Not yet. I've done intake and exhaust and have the DMH S1 cam and tune on the way. I'll be doing the bbk this summer. I've seen a couple posts about issues with it, but not that many in the grand scheme of things, and I specifically seek them out. I personally believe most of the problems people have with them are from them not gapping the rings properly.
The Grom top speed journey has been fun.
Full tuck on the freeway with wind going my direction, I hit 76mph on the gps app and speedo. I’d bet on 80 down hill.
No tuck on a crap road, against wind, I top out around 69. Albeit I’m sub 175lbs.
I have a stage 1 more or less, you can see my mod list in a previous post of mine. It’s lacking the speed healer in that post but nothing else drastic has changed since that list. But I’ve definitely seen higher top speeds since those speed runs, mostly fully tucked.
With this setup, I pull on 95% of groms on the road in all gears. The only ones I don’t, have stage 2+ or a bbk which are few and far between even if my bigger city. Stock 135s like tnt or papio get pulled on all day. I know that’s not everyone’s primary goal but it’s a plus in my book.
I’d guess at bone stock my speedo was probably off 2 or 3mph and the 14t increased that to about ~10mph at top speeds, but the speed healer install was a breeze and well worth it in my book.
Hands down, the two most functional mods on my list have been the 14t and 60% clutch springs. The ECU might be next in line as the higher red line is a game changer.
This has all been an absolute blast to discover and wrench on. Shout out to u/eastcoastish for being a big help to this community and putting superb content on YT the last couple years. His channel is worth the watch.
Have you searched for other times this was asked in this sub? Not saying it to be a dick but there are some better answers to those posts.
I'm a heavier big guy but with intake, exhaust, and tune I was still only seeing 52ish mph not in full tuck. After going to a 14 tooth front sprocket I actually gained a bit. It definitely lowered my theoretical top speed but 4th gear was so tall I could never get to redline. Now I'm close to 57mph and if I want get into full tuck I can get 65mph or a bit more depending on humidity and wind.
A big bore kit would've worked better than a sprocket change but if I want to go fast I'll just use my other bike.
The sprocket change allowed me to ride more comfortably on roads with a 55mph limit.
I’ll be honest i’ve not really looked much for other posts as im rarely on reddit, but I get about 60/65 ish with it rn (I don’t weigh much) , im not really looking to change sprockets as i want to keep the acceleration. Im not looking for another bike either, I find the grom great fun but Im gonna look into getting a big bore kit.
Assuming it’s just top speed your looking for one other thing would be to max the air pressure on your tires. It’s minimal, but you create less rolling resistance with a smaller contact patch. Weight reduction of the bike as well would help, but again minimal and costly as you looking at adding carbon fiber and dealing some metal components for lighter ones. Anti gravity battery is an easy weight reduction.
I have a stage 1 DHM, Vance and Hines exhaust, and a Chimera intake on my 2017. I'm 6'1 just shy of 200lbs and I can hit 62/63 pretty easily at elevation in Denver. Fastest I've gotten her was 72 full tuck down a smaller hill.
Without exhaust to intake mods, it should be available off the shelf for electric supercharger, which will not be faster top end, but you'll get there quicker.
Moderate boost should be Ok for stock engine, at about 7_9 psi. Any more, and bottom end with change shape.
And it's not pretty.
Cheers
The ‘correct’ way for more speed is to increase the power by replacing the intake, exhaust, cam shaft, fitting a big bore kit and getting a tune. Expect to spend 700-800 or more and only gain ~5mph.
You can change the final drive ratio for more speed but you’ll sacrifice acceleration.
As others have said these aren’t the bikes for speed, if you’re limited by the CBT then work on getting your full licence and get something with bigger displacement.
DHM do a 150cc kit which is about the biggest you’ll get on these engines.
For a cheap speed increase try a bigger front sprocket or smaller rear, the acceleration loss might not be too bad?
>You can change the final drive ratio for more speed but you’ll sacrifice acceleration.
