2018 Xtracycle Edgerunner Swoop (longtail cargo bike) electric conversion with a Grin All Axle v3 direct drive hub motor with integrated torque sensor and SuperHarness
TLDR; I like it, got a few things to sort out still.
Photos up front: Xtracycle Edgerunner swoop ebike upgrade with Grin All Axle v3
Background
I have been a full-time bike commuter for a few years, and a full-time baby hauler for the past 3 years. For most of that time my child was on a Yepp Maxi seat on the back of my Jamis Aurora Elite touring bike. It was a great setup for our daily daycare commute and my occasional in-office work days.
We got pregnant with our 2nd child around the time my 1st child came up against the weight limit of the Yepp Maxi seat (42 pounds, though it is the same seat in Europe with a 48 pound weight limit). Always eager to have a reason to buy a new bike I went on the hunt for an e-bike.
To further spark my interest in a new bike, DC had recently announced a new e-bike incentive program offering $1,000 rebate for e-cargo bikes purchased locally. The more I read up on this program, however, the more it became apparent it was under funded and the rebate program was going to come down to a lottery.
I test rode a few e-bikes – Tern GSD, Xtracycle RFA, and an Urban Arrow. Although my child really loved sitting in a bucket in the Urban Arrow, I didn’t like that it didn’t feel like riding a normal bike, and the practicality of trying to get it in and out of my storage area every day seemed daunting (not to mention the cost). The Tern is beloved by many and probably accounts for half of all e-cargo bikes I see in the city, but it was very uninspiring to ride. I really enjoyed the natural feel of the Xtracycle, likely due to the larger 24” wheels, and was pretty set on purchasing one.
Shortly after my test rides I visited my brother-in-law who had converted a number of bikes with Bafang mid-drive systems and I decided that was something I could do too. I didn’t like the cadence sensor of the Bafang units but discovered there were some other mid-drive motors on the market with torque sensors, promising a more natural feel of the purpose built bikes I had test rode.
The Bike
I found an Xtracycle Edgerunner Swoop used on Craigslist that turned out to have been a garage queen. Nearly perfect condition and outfitted with most of the accessories I’d want for hauling around some kids. Other than a missing saddle and leaky brake caliper it was in tip-top shape. Quickly getting it in working order I was ready for daycare runs once again. Unlike the Xtracycle RFA I’d previously test rode, the Edgerunner is a full size longtail with a larger passenger deck atop a smaller 20” rear wheel. The Edgerunner also has a larger 26” front wheel and has been produced and refined by Xtracycle for a number of years. It’s a premium chromoly frame in a market full of aluminum bikes.
The 2018 Edgerunner I purchased was the last year that Xtracycle offered non-electric bikes. That year in their catalog the Edgerunner existed in both manual and electric form with virtually no differences between the two frames besides the bottom bracket/motor mount. The Edgerunner has a dedicated battery mounting area between the chainstays just behind the seat tube, and Xtracycle has some mount adapters to offset it to the non-drive side to give better clearance for the chain.
The Motor
Bike in hand I started to research my mid-drive motor options with torque sensors and settled on the CYC Photon. However, on Black Friday 2023 I went on a bike ride with a local group and met someone who turned me onto the idea of a Grin hub drive motor with their regenerative braking technology. Educating myself more on hub motors I also discovered that the smaller 20” rear wheel of the Edgerunner allowed a hub motor to be more powerful, calming any concerns I had about missing out on the power offered by mid-drive units. About that same time Grin released the v3 All Axle motor with integrated torque sensor, allowing a more streamlined install, how perfect!
I spent the winter biking on the Edgerunner and waiting for our 2nd child to be born. I even managed to get out for an overnight bike camping trip on the Edgerunner with my 3yo. This spring, while on paternity leave Grin announced the new SuperHarness kits allowing a streamlined installation with modern displays. Although I like to tinker, I’ve got plenty of projects to keep me busy (and, ya know, a pair of kids) and since my longtail was going to be my daily driver I just wanted to set it and forget it. The SuperHarness kit seemed like a better fit than a Cycle Analyst installation for me.
