Polygon MT Bromo Series
The bike comes with 29x2.6” tires front and rear. Can I fit 27.5+ wheels to convert it to a ‘mullet’ or full plus tire set up?
The frame has clearance for a 27.5x2.8" tire so a mullet (29” front, 27.5+ rear) is possible. However, the diameter of a 27.5x2.8" tire is significantly smaller than the standard 29x2.6" tire, hence changing to a mullet set up would reduce BB height and pedal to ground clearance while also slackening both the effective seat and head tube angles. The fork will also fit a 27.5+ tire, however, this is highly discouraged as the BB drop would become dangerously low. We recommend staying ready for business with 29" all-round.
Can I use a different rear shock?
Most 205mm x 65mm Trunnion Mount shocks should fit. The leverage curve can work well with a coil shock. However, it’s worth noting that Polygon has Fox tune the stock rear shocks to work best with the specific bike model, so a standard tune replacement shock may not offer optimised performance.
Can I change the fork?
You’ll need to use an e-MTB rated fork to ensure it is strong enough to withstand the additional forces and punishment that can be encountered by e-MTBs. The standard forks are 160mm travel, but you can run up to 170mm travel if you like. You cannot use a dual crown fork as the frame is not designed or tested to withstand the different loads.
Can Mt Bromo N fit a chainguide?
For sure. In fact, both N7 and N8 models come equipped with an e*thirteen E*Spec Plus top guide. The chain guide mounts directly to the drive unit and the bolt pattern is different to traditional ISCG/05, so most ‘normal’ chain guides are not compatible.
What size rotors can I use?
You can run up to 220mm rotors front and rear. While you can downsize from the standard 203mm to 180mm, we suggest not to.
How do I adjust the seat post insertion depth?
Remove the battery from the downtube using a 4mm hex key. Slightly loosen the fixing bolt of the cable guide where the dropper post cable enters the downtube. Loosen the seat post collar bolt. Locate the dropper post cable inside the downtube and gently push or pull the cable from this point to assist with lowering or raising the seat post position within the seat tube. Once the correct seat post height is set, tighten the seat post collar to 7Nm, tighten the cable guide and re-install the battery.
How do I remove the battery?
Insert a 4mm Allen key into the hole above the battery cover on the underside of the downtube. Rotate it in the direction depicted by the arrow to release the battery lock. This will allow the battery to hang slightly down from the tube, creating access to the battery release lever at the top of the battery. Be sure to use two hands when releasing the battery as it’s quite heavy and shouldn’t be dropped.
How do I install the battery?
Ensure the battery connections are clean and dry. Install the base of the battery into the lower mount closest to the motor, then press the top of the battery into the downtube until you hear and feel a “click”. Then your battery is installed.
How do I charge the battery?
The battery can be charged either installed in the bike, via the charging port on the left side in front of the motor, or detached from the bike using the additional connection port supplied with the charger.
I like to ride in mud, are the electronics weather-proof?
Yes. The SHIMANO STEPS systems are waterproof for use under normal riding conditions, including heavy rain. Please do not use a high pressure washer to clean your bike.
How fast can I ride?
When gravity is on your side, there is no limiting your speed beyond that of a “normal” MTB with 160mm of awesome suspension. As far as motor assistance is concerned, the Shimano STEPS systems will provide motor assistance up to 20mph (32km/h) in the USA and Indonesia, or 25 km/h in Europe and Australia.
How far can I ride?
The range of any e-MTB depends on many variables, including terrain, gradients, rider weight, assistance mode, rider input, ambient temperature, etc. While 100km adventures are definitely achievable aboard the Mt Bromo N, we recommend using the Range overview on the display for the best estimate. The range overview is recalculated continuously by calculating speed, rider behaviour and power consumption. This means that range overview makes a prediction, which can vary depending on these different factors.
Can the Mt Bromo N fit a larger battery?
No, Mt Bromo N was designed around Shimano’s BT-E8035 504Wh battery as it helps Bromo hit the sweet spot of lighter weight for agility, attainable price points while still offering enough capacity for very big rides. The larger 630Wh battery is too long to fit in the frame.
Can I get a spare battery?
Yes. A BT-E8035 504Wh battery can be purchased through your Polygon retailer or most good bike shops. The bolt on battery cover (Article Code #733723) will need to be purchased through Polygon or a Polygon retailer.
Can I run a headlight from the Shimano battery?
Yes. Shimano approved front lights can be connected to ports in the STEPS drive unit (motor). This requires significant internal routing and e-system component removal so we recommend having this upgrade made by a certified Shimano STEPS workshop.
The display states W013 error code and the motor has no power. How can I fix it?
W013 is likely the most common error for first time STEPS users. Officially, W013 means Initialization of torque sensor not completed successfully. Don’t fret. It typically occurs when the system is turned on while a load is applied to the crankset. Try turning the system off, ensuring your foot is not on a pedal and the cranks or pedals are not leaning on the ground or against a wall; then turn the system back on again. This should solve the issue. If you still see the issue try a 'hard reset' - press the power button for 12 seconds and power on once again. If W013 or any other error code persists, contact your place of purchase or a certified Shimano STEPS workshop.
I want my drivetrain to last a long time. Are there any tricks to smooth shifting on an e-MTB?
While Shimano’s HYPERGLIDE+ 1x12 drivetrains offer very smooth shifting even under the load of EP8’s 85Nm, we recommend only shifting one gear at a time (up or down the cassette) and try to back off the power through the cranks a little as the integrated torque sensor will immediately react and also back off the motor’s power. Trail mode is much more intuitive with this than Boost mode. We recommend saving Boost mode for cranking straight up big climbs where gear shifting is limited.