Diamondback OverDrive 27.5 "RidgeRunner"

Alan B

100 GW
Sep 11, 2010
San Francisco Bay Area, USA

Here's the photo album for this bike: https://goo.gl/photos/Swc4DiKoYkypqLhw9

Hi folks. I've been keeping busy since retiring, and recently built another ebike, my first mid drive. For this project I selected the BBSHD to install in a 2016 Diamondback hardtail mountain bike. I call it the "RidgeRunner" because several of my initial trips with this bike were partly on ridge trails, and it worked so well there. It seems to be in its element when climbing.

The triangle pack is 14S8P of Samsung 18650 type 26f cells yielding 52V 20AH, the BBSHD has the Eclipse chainring and 3mm spacer, all from Lunacycle. Brakes are Tektro Dorado hydraulic eBrake 203mm with Bafang plugs from EMPowered Cycles. Rack and trunk are Topeak, seat is Bell Recline from Amazon. Charger is Satiator from Ebikes.ca. Water is San Pablo Reservoir from recent rains. Most of the rest is stock equipment on this 2016 Diamondback Overdrive Sport 27.5 medium.

I made a conformal spacer of Loctite epoxy putty to spread forces between the motor and protect the downtube, in an effort to avoid the damage that some have experienced if the motor works loose.

A few days ago I added a Batt-man to the setup to get better range anxiety management. Range is 25-50 miles depending on speed and terrain.

This machine climbs like a mountain goat. Without getting hubmotor hot.

More information in this complete article: DIY Mid Drive for Street and Trail

(note the image error comments below are old and the errors have been fixed)

(note that Diamondback made a bike called the Ridge Runner in 1983, which I just discovered in 2019. Unfortunate name collision.)
The shared album is now populated. Here is the link again.


Below is the conformal spacer made with epoxy putty that spreads out the recoil torque force on the downtube:


The 14S8P 52V 20AH triangle battery and frame pack fit nicely into this medium size frame. This is probably the smallest model of this frame that would fit this combination. There is some room for wires and connectors. There is a voltage display on the lower right edge of the battery, so to protect that from contact a few square inches of floor foam are taped to the upper right edge of the triangle battery. This keeps clearance for the display and the readout triggering pushbutton.

Charging is via the XT60 in the lower right, discharge via the anti-spark XT90 in the upper center. The BBSHD came with PowerPoles so I made an adapter from XT90 to PowerPoles to simplify installation and make up the length so the wire channel in the triangle bag can be used. Missing is a wire entry / drain in the lower corner of this bag that would make it even more useful. It wasn't essential in this build but would have been convenient.

This adapter was replaced with the Batt-man current sensor which is what is shown in the above photo.

I selected the Bafang BBSHD for several reasons:

1) it is quiet

2) it has good power and adequate cooling

3) it was available quickly which suited the timeline for this build

4) it has a very straightforward install so not a lot of time was needed and no custom components were required (aside from a simple battery plug adapter)

5) it has very clean wiring and minimal visual impact on the bike

6) the prices were good considering the completeness of the kit
What's the CA-like display in the middle?

Nice clean setup. I want to test a Bafang sometime to see how it does on the hills around here.
fechter said:
What's the CA-like display in the middle?

Nice clean setup. I want to test a Bafang sometime to see how it does on the hills around here.

Hi Richard,

Thanks for the feedback. I think you'll find it climbs quite well, not at the rocket speeds of a Cromotor, but better than most hubmotors at the same power input (on the steeper slopes where they struggle).