Purchasing
I emailed back and forth with both Grin and Xtracycle about the fine details of my build. I had noted in Xtracycle literature that they designed the Edgerunner with an offset rear wheel to provide a stronger wheel build. Apparently, this translated into needing to build the rear wheel with a 5mm dish, which Grin was happy to do. Grin was also patient with my questions and confirmed the details of my purchase to make sure everything looked good.
Given that the Xtracycle I owned was setup for hauling heavy loads it was geared very low. I realized this wouldn’t work with the motor and I’d probably be permanently sitting on the largest chainring and smallest sprocket. I went ahead and got parts together to do a 1x crankset with a larger 50t narrow-wide chainring in hopes that I’d have useable gearing across all 9 cassette cogs.
I could have kept using my USB lights but opted to purchase dedicated e-bike lights to be controlled via the display. I’ve used the B&M IQ-X lights on a few conventional bikes with dynamos and decided to purchase their e-bike variant for this bike as well. Although my existing hydraulic brake setup worked great, the geometry of the levers was not conducive to using those magnetic brake cutoff sensors so I went ahead and purchased a single Shimano MT200 e-bike brake to control the motor cutoff and regenerative braking.
Installation
I’ve been doing all my own bike work for a number of years so I expected installation to be pretty smooth. Removal of my old front shifter/derailleur/crankset was straightforward, as was installation of my new cranks and chainring. I did learn not to waste time with aluminum chainring bolts, having quickly stripped one. After installing some steel chainring bolts I was good to go. I had a square taper bottom bracket laying around that was a much wider spindle than the FSA Vero cranksets called for, but it seemed fine and I always enjoy using parts from my parts box.
Moving on to the rear wheel also proved to be relatively straightforward Transferring the cassette, rotor, tube, and tire from the old wheel was easy. The All Axle motor is designed to fit a variety of axle standards and the endcaps for my traditional 135mm QR configuration were straightforward to install. Grin’s torque arm was a little fiddly, but I think that’s the nature of having something designed to fit a wide variety of bike geometries. The hose clamps holding the torque arm on are way oversized and I may replace them with something that’s a more appropriate diameter.
When I unboxed the 52v 20Ah battery I couldn’t believe how big it was! Just sticking it into the Edgerunner frame it became apparent I was going to have some fit issues. Trying to use Xtracycle’s battery offset brackets was a no-go as they cause the battery to sit nearly an inch higher. I tried to install the battery with Grin’s triple bob battery bracket on the threaded frame bosses but the Xtracycle uses M6 and the triple bob adapter is M5 so I had to resort to hose clamps. No matter, without the Xtracycle offset adapters I was unable to shift the cassette into the 4 highest gears without the chain rubbing on the battery housing.
Going back to the drawing board I reached out to Grin, Xtracycle, and a local frame building to see what some options were. It turns out Grin used to sell converted Edgerunners themselves and had used custom brackets in the past, but they didn’t offer them for sale and there were no designs/drawings floating around. My local frame builder came up with some brackets similar to Xtracycle but without the added stack height and I was considering getting a pair of those machined. But then Grin suggested simply using the triple bob adapter but rotating it along the tube so that the battery sat slightly to the side. Since I already had everything installed with the hose clamps this was pretty easy to test fit and lo and behold it worked! The battery looks a little funny being tilted and getting the battery in and out of the mount is a bit of a difficult task but it DOES go in and out and works fine with no clearance issues. I think I’ll take the drawbacks for having the absolute unit of a battery pack in there.
Looking into the Edgeruner frame some more this appears to only be a problem with the “Swoop” variant that I have. The low step over height significantly reduces the space available for a battery. All of the standard Edgerunner models have significantly more space in this area for a large battery.
Moving up to the front of the bike installing the SuperHarness display, throttle, and associated cabling was relatively straightforward. Grin had some cable management tips in the manual and I think all things considered it looks OK as an aftermarket solution. If this was an integrated e-bike it certainly would not be winning any awards for streamlined install!
As far as cables were concerned, a 9 pin mains connector cable extension was needed given the nature of the Edgerunner being a longtail. The built in cable was just a bit short and would certainly be fine on installations where the battery mounts to a typical water bottle boss inside the main triangle of the bike. Extensions were also needed for the DC barrel connectors for the rear light. The front light’s connector had to be cut off and soldered to a DC barrel jack and the e-brake cutoff, typically a 2-pin Higo had to be spliced into a 4-pin Higo for the SuperHarness.
