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Seriously though I can only get my grom to 59/60 mph full tuck 220lbs. Is everyone that's hitting 70 that much lighter? I haven't taken it on a highway but some long strait roads and its topping out at 60? How long does it take to get to 70mph? 10 minutes?
 

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I'm a buck 50, and mine likes to stay around 55. 60 on long straights, and I just got her to 64 on a slight hill yesterday
 

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Seriously though I can only get my grom to 59/60 mph full tuck 220lbs. Is everyone that's hitting 70 that much lighter? I haven't taken it on a highway but some long strait roads and its topping out at 60? How long does it take to get to 70mph? 10 minutes?
Seems about right.

Im 190~ and with an intake mod I can do around 60 on flat ground...with a hill I can get to 64-65.

I think the best thing to do is to change sprockets. Im dropping my front from 15 to 14 teeth, less than 10 bucks for this mod and supposedly should pick up 5 mph on the top end at least thats what others have reported.

Speedo will read a bit off though. Top speed drops from 74 to 70 mph and when you're going 65~ you're probably actually going 62 mph.

Another user said his previous top speed was 58 and with the mod he was able to go 66 which is actually 63 if you calculate for the speedo being off.

Basically it lets you get more into the power band in 4th gear and multiply some more tq.

This is the part I ordered for those of you wondering.

Amazon.com: JT Sprockets JTF252.14 14T Steel Front Sprocket: Automotive

Combine the sprocket mod with a little better flowing intake/exhaust and you might have close to a 70 mph bike.
 

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Well I haven't been on a top speed run yet but im 119lbs and 6'. So I assume Ill hit 70+ easily. But I think elevation plays a large roll in the speed factor.
 

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Well I haven't been on a top speed run yet but im 119lbs and 6'. So I assume Ill hit 70+ easily. But I think elevation plays a large roll in the speed factor.
Lol..I wouldnt think your weight would make that much of a difference.

60-70 lbs = 10mph+? Seems a little optimistic.
 

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Haha. Idk we will see as quite a few have it the 70 mark. I know the elevation plays a large part. When i'm tuning cars I correct for that as well as the fuel thats used most of the time. As the grom just like a car. Its not tuned from the factory based on where you live/elevation. My neighbor has took mines out and reported 71 mph and he's about 45lbs more than I am. I ride to and from in rush hour traffic. If I see 50mph thats a good day.
 

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Haha. Idk we will see as quite a few have it the 70 mark. I know the elevation plays a large part. When i'm tuning cars I correct for that as well as the fuel thats used most of the time. As the grom just like a car. Its not tuned from the factory based on where you live/elevation. My neighbor has took mines out and reported 71 mph and he's about 45lbs more than I am. I ride to and from in rush hour traffic. If I see 50mph thats a good day.
He must have the longest 45 degree hill in the US or something cause mine struggles to break 60 on flat ground in full tuck. lol

I think your neighbor is full of it but what do I know.

I live at sealevel basically
 

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I hit 69mph. I'm 6' and 200. Intake open and exhaust.
 
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Hey its not just him others have hit 70 so i guess they are all lying and the vids are fake.

Edit: there you go 69mph.
 

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I did not test it stock. Exhaust went on at 17 mi. Intake happened around 190. Currently at 430+

Tucked, as in my chest on the tank, helmet Laing on speedo, left arm behind me, and absolutely 0 cars in front of me so no drafting assistance and on flat ground, hi 70's for weather.

I DO know that my midrange is quite healthy, and first and second are good. 3rd and 4th seem to run out of steam. I'm assuming its a lack of fuel. Pipe is getting real nice and purple. Lol. Really really want a fuel controller to bump this baby up. I think it could really use it.
 

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Got to 72 on the interstate. 6'2" 170 pounds. Once I was in the draft of a caravan the speed just kept rolling on. When I got out of her draft slowed real quick to around 60 wot.
 

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Got to 72 on the interstate. 6'2" 170 pounds. Once I was in the draft of a caravan the speed just kept rolling on. When I got out of her draft slowed real quick to around 60 wot.
You almost had that bitch topped out! lol


And before you quote this toyotabb, im talking about flat ground, not drafting a semi going down a 45 degree hill lol.
 
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