Northrock XC00 fat bike converted to BBSHD efatty

[dn325ci]

Hi everyone. I got interested in building my own ebike after buying a Lectric XP last fall. Had fun with that and wanted more. I like the fat bikes in part because I think they're cool and in part because I'm a big guy (260 lbs) and I like the stability of these big bikes. I didn't own a pre-existing fat bike however, and to buy a pre-built efatty is super expensive for great components, so I set about to build it myself. I settled on the Northrock XC00 as it seemed like a good quality base to build around for not a lot of money. Took me a few weeks to research, order and receive the parts. Build took a few hours total, spread over a couple days, and it was complete just a couple weeks ago, July 2021.

The Northrock XC00 almost seems built for this purpose! A 100mm BBSHD fits literally perfectly. No spacers. Good clearance with the frame. This bike already comes without a front derailleur so I didn't even have to open the chain at all.

Components used:
- 2021 Northrock XC00 from Costco
- BBSHD 100mm from Luna
- 40T one piece chainring from Luna
- DPC18 color display from Luna
- 52V 20ah battery from Unit Pack Power bought through Amazon. Probably would have bought Luna, but they have been out of stock forever. Johnny Nerd Out recommended UPP to me.
- Gear shift sensor from Luna

I didn't like the seat or the tires, and upgraded both. Most of my riding is on bike paths or very well groomed trails, so I went with the more pavement-oriented Origin8 Supercell tires. I may at some point add a suspension seat post as I did on the Lectric XP, but after a 25 mile ride last night I'm finding this set up pretty comfortable so far.

This bike went pretty much straight from box to Ebike conversion, and I didn't bed the brakes in very well before repeatedly stopping from high speeds. Now they are kind of squeaky and I need to figure that out. I may at some point put larger rotors on it, as this bike is carrying a lot of weight and speed.

Anyway, just thought I'd share! Cheers, everyone.

Don

[hoggdoc]

Don would you share what you have spent so far on this project? I'm curious because before buying my E bike I priced out all the components necessary to convert my current Trek bike to an E bike. The few hundred dollars didn't seem worth the potential issues with building a DIY.

Generally speaking I'm happy with my current e-bike but do wonder how much better a mid-drive bike would be in the hills around here. I have even considered converting my current hub drive bike to mid drive by lacing the rear wheel to remove the hub motor. I figure I maybe able to resell the motor, controller and display to recoup some of the costs.

[dn325ci]

Happy to. Here's all my prices before taxes, since taxes vary everywhere, but inclusive of shipping (basically because shipping was free except for noted on Luna):

2021 Northrock XC00 from Costco.com = 429.99
BBSHD ("Hot Rod Programming3") + DPC18 Display + Gearshift sensor + all mounting hardware = 739.95
Luna 40T Eclipse one piece chainring = 84.95 (EDIT: probably wasn't necessary as it drove a freewheel gearing change to compensate below)
Luna shipping = 35.00
Unit Pack Power 52V 20ah battery from Amazon = 487.00 but has recently gone down to 459.00. (EDIT: could have gone smaller for lower cost/weight)
XT60-to-Anderson adapter to connect battery to BBSHD = 12.59 (I believe I could have avoided this by asking UPP to put Anderson on it)

So for the fully converted ebike I had 1,789.48 in costs before taxes. Beyond this I also bought a couple small hand tools along the way.

Not necessarily needed, but the Origin8 Supercell tires I put on were 67.79 each, and if you want to do some custom programming on the BBSHD, the cable is 17.99 from Amazon.

I forgot to mention in my first post that after a couple weeks of riding I wanted a taller top gear, so I purchased an 11T - 28T freewheel for the back for 28.78 on Amazon. That actually gave me two gears taller than the 14T on the OEM Shimano freewheel - 11T and 13T. You might need that if you want to contribute to pedaling at higher speeds. It's super easy to change the freewheel, by the way.

So there you have it. Cheers.

Don

[jsail4fun]

Thank you Don! This Northrock bike is my current (analog) bike. I was looking at e-bikes but quickly I'm looking at $3K-$4K and I'm wondering if it would be better to convert this bike. I'm happy to hear its basically bolt-on. I've never built an e-bike before.

