creativepart

Not my first rodeo, but I'm installing a BaFang BBS02 mid-drive on a newly purchased 2022 Specialized Rockhopper 29 Expert. Prior to this I had a Blix folding ebike that I sold after 900 miles. Then I put a Dillenger rear hub-drive kit on a 2018 Specialized Crosstrail Sport Disc. After 1200 miles of that I replaced the rear hubdrive with a BaFang Mid-Drive BBSHD from JohnnyNerdOut. Sadly, after 800 miles I lost that bike on the road while it was in the rack on the back of the car. Long story, but bike is gone.

I've got all the parts coming this week, and I've already stripped down the crankset and BB to prepare for what should be a one-day install of the new system.

Then I can start the process of adding miles to this new ebike.

I could have simply purchased a new eBike from a major manufacturer but what's the fun in that? Building your own is a great way to go and I highly recommend it. Plus my new ebike, when done will have a $1,500 into it and to come close with a manufactured eBike of similar specs would be $3,700. BONUS!

PS. 2022 Specialized Rockhopper 29 Experts are on sale. Original price was $1,400 sale price is $1,049

Here's the bike... pre-electrification

2022 Specialized Rockhopper 29 Expert - pre-ebike

2old

Good luck. I had an MTB depart my rack at about 80 mph and watched in my rear view mirror as it bounced down the eight lane (four each side) freeway. I drove back and located it nestled next to an on ramp with minimal damage, and only the seat was beyond repair. If the RH has a 73mm wide BB, FME, you won't be able to use the jam nut to secure the motor; Locktite on the "main" nut, a Lekkie ONENUT or a stabilizer (Lunacycle and others) may be necessary.

creativepart

Yeah, I've been told to expect this. I'm pretty sure I had this same limitation with my Crosstrail (68mm) when I installed the BBSHD and it wasn't a problem. The motor never came loose in 800 miles. But those suggested solutions are a big help. I'll use Locktight to begin with.

I'm expecting I'll need to do a bit of fine tuning to the whole thing as I've ordered the 44T stock Bafang chainring and don't have any offset cranks. I figure I'll see what works and buy more stuff as necessary. Another RH owner that's done the conversion said to use both a 42T Lekkie and offset left crank.

2old

The Lekkie cranks and chainring resolved the offset in the BBS02 for my mid(s). On one bike I used just three rear cogs, 11-17-28 spaced 8-speed. The gears lasted several years since the chainline was straight with the "17" so the larger and smaller didn't have much offset.

creativepart

When I added the BBSHD to my Crosstrail I had to change the stock 9-sp cassette to 8-sp and get a new clickshifter, to keep from getting chain hop. But I found that in real world riding that I rode in 7th gear about 80% of the time. I know you're not supposed to do that. But I had a shift cutout and it was so slow acting that I didn't really want to shift all that much. The RH has a 1x12 drivetrain and others that have made this conversion say it's working for them. I don't plan using a shift cutout on this bike. But that's really another wait and see item.

Lekkie cranks have really gone up in price - plenty of other places sell Offset cranks for reasonable prices. Yet again... wait and see.

2old

Electrify Bike has them for $120; otherwise they're about 50% higher than when I purchased mine.

creativepart

The kit arrived from JohnnyNerdOut.com last night and It only took about 5 hours today to finish the entire bike - I had already removed the bottom bracket while waiting on UPS to complete shipping.

Only had enough time for a very short ride, maybe a couple of tenths of a mile, but everything worked great. I didn't push my luck and test shifting yet. I'll do that tomorrow. So, I just rode in the smallest/highest gear for the test ride.

Turns out 2old that I didn't need to buy any offset cranks - I had a pair of FSA Offset cranks that were take-offs from the last ebike build. They worked great and are 175mm instead of Bafang's 170mm length.

As I said I didn't test shifting yet - but the 44t Stock Bafang chainring worked perfectly in the highest gear.

Typical South Texas "winter" it was freezing overnight and low 50's today but will be back up in the 70's and 80's this coming week. So, I'll get some longer rides in the warmer weather.

creativepart

Today I completed final testing and everything seems good. I did end up adding the brake cutouts to help with shifting without a shift sensor.

The stock Bafang 44T is shifting fine with the Sram 12-sp cassette that comes stock on the RH 29 Expert.

