Assembling my second bike from scratch - light, urban, agile

I bought an Optibike Pioneer Allroad about two years ago, before I knew much about bikes. I've put >2000 miles on it all in New York City. It's been a fun ride with some hiccups, and over time I've upgraded virtually every component and learned a lot. I'm now thinking of selling it and building something from scratch that will better suit my riding style.

Apologies in advance for the massive text dump, I'm trying to resolve a host of questions all at once.

I have a closet full of tools and a stand, and I'm not bad at basic repairs, but I'm pretty far from being an accomplished mechanic. Ideally, I would put together something that will last a long time and can be upgraded as technology improves.

Price:
Willing to spend as much as $2000-3000 upfront, depending on how much I get for my old bike.

Environment:

I'm 6', 155lbs, and often haul stuff around, so figure a 160-175lb rider. I'm reasonably fit and like to put in a lot of effort at high cadence most of the time. The speed limit here in NYC is 25mph for cars (yeah, right), so anything above that is rather unnecessary. I have to climb some hills that are long, but not very steep, but the only serious "hills" are the various bridges that connect the boroughs (3-4% grade). Traffic is start-and-stop, so being able to get a quck start and maneuver around cars and obstacles is more important than maintaining a high top speed. The speed on the Allroad is limited to 20mph, which is basically fine, though I only get around 15mph on the ascents with a lot of effort.

While most ebikes are theoretically illegal here, you'll see a hundred delivery guys riding Chinese SLA hub-motor bikes every day. I've never had a problem with law enforcement.

Wishlist:

The aspects of the experience I would like to improve are:

• Weight of bike / handling - The Allroad is 48lbs stock, which makes it a pain to carry on stairs, for example in the subway or visiting a walk-up apartment. It would be nice if I could take the bike on the subway without major effort if the battery dies or weather gets bad. I would happily trade power for agility, especially if it means being able to keep the bike upright at lower speeds, for example when traffic suddenly slows.
• Range - I can get 25-35miles out of the Allroad's 10.5ah 36v battery, mostly riding on PAS 3 (out of 5). Extending this range or increasing the power over this range would be nice.
• Acceleration/motor response - From what I can tell, the Allroad motor just uses a speed sensor that kicks in once you start pedaling. It stops a few seconds after you cease pedaling, or when you apply the brakes / pedal backwards, but there is a delay of a few seconds. This is less than ideal when trying to get a quick start in traffic or quickly adjust speed.
• Durability - While the aluminum frame has held up pretty well, the bottle mount battery pack has given me a fair amount of trouble. There are few shops that work on ebikes here, and they charge an arm and a leg, so a widely used model like the BBSHD with interchangeable parts is ideal.
• Fit / Comfort - A high priority is finding a frame that fits well and allows me to maintain a somewhat upright position, which I prefer for visibility and comfort.

Ideas:

• I'm thinking of starting with a rigid steel frame like a Surly Krampus. Suspension seems like more weight than it's worth, since the largest drop I'll hit is a 1ft curb, so I'm mostly dealing with potholes and crummy pavement. A suspension seat and/or seatpost like I have currently would probably handle bumps well enough.
• To this I would add a mid-drive motor like a BBS02/BBSHD. Since I don't need a ton of power, it might make sense to go with the 500W and shave off a few kilos, but I could be convinced to go to 750W if the power difference is worth it. It looks like the 1000W version doesn't weigh any more, so I might as well get that. A torque sensor seems like a huge improvement in terms of smoothing out acceleration and increasing responsiveness.
• To further reduce weight of the bike and improve handling, I'm tempted to go with a backpack battery setup. I'm always wearing a backpack anyway, and it seems like this would also reduce theft risk and need for suspension, make it easier to carry the bike, and reduce weight as the battery wouldn't need so much protection from shocks and the elements. Upgrading to 48v seems to make sense to improve range/power without adding too much weight.
• I'd like to try using a Gates belt drive, as the idea of not having to deal with chain maintenance or grease on my pants is very appealing.
• For transmission, I'm a big fan of the Shimano Alfine 8 internal hub I put on the Allroad, so I think I will stick with IGH. For If I boost power, it seems like it might be worth saving some money and getting a cheaper and less finicky Nexus 3, since I probably don't need so many gears to maintain good cadence.
• I'd like to go with pretty wide (say 3") tires to get some cushioning, defend against potholes and grates, and compensate for the lack of suspension.