Does the BBSHD have an integrated controller? I thought I would have to buy a separate controller box?

[AZguy]

It's integrated as a separate module in the motor assembly that's accessible externally without requiring motor removal

[dn325ci]

BTW, I love the performance of it. This is a lot of bike for the money - top shelf performance, battery capacity/range on a very good base bike, for probably 50% or less of a pre-built bike. I looked at pre-built fat bikes before deciding on this path to get maximum performance for the minimum cost. Even the basic pre-builts are more money and usually significantly less powerful, and anything with comparable performance seems to be $3K and up right now.

[dn325ci]

I guess one final note: if I were to do it again, I might actually go for a smaller battery than 20ah. As you can see it was pretty big to fit in the frame. I think I could have gotten by with 14ah or 17ah, saved some costs, and the battery would have looked a little leaner. Just a thought.

[Dshue]

In most instances the battery case will be the same size whether 20ah or less 17ah and likely even 14ah.

[Retrorockit]

A big battery is good for long out and back rides. As it gets older and loses some capacity it will still be good enough. Small batteries are OK for commuters when they can be recharged before riding home. I think you made the right choice.
As far as brakes go, get the big front rotor, and since you have cable brakes look into some EBC metallic pads. If you have long downhill runs upgrade the rear rotor size also. Any rotor that has had organic pads sunning on it will need to be lightly sanded to use metallic pads. The metallic pads aren't silent but will stop the bike from any speed, and reduce the need for adjustment by about 5x.

[dn325ci]

A big battery is good for long out and back rides. As it gets older and loses some capacity it will still be good enough. Small batteries are OK for commuters when they can be recharged before riding home. I think you made the right choice.
As far as brakes go, get the big front rotor, and since you have cable brakes look into some EBC metallic pads. If you have long downhill runs upgrade the rear rotor size also. Any rotor that has had organic pads sunning on it will need to be lightly sanded to use metallic pads. The metallic pads aren't silent but will stop the bike from any speed, and reduce the need for adjustment by about 5x.

Agree with this sentiment on the 20ah battery now. After more riding, I’m finding a real world range for a big guy on a big bike is 30 miles, maybe 35 outside.

Thanks for the input on brakes. I’ve never changed rotors before but really like this idea. What’s a good rotor for this application?

[hoggdoc]

Wow I'm really surprised the 30 to 35 mile range you're getting that big battery pack. My bike has a 17.5 Ah battery pack that gets me about 33 miles combination of pedal assist and throttle only. I also live in an area where I have a steep climb to get back home from any ride in town.

On the brakes I would suggest going to a 203 rotor on the front and probably a 180 in the back. If you're using mechanical brakes now you can either go to full hydraulics or a hybrid caliper that his cable operated but hydraulic in it's operation. Bolton E-Bike in NORCAL have some very good calipers they sell that hybrid.

[Retrorockit]

The big rotors are now 200mm. Older ones were 203mm. Just get the caliper bracket and matching rotors together. The big brakes will have enough authority to match the speed and weight then. But the rotors will be moving much faster through the pads. So upgrade those too. When you double the speed there is 4x as much heat through the brakes.With good brakes you should have enough power the first pull, and then back off the pressure as the bike slows. You shouldn't have to "ask twice" for braking power, and if you need to increase pressure as the bike slows instead of backing off, the pads are melting. But the long life and fewer stops for adjustment make the metallic pads worth the money. Rotors are either 6 bolt IS, or Shimano Center Lock type. 6 bolt is pretty obvious.

[BKFM]

I was looking at this exact bike on Costcos website but was unsure if BB casette was good for the BBSHD. Im doing this instead of converting my old bike.
Is there a reason you did not but the brake cutoffs?
What size chainring do you think would have been the right one instead of 40T?

[AZguy]

Installing brake cutoffs can be a real pain and many installations often fail where you have to unplug the sensor

After dealing with them for a few thousand miles I actually prefer not having them anyway... they have very little value IMO... think about it... if you were riding a moto (or scooter or moped, etc.) would you want the motor to cut out (and the clutch to open) every time you touched a brake?

[SR68]

GLAD you posted this as I was coincidentally considering this exact bike and motor combo. Really helps save headaches and or legwork when someone else has already done it. THANKS