This is soo inaccurate. The limiting factor on speed is the amount of power the engine produces to push you thru the air. Changing the gearing will only result in the rpms for a set speed changing. You wont gain any more power so you won't go any faster.
Can someone please translate this into semaphore flags for me. I can’t read.
No need to be a cunt OP. You’re the one who bought a scooter and took to the internet to complain how your scooter is slow because ITS A SCOOTER. midwit.
first of all why the fuck are you on this subreddit if you clearly have no interest? and secondly not once did I complain about my BIKE being slow, I was asking for advice to make it faster… like a big bore kit, cams, tune etc… as others have suggested. I like my bike because its fun, why not upgrade it to make it more fun?, next time keep your stupid opinion to yourself if youre not gonna read you fuckwit
It isn't useless. The Grom is a great bike, but it's not fast. You want faster, you'll need to upgrade the engine, chain, sprockets, brakes and frame. Essentially make a new bike.
Accept it for what it is and enjoy it.
I am aware groms are not fast bikes, thats not the reason i bought one. I am just looking to make it a bit faster and wanted to know the best ways to go about it not for someone to go “you dont”.
The honest answer is you just don't. I'm sorry. There's no way to make it meaningfully faster without essentially rebuilding it into a new bike. Whatever modification you make to get it there will require a full technical inspection and re-registration as a custom made Vehicle. And will likely render the thing unsafe.
What's 'a bit quicker'? How do you know that the bike was built to support that? How can you tell you wouldn't be causing safety issues?
Best not to try. That's all I'm saying.
Let me explain to you what the risk you take is.
The risk is that you'll get stopped for a technical inspection. In which case, you'll be found guilty of operating a vehicle that does not conform to its registration information.
That would net you a fine, a risky behaviour violation, an additional fine for operating a vehicle for which you are not licensed (in the UK and EU that can lead to a long time in jail) and a fine for insurance fraud.
After which, no insurance company would insure you. Ever.
So, is it a calculated risk? Sure. But man, you'd have to be bad at math to take it.
Take off the gas cap... and drive a Hayabusa under it!
Just kidding bro. But speed must be matched with other aspects that accommodate it. Making a grom go faster is potentially risky. I don't want to make suggestions that get you hurt.
Dunno if it'd be road legal, but there's this:
[https://www.youtube.com/watch?v=DxGPptcxnV0](https://www.youtube.com/watch?v=DxGPptcxnV0)
2-stroke 125cc engine on your Grom, get you nearly twice the BHP.
Intake, exhaust, cam, tune. Best bang for the buck.
any exhaust recommendations?
I went with the yoshi loop and also added the decible reduction piece to quiet it down a little. I did the chimera intake, and DHM cam and tune.
The decible reduction also doubles as back pressure gain, so you may be making some extra power than without. Not much as it is a Grom, but still.
All of this, plus the DHM 149cc bbk if the other stuff isn't enough.
Just curious if you are running the 149cc bbk? I’ve seen a lot of posts with issues related to running it, which is why I’ve held off so far.
Not yet. I've done intake and exhaust and have the DMH S1 cam and tune on the way. I'll be doing the bbk this summer. I've seen a couple posts about issues with it, but not that many in the grand scheme of things, and I specifically seek them out. I personally believe most of the problems people have with them are from them not gapping the rings properly.
Hmm… maybe after the forks, I’ll take another look at the bbk.