That's a Batt-man. It has been around awhile but this is the first time I've used one. It has a USB interface and PC program to set up the parameters like amp-hour capacity for the fuel gauge, wheel size for speed, and calibration so it can be fine tuned for voltage and current scaling and offset. The unit includes an external shunt. It is appropriate when the control functions of a Cycle Analyst are not needed, but a simple readout of voltage, power, speed and battery state are desired. It has some useful peak readings and three screens of info with a pushbutton to select and reset after charging the pack. It's good when the user wants something simple and small.



was thinking about building a 27.5er BBS/Cyclone with this frame...since we don't use the cranks we only need a few parts.. Mainly its just the forks/wheelset that will be pricey. Honestly could use a 8 speed setup since its stronger(cheap now too) and we don't need every gear due to motor but you loose the new clutch feature of a 10/11speed setup.
So far I haven't missed the clutch feature, I suspect that is important for folks who ride a lot harder than I'm likely to. The BBSHD and I just torque up those big hills kinda slowly and save the air-time for the younger set. I'm sure the setup is capable of more than I'm using, but it does what I ask quietly and without hesitation. My rear tire is losing the nubs, the one thing about 27.5 is a fairly limited selection of tires, though more are coming all the time.
yeah the 27.5" is growing, pushing 26" out of the industry now.. i could build a 29er also, however these usually have way less frame space.

I might pull the plug on the cyclone since its 1/2 the price, however I think a full suspension bike would be better suited for the high power fun that the motor can provide.
I'm operating a BBS02 with three speeds (11-17-28) with 8-speed spacing (primarily for chainline issues), and that's enough, plus it shifts perfectly with a $20 Shimano Altus derailleur. Also went to the Luna 30 tooth ring since I'm using this mainly off road and don't miss the top speed. The motor more than makes up for the lack of gears, and with the 30/28 combination can climb most anything around SoCal (THAT I'VE ENCOUNTERED).
Sounds excellent. I'm running 42:36 in low gear with this BBSHD and even when I forget I'm in 3rd and not low it still climbs like crazy without getting warm.

What warms up the BBSHD is a high speed run, 42:12 or 42:14, going uphill. That seems to load it down and get it to warm up. The steep stuff in low gear is too slow to load the motor much.
Today I spent some time with the various Luna batteries and chargers I have, and went for a ride. The blue alloy charger from Luna is set up for 58.8V and 1-2-3-4-5 amps. It has a voltmeter and a switch to select the charge current. I used it to charge a 14S2P Luna Might Mini, a 52V 6AH tiny pack that can put out 30A plus for the BBSHD. Using a clamp-on DC Meter I measured the charge current at each setting, and it is close to the advertised 1-2-3-4 or 5 amps. It was the first charge cycle for the small pack, so I started at 1A, ramped up to 5A and then as it approached full I ramped back down and finished at 1A. It is nice to be able to do that so easily. The temperature of the pack was monitored carefully and it didn't warm at all. It tripped off at about 80mA or so, but that isn't a very accurate reading due to the zero drift of the DC clamp on meter.

On the short 4.5 mile shopping trip the MightyMini performed just like a big pack, and did not get warm with the moderate loads I was drawing. It was still cool when we reached home, and I put it on the Satiator to get some amp hour numbers. According to Battman it was 4.5 miles and 2.2 amp hours, which is about right. The Satiator is hitting it a bit harder at over 6 amps, so the pack is warming slightly. Not sure if that is the batteries or just the BMS. The Satiator is good and hot, while the battery is just warm, and the current is already tapering. Most of the heat seems to be in the bottom of the pack which is where I suspect the BMS is, but I don't really know, but that's where it got slightly warm at the end of the charge cycle as well.

As usual the BBSHD on the RidgeRunner performed well. I spent the whole trip in gear 3 which is low enough to accelerate smartly from a stop while wanting to lift the front wheel mildly and high enough to reach almost 20 mph. I didn't need more speed on this trip or I'd overrun my son on his 10S 9C hubmotor bike, especially on the uphill segments. On the way back he hit a nail, driving it through the center of the tread and out through the sidewall, so we've got another repair to deal with. Even the fancy Schwalbe Kevlar won't stop a sharp nail.