Thanks so much for reading this and any suggestions. I'm familiar with most ebike basics but don't understand controllers particularly well.

I don't know, but almost $2000 for a bare bones steel framed bike who's main feature is slightly wider wheels and tires seems a bit steep. Maybe there is more to it that I don't get.
I've always found real suspension components to provide a better suspension than air in the tires or springs on the seat post.
In my part of the country, slightly used, high tech mountain bikes w/ the now out of favor 26 inch wheels abound on Craigslist and they go for a song. I just bought a like new model for less than it's Fox shock costs new. Probably mountain bikes are not so plentiful in NYC though.

Thanks for the suggestions. I actually meant to link to the Surly Straggler, which is a lot lighter than the Krampus at around 27lbs fully loaded (without motor). In terms of cost, I've seen this and similar Surly bikes with components on craigslist for around $1000.

The suggestion to go with a hub motor really threw me. I guess I was brainwashed, or maybe technology has advanced since I last looked into it, but I always thought that mid-drives were superior in every way but cost. I definitely had the impression that they were less likely to wear out/burn out, even though you end up spending money to replace drivetrain components. In terms of hill-climbing, this Strava segment shows the route that's likely to be the biggest challenge.

I had a Prodeco Phantom X2 (throttle-only 500W rear DD hub motor) for a little bit before I bought the Optibike. It was heavy at around 60lbs and something of a disaster due to the poorly mounted rear-rack battery, but it did have nice pick-up. I prefer my current mid-drive setup because it seems a lot more rewarding to pedal, rather than just leaning on the throttle all the time. But it may not actually make much difference if the hub motor is equipped with PAS.

With these comments I'm now contemplating a lower-power geared hub with PAS/throttle. Going to try out some of these guys at local shops and see how it compares to my existing mid-drive.

I also didn't realize that the BBSHD is not really compatible with belt drives, at least without serious tinkering that may be beyond my skill level. I may save myself a lot of headache and money just popping a weak front hub motor on a bike that's already equipped with bells and whistles like a Nuvinci and a belt drive.

I built a slightly over 40 pound bike with 36V, 350w front hub motor on a mid-90's Diamondback steel frame and Surly steel fork. Brooks suspension saddle is adequate for CA roads and PAS (rpm only) works great. Accelerates to 20 mph pretty quickly which is fine for errands. Look at Chas58's builds for similar "rides".

Urban commuter I would go 29er as the fatter wheels make them fairly compliant on the road with combination of disc brakes for stopping power and geometry make them very nimble compared to a road bike. You dont have any hesitation jumping a curb or rolling through fields/gravel paths unlike a road bike.

The BBS02 is good for cruising and efficiency, but if you want to punch it off the line at the lights, get a geared hub at 30 to 40A. The mid drive weight distribution is much more better for handling, but if you're not doing anything technical, a hub is much better.

I'm right there with you on my second eMTB. The first was a low end MTB with a BBS01 350W/36V that I added many upgrades to like: stem, bars, saddle, air forks, thudbuster seatpost, E-rated tires, 42T Lekkie Bling Ring, pedals, etc... All those items that made that bike "mine" were removed when sold, so they can be used on my new custom build.

I went with a Soma B-Side V.2 Belt Drive frame. The plan is to use a BBS02 750W/48V on this one. Here is where it is at currently all built up except for the power system.



I found that I only really needed 3 gears for the majority of my riding, so I selected the Sturmey-Archer 3spd IGH 8-9spd cassette disc brake rear hub (CS-RK3). Single speed chain and belt drive cogs can be installed on the rear cassette with infinite alignment adjustment. Gear spacing is 33% (Shimano 3spd IGH's are 36%). Planning to use 2nd as my 1st gear and 3rd as my 2nd high gear, with 1st reserved for a granny low for climbing. The BBS## power levels also act like additional gears, so when you are riding bumping up the level makes you go faster without changing gears. You can set them for 9 levels if desired. Some might say a 3spd IGH with 9 levels of power is a quasi 27spd. :lol: Plus, if that doesn't work out or future needs change I can always add a 8-9spd (or 10spd I'm now told) cassette and have a 24-30spd setup. Hoping to work out the gearing using a chain, then switch to a Gates Belt Drive once I figure out the sweet spot for my type of riding.


