Honda Grom: The aftermarket catches up.

Words: Zac Kurylyk Photos: As credited

As we told you in Friday Fudge last week, the Honda Grom is becoming Honda’s latest niche bike, an unlikely canvas for whacko custom builders. Hey, it worked for the Ruckus, right? Check below for a list of a few interesting mods you can throw on your 125 cc hooligan bike. By the way, here’s our initial review of the bike.


It didn’t take long for Race Tech to put together a Grom kit. Their Gold Valve fork kit supposedly adds an inch of front suspension travel. They also have a G3-S rear shock available for the Grom with Gold Valve technology. Both front and rear suspension kits are personalized for the purchaser’s weight and other requirements. Cost ranges from $699 to $1099 US. Find our more about Race Tech’s kit here. They also offer beefed-up fork springs ($149) and a DIY fork valve kit ($299).

Ohlins has also put together a replacement shock for the Grom; you can order them here for $536 US.

Gas tank

The Grom gets fantastic fuel mileage (roughly 100 mpg in our short test), meaning its 5.5-litre fuel tank will take a rider pretty far. However, some riders have taken to strapping on MSR fuel bottles, just in case they run low on dino juice.


An aftermarket can is one of the cheapest upgrades you can do that affects your bike’s look and (in theory) performance. There are several exhausts available for the Grom, including a carbon-fibre system from Two Bros ($530 US), a stainless steel system from Yoshimura ($323 US), and several different systems from Tyga (around the $250 US mark).


There’s no replacement for displacement, and in this department, the 125 cc Grom has nowhere to go but up. Two Brothers has addressed that by coming out with a 143 cc big bore kit that includes a performance cam and modded fuel controller.  It’ll set you back around $500 US.

There’s another kit available from Yuminashi that brings displacement up to 160 cc. It also has a new cam and fuel controller, and a replacement ECU that senses when your engine is overheating and detunes it to cool it off. There are different prices available, depending which kit you buy. Their site says the full kit runs roughly $535 US.

For a while, Yuminashi also supposedly offered a 180 cc big bore kit, but they seem to be out of production. Rumours have some riders boosting displacement to 200 cc, or even higher, but these motors are likely one-offs and involve stroking as well as a big-bore, which significantly complicates the procedure and raises expense.


The stock stoppers work just fine on the Grom, but if you want to make stoppies even easier, you can get a set of braided brake lines from Spiegler ($48 US). Galfer also offers new front and rear brake lines, front pads, and front and rear discs. Find more details and some prices here. Several DIY types have also been fitting Brembo calipers, with help from Tyga’s custom brackets.


OK, this isn’t exactly an over-the-counter accessory, but some people are working on putting turbos on their Groms. Like this guy …


  1. Some of the customization I’ve seen here in Japan has been fairly impressive. And amusing. The best example yet was an ADV version, replete with hard luggage (aluminum camera cases strapped to racks and rails). The ultimate mount for the extremely short of inseam who aspires to GShood.

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