2023 Norco Bigfoot VLT Shimano EP8 speed calibration — DIY fix without third-party soft...

My 2023 Norco Bigfoot VLT with a Shimano ep8 is robbing me of about 3 miles per hour short of 20 miles per hour by virtue of the factory set calibration. Is there a way I can properly calibrate without using banned third party software? And without having to take it to a dealer?

@Greg Watts

That speed loss is almost certainly down to your wheel circumference setting, not a power or assist issue — and the good news is you can fix it yourself, legitimately, with no banned software and no dealer trip.

Here's the mechanism: the EP8 calculates speed from wheel rotations × the stored circumference value. If that figure is set too small, the motor thinks you're going faster than you actually are, so it cuts assist early — exactly the "3mph short of the limit" symptom you're describing. @Backflip flagged on here that new STEPS drive units sometimes ship with odd wheel circumference defaults (he's seen them set to the 3000mm maximum, which throws the limit out the other way), so a wrong factory value is a known thing rather than a one-off.

The fix — official Shimano E-Tube Project app
This is Shimano's own free app, fully legal, nothing third-party about it:
• Install E-Tube Project Cyclist (phone) or the desktop version
• Connect to the bike — Bluetooth on the phone app, or via the charge port / SC display unit
• Go into the drive-unit settings and find wheel size / tyre circumference
• Set it to match your actual tyre. A 29×2.4 Bigfoot tyre is roughly 2326–2340mm circumference; the cleanest method is to enter the measured value — mark the valve, roll one full rotation with your weight on the bike, measure the distance, and use that in mm

Get that number right and the cutoff returns to the proper ~15.5mph (25km/h EU) point. Nothing about this de-restricts the bike or touches the legal limit — you're just making the speedometer honest, which is entirely within Shimano's intended settings.

One caveat worth knowing: @steve_sordy and others have noted the EP8 also lets you user-configure torque and assist profiles in E-Tube, so while you're in there don't accidentally knock those about — you only need the wheel-size field for this job.

If E-Tube won't let you edit circumference on your firmware, a quick motor firmware update through the same app (then re-checking the wheel value) usually frees it up.

Tell me what tyre size/width you're actually running and I'll help you pin down the exact circumference figure to enter.

My Shimano motor is the ep8 800 not the updated 801 and it does not appear to offer any option to enter tire size to calibrate. The Drive Unit section just shows 20 mph and an option for zero, plus 0.5, or -.5. I'm hesitant to check for updated firmware , which was updated in December of 2025 anyway, because Shimano issued a warning to not update Android phones because the Shimano software doesn't work with the latest Android updated operating system.

Stocky27 said:

My Shimano motor is the ep8 800 not the updated 801 and it does not appear to offer any option to enter tire size to calibrate. The Drive Unit section just shows 20 mph and an option for zero, plus 0.5, or -.5. I'm hesitant to check for updated firmware , which was updated in December of 2025 anyway...

Click to expand...

@Stocky27 - that's actually useful detail, and it changes the answer a bit. What you're describing - the +0 / +0.5 / -0.5 mph offset options - is the speed limit adjustment within E-Tube, not a full circumference calibration field. The DU-EP800 (your pre-2022 motor) has a more limited E-Tube interface than the later EP801, and from what you're describing, it sounds like your firmware may not expose a raw circumference entry - just that coarse ±0.5 offset.

Here's what that offset actually does: -0.5mph would make the motor think you're going slightly faster than you are, cutting assist earlier - the opposite of what you want. +0.5mph shifts the cutoff point up slightly. If you're losing about 3mph, half a mile-per-hour increments aren't going to solve it on their own.

The honest answer on your specific situation: Without the SM-PCE02 hardware interface, the DU-EP800 cannot have its speed limit properly recalibrated by the owner. That's a verified limitation - it's in our corrections database and it applies to your motor generation. The ±0.5 offset is all E-Tube Bluetooth exposes on that unit.

On the Android firmware warning - your caution is sensible. I can't confirm the specifics of the December 2025 update behaviour on current Android versions without checking, so I wouldn't push you to update blind.

Realistically, your options are:

• 
  
  []Accept the ±0.5 fudge (limited help) []Borrow or hire an SM-PCE02 - some LBS will run a calibration session without a full service charge
  
• Contact Norco/your dealer about whether the factory setting was ever correct for your tyre size

Not the answer you were hoping for, but better than chasing a setting that isn't there.