Sweet belt drive frame break and infinite cog adjustment!

Here are the current build spec's:

SOMA B-SIDE Frame (Large - 18.5")
Cane Creek ZS44/28.6 Tall, EC44/40, 52/30 Conversion Race
RockShox 30 TK Gold Solo Air Fork
Single 40mm Fork Stem Spacer
Q2 40* Riser Stem 110mm
Fouriers Trailhead 58* Sweep Bars
ESI Chunky Sylicone Grips 32mm
SRAM X9 Front Hub
SRAM X9 front 3 Speed Trigger Shifter
Strumey-Archer 3spd IGH 8-9spd Cassette Disc 135mm (CS-RK3)
Halo Vapour Rims 21mm
DT Swiss Stainless Steel Triple-butted Alpine III Spokes Black (14/15/13) Silver Brass Nipples
Shimano XT M8000 Hydraulic Brakes
SRAM Centerline 180/160mm Brake Rotors and Adaptors
Schwalbe Smart Sam Plus Tires with Green Guard (Rated 31mph)
Schwalbe 27.5 x 2.25 Tubes
Circus Monkey 27.5 x 18mm Rim Tape
Cane Creek Thudbuster ST 27.2 x 410mm
Soma 29.8mm Seat Post Clamp
WTB Volt Saddle
Aset Titanium Spindle Alloy Flat Pedals

Soma has announced that they will be making 27.5+ and 29+ frames shortly, but I don't believe they will be including the belt drive option currently.

Very interested in your build. Subscribed!

Hey SantasLittleHelper, that's an awesome build and very close to what I want to do. Agree that there's not much need for tons of gears on the mid-drive. I'm hoping that a little fiddling with software will also allow me to achieve good cadence, for instance by adjusting PAS levels depending on RPM or the like.

I'm curious how you decided to go with the belt drive. From what I've read and heard, it's not very easy to get a belt to work with a BBS without significant modification. Do you have any resources or personal experience on setting this up?

Surly's new line of Karate Monkey frames are 27.5 mid fat wheels (3" width tires or less). Can be swapped to 29er (700cc) wheels (probably 2.5" tires or less). The rear horizontal dropouts can now accept a variety of axles (including through axles using an adapter). 135mm rear dropout spacing, so most IGHs can be used (I'd go 3sp w/electric assist IMO).

I bet the Surly frame you're looking at has similar features, but with different geometry & handling.

alkatraze said:

Hey SantasLittleHelper, that's an awesome build and very close to what I want to do. Agree that there's not much need for tons of gears on the mid-drive. I'm hoping that a little fiddling with software will also allow me to achieve good cadence, for instance by adjusting PAS levels depending on RPM or the like.

I'm curious how you decided to go with the belt drive. From what I've read and heard, it's not very easy to get a belt to work with a BBS without significant modification. Do you have any resources or personal experience on setting this up?

Click to expand...

Well I have always wanted a belt drive bike. Being this is my first custom build from the frame up I wanted to have that "option" on the frame I selected. The nice thing about using an add-on kit like the BBS02 over a purpose-built E-bike is that you always have a standard bike if you want to remove the electric assist.

I am not aware of any issues with running a Gates Belt Drive off a BBS02? Maybe others have had issues getting the sprocket in alignment, that is why I went with a 3spd IGH "cassette" hub. The cassette gives you a very wide alignment range across the cassette so you don't have to mess with alignment at the crank sprocket. With that said, I haven't actually done it yet, but with a standard sprocket adapter on the BBS02 a belt drive sprocket can easily be bolted to it.

It is worth mentioning that Gates Belt Drives are not rated for super high power electric motors. IIRC they are rated for 350W motors, but don't quote me on that. I run my eMTB pretty smoothly and the higher watts and torque of the 750W-48V motor will always be applied gradually.

The Gates Belt Drive components are a $150-$200 additional expense. I happen to have a 42T Lekkie Bling Ring that will be used first with my 11-34 cassette with only one gear attached at a time to fine tune the gearing. The nice thing about the setup I went with is that it can be almost anything you want it to be. If you add a 8-10spd cassette and shifter you have a 24-30 gear option, but at the 750W level you really only need 2 gears and a ganny low for climbing (personal hands on experience for my type of riding). Take a look at these two articles if you haven't already.

https://www.electricbike.com/mid-drive-kit-igh/

https://electricbike-blog.com/2015/11/20/you-cann-have-it-all-power-speed-nexus-3-igh-paired-with-a-bbs02/

Do you have any links identifying problems using belt drives with a BBS02?