So a quick loop to the grocery store uses just over 1/3 of the Luna Might Mini battery, making this a 10-12 mile range brick, excellent for both range extension and short trips. With the triangle pack empty the bike is really light. I think my lock outweighs this battery. :)
Today's project is to install the DPC-14 display from LunaCycle. This new display has some additional features that are especially useful for those of us running 52V instead of the standard 48V.

To power the bike for the testing I used the small Mighty Mini pack. This little pack will put out 30A continuously which is adequate to run the BBSHD, and has a range of about 10 miles or a lot more if you add your pedaling power. It is about 4x smaller (and lighter) than the triangle pack I usually run, here it is barely putting a dent into the triangle pack's space:


The DPC-14 voltmeter can be displayed digitally so we can see the battery voltage, which the other BBSHD displays don't generally offer. It doesn't measure accurately at the full charge voltage of 58.8, but below 56.7 volts will produce a useful battery voltage display.

The DPC-14 also adds current or power displays (selectable) so you can see how much assist the electric system is giving you. In this photo it is configured for battery current in Amps. It also has a wheel size setting for 27.5 inch wheels so it should give a more accurate speed reading which I didn't have with the earlier displays that jumped right over that choice and didn't offer a setting for the newly popular 27.5 650b size wheels.


The display to the left is the additional Batt-man that I added earlier to get voltage and amp-hours, as well as accurate speed/distance readings. Now that the new display has calibration for the 27.5 wheel and Amps/Power/Voltage displays the Batt-man offers fewer advantages than before, though it still has amp-hours and the battery gauge. It is also more accurately calibrated with the USB settings. It remains to be seen how accurate the speed/mileage of the new color Bafang display are.

I almost forgot, this new display has a 500 mA USB jack for charging your phone or whatever you might need some power for.

I picked it up here: http://lunacycle.com/parts/bafang-parts/bbshd-parts/luna-full-color-display-dpc-14-for-the-bbs02-and-bbbshd/
Thanks for the heads-up on the image problems. This has happened a couple of times in this thread. For those interested in the details of posting links to Google Photos, read the rest of this posting, otherwise skip this posting (sorry for the off topic problem).

It is tricky to get the right URLs from Google that work for everyone. The pics looked fine to me so it is hard for me to tell there's a problem. I fixed them and verified from another account. Please let me know if it works for you now.

Here's what you have to do to embed the new Google Photo images:

1) Upload image to Google Photos. This happens automatically from a smartphone if you have it set up. If you set it for medium resolution there's no charge for the storage and adequate resolution, the new smartphones have far more resolution that needed for forums and web pages. If you set the uploads to "full resolution" it will charge the space against your 15GB free Google space allocation (or whatever Google allocation you have).

2) Go find the photo in today's Google Album and copy it to a Google Photos Shared Album.

3) Go to the shared album and view the photo there.

4) Right click on the photo in the shared album and select "open image in new tab". Don't skip this step.

5) Go to this tab and open it, point at the image and select "copy image URL" (or equivalent for your browser).

6) In the forum editor select "image" and paste the URL in between the IMG tags.

7) Look at the image size which is near the end of the long URL. If either value exceeds 800 adjust them downward to reduce image size. Keep them proportional to maintain the aspect ratio.

8) Preview the posting to see the image. It will view for you whether you inserted the public URL or the private URL if you are logged into Google (eg gmail, etc). To really check the image to be sure it is publicly viewable inspect it from another account or incognito browser that is not logged into Google.

My mistake a few days ago in this thread was forgetting to launch the image into a new tab, instead I grabbed the URL from the shared album, but without having launched a new tab. The URL is different and viewable only by me. Looking at the URLs I can't tell which is the public one and which is the private, so everything looks fine to me. I have to launch a different, non-logged in browser to fully test the posting.

Earlier in this thread the problem was that Google Photos was new and worked differently from the old Picasa that I had used before. So this thread got hit twice. Apologies for the distractions.

Now, back to ebikes.

Ride safe, have fun.

Choose appropriate safety equipment for your next crash.