teslanv
1 MW
This is the 5th evolution of my BBSxx Series of builds, and my return to Mid-drives after an extended hiatus building and riding much more powerful DD hub bikes.
I am thoroughly pleased with how this bike rides.
I call this build "Super Deluxe" because In my humble opinion, it refines the mid-drive experience well beyond the level of most other production bikes. The most prominent of which is the Sturmey-Archer 3-speed Internally-geared hub.
My very first build was this one based a Craigslist-Purchased bike:
https://endless-sphere.com/forums/viewtopic.php?f=6&t=56512
The referenced build used a hardtail frame, and based on my appreciation of triangle space with front suspension, I repeated that choice here, albeit with a new Gravity 27.5" frame.
http://www.bikesdirect.com/products/gravity/650b-27.5-bikes-g275fs.htm
The obvious lack of rear suspension is a small price to pay for the generous space for battery options, and helps to keep the cost down. (Cost was not a deciding factor on this build, but I did manage to keep it quite reasonable.) In the future I may add a Cane Creek Thudbuster suspension seat post, but honestly, I like the more responsive feel of a hardtail on the light trails and paths that this bike will see most. This is not a downhill bomber or street commuter, after all.
The Forks that Came with the $399 (Including shipping, and no sales tax) bike are nothing special, but easily upgraded in the future. For now I have no major complaints about them. They do have a lock-out feature that seems to work well.
One of the other key features of this frame is the horizontal drop-outs. (It's a single-speed frame.) After building a similar IGH Fat bike that originally came with a cassette and derailleur, and subsequently having challenges getting the chain tensioned well enough to avoid tooth skip, I specifically sought out a single Speed frame to eliminate this issue altogether. Horizontal Drop-outs with BMX style tensioners on either side of the axle are hands-down the best method for eliminating tooth-skip.
Once the bike arrived, I measured the Bottom Bracket Width (It's 68mm Wide), and ordered the BBS02 Kit. (I'll spare you my vendor preferences in this regard. You can make up your own mind on which vendor to buy from.)
The BBS02 Kit included the following Options/Components:
Programmed for 25A, 9 PAS levels and 100% Throttle in all PAS modes. 41V LVC (Best for a 12S LiPo Battery Set-up)
IGH version of Gearsensor
Full Color DCP14 Display.
44T Chainring
Standard Bafang Ebrake Levers (the ones I received must be new, and look very nice with comfy rubber on the handles.)
I did not opt for the BBSHD kit, because frankly I did not think I needed the additional 5A of power, nor the additional weight. After riding it for the last day or so, I can confirm that this was a prudent choice. More power is not needed.
The Sturmey-Archer Internally-Geared Hub:
I used the 3-speed SX-RK3 hub for 135mm wide drop-outs, along with the TSS33 twist grip shifter.
http://www.sturmey-archer.com/en/products/detail/sx-rk3
http://www.sturmey-archer.com/en/products/detail/tss33
The bike's rims were non-branded 27.5" Double Wall rims, with 32 Spokes. So I was sure to order the SA Hub with 32H option. I unlaced the original rear wheel, and measured the Rim. I calculated the Spoke length at 270mm and used Sapim Strong Stainless steel spokes (2.3mm/2.0mm butted spokes) to lace the Sturmey-Archer Hub into the Stock rim. This was actually my first full wheel build, since my traning session with our master wheelsmith Eric. It was quite satisfying.