Do you have any links identifying problems using belt drives with a BBS02?

Click to expand...

I've seen a couple of threads where people discuss the difficulties with that. It looks like it was accomplished by ES user c-cap in this thread, but it sounds like he had to do some custom machining that is a little out of my league:

https://endless-sphere.com/forums/viewtopic.php?f=28&t=71057&p=1195798#p1079610

It's possible that your hub provides enough adjustment to avoid these issues, I don't know enough to say.

More discussion:
http://electricbike.com/forum/forum/builds/new-builder-questions/8328-will-luna-eclipse-mate-to-130-bcd-5-bolt-gates-cdx-sprocket
https://endless-sphere.com/forums/viewtopic.php?f=28&t=65093

alkatraze said:

I've seen a couple of threads where people discuss the difficulties with that. It looks like it was accomplished by ES user c-cap in this thread, but it sounds like he had to do some custom machining that is a little out of my league:

It's possible that your hub provides enough adjustment to avoid these issues, I don't know enough to say.

Click to expand...

Interesting issues they are encountering... I haven't done any actual measurements, because I assumed the cassette would give me plenty of adjustment, but it appears some of their problems are related to installing a Gates CDX front sprocket on the 104/130 star adaptor on the Bafang. Honestly I didn't think that would be an issue, they are the same pattern 104/130 (?). If it needed to go close to the frame then simple spacers could be added at the sprocket attachment points. I guess some of the problem is clearance for the CDX similar to what the Lekkie Bling Ring resolves and there may not be additional clearance for spacers at the 104/130 diameter point (?). Again, I assumed a 46T CDX would clear because the Lekkie 42T does and my rear adjustment would allow outward movement in the rear, but if I'm reading their post correctly only the 50T CDX clears and it is close to the same size as a standrad 42T ring. Is that your understanding at this point?

Below is a picture from above of the belt line for a Soma B-Side with CS-RK3 3spd cassette hub (Too bad I don't have a BBS02 here yet to slide in).

I don't think the Soma B-Side frame rear chain stay will be an issue. The frame is made for a belt drive and has that thin solid piece where the belt ring comes close to the chain stay. Here are their FAQ's for belt drive setups:

Single Speed:
46t front x26t rear x115 belt - 435.19mm chainstay setting

Rohloff Hub:
50t front x20t rear x115 belt - 438.94mm chainstay setting
(So we know a 50T CDX will clear the rear chain stay and "IF" it clears the Bafang gear reduction hump when bolted to a Bafang 104/130 star chain ring adaptor, then I'd think I'm okay)

I may have to make a visit to Eric Luna in North Los Angeles County to see if we can work this out when I'm ready to purchase. He's about an hour away from me here in Orange County, CA.

Thanks for the links. If they work things out for the BBS02 and/or the BBSHD please post the solution here. I will let you know if everything aligns once I get around to it. I may be using this build to setup a custom MY1018 free-wheel mid-drive that will get transfered to my other MTB, before I buy my BBS02 for the final setup. The order of execution for these two builds is still up in the air...

Santa'sLittleHelper said:

<ADD PIC WHEN HOSTING SERVICE STARTS WORKING AGAIN>

Click to expand...

why not just attach it to the post directly, uploaded to ES?
(there is a thread called adding pictures if you need help with that)

amberwolf said:

why not just attach it to the post directly, uploaded to ES?
(there is a thread called adding pictures if you need help with that)

Click to expand...

Many sites don't allow picture uploads to THEIR site without special access. It looks like this site doesn't mind, so I attached it and will use your site so the pictures won't ever go away unless you delete them. Thx.

Santa'sLittleHelper said:

(So we know a 50T CDX will clear the rear chain stay and "IF" it clears the Bafang gear reduction hump when bolted to a Bafang 104/130 star chain ring adaptor, then I'd think I'm okay)

I may have to make a visit to Eric Luna in North Los Angeles County to see if we can work this out when I'm ready to purchase. He's about an hour away from me here in Orange County, CA.