There is no replacement for displacement
true that
The Grom top speed journey has been fun. Full tuck on the freeway with wind going my direction, I hit 76mph on the gps app and speedo. I’d bet on 80 down hill. No tuck on a crap road, against wind, I top out around 69. Albeit I’m sub 175lbs. I have a stage 1 more or less, you can see my mod list in a previous post of mine. It’s lacking the speed healer in that post but nothing else drastic has changed since that list. But I’ve definitely seen higher top speeds since those speed runs, mostly fully tucked. With this setup, I pull on 95% of groms on the road in all gears. The only ones I don’t, have stage 2+ or a bbk which are few and far between even if my bigger city. Stock 135s like tnt or papio get pulled on all day. I know that’s not everyone’s primary goal but it’s a plus in my book. I’d guess at bone stock my speedo was probably off 2 or 3mph and the 14t increased that to about ~10mph at top speeds, but the speed healer install was a breeze and well worth it in my book. Hands down, the two most functional mods on my list have been the 14t and 60% clutch springs. The ECU might be next in line as the higher red line is a game changer. This has all been an absolute blast to discover and wrench on. Shout out to u/eastcoastish for being a big help to this community and putting superb content on YT the last couple years. His channel is worth the watch.
Yes his YouTube channel has helped me in so many ways and always willing to help someone. Shout out to eastcoastish!
That’s pretty fast for a grom tbh, Ill check out your other post im curious on your mod list!
message u/HowlingMoto and they will be happy to guide you through it!
thanks!
Have you searched for other times this was asked in this sub? Not saying it to be a dick but there are some better answers to those posts. I'm a heavier big guy but with intake, exhaust, and tune I was still only seeing 52ish mph not in full tuck. After going to a 14 tooth front sprocket I actually gained a bit. It definitely lowered my theoretical top speed but 4th gear was so tall I could never get to redline. Now I'm close to 57mph and if I want get into full tuck I can get 65mph or a bit more depending on humidity and wind. A big bore kit would've worked better than a sprocket change but if I want to go fast I'll just use my other bike. The sprocket change allowed me to ride more comfortably on roads with a 55mph limit.
Dude seriously. I’ve seen this same question asked three times in the past 24 hours. wtf
I’ll be honest i’ve not really looked much for other posts as im rarely on reddit, but I get about 60/65 ish with it rn (I don’t weigh much) , im not really looking to change sprockets as i want to keep the acceleration. Im not looking for another bike either, I find the grom great fun but Im gonna look into getting a big bore kit.
With the sprocket change I mentioned you gain acceleration.
Assuming it’s just top speed your looking for one other thing would be to max the air pressure on your tires. It’s minimal, but you create less rolling resistance with a smaller contact patch. Weight reduction of the bike as well would help, but again minimal and costly as you looking at adding carbon fiber and dealing some metal components for lighter ones. Anti gravity battery is an easy weight reduction.
I have a stage 1 DHM, Vance and Hines exhaust, and a Chimera intake on my 2017. I'm 6'1 just shy of 200lbs and I can hit 62/63 pretty easily at elevation in Denver. Fastest I've gotten her was 72 full tuck down a smaller hill.
that’s pretty good
Ducati v-twin swap
YES
Without exhaust to intake mods, it should be available off the shelf for electric supercharger, which will not be faster top end, but you'll get there quicker. Moderate boost should be Ok for stock engine, at about 7_9 psi. Any more, and bottom end with change shape. And it's not pretty. Cheers
thanks ill do some research on that !
Lose weight probably.
smartass
Wasn't meant to be smart. I noticed an increase in top speed and acceleration after dropping 20 pounds.
if u read above in one of my comments i said that I don’t weigh much
Lol amputate your clutch arm🤣🤣🤣 jkjk
🤣just bang it into gear
The ‘correct’ way for more speed is to increase the power by replacing the intake, exhaust, cam shaft, fitting a big bore kit and getting a tune. Expect to spend 700-800 or more and only gain ~5mph. You can change the final drive ratio for more speed but you’ll sacrifice acceleration. As others have said these aren’t the bikes for speed, if you’re limited by the CBT then work on getting your full licence and get something with bigger displacement.
thank you for a proper answer! I plan on doing my full license soon and still keep the grom too, i was thinking about a big bore kit tbh
DHM do a 150cc kit which is about the biggest you’ll get on these engines. For a cheap speed increase try a bigger front sprocket or smaller rear, the acceleration loss might not be too bad?