[youtube]CZ3Ji72-qM4[/youtube]
I went with a 22T Rear Sprocket on the SA Hub. This was based on carefully calculated performance desires. (I wanted Good Hill-Climbing, and a top speed under 20 MPH was adequate for this build) I based my 44T Chainring and 22T Rear Sprocket choice using a spreadsheet I developed to calculate the equivalent range of speeds. And my comfortable pedaling cadence of 80 RPM at the crank. My Spreadsheet is below, and you are welcome to use it to do the math for your own build:
View attachment Pedal Speed Calculator with Thrust.ods
Battery:
I have been using the Hailong type battery enclosure for Mid-Drive builds lately, and they are clean, but for this build, I wanted to keep the weight down, so I opted for 12S-10Ah of Multistar LiPo. 3 of these packs in Series, fully charged are 50.4V.
https://hobbyking.com/en_us/multistar-high-capacity-4s-10000mah-multi-rotor-lipo-pack.html
There is room in the triangle bag for about 32 Ah, if I wanted the range, but I don't anticipate doing 100-mile rides on this bike. With a 12S-10Ah pack, and a light pedal-assist setting I expect a realistic range of about 20-25 miles, at 15 MPH. For me, this is adequate, and as I said, weight was important.
All in, including the 10Ah battery, the bike weighs 50.2 lbs.
Only 3 Speeds.
The Internal Geared Hub is a 3-speed. The gear spread on it is 75% / 100% / 133% This provides for an effective rear cog tooth count of 16.5T / 22T / 29.3T. More gears are not necessary at all, but I wouldn't mind a larger spread on the low and high gears. Ultimately this is a function of the planetary gear-set inside the IGH, and for a very stoutly-built IGH, it's all that Sturmey-Archer offers. Moving up to a 5-speed IGH was tempting, but after my extensive experience with shifting an 8-speed derailleur set-up with my first BBS02 bike, I resolved myself to keep shifting to a minimum. 3-speeds is perfect, IMHO.
I've gotten lazy with my high-powered DD hub builds. They are way too fast to pedal along with, so they are pretty much just glorified light-weight motorcycles. I wanted something to give my legs a bit of a work-out, but still be able to enjoy the pleasure of instant acceleration on demand, and long adventure rides.
Having 9 PAS levels in tandem with the 3-speed IGH shifter provide a very similar feeling to riding a 27-speed set-up. Generally, I will start in the low mechanical gear and a 4 or 5 level PAS setting. On steep inclines I keep the IGH on Speed 1, and ramp up the PAS level a bit. Maybe to a 6 or 7 power level - wherever the PAS can just keep up with my natural pedaling cadence. As the incline flattens, I ease off the PAS, until the point where it makes sense to shift to gear 2 on the IGH. On flats and declines, I shift to Speed 3 on the IGH, and drop the PAS a bit more. This effectively give my legs a consistently resistive work-out, while allowing me to tackle a wide variety of terrain. This is how low-powered ebikes should operate, as they allow the rider to moderate their activity, by providing the perfect level of work-out, with the motor system providing the balance needed in any given situation.
Shifting an IGH is smooth and without hassle. So long as the motor is not under high load, the bike shifts up or down flawlessly, and into any gear I choose. There are no cogs for the chain to shift to or need to pedal a cycle or two to lock into the intended gear. This is the fabulous world of the Internal Geared Hub, and I really like it. Add the Gearsensor (Which has itself been much improved on since my first experiment with it) adds a nice safety mechanism to eliminate potential damage to the IGH's gearsets.
I purchased and installed a single speed Chain, SRAM PC1, silver, to wrap up the project, as the stock chain was just a few links too short with the Bafang's larger 44T Chainring.
Summary of Build and Budget:
Frame/Donor Bike: Gravity 27FIVE FS - $399
BBS02 Kit: $570
Sturmey-Archer 3-speed IGH: $120
Sapim Spokes & Nipples: $32 (Laced myself, or add ~$75 for your LBS to lace)
Battery Bag: $40
Battery Pack: Mine only cost $100 as I bought my 4S-10Ah Multistar packs when they were on sale for $30 each. For a Hailong style Battery with decent cells, plan to spend about $400-$500.
Charger: I use a Mean Well HLG240-48A Charger set to 50.0V and 5A for bulk charging: $70. And an iCharger 106B for balancing cells when needed ($100) - For Hailong Battery, the standard 3A charger is usually about $40.