Here's the bike in my bike work stand. Weather will be better later in the week. You'll see my Dillenger brand shark battery. It's 48v with 14aH and it came with my first ebike hub drive build. When I lost my bike as mentioned above the battery and charger were in the back of my SUV so at least that's something I didn't have to replace. The battery is nearly 3-years old and it works great but doesn't seem to last as long. The voltage drops quicker than it used to. I'm torn between sending it out to be refurbished or buying a new battery so I'll have two.

2old

Great job, and I'm glad you were able to save some coins with the FSA. You might take a look at bicyclemotorworks; I purchased a 52V, 4ah battery from them about three years ago and it's still going strong powering my BBS02. It worked so well that I just purchased a bigger one for a 1500w DD bike. The batteries are manufactured in the US.

Silver Steve

I'm not an E-bike expert but it looks like your fork is on backwards?

cat0020

Yeah, that fork needs to do a 180.

creativepart

Yeah it was. Oversight on my part. I fixed it right after this photo. Thanks

vrun

Hey, I'm looking to convert my Rockhopper Sport. Did you have any issues with installation? Any spacers needed? Thx!

creativepart

No, everything worked fine - just got off the bike to write this response. I don't remember any thing special needed, But this is my 3rd build and I always order extra BB spacers with my kit. I think I ordered two 2.5mm bottom bracket spacers and used only one to make the BB fit right with the chain stay. It was a year ago and honestly can't recall.I did need new offset cranks with a bowed out right crank, but I happened to have an old pair discarded from another build that worked perfectly. The standard Bafang chain gear works fine, but I ordered a Lekkie 42T Bling Ring that wasn't quite as offset. I think the stock Bafang gear is 44T

My advice, is to be sure to get all the tools you'll need, especially crank pullers and the proper bottom bracket removal tool. The OEM BB was on there very tight. I needed a 2nd person to steady the bike while I stood on a 2' length of pipe as breaker bar over my largest ratchet wrench to get it to budge. But once loosened it was a piece of cake. There are two ways to do this - get all the tools, adapters, spacers, etc you need before you start OR take it slow and every time you find you need a part or tool order them as you encounter the roadblock.

Some bike shops will remove the BB for you if you can't get your's to budge.

Since it was my 3rd conversion I had everything in advance and knew what to order with the kit. Once you do it the first time you can do it in a day easily.

Does the sport have hydraulic disk brakes? If not, I'd suggest changing to those. My RH Expert did come with them. I've used mechanical disks before but would not recommend them.

2old

CP; great job; anything amiss with the BB or has the LockTite held?

vrun

Thx! Few more questions if you don't mind:
1. OK, will get a spacer for the drive side. Did you use any spacers on non-drive side for the bracket that attaches to the motor? I saw Lekki have 2 sizes for 73mm BB - 5mm and 6mm thick...
2. Any issues fitting 42Pro? Is there a large enough gap with chainstay?
3. Sport comes with hydraulic brakes... Will see how they work, I might replace them with Magura later for a more clean build...
4. Any issues with chainline? Sport comes with Microshift 9 speed 11-36 and chain line not that great by default on lowest gear... I was thinking of getting Lekki's 40T with their thinner cap and replacing the cassette with 11-46... have 7-8-9% grades around me.
5. Based on your experience, what mileage would you expect from a 13Ah battery?

Thx!

creativepart

I've never had any issues with the motor getting loose. I don't even use lock tight. I just bought the cheap flat steel "wrench" and hit it with a rubber mallet.

creativepart

No issues on my bike with the 42T. I didn't like the Local brand brakes, but they've been fine.
I can't speak to your chainline as mine is a 12-speed Sram. All I do is try it and if it works. Great. If it doesn't figure it out and make changes.
My battery is now 5-yrs old. I'm now seeing 20+ miles it used to be 25+. I'm an old guy. I don't shift much. Not even on hills. Every bike, rider and terrain is different. You'll get what you get when it comes to mileage. If you need more, get a bigger battery.
You will need spacers for the motor bracket. You want to use enough to hold the outer ring tight without bending to make up the spacing. My kit came with a couple of spacers and I used some black washers from Home Depot to make the fitment tight but not bending the outer ring.
I pulled off the knobby tires from day one - and put on 2" wide Schwalabe Green Marathon tires on my stock rims.