Grin uses a 4-pin Higo because the SuperHarness has the ability to use “analog” or variable output brakes allowing the brake lever to modulate the regenerative braking. Brake levers do not yet exist for hydraulic brakes with this functionality so for now I’ve got a simple “digital” or on/off regenerative braking setup.
The SuperHarness has some basic programing functionality built in. You can adjust the front light behavior, the rear light behavior, and the regenerative braking behavior. By default, the front and rear lights are set to always on if the battery is connected. I set these to be controlled by the display instead but found that the front light is still always on even though the rear light can be controlled by the display. I’ve contacted Grin’s customer support and they are attempting to replicate this behavior and troubleshoot.
Going for a Ride
With everything installed and wired up I was amped to go for a ride. My 3yo jumped on the back and we took off onto a local trail for a quick spin around the city to try things out. Having extensively ridden the bike the previous few months (about 300 miles) the e-assist output was immediately noticeable, even on the lowest level (the SuperHarness/baserunner ships with 9 assist levels). I plan on using this bike in e-assist mode only with no throttle, but of course I had to try the throttle out on a few hills.
For the few rides I’ve done so far the weight of the passengers and cargo has been about 250 pounds. No rides have been done in hot weather, and there have been no extended hills. The motor has provided plenty of assist power even at low assist settings and the throttle has been able to get me above a speed I’d be comfortable cruising at with my kids on the back. My chainring size of 50t tends to keep me in the smaller cassette cogs and did not feel oversized going up a hill. If I was to do it over again I’d probably chose a 52t chainring as I’ve also got the ability to step up the cassette from a 34t to a 38t if necessary. The motor is pretty quiet but I do notice vibrations that I was not expecting. I’m not sure if this is a quick release that isn’t tight enough or a torque arm that needs to be realigned or maybe a misaligned wheel. More investigation is necessary.
The torque sensor feels pretty good. I don’t own any other e-bikes and I haven’t ridden any other e-bikes extensively so I don’t have much of a basis for comparison. There is maybe a little more output even on the lowest setting than I’d like. Not sure if this is configurable by the end user or something that is set by Grin, but I don’t anticipate myself going beyond the first power assist frequently.
The regenerative braking has been intriguing to play with. One of my initial concerns with a mid-drive on a longtail was the wear and tear on the chain and cassette. A hub drive has less wear and tear on these drivetrain components and add in regenerative braking and there’s also less wear and tear on the brake system. The SuperHarness has two regenerative braking baseline values to choose from, I’m using the higher value. You can also dynamically control the regenerative braking by using the throttle while the brake is engaged to increase regen amount. I thought I would like to do this more, but with my specific brake the e-brake sensor does not engage until there is already a fair amount of pressure applied to do the brake pads and I’ve found that increasing the regenerative braking amount causes too much brake force when combined with the actual brakes being engaged. I suspect this is dependent on what brake system you use. A brake system that engage the e-brake before the brake pads clamp significant on the rotor would be more useful for this dynamic regenerative braking.
I’m a cyclist. I like biking for exercise and fun. I like the feel of biking and I wanted to keep that in my e-cargo conversion. After a 15 mile ride this past weekend, mostly at assist level 1/9, I could feel it in my legs, which is great!
Points of Concern
I do have two items I need to address besides minor issue of the front light control not operating as expected. The first is an issue I’ve encountered where I will turn on the battery and then attempt to turn on the display. Several times now the display starts to power up and immediately shuts down. Afterward it cannot be turned back on, even if the battery is power cycled. The only fix I’ve found is if I remove the battery entirely and reconnect it. I don’t know what is causing this – maybe one of my spliced wires is shorting? And I haven’t had a chance to reach out to Grin for guidance yet.