Total spent: under $1500.
View attachment 3
I am thoroughly pleased with how this bike rides.
I call this build "Super Deluxe" because In my humble opinion, it refines the mid-drive experience well beyond the level of most other production bikes. The most prominent of which is the Sturmey-Archer 3-speed Internally-geared hub.
My very first build was this one based a Craigslist-Purchased bike:
https://endless-sphere.com/forums/viewtopic.php?f=6&t=56512
The referenced build used a hardtail frame, and based on my appreciation of triangle space with front suspension, I repeated that choice here, albeit with a new Gravity 27.5" frame.
http://www.bikesdirect.com/products/gravity/650b-27.5-bikes-g275fs.htm
The obvious lack of rear suspension is a small price to pay for the generous space for battery options, and helps to keep the cost down. (Cost was not a deciding factor on this build, but I did manage to keep it quite reasonable.) In the future I may add a Cane Creek Thudbuster suspension seat post, but honestly, I like the more responsive feel of a hardtail on the light trails and paths that this bike will see most. This is not a downhill bomber or street commuter, after all.
The Forks that Came with the $399 (Including shipping, and no sales tax) bike are nothing special, but easily upgraded in the future. For now I have no major complaints about them. They do have a lock-out feature that seems to work well.
One of the other key features of this frame is the horizontal drop-outs. (It's a single-speed frame.) After building a similar IGH Fat bike that originally came with a cassette and derailleur, and subsequently having challenges getting the chain tensioned well enough to avoid tooth skip, I specifically sought out a single Speed frame to eliminate this issue altogether. Horizontal Drop-outs with BMX style tensioners on either side of the axle are hands-down the best method for eliminating tooth-skip.
Once the bike arrived, I measured the Bottom Bracket Width (It's 68mm Wide), and ordered the BBS02 Kit. (I'll spare you my vendor preferences in this regard. You can make up your own mind on which vendor to buy from.)
The BBS02 Kit included the following Options/Components:
Programmed for 25A, 9 PAS levels and 100% Throttle in all PAS modes. 41V LVC (Best for a 12S LiPo Battery Set-up)
IGH version of Gearsensor
Full Color DCP14 Display.
44T Chainring
Standard Bafang Ebrake Levers (the ones I received must be new, and look very nice with comfy rubber on the handles.)
I did not opt for the BBSHD kit, because frankly I did not think I needed the additional 5A of power, nor the additional weight. After riding it for the last day or so, I can confirm that this was a prudent choice. More power is not needed.
The Sturmey-Archer Internally-Geared Hub:
I used the 3-speed SX-RK3 hub for 135mm wide drop-outs, along with the TSS33 twist grip shifter.
http://www.sturmey-archer.com/en/products/detail/sx-rk3
http://www.sturmey-archer.com/en/products/detail/tss33
The bike's rims were non-branded 27.5" Double Wall rims, with 32 Spokes. So I was sure to order the SA Hub with 32H option. I unlaced the original rear wheel, and measured the Rim. I calculated the Spoke length at 270mm and used Sapim Strong Stainless steel spokes (2.3mm/2.0mm butted spokes) to lace the Sturmey-Archer Hub into the Stock rim. This was actually my first full wheel build, since my traning session with our master wheelsmith Eric. It was quite satisfying.
