkie engineering. They don't plan to change anything at this point but I did point out the ring only fits BBHSD so why make it so spidery. Regardless, as I mentioned in another thread there is no other viable chain ring with 52t or greater available for the BBSHD.

 

[Van-Isle-Rider]

VanIsle:

Keep us updated, and send some pics too ...

I'm scoping out a conversion right now, and am looking at a similar mid-drive rig for mine. Would love to learn from your learning curve ... One reason I am big on the BBSHD is the configurability (you may want to explore an EggRider display as well).

Can you share where you sourced your kit? (esp. the 52V x 20ah Battery) and your experience with the supplier ....

Hey Kott. I can definitely share a few photos(shortly) and my experiences.

I'll google that EggRider in a few. Thanks!

This was my first time really doing any work on any of my bikes so my experience is elementary but my thoughts...
- I made some mistakes ordering and should have grabbed the 52t from the beginning and saved myself money.
- I also just realized that the stock chainring from Golden Motor is 46t so I'm going to look at changing that tonight. I didn't catch that I ordered the smaller Bling Ring and I think I found the problem. I hope that I don't need to pull it all apart to add spacers.
- It was a pretty straightforward install and the package came from a company called Golden Motor. Being in Canada I imagine it's more $$$$ here.
- On my bike I have hydraulic brakes and the magnetic cutoffs don't fit nicely when stickied on to the brake lever. I'll be looking at some brakes like the HD-E350-11 to replace them soon.
- I've had some issues with the left crank working loose and while I've snugged it up hard I'm concerned I may have an issue with either the bolts or the threads. I have access to a machine shop so I may get them to take a look.
- The supplier was incredibly quick to deliver once I ordered them. They had everything as ordered.

I did read the article that A-Dam linked that talked about programming changes and I'll definitely be taking a look at that.

I don't know if any of this was worthwhile to read but I'm glad to share.

 

[Van-Isle-Rider]

I run a 52-tooth Lekkie Ring with my BBSHD as I'm a country cruiser and like to keep my cadence down. In fact, I'm on my third Lekkie. I cracked a few by running too much power in 1st gear where the chain line was at its most misaligned. I had a discussion about it with Lekkie engineering. They don't plan to change anything at this point but I did point out the ring only fits BBHSD so why make it so spidery. Regardless, as I mentioned in another thread there is no other viable chain ring with 52t or greater available for the BBSHD.

View attachment 356993

Diggs, that is so disappointing. Going to go check you other thread.

 

[rudivb]

@Kottbullar @Van-Isle-Rider

Check out Daniel Nilsson's custom firmware:

BBS-FW: Open Source Firmware for BBSHD/BBS02 Controller

This open source project is finally ready for release! This firmware is intended to replace the original Bafang firmware on BBSHD/BBS02 motor controllers and can be flashed using the standard programming cable. Almost all functionality of original firmware has been reimplemented and additional...

endless-sphere.com

It's way better than stock firmware and you don't have to get the costly eggrider.
It has many extra features, better throttle modulation and a bit more power @ 33a.

Edit: an option for the motor cut-off is to use one of the mechanical "motor cut-off" brake levers as a third lever. You might need to get used to it, but I just grab both levers when braking and quickly tap the 3th lever when shifting, works perfectly fine for me.


@Diggs

Can't believe it cracks? Do you go very hard on your motor? Been running a cheap 52t chainring from Ali for a long time and never have issues.

Old bike;


New bike: (same chainring)

 

[Diggs]

Do you go very hard on your motor? Been running a cheap 52t chainring from Ali for a long time and never have issues.

Ya I was! Display was showing 1600+ watts which was stock settings on a fresh 52v battery. I've since turned it down to 25 amps. For my kind of riding I don't need the extra wear and tear on everything that the regular setting of 30 amps does.

I have several after-market chain rings (and adapters) and I couldn't get anything to work. Either they hit the BBSHD housing or there was no offset. Hmmm... Any pointers (linkage) on something bigger than 52T?

 

[rudivb]

Hmmm... Any pointers (linkage) on something bigger than 52T?

The one I got goes up to 60T, but has no offset, so probably no use for you, haven't seen any super large chainrings with offset.

https://a.aliexpress.com/_ExfwCBt

 

[Diggs]

For that kind of money I may pick one (a couple?) up and be creative on an adapter. (Hmm... Now where did I put those old chain rings and adapters....)

Thanks @rudivb !

 

[rudivb]

For that kind of money I may pick one (a couple?) up and be creative on an adapter. (Hmm... Now where did I put those old chain rings and adapters....)

Thanks @rudivb !

No problem, they are good chainrings, narrow-wide teeth. I just use one of those simple "spider" adaptors: https://a.aliexpress.com/_EvZUaef

Also 1 or 2 spacer is recommended (or you can use washers) as it runs pretty close to the motor cover and with some flexing and/or dirt it can grind/scratch the motor cover.

https://a.aliexpress.com/_EwKStmb

 

[Kottbullar]

VanIsle:

Thanks for the link, i've added it to my 'research' bookmarks.

FYI: I may look at the Eggrider because my plans include Euro touring and i want to be able to dial the power down at my fingertips, rather than having to reprogram it with a PC .....