On one of my rides I encountered a hill where I was putting out a lot of power and also adjusted the assist level up very high just to test. The motor entirely cut out on me a few times on that short hill. I’m not sure if I somehow overheated the motor? The weather was not hot and I’d only been riding on a relatively low assist level for 20 or 30 minutes up to that point. I didn’t get a good sense of what the display was doing when the motor cut out, but I think I saw a red exclamation point when it happened. It’s interesting because I’d also tested the motor out on a different steep hill using just throttle and it seemed to have no problems, so perhaps it was something with the torque sensor.
Conclusion
This is obviously a very preliminary review of my experience thus far. I’ve been happy with Grin’s customer service and my choice of a hub motor vs. mid-drive motor. The Grin kit is certainly a premium price point and approaches that of buying a whole new e-bike direct from Xtracycle with a Shimano mid-drive system. However, with the Grin kit I get a much larger battery, regenerative braking/hub motor, no speed cap, and a throttle.
There have been a few concerning items that I hope to get sorted and at this time I can’t rule out something I did wrong with my installation as the cause. More testing is needed in hot weather and with a higher cargo weight. More long rides are needed with hills and many more miles and years are needed to give a real long-term review. When my baby is big enough to be on the bike that will probably be about 40 more pounds of weight between the child and seat. Of course, as the kids get older too the cargo weight is going to keep increasing.
Build Kit
Grin Rear All-Axle SuperHarness Kit - USD$2,425 (battery was 25% off)
TLDR; I like it, got a few things to sort out still.
Photos up front: Xtracycle Edgerunner swoop ebike upgrade with Grin All Axle v3
Background
I have been a full-time bike commuter for a few years, and a full-time baby hauler for the past 3 years. For most of that time my child was on a Yepp Maxi seat on the back of my Jamis Aurora Elite touring bike. It was a great setup for our daily daycare commute and my occasional in-office work days.
We got pregnant with our 2nd child around the time my 1st child came up against the weight limit of the Yepp Maxi seat (42 pounds, though it is the same seat in Europe with a 48 pound weight limit). Always eager to have a reason to buy a new bike I went on the hunt for an e-bike.
To further spark my interest in a new bike, DC had recently announced a new e-bike incentive program offering $1,000 rebate for e-cargo bikes purchased locally. The more I read up on this program, however, the more it became apparent it was under funded and the rebate program was going to come down to a lottery.
I test rode a few e-bikes – Tern GSD, Xtracycle RFA, and an Urban Arrow. Although my child really loved sitting in a bucket in the Urban Arrow, I didn’t like that it didn’t feel like riding a normal bike, and the practicality of trying to get it in and out of my storage area every day seemed daunting (not to mention the cost). The Tern is beloved by many and probably accounts for half of all e-cargo bikes I see in the city, but it was very uninspiring to ride. I really enjoyed the natural feel of the Xtracycle, likely due to the larger 24” wheels, and was pretty set on purchasing one.
Shortly after my test rides I visited my brother-in-law who had converted a number of bikes with Bafang mid-drive systems and I decided that was something I could do too. I didn’t like the cadence sensor of the Bafang units but discovered there were some other mid-drive motors on the market with torque sensors, promising a more natural feel of the purpose built bikes I had test rode.
The Bike
I found an Xtracycle Edgerunner Swoop used on Craigslist that turned out to have been a garage queen. Nearly perfect condition and outfitted with most of the accessories I’d want for hauling around some kids. Other than a missing saddle and leaky brake caliper it was in tip-top shape. Quickly getting it in working order I was ready for daycare runs once again. Unlike the Xtracycle RFA I’d previously test rode, the Edgerunner is a full size longtail with a larger passenger deck atop a smaller 20” rear wheel. The Edgerunner also has a larger 26” front wheel and has been produced and refined by Xtracycle for a number of years. It’s a premium chromoly frame in a market full of aluminum bikes.
The 2018 Edgerunner I purchased was the last year that Xtracycle offered non-electric bikes. That year in their catalog the Edgerunner existed in both manual and electric form with virtually no differences between the two frames besides the bottom bracket/motor mount. The Edgerunner has a dedicated battery mounting area between the chainstays just behind the seat tube, and Xtracycle has some mount adapters to offset it to the non-drive side to give better clearance for the chain.
