Updated October 16th, 2024
The Birch Grolar is a high powered e-bike designed for hunting. It has dual 750 watt motors, all-wheel drive, a 25-hour battery, and a torque sensor. At the front end you’ll find a beastly double crown, air spring, front fork with 180mm travel. This ebike rides and has power like a Chevy Tahoe with a turbocharged V8. It’s got gobs of power, a smooth ride, and it gets a bit thirsty too. Let’s get into the details.
Birch Grolar
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Overall Score
What we liked:
- This bike has very high power for hills and accelerating with it’s 2 motors
- The bike is very comfortable to ride. The upright position combined with long travel fork and suspension post smooths out the bumps
- The menu has a lot of options for customizing top speed and power levels
- It is very fun to ride both on and off road and makes a great exploring bike
- The front and rear racks give it lots of on board storage
- The large front headlight makes it easy to see while riding at night
What we didn’t like:
- The bike is a challenge to transport with it’s 109 lb weight
- The frame and step thru are really too big for smaller riders
- The bike gets a bit thirsty if you lay on the power a lot
Specifications
- Max Speed – 32 mph
- Range – 85 miles
- Max Rider Weight – 400 lbs
- Bike Weight – 109 lbs
- Motor Power – Dual 750 watt hub motors
- Battery – 48 volt 25 ah
- Speeds – 9 Speed Shimano
- Brakes – Hydraulic disc
- Wheel Size – 26 inch x 4 inch tires
Video Review
Birch Grolar Review and Test
Birch contacted us and asked if we wanted to review this bike on our site and YouTube channel. The bike is designed to be used by hunters instead of an ATV. I will mention it here that I do not hunt. The Grolar turned out to be a great bike for going on any kind of outdoor adventure. It’s size and power make it good for the larger ebike riders out there that want something built for their size and weight.
Let’s talk about some of the key features of the Grolar
1 – Dual 750 watt hub motors
Everyone wants all wheel drive for their SUV to get better traction. Why not AWD for a bike too? The Grolar gives you 2 750 watt hub motors giving to tons of power and traction for climbing up loose surfaces. The bike can be set to use just the rear or front motor or both depending on what you want to do.
2 – 48 volt 25 ah removable battery
Most fat tire ebikes come with a 15 ah battery. Sometimes you get a 20 ah battery. Birch went one step further and gave you a 25 ah battery. This is a good thing because this bike can get a bit power hungry with it’s 2 motors. There is a planned second battery coming for those who want even more range from the bike.
The battery is not UL listed. There is no mention of it on their website or label on the battery. There is also no mention of who makes the cells.
It takes about 8 hours to recharge this battery from fully dead with the included charger.
3 – 180mm travel double crown air fork and suspension seat post
This bike has a massive front fork on it with an actual air spring. You can fine tune the stiffness for different rider weights with a shock pump (not included). This is a huge improvement over the coil sping forks that almost every other ebike comes with. Those rarely have enough pre-load adjustment to work well for heavier riders.
The downside to this fork is that it does limit the turning radius of the bike. The upper part of the fork hits the frame when doing very tight turns.
At the back end of the bike you get a suspension seat post. This gives the bike a smooth ride without all the extra weight and maintenance that comes with a full suspension bike. The suspension seat post has adjustable pre-load to adjust it for different rider weights.
4 – 400 lbs capacity with front and rear racks
This bike is designed to carry a lot of weight. It has a published 400 lb weight limit. The front rack can hold up to 50 lbs. The rear rack can hold up to 100 lbs. That’s 150 lbs worth of rack storage capacity. That still gives you 250 lbs for the rider if you fully load up the racks.
4 – Torque sensor and throttle
The Grolar uses a torque sensor to control the motor. This gives it a very smooth feel when the power comes on. It makes it very easy to control at low speeds. The bike is geared high enough that it isn’t too hard to pedal at max speeds.
Sometime you don’t want to pedal and just want to take it easy. The Grolar has a twist throttle for those times.