Click to expand...

Or is it only the 55T Gates CDX front sprocket that will clear the BBS02 gear reduction hump?

I just noticed that Honey Badger BBS02 belt drive used a 55T front sprocket...

If anyone can supply the "I.D." of the Gates 50T & 55T front sprockets below the lip that widens on each side, please do.

Alkatraze -

I did a quick photocopy blowup to scale of the Gates Carbon Drive CDX 130BCD front sprocket that Gates states measures 173.2mm O.D., then I measured my BBS02 (not BBSHD) 42T Lekkie Bling Ring's I.D. at the lip that goes inward; it's about 154-155mm. So I drew in lines at 155mm on the blowup attached below.

I looks like it will clear, but if it doesn't there appears to be enough room to lathe out a little bit more. I went ahead and ordered a 50T 130BCD Gates CDX front sprocket based on this, so I should have an answer soon if it will work on the BBS02's.

I know you are thinking about a BBSHD which is a completely different animal sprocket wise, but I thought I'd post this up for others. Eventually I'll create a build thread for the Soma B-Side Belt Drive eMTB in progress.

Cool! I have pretty much settled on a Surly frame and BBSHD. I was dissuaded from starting with the belt drive due to compatibility issues and potential problems getting it serviced, so I'm going to start with a chain and think about it for another bike or down the road if I want to get the frame modified to take a belt. Will post as the bike comes together.

The Gates Crabon Drive 50T 130BCD arrived. It looks like a winner to my eye when compared with a 42T Lekkie Bling Ring as far as the outer lip clearing the BBS02 gear reduction hump. If not, there is plenty on meat to lathe off a bit if needed.

It's worth noting that the overall diameter of these two sprockets is very close even though one is a 50T CDX and the other is a 42T chain.

Alkatraze how is your planned build coming along?

This thread might help your quest.

https://endless-sphere.com/forums/viewtopic.php?f=28&t=83911&p=1244724#p1244724

It's dedicated to mid belt drive setups.

alkatraze said:

Cool! I have pretty much settled on a Surly frame and BBSHD. I was dissuaded from starting with the belt drive due to compatibility issues and potential problems getting it serviced, so I'm going to start with a chain and think about it for another bike or down the road if I want to get the frame modified to take a belt. Will post as the bike comes together.

Click to expand...

Alkatraze,

I am building up a similar light urban commuter as well. I was the one who wanted to go down the road of converting the Priority 8 to a BBS02 or BBSHD, but chose not to go that route since it would be a project involving custom made parts to get the belt back in line and there was no way of knowing what would be required until after i bought everything. I did not want to take that risk. However I will say the owner of Priority 8 was a great guy to work with and he was more then helpful. I may still buy a bike from him for my wife. In the end, I ended up buying a Charge Grater 4 in XL which is 25lbs and has a carbon front fork for about the same price as the priority 8. 25lbs is not too shabby for an XL frame. I also chose this bike as it left my options open between Q100/Q128 hub motor build as well as BBSxx. Work has kept me so busy I have shelved it for a bit and I am still a bit on the fence between geared hub vs BBSxx. With the hub you can get a very light setup with better PAS feel than you can with a BBSxx setup. However the hub gives up versatility for extreme hills that a BBSxx can do and the BBSxx does not feel as good pedaling power off.. Ie it broke down and have to bike home. The small Q motors have less drag powered off and Chas58 has some great posts about his lightweight builds worth looking at where he talks about how the Q series hub still kept the bike feel over the mid drives..

I see you have settled on the BBSHD and curious if you chose it for its more robust build and possibly higher reliability. Seems a BBS02 would do the trick as well and save you a few bucks.

An update after a long while. Spent most of the winter gradually getting this together. Though I've put about 100mi on the bike so far, today was the first real day of spring that I was able to go for a bike ride that a normal person would consider pleasant.

View attachment 3

The donor bike is a 54cm Surly Straggler put together from new parts by a nice old Italian mechanic who works for the city. We've struck up a friendship where I text him to see if he can get me discounts on bike parts and he tells me he's out of town.

The Straggler isn't the most obvious choice for a BBSHD conversion; it's a somewhat aggressive road bike suitable for an urban commute. However, the frame is sturdy and pretty versatile, providing a lot of space to mount things. The geometry is such that the bottom bracket is pretty high off the ground, providing a lot of clearance for the motor.

