Wheel diameter vs. Speed restriction

MikeyRides46

Finding my (electric) wheels
Jul 11, 2023
16
0
What role does the wheel play on your e-bikes actual top speed?
Would choosing the smallest possible wheel size on the controller display mean an actual higher top speed (before restrictive limits). Obviously the speed displayed would be wrong. I have a 700C wheel- what happens if I select a 15” wheel on the display?

thx
 

Peter.Bridge

Esteemed Pedelecer
Apr 19, 2023
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Yes, if on a 26 inch wheeled bike you set the wheel size to 16 inch and the display to km , then when the display shows 20km/h you would actually be doing 20 mph and the motor assist cut out would happen if the speed reached a displayed 25km/h (actually 25mph), not that many motors could go that fast
 

Peter.Bridge

Esteemed Pedelecer
Apr 19, 2023
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I think 700c is 28.5 inches, so mph/kmh conversion would be 17 inches approximately if you are able to set it to that
 

saneagle

Esteemed Pedelecer
Oct 10, 2010
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Telford
Try it, but be aware that some controllers are cleverer than that. They take the wheel speed directly from the hall sensors. When you set a different size wheel in the LCD, all it does is change the way the speed is displayed.
 

WheezyRider

Esteemed Pedelecer
Apr 20, 2020
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Also, whatever you set it to, your motor will have a maximum speed for it's given voltage, meaning you will generally not exceed 20 mph
 

MikeyRides46

Finding my (electric) wheels
Jul 11, 2023
16
0
Did it work? What bike / kit have you got?
I have a YOSE 250w front hub. I set the wheel size to 16” but left the speed displayed in MPH rather than KMH. Did not see the speed display much more than 10-14 MPH but the bike felt fast and I completed my commute in a time which translates to a 20 MPH average. I will now set the display to KMH and see what speed is displayed. Rgds

Mike
 

WheezyRider

Esteemed Pedelecer
Apr 20, 2020
1,690
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I have a YOSE 250w front hub. I set the wheel size to 16” but left the speed displayed in MPH rather than KMH. Did not see the speed display much more than 10-14 MPH but the bike felt fast and I completed my commute in a time which translates to a 20 MPH average. I will now set the display to KMH and see what speed is displayed. Rgds

Mike
What system do you have, does it have a C500 LCD display?
 

joelectric

Pedelecer
Feb 22, 2019
144
93
Motherwell
I have a YOSE 250w front hub. I set the wheel size to 16” but left the speed displayed in MPH rather than KMH. Did not see the speed display much more than 10-14 MPH but the bike felt fast and I completed my commute in a time which translates to a 20 MPH average. I will now set the display to KMH and see what speed is displayed. Rgds

Mike
Download a GPS speedometer app on your phone and it will tell you.
 

MikeyRides46

Finding my (electric) wheels
Jul 11, 2023
16
0
What system do you have, does it have a C500 LCD display?
Yes I am using the c500. I also tried the KT LCD4 display yesterday but this does not show any speed or battery condition and after 5 minutes switches off although whilst it is on you can feel the PAS. Would be nice to be able to get the full display features. I did like this small screen size though and can handle having to turn it back on after five minutes.
 

MikeyRides46

Finding my (electric) wheels
Jul 11, 2023
16
0
I have a YOSE 250w front hub. I set the wheel size to 16” but left the speed displayed in MPH rather than KMH. Did not see the speed display much more than 10-14 MPH but the bike felt fast and I completed my commute in a time which translates to a 20 MPH average. I will now set the display to KMH and see what speed is displayed. Rgds

Mike
Made the changes. The display only shows a max speed of 10 KMH so I think I will reset the wheel size to 700C.
 

WheezyRider

Esteemed Pedelecer
Apr 20, 2020
1,690
938
Yes I am using the c500. I also tried the KT LCD4 display yesterday but this does not show any speed or battery condition and after 5 minutes switches off although whilst it is on you can feel the PAS. Would be nice to be able to get the full display features. I did like this small screen size though and can handle having to turn it back on after five minutes.
A KT LCD will not work with the Yose Power kit as it uses a Lishui controller, which uses a different coms system.
 

WheezyRider

Esteemed Pedelecer
Apr 20, 2020
1,690
938
Made the changes. The display only shows a max speed of 10 KMH so I think I will reset the wheel size to 700C.
You need to have an independent means of measuring speed, like a simple bike odometer, or a GPS app.

The other thing to check with the C500 LCD is the max current setting. The default seems to be set to 14 amps (from the kits I've had), which is less than the spec of the 15A controller. You can find this by going into the advanced settings. You can tweak the current up a bit, to give you a bit more pep, but don't go mad or you will burn out the controller.
 

Peter.Bridge

Esteemed Pedelecer
Apr 19, 2023
1,262
584
I have a YOSE 250w front hub. I set the wheel size to 16” but left the speed displayed in MPH rather than KMH. Did not see the speed display much more than 10-14 MPH but the bike felt fast and I completed my commute in a time which translates to a 20 MPH average. I will now set the display to KMH and see what speed is displayed. Rgds

Mike
I think an indicated speed of 10mph with the 16" wheel setting would correspond to 10 * 28.5/16 = 17.8 mph which ties in with your 20mph average
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
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West Sx RH
Yes I am using the c500. I also tried the KT LCD4 display yesterday but this does not show any speed or battery condition and after 5 minutes switches off although whilst it is on you can feel the PAS. Would be nice to be able to get the full display features. I did like this small screen size though and can handle having to turn it back on after five minutes.
Because KT LCD's are incompatible.