6 – Power (10/10)
The dual motors of this bike give it tons of power. It accelerates very fast using the throttle from a stop. It can blast up hills like it’s running from a bear. We did some tests with the bike to see how powerful it really was.
Top Speed
The bike comes set with the top speed limited to 20mph. This applies to both throttle and pedal assist. You can set the top speed up to 32mph in the menu settings.
When the top speed is set at 20mph. The bike will accelerate up to 22-23mph and then setting back down to 20mph. This applies to both throttle and pedal assist. It lets you have a little more for passing or crossing a street fast.
I opened up the menu and set it to the max speed setting which is 32mph. This applies to both throttle and pedal assist. I measured the speed with a GPS to see how fast it really went.
- Throttle – Max Speed GPS – 30.1 mph
- Throttle – Max speed shown on display – 31.6 mph
- Pedal Assist – Max Speed GPS – 28.6 mph
- Pedal Assist – Max speed shown on display – 30.0 mph
This bike is very smooth and comfortable to ride at 28mph. Above 28mph I feel like the bike is a little bit on the edge. I personally would leave the speed limited to 28mph or 20mph depending on where I was riding. The bike is capable of going over 30mph.
Hill climbing
I took the bike to my standard hill climb test hill. This hill is a half mile long with several section of 10% grades. It also has some corners and loose surfaces. I do the test with a 250 lb rider with full throttle and maximum pedal assist. I recorded the following times.
- Throttle Only – 1 min and 32 seconds
- Pedal Assist – 1 min and 37 seconds
This bike accelerates very quick at full throttle. I had to let off the throttle at several points on the climb because of corners and gravel surface. I can hold full throttle on most other ebikes during this climb. The Grolar has so much power that I needed to slow it down.
For reference we got the following times with a couple other popular ebikes.
- Aventon Aventure 2 – Throttle – 1 minute 53 seconds
- Himiway Zebra D5 – Throttle – 1 minute 57 seconds
The Grolar smoked every ebike we have tested on this hill by a large margin. If you want power and want it now. This bike has it.
7 – Range (9.5/10)
I took the Grolar out for a ride to see how far it would go on a full charge. The bike can be used in single motor mode to make it less thirsty. No one is buying this bike to ride it with only 1 motor. We did the range test in “auto mode” that uses 1 or 2 motors depending on what you are doing.
Our range test loop involves several steep long climbs including the hill we uesd for the above hill climbing test. I use a 250 lb rider. I ride as close to 15mph as possible. These are not ideal conditions for maximizing bike range.
We did the hill climbing test during the range test for this bike. That caused a few mile reduction in range during the test.
Pedal assist
The Grolar went 49.9 miles before the bike would go no further. The published range for this bike is 85 miles. Our range was about 35 miles short of the published range. 50 miles is still good considering how much power and performance this bike has.
For reference, the longest range we have gotten out of a fat tire ebike was the Himiway Zebra D5 that went 63.2 miles with a 20 ah battery on the same route. That bike was also 20 seconds slower on our hill climb.
You could stretch the mileage farther by setting it to rear motor only mode, riding on a flat path and using a lighter weight rider.
There is some power drop off that becomes noticeable below 15%. The bike goes into a limp home mode where it limits you to rear motor only below 5%. The bike went on few a couple of miles after the battery started reading 0%. The bike gives you an low voltage error and completely shuts down. Then your done.
Throttle Only
I did the test again using only throttle. The bike was still in dual motor mode and I rode it as close to 15mph as I could. The bike went 38.4 miles. The range could be stretched out more by setting it to single motor mode and avoiding hills. What would be the fun in that?
Optional Second Battery
Birch is planning to release a second battery for the Grolar that mounts in the frame step thru. There is an expansion power plug on the bike. This will satisfy everyone who wants to go on 80 to 100 mile rides and operate in dual motor mode the whole time. It is not available yet. I will update this with a link when it becomes available.