The motor is from Hi-Power Cycles, shown as "1500W HPC MID DRIVE CONVERSION SYSTEM" on their site. From what I can tell, it is effectively a BBSHD with a better controller and some custom programming. I went with the BBSHD over the BBS02 mostly due to concerns about the reliability of the older model, but it's great to have the extra power even if I don't use it much. The weight difference between the two motors is small, so it seems to me that the only reason to prefer the BBS02 is cost.

The battery is a 52V 21Ah Li-NMC beast weighing in at about 9lbs. It's definitely overkill, but it's nice knowing that it's basically impossible for me to drain this battery without really trying.







(Excuse the rats nest of cables--I just undid all the cables to put the fenders on, and haven't gotten them neat again yet).

The transmission is a Nexus 3 IGH with a Sturmey-Archer 3-speed thumb shifter. After I set the motor's "time of stop" (time after you stop pedaling to cut power) to 5ms, I had zero problems shifting as long as I stop or slow down my pedaling very briefly.

The bike doesn't have any native suspension, but the steel frame does a lot to mitigate the "trail buzz" on city streets that I've encountered with aluminum bikes. It takes tires up to 45mm according to Surly, and a bit wider according to folklore. I fitted it with 29x2.0" Schwalbe Big Apple tires with no apparent issues. The Big Apples are nice because you can run them at really low pressure for a cushy ride. The seatpost is carbon fiber, which is surprisingly helpful, and I also have a cushy Serfas Comfort gel saddle. I had planned to get a Thudbuster for further rear comfort, but it hasn't seemed necessary so far.

Finally, it may not seem like much, but this bike fulfilled my longtime dream of having full-wrap fenders front and rear. Those are Planet Bike Cascadia 29er Fenders, which amazingly fit with no modification, albeit barely.

How does it ride? To me it's a dream -- I can jackrabbit from a stop without putting much stress on the motor, and the range of PAS power provides enough flexibility that I don't need to shift gears too often. I'm too timid to find out the top speed, but I've made it to 31mph without really trying to push the envelope. It's pretty comfortable cruising around 20mph, and I can easily exceed 20mph on steep hills.

Now, did it fulfill the criteria set out in the original post? In some ways, hell no. This ride weighs about 52lbs, which isn't exactly setting any records. On the other hand, the aggressive and relatively compact geometry allow me to maneuver quickly through traffic with good visibility. The wide 29er tires allow me to roll over a lot of obstacles without worry. And there are numerous options if I wanted to drop a bit more weight and get it closer to 40lbs. As it is, the weight is balanced enough that I don't have much problem carrying it up stairs with the handy Tourbon bike lifter strap (well worth the $12 on Amazon).

I'm very happy with how this turned out. Both the motor and battery are more than I really need, but it's nice to have the extra power and range available when you want it.

My plans for future modifications are pretty modest. The brakes are some entry-level Shimano discs, and I probably need more stopping power to be safe. I may spring for a carbon handlebar or a suspension seatpost to dampen vibration somewhat, but so far it seems tolerable. I need to put together a longer XT90 cable so I can try out the battery in a backpack. I'm also thinking of using two LiGo batteries in series to have a light battery I can throw on for shorter rides.

Comments, suggestions, insults, etc., welcome. I will post if issues arise or I make some material modification to the bike.

Alkatraze, A very nice looking bike. Is your NYC location where you ride it? Just curious if you're worried about getting hassled by ebike hating cops if you happen to buy a sub sandwich and are just lazily pedaling along with the bag handing from the handlebars.

Thanks. Ebike legality in NYC is pretty mysterious. I've heard a lot of different versions, from "all ebikes are illegal" to "only throttle bikes are illegal", and reading the statute doesn't clarify month. Every 4 months or so, NYPD does a big operations where they stop like 300 delivery guys and seize their bikes, but from what I can tell they only seem to be able to recognize one kind of bike as electric, the standard Chinese bike with the big rectangular battery. However, you still see those bikes on every street, so it's not like it makes much difference. I've never had any kind of problem, even when I've been stopped by cops for running a red light on my bike or things like that. I don't know anyone who has an electric bike who's ever been stopped either.

Nice, thanks for the update. Good job - that has to be a fun ride!