How To Change Wheel Circumference On Bosch Electric Bike

[@puchalkasport]

Thanks for this video. My issue is that I`ve just changed rear wheel from 29 to 27,5" to have more agressive fork angle - front one is stil 29". Is it possible to change wheel circumference more than 5% in Bosch settings ? Or what to do in this case ? Regards :)

[@desoxy2093]

Thanks ! Helped a lot

[@SCOOTERETTI]

Glad the video was helpful. 👍

[@dilzila1]

Great ebike for the money

[@richardletourneau7098]

Thank you for those information. Do you know how to do the same on Bosch smarthub ebike? with Cobi app.

[@RichSera2-qm5rl]

Hi, i have a focus sam2 2023 full 29er and id like to change tge rear wheel to 27.5 as mullet setup. Is it possible and how to know the circumference? Thanks

[@SCOOTERETTI]

We suggest reaching out to the retailer where the bike was purchased from as this is not a brand we sell.

[@mirageycq]

Something weird. 2 bikes same tire same rim a FS5 2019 with 2109 mm and Open Xroad 5 2018 with 2148 mm. How could it be possible ? 39mm is this a lot in speed difference ? My FS5 will not go more than 30.3 km hr has my Open will go 32.3 while pedaling. Thanks fr your help.

[@toolman95]

So does the 5% relate to the circumference of the wheel/tire diameter ? Will Bosch still Give warranty if we adjust the settings due to a tyre change? My new tyre is slimline 2" smaller in diameter. Can I adjust the figures without any reprocussions ?

[@SCOOTERETTI]

Hello, You can certainly adjust to accommodate the difference in overall diameter contained within the standard set parameters within your system without any issues or affecting your Bosch warranty.

[@toolman95]

@@SCOOTERETTI I can't using my system it's only available with the dealer apparently when the computer is connected via USB

[@DanielDOBREA]

Hi! I have intuvia display and in settings, wheel circumference isn't there... do you know why my intuvia dosen't show me the wheel circumference? How can I change circumference from menu setting? Thx a lot My ebike is 2019 model , 27.5inch wheel, motor bosch performance cx with intuvia display

[@SCOOTERETTI]

Hi Daniel, What you need to do is press "reset" & "i" at the same time to enter the config menu. Once in press the "i" once and you will see the wheel circumference setting. You can then use the power button & light button to increase or decrease the circumference.

[@DanielDOBREA]

@@SCOOTERETTI yes I know, but it isn't there...in configuration settings I only have , in this order: clock, language, km/miles, time, shift recomandation, power on hours and display version.... only this ones... nothing else.

[@SCOOTERETTI]

@@DanielDOBREA I suggest taking into the closet shop to have this checked out as it should be a standard feature for you.

[@BilloBob1231]

@@DanielDOBREA Hi Same problem as you, have you got a way to get this setting menu?

[@DanielDOBREA]

@@BilloBob1231 just pulled out the display and inserted again...

[@RoerDaniel]

if you reduce the wheel diameter to the minimum -5% does it increase top speed by +5% ?? and if you add a lets say 5% bigger tire minus the 5% will it be 10% faster??

[@Big2009Gee]

5% smaller circumference gives you 5% more speed

[@SCOOTERETTI]

Even with a circumference change you bike will cut off at the set maximum speed for your region 25 Kph or 32 Kph or 45 Kph

[@macaocan]

@@SCOOTERETTI Hello, the reference speed for the cut off is the one on the display, rigt? Since the computer should calculate the speed basing on the RPM of the wheel+the wheel diameter, if you set a diameter that is LESS that the real one, the bike should calculate and display a speed that is lower than the real one, so cut off will happen at a display speed of 25 kph, but at a real speed higher than 25Kph. Correct? Thanks.

[@jeffreyvanzeijst7932]

Used this in the hope to allow for a slightly faster ebike.. lowered the wheel circumference , however unfortunately it just alters the displayed speed. It's not like the supporting motor is later undercut than normal.. somehow the motor is cut off at a fixed chosen Factory setting..and our cargo bike displaying me pedalling at 25/26kmh opposed to the former displayed 27/28kmh. Was hoping since the Display was programmed for a smaller.tire and thus slower speed, it'll stayed longer supportive to the motor and propelling us to 30ish..but it doesnt Motor quickly cut off

[@tortueg090090]

Thank you for those information. Do you know how to do the same on Yamaha ebike?

[@SCOOTERETTI]

On the Yamaha system it would be more like a traditional bicycle changeout. You won’t need the Bosch tool just the crankarm puller and hex/allen key I will try to do a video on that in the coming weeks.

[@tortueg090090]

Thank's a lot!

[@nikakhomasuridze6618]

pl help me pl help me.. i need wheel circumference for same display .. my bike is cube reaction hybrid 29 er (622x30 tire size 2.6 noby nic ) ..what is number of wheel circumference? it won't 25km/h over .. hybrid turn off When the speed is up to 25 km/h ..what i can ? i think wheel cirumference changed ...

[@mirageycq]

A Moustache dealer around here say that Moustache do no want to change the gear ratio as it could be seen as tuning and this may void the warranty. Is he right ? I want to buy a different gear for my bike but without affecting the warranty, could you help me on this matter please ?

[@SCOOTERETTI]

Depending on which bike you have and if you have enough clearance you can adjust the sprockets by a few teeth. You won't be able to change it too much though.

[@jaybeeworks]

How about using it with a Purion display and 20'' wheels?

[@SCOOTERETTI]

Hello, this can be done but only through the software at a Bosch ebike Service centre. Unfortunately this cannot be changed directly on the Purion unit itself.

[@tiredofeverythingnew]

Bosch are dicks for requiring this.

[@lovemadeinjapan]

Does it have to be on the bike? If you take the display inside, the option is not there.

[@lovemadeinjapan]

It seems to be there when you plug it in. Strange enough, if you make the tires smaller, the max speed goes down as well. So how the heck does the system know your speed?

[@SCOOTERETTI]

@@lovemadeinjapan the most accurate way to get true speed is to measure the exterior circumference of the tire while the rider is on it 🚴. Mark the tire and ground and with the rider on the bike (have a helper hold you up) and complete one full rotation and then the mark on the tire comes back in contact with the ground mark that spot. Then measure 📏your starting mark with the end mark to get your true circumference. (Note that different tires pressures and loads will affect this measurement) but it's pretty darn accurate.

[@lovemadeinjapan]

@@SCOOTERETTI That was not what puzzled me. The thing is, no matter the setting of the diameter, the max speed stays the same, so how does the bike know that? Is there a GPS in it?

[@SCOOTERETTI]

@@lovemadeinjapan The Bosch system reads the speed from the speed sensor at the wheel as well as from the cadence sensor. Each bike model produced from the OEM's has its own defined firmware created for it which calculates the pedal-assist cut-off speed.

[@lovemadeinjapan]

@@SCOOTERETTI The wheel sensor does not much. Only affects the displayed speed, not the actual speed. Too bad this isn't open source software.....

[@jameswatkin3300]

Anyone know how I can do this on my giant ebike?

[@SCOOTERETTI]

As Giant has their own displays You may see it mentioned in the owner's manual or you may have to reach out to your local Giant retailer for assistance. Before calling them make sure you have the year and model name as there are different displays that were used with Giant's.

[@andreafair7616]

thank you!!

[@SCOOTERETTI]

You are welcome, glad you found the information useful. All the best, Will

[@403fth]

I cant do it anymore