[youtube]CZ3Ji72-qM4[/youtube]
I went with a 22T Rear Sprocket on the SA Hub. This was based on carefully calculated performance desires. (I wanted Good Hill-Climbing, and a top speed under 20 MPH was adequate for this build) I based my 44T Chainring and 22T Rear Sprocket choice using a spreadsheet I developed to calculate the equivalent range of speeds. And my comfortable pedaling cadence of 80 RPM at the crank. My Spreadsheet is below, and you are welcome to use it to do the math for your own build:
View attachment Pedal Speed Calculator with Thrust.ods
Battery:
I have been using the Hailong type battery enclosure for Mid-Drive builds lately, and they are clean, but for this build, I wanted to keep the weight down, so I opted for 12S-10Ah of Multistar LiPo. 3 of these packs in Series, fully charged are 50.4V.
https://hobbyking.com/en_us/multistar-high-capacity-4s-10000mah-multi-rotor-lipo-pack.html
There is room in the triangle bag for about 32 Ah, if I wanted the range, but I don't anticipate doing 100-mile rides on this bike. With a 12S-10Ah pack, and a light pedal-assist setting I expect a realistic range of about 20-25 miles, at 15 MPH. For me, this is adequate, and as I said, weight was important.
All in, including the 10Ah battery, the bike weighs 50.2 lbs.
Only 3 Speeds.
The Internal Geared Hub is a 3-speed. The gear spread on it is 75% / 100% / 133% This provides for an effective rear cog tooth count of 16.5T / 22T / 29.3T. More gears are not necessary at all, but I wouldn't mind a larger spread on the low and high gears. Ultimately this is a function of the planetary gear-set inside the IGH, and for a very stoutly-built IGH, it's all that Sturmey-Archer offers. Moving up to a 5-speed IGH was tempting, but after my extensive experience with shifting an 8-speed derailleur set-up with my first BBS02 bike, I resolved myself to keep shifting to a minimum. 3-speeds is perfect, IMHO.
I've gotten lazy with my high-powered DD hub builds. They are way too fast to pedal along with, so they are pretty much just glorified light-weight motorcycles. I wanted something to give my legs a bit of a work-out, but still be able to enjoy the pleasure of instant acceleration on demand, and long adventure rides.
Having 9 PAS levels in tandem with the 3-speed IGH shifter provide a very similar feeling to riding a 27-speed set-up. Generally, I will start in the low mechanical gear and a 4 or 5 level PAS setting. On steep inclines I keep the IGH on Speed 1, and ramp up the PAS level a bit. Maybe to a 6 or 7 power level - wherever the PAS can just keep up with my natural pedaling cadence. As the incline flattens, I ease off the PAS, until the point where it makes sense to shift to gear 2 on the IGH. On flats and declines, I shift to Speed 3 on the IGH, and drop the PAS a bit more. This effectively give my legs a consistently resistive work-out, while allowing me to tackle a wide variety of terrain. This is how low-powered ebikes should operate, as they allow the rider to moderate their activity, by providing the perfect level of work-out, with the motor system providing the balance needed in any given situation.
Shifting an IGH is smooth and without hassle. So long as the motor is not under high load, the bike shifts up or down flawlessly, and into any gear I choose. There are no cogs for the chain to shift to or need to pedal a cycle or two to lock into the intended gear. This is the fabulous world of the Internal Geared Hub, and I really like it. Add the Gearsensor (Which has itself been much improved on since my first experiment with it) adds a nice safety mechanism to eliminate potential damage to the IGH's gearsets.
I purchased and installed a single speed Chain, SRAM PC1, silver, to wrap up the project, as the stock chain was just a few links too short with the Bafang's larger 44T Chainring.
Summary of Build and Budget:
Frame/Donor Bike: Gravity 27FIVE FS - $399
BBS02 Kit: $570
Sturmey-Archer 3-speed IGH: $120
Sapim Spokes & Nipples: $32 (Laced myself, or add ~$75 for your LBS to lace)
Battery Bag: $40
Battery Pack: Mine only cost $100 as I bought my 4S-10Ah Multistar packs when they were on sale for $30 each. For a Hailong style Battery with decent cells, plan to spend about $400-$500.
Charger: I use a Mean Well HLG240-48A Charger set to 50.0V and 5A for bulk charging: $70. And an iCharger 106B for balancing cells when needed ($100) - For Hailong Battery, the standard 3A charger is usually about $40.
Total spent: under $1500.
View attachment 3