The Motor
Bike in hand I started to research my mid-drive motor options with torque sensors and settled on the CYC Photon. However, on Black Friday 2023 I went on a bike ride with a local group and met someone who turned me onto the idea of a Grin hub drive motor with their regenerative braking technology. Educating myself more on hub motors I also discovered that the smaller 20” rear wheel of the Edgerunner allowed a hub motor to be more powerful, calming any concerns I had about missing out on the power offered by mid-drive units. About that same time Grin released the v3 All Axle motor with integrated torque sensor, allowing a more streamlined install, how perfect!
I spent the winter biking on the Edgerunner and waiting for our 2nd child to be born. I even managed to get out for an overnight bike camping trip on the Edgerunner with my 3yo. This spring, while on paternity leave Grin announced the new SuperHarness kits allowing a streamlined installation with modern displays. Although I like to tinker, I’ve got plenty of projects to keep me busy (and, ya know, a pair of kids) and since my longtail was going to be my daily driver I just wanted to set it and forget it. The SuperHarness kit seemed like a better fit than a Cycle Analyst installation for me.
Purchasing
I emailed back and forth with both Grin and Xtracycle about the fine details of my build. I had noted in Xtracycle literature that they designed the Edgerunner with an offset rear wheel to provide a stronger wheel build. Apparently, this translated into needing to build the rear wheel with a 5mm dish, which Grin was happy to do. Grin was also patient with my questions and confirmed the details of my purchase to make sure everything looked good.
Given that the Xtracycle I owned was setup for hauling heavy loads it was geared very low. I realized this wouldn’t work with the motor and I’d probably be permanently sitting on the largest chainring and smallest sprocket. I went ahead and got parts together to do a 1x crankset with a larger 50t narrow-wide chainring in hopes that I’d have useable gearing across all 9 cassette cogs.
I could have kept using my USB lights but opted to purchase dedicated e-bike lights to be controlled via the display. I’ve used the B&M IQ-X lights on a few conventional bikes with dynamos and decided to purchase their e-bike variant for this bike as well. Although my existing hydraulic brake setup worked great, the geometry of the levers was not conducive to using those magnetic brake cutoff sensors so I went ahead and purchased a single Shimano MT200 e-bike brake to control the motor cutoff and regenerative braking.
Installation
I’ve been doing all my own bike work for a number of years so I expected installation to be pretty smooth. Removal of my old front shifter/derailleur/crankset was straightforward, as was installation of my new cranks and chainring. I did learn not to waste time with aluminum chainring bolts, having quickly stripped one. After installing some steel chainring bolts I was good to go. I had a square taper bottom bracket laying around that was a much wider spindle than the FSA Vero cranksets called for, but it seemed fine and I always enjoy using parts from my parts box.
Moving on to the rear wheel also proved to be relatively straightforward Transferring the cassette, rotor, tube, and tire from the old wheel was easy. The All Axle motor is designed to fit a variety of axle standards and the endcaps for my traditional 135mm QR configuration were straightforward to install. Grin’s torque arm was a little fiddly, but I think that’s the nature of having something designed to fit a wide variety of bike geometries. The hose clamps holding the torque arm on are way oversized and I may replace them with something that’s a more appropriate diameter.
When I unboxed the 52v 20Ah battery I couldn’t believe how big it was! Just sticking it into the Edgerunner frame it became apparent I was going to have some fit issues. Trying to use Xtracycle’s battery offset brackets was a no-go as they cause the battery to sit nearly an inch higher. I tried to install the battery with Grin’s triple bob battery bracket on the threaded frame bosses but the Xtracycle uses M6 and the triple bob adapter is M5 so I had to resort to hose clamps. No matter, without the Xtracycle offset adapters I was unable to shift the cassette into the 4 highest gears without the chain rubbing on the battery housing.
Going back to the drawing board I reached out to Grin, Xtracycle, and a local frame building to see what some options were. It turns out Grin used to sell converted Edgerunners themselves and had used custom brackets in the past, but they didn’t offer them for sale and there were no designs/drawings floating around. My local frame builder came up with some brackets similar to Xtracycle but without the added stack height and I was considering getting a pair of those machined. But then Grin suggested simply using the triple bob adapter but rotating it along the tube so that the battery sat slightly to the side. Since I already had everything installed with the hose clamps this was pretty easy to test fit and lo and behold it worked! The battery looks a little funny being tilted and getting the battery in and out of the mount is a bit of a difficult task but it DOES go in and out and works fine with no clearance issues. I think I’ll take the drawbacks for having the absolute unit of a battery pack in there.