8 – Ride and Handling (9.5/10)
The Birch Grolar has a very upright riding position that gives it a nice relaxed feel. The front suspension combined with suspension seat post makes it feel very cushy. 4 inch wide fat tires tend to feel cushy before you start loading on suspension.
The front fork geometry is slack enough to make the bike feel smooth and stable at higher speeds. This bike felt very solid and in control at 20-25mph. It didn’t start feeling like it was on edge until going over 28mph.
Cornering
The bike felt very smooth going around street corners at high speeds. The double crown fork does limit the turning radius of the bike, making it hard to ride in tight spaces. I do not recommend trying to ride this bike on a very crowded sidewalk or boardwalk where you are weaving in and out of people.
9 – Off roading with the Birch Grolar
Off roading is where the fun really starts with the Grolar. This bike goes into beast mode when it hits steep climbs. I found that I had to throttle down on several steep climbs because the bike was accelerating and started going too fast.
The Grolar goes like a rocket ship down dirt roads and fire trails. I didn’t have a chance to ride it on a good flow trail. I think it would be really fun to ride it somewhere with banked berms.
The torque sensor makes this bike very controllable at slower speeds. When you need to crawl across rocky, bumpy terrain, this makes it easy. If you load this bike up with a lot of gear, you can shift down to low gear and slow crawl up almost anything.
The one place where the Grolar isn’t great off road is very tight corners. The double crown fork does limit the turning radius. Some mountain bike trails, have very sharp corners weaving through trees and rocks. The Grolar just can’t turn that sharp and you’ll need to stop and pick the front end up to get it through these places.
10 – Braking (8/10)
The bike comes equipped with Tektro hydraulic disc brakes with 180 mm rotors at the front and back. These are brakes designed for a standard mountain bike. This is a very heavy bike capable of going very fast. These brakes are just adequate for stopping it.
For it’s weight and speed, the bike really should have gotten a 4 piston brake and 200mm rotor at least on the front brake.
11 – Controls (9.5/10)
Let’s talk about the controls on the Grolar
LCD Display
The bike has a color LCD display that shows speed, battery remaining, motor power, distance along with some other bits of information. It is easy to read in both day light and night riding conditions.
Control buttons
There is a 4 button controller on the left handlebar along with a second set with turn signals and horn. The power and menu buttons are small and hidden on the side of the 4 button controller and not labeled for what they are.
The buttons are easy to reach and press while riding except for the power and menu button. You don’t need those 2 while in motion on the bike.
Menu Options (Activating top speed and dual motors)
The Grolar has a lot of customization possible in the menu. You’ll have to go to the menus to activate dual motor modes and the higher top speeds.
You get the menus by powering on the bike and then holding down the “i” button. This is the small button below the small power button.
The manual tells you that the “advanced menu” items are for professionals only to adjust. The bike ships with rear motor only active and the top speed set to 20mph. Both of these items are in the advanced options. No one bought this bike to just ride it with 1 motor.
Top Speed
The top speed is set to 20mph from the factory. You can set it up to 32mph in the advanced menu. The top speed setting affects both PAS and throttle. This bike is not limited to 20mph for throttle.
Dual Motor Modes
There are 4 options for the motors. Rear motor only, front motor only, front and rear motors, and auto. Auto automatically switches it between single and dual motor mode and where I have spent most of my time riding the bike.
Auto seems to most of the time give an equal split between front and rear motors. There was only 1 instance where I noticed it doing anything different. This was riding at a constant 20mph on flat ground on PAS 1. This was the only time I noticed the bike operating on only 1 motor in auto mode.
Pedal Assist and Throttle
The bike has 5 levels of pedal assist. There is a very noticable difference in power between PAS 1 and 2. PAS 2 gives you tons of power. The difference is less noticeable going to higher PAS levels above 2.
Throttle is controlled with a twist throttle on the right handle bars.
Automatic Head lamp
The front lamp automatically turns on and off when it is dark or light where you are riding. You can also manually turn it on by holding down the plus button for several seconds.
