17t Upgraded Front Sprocket Boom Vader Top Speed Test.

Well, I’m here to give you the results of the latest top speed test of my Boom Vader. My stock Boom Vader speed tests ( Stock Boom Vader’s Top Speed Test ) were sad but not too surprising. I was hopeful with a 17 tooth front sprocket upgrade to my Grom Clone, and I believed I could get this motorcycle faster!

Upgraded front sprocket left, stock Boom Vader motorcycle sprocket on right.

Real quick, my Boom Vader has stock exhaust and stock carburetor, so don’t expect any performance results from any other upgrades. This front sprocket change is the only speed upgrade I’ve done on my little Boom Vader motorcycle.

Now for the results… Drum roll, please!!!!

Wait! Top Speed Test Boom Vader Disclaimer:

With the wind against my back, heading downhill in a full tuck was the only way I could red-line the tachometer at 7500+ RPMs.

This front sprocket upgrade took away a lot of torque delivery to the rear wheel. So, time for the speed results!

My Boom Vader125cc Motorcycle’s Top Speed Was:

On the Speedometer, 65MPH!

65 MPH

Don’t jump for joy yet; I’ve been having speedometer issues with my Boom Vader, and it seems to be a Grom Clone thing.

Now for top speed per my cellphone app GPS speedometer. Per the GPS 51 MPH!

51 MPH

This speed was in fourth gear, engine @ 7500+ RPMs, full tuck, downhill, and wind behind. 

Not much, and this top speed seems a little anticlimactic, but this upgrade was worth it.

Stock on top of larger upgrade front sprocket.

Boom Vader 125cc Front Sprocket Upgrade Pros:

  • I can spend a little more time in the lower gears than with the stock front sprocket.
  • No need to immediately shift up through gears from a stop.
  • In the city, I can cruise around between 3rd and 4th gear.
  • In the city, I don’t have to have the little Boom Vader engine running at high RPMs.
  • On level roads, cruising is about 45 MPH comfortably in the town.

These were real improvements for city driving.

This section is where the upgrade cons come in.

Boom Vader 125cc Front Sprocket Upgrade Cons:

  • Loss of torque. I have a downshift more often to accelerate.
  • Loss of climbing power, hills now require me to downshift.

Do ride on the back-country roads, and I have to travel over hills and on curvy roads. Some hills are so long and high that I can only travel them in 3rd gear, and the Boom Vader’s red line(7500+ RPMs) speed in 3rd gear is 40 MPH.  

The good news is that 40MPH was on par with the top speed with the stock front sprocket. So not much of a loss here compared I can now.

My Thoughts About The Larger Front Sprocket Upgrade.

It’s worth it.

I did a similar front sprocket upgrade for my TBR7 motorcycle, and well worth it for street riding.

I wouldn’t get much speed maxing out the RPMs on the stock front sprocket, and now my Boom Vader is more an in-town cruiser. The Boom Vader engine isn’t always revved to the max, and I don’t have to shift so quickly to get to max speed.

Guessing with my weight, about 200 pounds, I can’t get the red line on level roads, but I have future upgrades I’m going to do to the little Grom Clone.

Author’s Notice: This page contains affiliate links, for which I may earn a commission by their use. As an Amazon Associate, I earn from qualifying Amazon purchases.

Also, this front sprocket upgrade was cheap (check for current Prices 17T 17mm Front Engine Sprocket) and easy to do ( Boom Vader Front Sprocket Upgrade Steps ).

If you had different results with your Boom Vader or any Grom Clone motorcycle after a front sprocket upgrade, please comment below.

Ride Safe, Ride Fun!

Click To See My Recommended

Boom Vader Gen 2 Upgrades

Update – Boom Vader Top Speed With Larger Front Sprocket:

With the original top speed tests(Stock Boom Vader Gen 2 Top Speed and Boom Vader With Larger Front Sprocket Speed Test), I limited the RPMs to about 7500+. I increased my RPM max with the latest test and got higher speeds! As I keep pushing the little 125cc engine further and further into the red, I will update you about the speeds I reach.

Read More: Boom Vader 125cc Top Speed, Faster!

Picture of me, as a New Motorcyclist.
Just Me…Newly Licensed.

Hi I’m Tom, A New Motorcycle Rider and Blog Author.

I am a new rider(Pa Learners Permit at the end of 2020, and I received a Pa Motorcycle License in 2021 after passing a Motorcycle Safety Course).

I bought my first motorcycle, a TaoTao TBR7, at the beginning of 2021 and have been doing upgrades on that motorcycle since.

I added to my motorcycle collection by buying a Boom Vader Gen 2 in 2022, and that Grom-Clone motorcycle has been upgraded by me as well.

I continue to ride my Boom Vader Gen 2 motorcycle as well as my TaoTao TBR7 dual-sport bike.

Read more on my About Me page.

Fun Fact: I’ve only been on one group ride.

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