Try entering your setup here:. https://www.gearingcommander.com/
This is a discussion on 15/37 gearing. How far up or down accurate speedometer? within the Grom Performance forums, part of the Honda Grom Garage category; Hit 67 mph on stock speedo, wondering if accurate or true speed is off by how far.thanks in advance for any info....
Hit 67 mph on stock speedo, wondering if accurate or true speed is off by how far.thanks in advance for any info.
2015 OG Grom in Yellow - AODRacing loop exhaust, ContiScoot tires, EBC HH front pads, RideItMoto levers, Renthal kevlar grips, Road low bars, CJR ECU, TB cam, MNNTHBX Mtake, Outerwears, Koso temp gauge, short shift linkage, TST sliders, Aliexpress tail tidy, Aliexpress axle sliders
Pending - oil cooler, CoreMoto braided lines, high mount exhaust, rearsets and GP shift conversion
2018 GROM: Modified for reliability longevity gas mileage... and fun.
I have one method to recommend. There are numerous speedometer apps that you can download for free.
1. Download an app.
2. Turn it on and run the Grom on a level space at 60mph (based on the phone app speed). Identify the speed you Grom indicates.
3. Upon returning from your ride, you can calculate the variation of Grom indicator/Actual speed.
There are several electronic correction devices which can be wired (Plug and Play) into your wiring harness to adjust the corrected speed error with whatever gear choices you make.
Download a speedo app for your phone and check your speed with that.
Thanks for the other suggestions to figure out actual top speed vs speedometer. Much appreciated.
I have ridden a Grom with lowered gearing and found the stock setup to be much better, I think most of what people 'feel' when they mess with the gearing is a placebo based partly on their expectations, and partly on their now-inaccurate speedometer readings.
If you do change your gearing though, you should consider a speedometer recalibration tool. In addition to avoiding the nuisance of constant mental adjustments to guess your speed, you will also preserve the accuracy of your odometer for maintenance intervals, resale value, and in some cases insurance purposes.