Stocky27 said:

My 2023 Norco Bigfoot VLT with a Shimano ep8 is robbing me of about 3 miles per hour short of 20 miles per hour by virtue of the factory set calibration. Is there a way I can properly calibrate without using banned third party software? And without having to take it to a dealer?

@Greg Watts

Click to expand...

@Greg Watts: Thanks for your reply and reference. The official E-Tube-Project software from Shimano (Bluetooth based Cyclist - app or Windows based Professional program) NEVER let you change wheel circumfernce value as an end user (owner of the bike).
Only some very privileged Shimano employees can do so via some high level access to the Windows based E-Tube-Project-Professional software connected via the cable-bound SM-PCE02 interface from Shimano to the bike.
Also regular bike shops CANNOT change the wheel circumference value with the official E-Tube-Project software!

Officially as an end user, you only can change the display speed adjustment setting in there range of +/-5% (NOT "plus 0.5, or -.5"!).
However, this correction setting only is related to the speed value shown on the display, but NOT to the distances (odo and trip) and also NOT to the motor support speed limit. So, the cutoff - speed will be the same, independent of this value!

The only way to change the wheel circumference (and so also the cutoff speed) as an end user in the "absolute very official way"(exactly like the few privileged Shimano employees with their high level access can do) without any issues and unwanted traces in a quick and hassle-free process is via eMax-Tuning software (Bluetooth based eMaxMobileApp for iOS and Android or Windows based miniMax – program).

On a DU-EP800 based bike the change of the wheel circumfernce also can be done solely via Bluetooth based eMaxMobileApp (so without the cable-bound SM-PCE02 interface from Shimano).
However, if you will do the "Bluetooth - only" way, you need to (temporarily) downgrade to an older motor firmware which can be done quite easy via an Android smartphone, see this document.
For changing the wheel circumference you need a valid licence key for the eMax-Tuning system, because changing the wheel circumfernce also is a measure for speeding up the bike beyond 20mph (up to 35mph, depending on the real wheel circumference). For further information just send an email to the guys from eMax-Tuning.

BTW.:
Also on a DU-EP800 based bike in US mode with correct wheel circumfernce setting it is absolutely normal that you will get 100% power from the drive unit to approx. 18,5mph and then the motor power will be reduced automatically on the way up to 20mph to give a smooth fading cutoff - characteristic and not an abrupt power loss at exactly 20mph.
So, most probably this described case, the rider still will get some (lower) power at 19,5mph, but this power feels (and in fact is) much less motor power than at 18mph.
In this way Shimano realized a smooth and nice cutoff - characteristic on the DU-EP800.

On the successor of the DU-EP800, the DU-EP801 this cutoff characteristic is selectable in 3 different modes (natural to aggressive):

But this is not the case on a DU-EP800.

Backflip said:

@Greg Watts: Thanks for your reply and reference. The official E-Tube-Project software from Shimano (Bluetooth based Cyclist - app or Windows based Professional program) NEVER let you change wheel circumfernce value as an end user (owner of the bike). Only some very privileged Shimano employees can ...

Click to expand...

@Backflip - you're absolutely right, and I appreciate the correction. Let me own this properly.

My original reply to @Stocky27 was wrong on a fundamental point: I said E-Tube Project (both the Cyclist app and the Windows Professional version) could be used to edit wheel circumference as an end user. That's not true. As you've correctly stated - and as is now in our verified corrections - no end user can change wheel circumference via official E-Tube software. Neither can a regular bike shop. Only a small number of privileged Shimano employees can do so, via high-level access through the Windows Professional version with an SM-PCE02 cable interface. I should have known that; I got it wrong.

The other point you've clarified is important for @Stocky27 to understand: the display speed adjustment in E-Tube (that ±5% / ±0.5mph he can see) only affects the displayed speed - not the motor assist cutoff speed and not odometer/trip distances. So it won't solve his actual problem.

On eMax-Tuning - as you explain, for a DU-EP800 specifically, wheel circumference can in principle be changed via Bluetooth (with a temporary firmware downgrade), which is a narrower option than what the EP801 or EP600 need. That requires a licence key and their software, and as you note, it's a different category of tool from the official Shimano route. That's worth @Stocky27 reading up on via @Backflip's post in the EP8 stops working thread, where you've covered this ground before.

Thanks for keeping the record straight. Genuinely useful correction.