Any way to adjust EVO display for different tire size?


New Member
Hi I have a 2019 Toughroad Gx E+ (Canadian version). I changed out the tires to 40mm tubeless and the display now reads a couple of kph faster than my Garmin Head unit. Not a massive problem, but it would be nice to be able to be able to adjust for different tire sizes. I couldn't find a method in the manual - anyone else find a way?
Same problem on my Explore. I changed the 700/45 tires for 700/32. Now the electric assistance stops at 29 (true GPS speed) km/h instead of 32. This is too slow for me. My riding friends go over 30 km/h. I can configure tire size on any cheap odometer but not on the one installed on a 4,000$ ebike?
I wrote Giant about this and waiting for a reply.
Not yet. Dealer tells me not possible because owners could cheat the 32. Km/h limit by programming a smaller tire size than they actually have installed.
I am interested in this too, contemplating downsizing from 50mm to 38mm on a ToughRoad. The argument about cheating the 32km/h is a bit weak considering that a Road E+ can be upgraded from 32mm to 38mm. Hoping to convince Giant with that fact!
Merci Pierre,

I went to my LBS today to enquire about this and they said that it needs to be done in the shop and they simply reprogram with their software. Seemed like it wasn’t a big deal. I won’t yell victory yet but have to take an appointment at the end of season to have the tires replaced and the settings modified. Will let you know how it goes.

It might be hard to validate, I tested my speed with a phone GPS today and the EVO already seems about 1kph higher than my GPS. Anyway, if I can have less drag, I think I can live with a slower cutoff.
I contacted a local dealer about reprogramming the speed sensor. They called Giant and were told the bike cannot be reprogrammed. This seems like a big oversight In the design.

One idea would be for the phone app to use gps speed to calculate and automatically write the wheel diameter value back to the bike’s cpu.
That could work but usually odometers are calibrated with the tire outside circumference, not the wheel diameter.
reviving an old thread - my Giant Revolt e bike display speed is higher than my gps speed, and others' cycle computers when riding together.

Can it be re-calibrated (by the LBS or who-ever?)

Old thread, but still valid.

My 2 cents...indicated speed vs actual speed...a discussion amongst motorcyclists and racers for decades.

As an avid motorcyclist, (and car owner) I know that wheel diameter will affect indicated speed, as all vehicles speedos are calibrated with the tires they came with new. All the manuals state that changing tire size will affect...albiet slightly in most cases, the indicated speed.
I have yet to find a bicycle speedometer that reads exactly the same as a GPS speedo...Strava/Cyclemeter/Giant app.
I also have one of those flashing speed reminders on the last leg of my rides, and It's my bit of fun trying to get over legs always tell me what my odds are ;-) ...but yes, even that reads lower than the speed on my display, and different yet than my Cyclemeter (my go to app) but I don't sweat it.
It matters little to me which one is correct, I doubt i'll be attracting "officer Friendly" anytime soon lol.

Tire size...who cares? you have an E-bike!...I run those 50's like a boss and get loads of kms per charge on Eco+...and...on the flats oe slightly downhill, I can easily maintain over 32kph...when the rise begins, I technically have 44 options to chose from, so I don't fret :)