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.

crabbysalt

I know this is quite an old thread, so I hope you don't mind me bumping it slightly. I would have PM''d you directly, but as a new user that isn't possible just yet. And I don't know if you'll ever see this post, as I don't believe you've been active on here in a while.

I've been scouring the internet to find people who have built a e-bike from a 2022 Specialized Rockhopper, and never really found one ... until now, you are literally the first (and only?) person to have done this!

The reason behind my specific search is that I own a 2022 Specialized Rockhopper Elite, and originally I would throw it into the back of the car to take it somewhere else to ride. The simple reason behind this is simply that no matter what direction I leave my house within minutes there are hills to climb! And when you're just starting off you ride it doesn't set you off in the right mood. but if I add a little motor to do the grunt work (assisted of course, I'm not lazy... just a bit overweight) I would probably use it more frequently.

From what I understand, generally Specialized Rockhoppper's (at least from the same year) are all practically identical in terms of the basic frame etc, the difference in the Elite, Expert etc. names are the additional components that are added, so essentially we have the same bike. Now I've gone through many of your posted related to this bike and seen that you have used the Bafang BBS02, but I've have already ordered the BBSHD ... may as well got all out. But there are two main things that are making me a little nervous, (and a few general questions) and hopefully you may be able to shed a little light on them.

1. Does the motor require any spacers? I know the crank set (?) is 73mm, so I've ordered the 68-73 model, but will it interfere with the chain stays, as it does look like it is quite a sudden and sharp bend.
2. I have a 11-Speed cassette on the rear (I believe yours is a 12), are you able to use all 12 (11 in my case) gears without any issues?
3. Do you use any chain guides to assist in a clean, smooth chain line?
4. Did you use a gear sensor?
5. Did you use a brake sensor? (I think I read you did for this one)
6. Have you used any kind of motor cut off sensor?
7. I've ordered a Lekkie Bloing Ring HD 42T Chainring, which I notice quite a few people recommend... is this a good choice for THIS setup?
8. I've also ordered a Lekkie One Nut, again I notice quite a few people recommend... is this a good choice for THIS setup?
9. Did you need a new/longer chain?

I think that covers most things, I hope to have the parts in the next week or two and can properly crack on with the build... but if you have any answers to the above it would be GRATELY appreciated.

Thanks in advance.

creativepart

If I remember I did need two spacers for everything to line up. I "think" they were 1mm each. But it's been a couple of years so don't count on me. I tell everyone order 3 or 4 spacers and use them as you need to. I'm pretty sure mine was a 68mm. But I did order the 68-73 motor as well.
If you have 11-speed then you have a different brand of gearset. My Sram 12-sp works great in all gears.
No, nothing added. I did do a Lekkie ring I can't remember if I got a 38 or a 42. Whatever it works.
At first I left it off. It's not manditory. You just have to stop pedaling and wait a sec before shifting. But I found it easier to use the gear cutout and added it later. 6 of one half dozen of the other.
Yep, I put sensors and magnents on the hydraulic brake levers - I ended up gluing the magnets in place, they kept shifting position in hot weather.
No, other than the gear sensor and the brake sensors.
Should be fine. If it's not, fix it.
It's fine but not needed. I've never had the motor nuts loosen on me on any of my builds even after 1000 miles. I see folks that say the motor came loose right away. BE SURE to have plenty of spacers or washers to use as spacers between the motor and the bolts that you hold the motor on with. You don't want any space between the motor bosses and the front of the nut. If you have space there when you crank the bolts you'll bend the nut and that's no good. I had a couple of spacers and when to home depot and bought a bunch of small washers to use on those bolts.
No, everything is stock... EXCEPT my cranks - the Bfang cranks don't have much offset. And I kept hitting my foot on the chain stay. Not a problem if I remembered to angle my foot away. But, I had a pair of OEM cranks from a previous build that had an offset left crank and I used those. Now no clearance problems.

Here's my advice - be prepared for anything. Your bike isn't the same as my bike. Heck your kit my be different, too. Have ALL the tools up front if you can. Especial the BB wrench, which is the most common one for 68mm square taper BBs. Nothing special. I had to use a 2" breaker bar on that wrench to get mine to loosen. Had to stand on it. Also, have a crank puller. One other special tool is needed for the speed sensor magnet screw. It's torx with a center hole. I got extra super lucky I had installed a Ring doorbell - stay with me - and it came with one of those that was the exact size needed. Strange but true.

Take your time. When you put it together expect problems and just swing with it and fix them. That's the only way to know for sure. Same with tools, if you're building and you don't have the right tool stop working and get the right tool, then move on.

After getting everything done you'll spend a full day arranging cables and adjusting zip ties. Then go for a ride and be prepared to make changes on the road or be near home to make adjustments. I takes me a week to feel like the bike works the way I want it to.

Oh, I bought a nice bike work rack a few bike builds back and find it invaluable. I'd add it as a must have tool.

creativepart

Here's a link to the special tool for the speed magnet:
https://www.amazon.com/Doorbell-Scre.../dp/B0892KWDG7

The screw has a pin in the center so you need a torq driver with a hole in the center. At least mine did. Yours may not.

crabbysalt

Hey, thanks for coming back to me and thanks for answering the questions. The motor arrived today, so that's a job for the weekend! .

Broctoon

A few years ago, I installed a Bafang BBS-02 kit on a bike for my wife. (Her mid-90s era Schwinn MTB). It went together pretty easily, and she's been really happy with it.

So when my daughter recently asked me what I'd recommend to electrify her Trek FX hybrid/city bike, I said "Why not a Bafang kit like Mom's?" She ordered one, and I installed it for her. As with the previous one, its installation presented no big problems. She's taken it on a ride or two and told me it works great; she's very happy.

My wife got an 11.6 Ah battery, and it gives her a range of about 25 miles or so. My daughter wanted more battery capacity, because she lives in a hilly area and she wants to tow a trailer with her son in it. She got 17 Amp-hours. The battery is HUGE, but it came with a really beefy rack to mount it on the back of the bike, and this setup works pretty well.

Prices have come down. We bought my wife's kit directly from Bafang, and it was just over $1000 for everything. My daughter only paid about $700, including the huge battery, from Amazon.

I think it's dumb that the speed sensor magnets have that tamper resistant Torx screw. When installing both kits, I just grabbed the screw head with vise-grips to tighten it.

One little snag that I ran into with both kits: the screw that attaches the plastic shift cable guide under the bottom bracket. It protrudes into the BB shell too far and will not allow the Bafang motor to fit. I ground down the screw length... problem solved. This is one example of minor issues to deal with, which incline me to say these kits are not for beginner mechanics.

On a Skill Level scale where Level 1 is "Fixing a flat tire is about the most advanced task I've ever attempted, and I take my bike to the shop when it needs a new chain" and Level 5 is "I've built my own frames from raw tubing, built dozens of wheels, and installed every kind of drivetrain and braking system invented in the past 50 years," a Bafang installation would be a 2.