1. BST Carbon Fiber Wheels


Definitely the single item for our Grom we’re most excited about testing are these carbon fiber BST wheels, provided to us by Brock’s Performance, as you can see in the sticker. At $1500.83 (no, that’s not a typo), the BST wheels are almost half the cost of the bike itself. However, there’s no arguing the dramatic decrease in weight – approximately 2 and 3 lbs. lighter, respectively, from the stock 6-lb. front and 7-lb. rear. That’s a significant drop in weight to be sure, made more so by the fact the drop in rotating mass will greatly benefit every performance aspect of the bike. The wheels are available in two sizes; OEM sizing (2.75-inch x 12-inch front, 3.5-inch x 12-inch rear) or a wide option, which includes a 140/70-12 rear tire (instead of the standard 130/70-12) mounted on a 4.0-inch x 12-inch wheel. A 120/70-12 front tire is standard on both.

Speaking of tires, sharp eyes will notice the Michelin Power Pure SC rubber mounted to our wheels. They offer sticky edge grip plus exceptional durability, thanks to their dual-compound design – Michelin says they are the only dual-compound scooter tire on the market. If ordering tires with wheels from Brock’s, they are shipped mounted and balanced, plus they can be inflated with temperature-stable nitrogen instead of regular air. Were you to buy the tires separate from the wheels, it would cost you $73.95 front and $77.95 for the 130/70-12 rear. Add two more dollars for the 140-rear.


  • Old MOron

    Wow, you MOrons are going to have a TRICK Grom. I remember there were some souped up bikes when I rode in the M1GP24 last year. You may recall that I signed up for that race after reading your story about riding with Hollywood Electrics. Sheesh, now that I see just how souped up the bikes can get, I don’t feel so bad[1] about finishing in the bottom half of the field on a bone-stock TTR125. Well, we did change out the knobby tires.

    About the oil cooler, I wonder how necessary that is. I’m guessing the TTR125 is designed for putting along on trails, but we rode that thing for all it was worth, for 24 hours, in the heat of Rosamond. Oh well, things will prolly run much better with the oil cooler.

    Here’s a question. I’m just curious. Why are you racing with UMRA instead of M1GP? I don’t expect you to air any dirty laundry here, but since you wrote so highly of M1GP’s event, why the switch? I notice that this will be UMRA’s first endurance race. They could’ve chosen any time at all to run it. Seems kind of not cool that they chose the weekend right before M1GP’s race.

    [1] Okay, i didn’t feel bad at all. The objective of the weekend was to have fun. It was an object we fully realized.

    • TroySiahaan

      Why UMRA? For a change of scenery, mainly. No dirty laundry here. Grange is a really fun track, and as you know, I’d already done the M1GP race at Willow. Change is good, right?

      • Old MOron

        I get it. Spreading the MOronic love around. Makes sense.

  • JMDonald

    I love this. I have lusted after a Grom since it first came out. Great modifications. Looks like a ton of fun.

  • fastfreddie

    You at MO should buy a grom,trick it out and take it racing.Make a series of articles on it.

    Cool mods.

  • DickRuble

    Are you going to test the hp gains your vendor claims? They sure sound dubious. The effort is a nice idea but it sounds a lot like an infomercial. As for weight savings..just skip the pizza and fries for a week before the race. No need for the $1500 wheels.

    • Kevin Duke


    • Dick, at 260Lbs, I must confess that we simply don’t have the time to lose the weight. Pass the pizza.

  • Luke

    I keep hoping one of my kids picks up one of these as her first bike, so I can borrow it with reckless abandon….

  • SRMark

    You guys have looked around to see what $7,600 buys these days right? Love the idea of making that little fart more fun but damn! But have fun and be careful out there.

  • Good Luck at the races @TroySiahaan:disqus – Can’t wait to see what you gentlemen can do with all of this ‘trickness’. I know you will look and sound sweet. Bring on the vids!

  • Old MOron

    Hey MOrons, look what I found. https://youtu.be/2mYTFuHk3gU

    Okay, Grange and Fontucky couldn’t be more different tracks, and a 10-minute sprint race is entirely different from a 24-hour endurance race. But still, the video production bar has been set high. I can’t wait to read the MOronic race report.

  • James Stewart

    Was I the only MOron to double take at the first photo? I thought you guys were building some kind of weird version of those Honda? scooters with the double back wheels! I guess you need max contact patch with all those 9 Horses… Can’t you guys jam in one of those cheater 155cc pit bike engines or something ? 🙂

    • Old MOron

      Yup, it tromped my oeil, too.

  • Old MOron

    Well MOrons, by my calculations you are now trying to get a good nights rest before the big day tomorrow – just like Valentino, Jorge, etc!

    Good luck, eh! Looks like whoever rides from about 1 to 8 AM on Sunday is going to have the best temperatures. http://www.wunderground.com/q/zmw:92307.1.99999

    • Evans Brasfield

      Hahahahahahaha!! Sleep? What’s that?

      Waiting in line at supermarket with supplies.

  • Old MOron

    So our wing-footed MOronic deities are in pit box number 2. Unfortunately I have a dumb phone, but if you have a smart phone you can download the Race Monitor App and follow the MOronic progress.


  • Old MOron

    Well, I got up at 05:00 to watch the Moto GP race. That was very dramatic and entertaining. Now I’m trying to piece together how our MOrons did in the 24-hour race.

    Looks like they started off pretty okay. They were losing about 5 seconds per lap to the fastest teams. They were doing about 42 laps/hour, and the fastest teams were doing about 49 laps/hour. After an hour and a half, they were down by 10 laps.


    But after almost six hours of racing, the MOronic lapping rate had deteriorated. They were now running at 35 laps/hour, while the fastest team was at 48 laps/hour.


    After 8 hours of racing, the MOrons were doing 33 laps/hour, while the fastest team remained at 48 laps/hour.


    Skip ahead to almost the end of the race. With about an hour and a half left to go, the MOrons were running at 40 laps/hour. The leading team was doing 46.5 laps/hour.


    Hmm, overall the MOrons and the winning team began and ended the race pretty consistently. But somewhere between hour 2 and hour 8, the MOrons must’ve had an issue. Oh well, I bet it was fun for them, and it was interesting for me to follow.

    • Kevin Duke

      Long story short: We had an issue with the fork that required a rebuild during the race; nearly 90 minutes sitting still. Then, since we were already so far behind, we made a shock change during the next pit stop to gain some trail. The bike was then good enough to run a podium pace. Bummer it didn’t start the race in that condition!

      • Old MOron

        At least you guys know when you need things like more trail and how to get it. Are you going to keep the Grom as an official MO errand bike? Or are you considering selling it… to one of your MOronic readers, maybe 🙂

      • James Stewart

        Kevin – can we just blame it all on Burns? Was he the last guy with snap-ring pliers seen near the fork tubes? That would satisfy most of us… 🙂

        • Kevin Duke

          We can’t blame any of it on JB! We forced him to stay at home to write most of our big adventure shootout and to avoid putting his fragile old body under threat from a small motorbike. 🙂

  • Bruce Nguyen

    all these “modifications” are unnecessary and a waste of money

  • RE: “should provide greater stopping power” and ” should provide greater stopping power ”

    This article would be MUCH MORE USEFUL If it was written after these were installed and tested…Also, are you getting any monetary renumeration for pimping these products ? A negative answer would boost your veracity

    • Evans Brasfield

      This was written prior to racing in a 24 hour event last year. You can read about our experience here:


      All the products were returned after the race.

      • Thanks for the update…I CKed out the build and race articles both…Egzacly what I was looking for…