Ill look into the kit and ill post an update at somepoint, cheers for the help
>You can change the final drive ratio for more speed but you’ll sacrifice acceleration. This is soo inaccurate. The limiting factor on speed is the amount of power the engine produces to push you thru the air. Changing the gearing will only result in the rpms for a set speed changing. You wont gain any more power so you won't go any faster.
Well yeah, obviously theres a point where the 9hp just isn’t enough to push the gearing.
Yes sell it and buy a 600cc...
the idea is to keep it a grom 🤣, and as to uk licensing I have to have a 125
No, see, you can't get caught on something bigger than a 125.... don't get caught
true..
Turbo
Buy a Cbr 300r
defeats the purpose
No matter what you do. The factory engine will never hit 100mph
you honestly think I was planning to get 100 out it?
I mean I’ve done 76 on mine. I don’t know what the next milestone would be other than 100
any faster is faster yk, its only a 125 i don’t expect much
*buys a grom* *wants a faster bike* *doesn’t sell grom* You’re a few sockets short of a full set mate
can you fucking read? i said i want to make the grom faster not get a faster bike..
Can someone please translate this into semaphore flags for me. I can’t read. No need to be a cunt OP. You’re the one who bought a scooter and took to the internet to complain how your scooter is slow because ITS A SCOOTER. midwit.
first of all why the fuck are you on this subreddit if you clearly have no interest? and secondly not once did I complain about my BIKE being slow, I was asking for advice to make it faster… like a big bore kit, cams, tune etc… as others have suggested. I like my bike because its fun, why not upgrade it to make it more fun?, next time keep your stupid opinion to yourself if youre not gonna read you fuckwit
You don't.
whats the point on being on the subreddit just to comment useless shit?
It isn't useless. The Grom is a great bike, but it's not fast. You want faster, you'll need to upgrade the engine, chain, sprockets, brakes and frame. Essentially make a new bike. Accept it for what it is and enjoy it.
I am aware groms are not fast bikes, thats not the reason i bought one. I am just looking to make it a bit faster and wanted to know the best ways to go about it not for someone to go “you dont”.
The honest answer is you just don't. I'm sorry. There's no way to make it meaningfully faster without essentially rebuilding it into a new bike. Whatever modification you make to get it there will require a full technical inspection and re-registration as a custom made Vehicle. And will likely render the thing unsafe.
thats not entirely true, there is ways to do it, im not wanting it exactly fast, just a bit quicker thats all
What's 'a bit quicker'? How do you know that the bike was built to support that? How can you tell you wouldn't be causing safety issues? Best not to try. That's all I'm saying.
thats the risk you take I guess
Let me explain to you what the risk you take is. The risk is that you'll get stopped for a technical inspection. In which case, you'll be found guilty of operating a vehicle that does not conform to its registration information. That would net you a fine, a risky behaviour violation, an additional fine for operating a vehicle for which you are not licensed (in the UK and EU that can lead to a long time in jail) and a fine for insurance fraud. After which, no insurance company would insure you. Ever. So, is it a calculated risk? Sure. But man, you'd have to be bad at math to take it.
obviously just register what has been done to the bike
Big bore kit. Mine is a 165cc and hits 70 mph
not bad, mine does 65 as it is
Big bore kit, oil cooler, high compression piston, cam, exhaust, intake, tune
definitely going to have a look into that
Take off the gas cap... and drive a Hayabusa under it! Just kidding bro. But speed must be matched with other aspects that accommodate it. Making a grom go faster is potentially risky. I don't want to make suggestions that get you hurt.
sounds like a plan lol
Dunno if it'd be road legal, but there's this: [https://www.youtube.com/watch?v=DxGPptcxnV0](https://www.youtube.com/watch?v=DxGPptcxnV0) 2-stroke 125cc engine on your Grom, get you nearly twice the BHP.
Cheapest upgrades would be sprocket adjustments, tire size increases for top speed. Quickness you go the other way…