Looking into the Edgeruner frame some more this appears to only be a problem with the “Swoop” variant that I have. The low step over height significantly reduces the space available for a battery. All of the standard Edgerunner models have significantly more space in this area for a large battery.
Moving up to the front of the bike installing the SuperHarness display, throttle, and associated cabling was relatively straightforward. Grin had some cable management tips in the manual and I think all things considered it looks OK as an aftermarket solution. If this was an integrated e-bike it certainly would not be winning any awards for streamlined install!
As far as cables were concerned, a 9 pin mains connector cable extension was needed given the nature of the Edgerunner being a longtail. The built in cable was just a bit short and would certainly be fine on installations where the battery mounts to a typical water bottle boss inside the main triangle of the bike. Extensions were also needed for the DC barrel connectors for the rear light. The front light’s connector had to be cut off and soldered to a DC barrel jack and the e-brake cutoff, typically a 2-pin Higo had to be spliced into a 4-pin Higo for the SuperHarness.
Grin uses a 4-pin Higo because the SuperHarness has the ability to use “analog” or variable output brakes allowing the brake lever to modulate the regenerative braking. Brake levers do not yet exist for hydraulic brakes with this functionality so for now I’ve got a simple “digital” or on/off regenerative braking setup.
The SuperHarness has some basic programing functionality built in. You can adjust the front light behavior, the rear light behavior, and the regenerative braking behavior. By default, the front and rear lights are set to always on if the battery is connected. I set these to be controlled by the display instead but found that the front light is still always on even though the rear light can be controlled by the display. I’ve contacted Grin’s customer support and they are attempting to replicate this behavior and troubleshoot.
Going for a Ride
With everything installed and wired up I was amped to go for a ride. My 3yo jumped on the back and we took off onto a local trail for a quick spin around the city to try things out. Having extensively ridden the bike the previous few months (about 300 miles) the e-assist output was immediately noticeable, even on the lowest level (the SuperHarness/baserunner ships with 9 assist levels). I plan on using this bike in e-assist mode only with no throttle, but of course I had to try the throttle out on a few hills.
For the few rides I’ve done so far the weight of the passengers and cargo has been about 250 pounds. No rides have been done in hot weather, and there have been no extended hills. The motor has provided plenty of assist power even at low assist settings and the throttle has been able to get me above a speed I’d be comfortable cruising at with my kids on the back. My chainring size of 50t tends to keep me in the smaller cassette cogs and did not feel oversized going up a hill. If I was to do it over again I’d probably chose a 52t chainring as I’ve also got the ability to step up the cassette from a 34t to a 38t if necessary. The motor is pretty quiet but I do notice vibrations that I was not expecting. I’m not sure if this is a quick release that isn’t tight enough or a torque arm that needs to be realigned or maybe a misaligned wheel. More investigation is necessary.
The torque sensor feels pretty good. I don’t own any other e-bikes and I haven’t ridden any other e-bikes extensively so I don’t have much of a basis for comparison. There is maybe a little more output even on the lowest setting than I’d like. Not sure if this is configurable by the end user or something that is set by Grin, but I don’t anticipate myself going beyond the first power assist frequently.
The regenerative braking has been intriguing to play with. One of my initial concerns with a mid-drive on a longtail was the wear and tear on the chain and cassette. A hub drive has less wear and tear on these drivetrain components and add in regenerative braking and there’s also less wear and tear on the brake system. The SuperHarness has two regenerative braking baseline values to choose from, I’m using the higher value. You can also dynamically control the regenerative braking by using the throttle while the brake is engaged to increase regen amount. I thought I would like to do this more, but with my specific brake the e-brake sensor does not engage until there is already a fair amount of pressure applied to do the brake pads and I’ve found that increasing the regenerative braking amount causes too much brake force when combined with the actual brakes being engaged. I suspect this is dependent on what brake system you use. A brake system that engage the e-brake before the brake pads clamp significant on the rotor would be more useful for this dynamic regenerative braking.