Turn Signals
Turn signals are controlled with a slider switch on the left handlebar. This is the best control setup I have seen for handlebars. You slide it left and right for the left and right signal. I hate when the buttons are stacked instead of side by side. I was happy to see this setup.
13 – Accessories
The bike comes with a rear fender, front and rear rack, and lights. It has several mounting points on the rear frame for adding more accessories. There are 2 sets of water bottle mounts on the frame.
Front and Rear Rack
The rear rack is rated for 100 lbs. The front rack is rated for 50 lbs. Both racks are very beefy looking and heavy duty like the rest of the bike.
Lights
The front head lamp is very large and much brighter than what normally comes on an ebike. It has a wider light beam. It is fine for street riding. If you ride on a bike path with sharper corners you will still want a helmet light so you can see in the headlamp blind spot while turning.
The head lamp turns on and off automatically as it gets darer or lighter outside.
Fenders
Only a rear fender is included. There is no front fender. The frame is wide enough and the front rack also blocks some of the dirt spray. I’m not missing the front rack while riding it even on dirt surfaces.
Horn
The bike has an electronic horn on the left handlebar with the turn signals. It is obnoxious and loud. It will get the attention of anyone walking on the trail. They will hate you for using it. I would prefer a bell that draws a little less negative attention.
14 – Size and Fit
Birch publishes a rider size range for this bike of 5’1 to 6’5″. I will agree with the 6’5″ end of this range. The lower end for this bike is closer to 5’6″. The step through in the middle of the frame is very high off the ground and requires a large step over. Shorter riders will have a struggle getting on and off this bike.
12 – Assembly Ease (8/10)
The Grolar will come shipped in a large cardboard shipping container. It will take about 2 hours to assemble it from opening the box to ready to charge and ride. The bike comes with a very large and will ullustrated instruction manual and there is also a video on the Birch website to walk through it.
Tools needed
No extra tools are needed beyond what is included with the bike.
Adjustments needed
Check the fasteners on the bike before riding. I found that my seat up and down angle was loose. As soon as I put weight on the seat, the back flopped down. I could rotate it by hand.
The suspension seat post comes shipped with the pre-load at the very lowest setting. It was much too soft for a heavier rider. You can add pre-load by turning the bottom end of the post with an M6 hex wrench. After making this adjustment it worked fine.
I had to contact Birch customer support with regards to the seat post pre-load. They responded within a day with a video showing how to adjust it. This was A Plus service for questions compared to what I have gotten from some other brands.
Another note on the seat. If you over tighten the seat post clamp, it will bind the suspension seat post. Do not be tempted to crank down on this one.
The front shock has an air spring. It was set appropriate stiffness for a 200 lb rider out of the box. The fork has 180mm travel. Sag should be around 36mm. They do not include an air shock pump. They are available cheap on Amazon if you want to adjust this.
12 – Transporting the Grolar
The Grolar weighs 109 lbs with the battery in it or 84 lbs with the battery removed. Most bike racks are rated for 40 to 50 lb bikes. The Grolar is in a whole different class when it comes to transport.
You will need something like a 1UP USA Super Duty rack that can handle 100 lb bikes. Another option is the motorcycle hitch rack from Harbor Freight that is rated for 400 lbs motorcycles.
Recommendation – Buy or No Buy?
If you are looking for a big and powerful ebike, the Grolar is an obvious choice. It’s dual motors give it more power than most bikes. The huge 25 ah battery helps feed this beast. The air suspension and adjustable seat post means you can adjust this bike for large riders. This bike might have been designed for hunters. It is a great bike for anyone wanting to go adventuring.
Ryan Craig
Co-Founder & Chief Editor
I am a total gear nerd and love learning how things work and thinking about how they could be improved. Nothing excites me more than trying out new gear. I’d rather spend 3 hours taking my bike apart and learning how to change something than go to a bike shop. These days, I reside in Michigan by the Great Lakes and go skiing, biking, and boating as much as possible. Visit our About Us page and learn more.
ryan@lowbudgetadventurer.com