I’m a cyclist. I like biking for exercise and fun. I like the feel of biking and I wanted to keep that in my e-cargo conversion. After a 15 mile ride this past weekend, mostly at assist level 1/9, I could feel it in my legs, which is great!
Points of Concern
I do have two items I need to address besides minor issue of the front light control not operating as expected. The first is an issue I’ve encountered where I will turn on the battery and then attempt to turn on the display. Several times now the display starts to power up and immediately shuts down. Afterward it cannot be turned back on, even if the battery is power cycled. The only fix I’ve found is if I remove the battery entirely and reconnect it. I don’t know what is causing this – maybe one of my spliced wires is shorting? And I haven’t had a chance to reach out to Grin for guidance yet.
On one of my rides I encountered a hill where I was putting out a lot of power and also adjusted the assist level up very high just to test. The motor entirely cut out on me a few times on that short hill. I’m not sure if I somehow overheated the motor? The weather was not hot and I’d only been riding on a relatively low assist level for 20 or 30 minutes up to that point. I didn’t get a good sense of what the display was doing when the motor cut out, but I think I saw a red exclamation point when it happened. It’s interesting because I’d also tested the motor out on a different steep hill using just throttle and it seemed to have no problems, so perhaps it was something with the torque sensor.
Conclusion
This is obviously a very preliminary review of my experience thus far. I’ve been happy with Grin’s customer service and my choice of a hub motor vs. mid-drive motor. The Grin kit is certainly a premium price point and approaches that of buying a whole new e-bike direct from Xtracycle with a Shimano mid-drive system. However, with the Grin kit I get a much larger battery, regenerative braking/hub motor, no speed cap, and a throttle.
There have been a few concerning items that I hope to get sorted and at this time I can’t rule out something I did wrong with my installation as the cause. More testing is needed in hot weather and with a higher cargo weight. More long rides are needed with hills and many more miles and years are needed to give a real long-term review. When my baby is big enough to be on the bike that will probably be about 40 more pounds of weight between the child and seat. Of course, as the kids get older too the cargo weight is going to keep increasing.
Build Kit
Grin Rear All-Axle SuperHarness Kit - USD$2,425 (battery was 25% off)
- V3 Rear All-Axle, Std Winding, HG Driver
- V3 Rear All-Axle Torque Arm Kit
- Rear Axle Adapters - 135mm Slotted Dropout Rear Adapters for V3
- Inject Motor with Statorade
- Wheel Build by Grin
- Rim20_DM30_32H
- 32 x Sapim Strong 13-14g Butted Spoke, Silver
- V6 Baserunner Controller L10
- Baserunner Controller Mount
- Reention battery baseplate, machined to fit Baserunner
- Motor PAS Extension Cable 6 Pin HiGo MiniB, 1m (not needed)
- Controller to SuperHarness 9 Pin Main Cable Extension, 1M (forgot to initially order)
- 600C Integrated Handlebar Display and Switch
- Main9 Superharness
- Button Thumb Throttle, Clamp. with Higo 3 pin Connector
- 52V 20Ah Downtube Battery
- 52V 2A ST3 Charger
- Triple Bob Battery Bracket
- Accessories
- Flexible E-bike Cable Raceway (did not use)
- Wire Route Kit (used about half)
- Laser 250W Power Rating
- Roxim Rear R1 E-Light
- DC Barrel Jack Extension, 180cm (needed some additional length as well)
- B&M IQ-X E headlight – USD $110
- DC barrel jack extension to splice to SuperHarness
- Shimano MT200 brake lever and caliper with e-brake cutoff sensor – USD $65
- Higo 4 pin extension cable to splice to SuperHarness
- Crankset – USD $65
- FSA Vero crank arms (used)
- DECKAS 50t narrow/wide chainring
- Steel chainring bolts (initially ordered aluminum and immediately stripped)
- Shimano square taper bottom bracket
- 2018 Xtracycle Edgerunner Swoop lightly used USD $775
- Xtracycle battery offset brackets to shift battery towards non-drive side to avoid chain interference
