Building the Gromster

In Guest Writers, Japan, Small Displacement by Abhi0 Comments

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Editor’s Note: About a year ago, David N (you’ll remember him from experiences like going to a Mecum auction or his recent visit to the AMCA Sunshine Chapter National Meet) told me that he was looking for a Grom to customize. When he explained what his plan was, I asked if he’d be willing to share the bike and his experience building it with you, and he kindly obliged. Enjoy the Gromster:

I’ve always liked the Honda Grom because I enjoy bikes which are not intimidating. But I’m mostly a vintage bike guy, so I used to think I’d probably never buy a Grom. They are just too new.

Then somewhere, and I’m not sure whether it was at a show with a prototype, an actual custom bike, a picture online, or whether I dreamed it, I thought saw a Honda Grom converted to look like a Honda CR250 dirt bike, painted in red with long travel suspension, knobby tires and a blue seat. But I never saw that bike again and I can’t find a picture on the web either. So, who knows? Was I hallucinating? Editor’s Note: No, you weren’t. I’m guessing you’re referring to a photo I took when I was in Austin last year for MotoGP. The only reason I remember this is because I was going back through old coverage a couple of days ago while applying for media credentials for this year. How’s that for a coincidence? Here’s the photo:

Either way, that vision spawned my epiphany to build a retro Grom, but I’m not a dirt bike guy. So, I settled on build that would harken back to Freddie Spencer’s Honda V4 Interceptor, the RC15, but with a Grom. Freddie won Daytona on an Interceptor in 1985. Then privateer John Ashmead won again four years later on a similar bike. I saw John’s winning race. What a feat! That 1st generation V4 Interceptor (1983-1985) was certainly a ground-breaking bike. Four years old and still beating factory teams! So, a Grom-Interceptor mine would be.

With my build in mind, I kept my eye out for a used Grom. Until just recently, used Groms garnered a premium. So I settled for a new one. This was last year when the 2nd generation Grom came out. Scott Powersports, (Coopersburg, Pennsylvania), offered me a deal on 1st generation leftover yellow Grom. Yellow was a hard sell for them and I was going to repaint it anyway. So, I snapped it up in yellow. Boy, that yellow looks ugly now!

A stock yellow Grom fresh off the dealer’s floor and ready to chop!

As it turns out, it doesn’t matter what color one buys, Grom plastics are very cheap. I bought a whole new set of exterior plastic in white for a $200-300, which was cheaper than working the yellow into a white base coat. So, I’ve got a full set of yellow plastic if anyone needs it.

Stock Honda factory Grom plastics are cheap! So get any color you want, it’s easy to change!

Next was designing my Grom to replicate the Interceptor. I thought about painting the whole frame silver to replicate the aluminum frame, but I chose to go with just a square aluminum swing arm from Spyker. The Grom’s frame is mostly hidden anyway.

A stock 1983 Honda Interceptor. Colors were blue on white with blue stripe, or red on white with red stripe. 1984 began the iconic red-white and blue paint scheme with different striping in various years. That’s how mine would be…a flashback to the 1984 VF750F

The aluminum swingarm listed for $235 from Steady Garage. I got a Chimera air intake and K&N filter from there as well ($133). I chose a V3 lower engine cowl and V1 windscreen from GoGrom ($160) and a big order from Scott Powersports: a Yoshimura rear fender eliminator, an Ohlins rear shock, Ohlins front fork inserts, Brembo dual pot rear brake caliper and a low mount M4 exhaust (about $1,500 before discount). Add in a $400 Power Commander and that’s about $2,500 in parts just to start.

My naked Grom showing off it’s new sporting internals!

The bike went together easily with only a few caveats. The aluminum swing arm required a longer drive chain. The Brembo caliper did not come with a proper banjo bolt. The Brembo threads are different from Honda’s rear caliper. And the underbelly fairing would not fit with the low pipe, but I don’t think any aftermarket cowl would fit with the low pipe. So, I trimmed about 30% of the engine cowl away. The cowl fit fine after its haircut. We also carved vents to match the original, both in the belly pan and the front fender.

Scott Powersports ran the dyno, which picked up about a pony and a half with the pipe and intake. I got 10.3 hp over the stock 8.9 hp, which is a noticeable improvement when riding. Yes, it will do 55mph fairly easily but will still run out of steam on the hills. It also seems to rev more freely to redline, but that could be me. Doesn’t seem to hurt it much though!


The paint work was done by McKeever’s Custom Cycle in Emmaus, Pennsylvania after I laid out the stripes. McKeevers normally does just Harleys but I’ve given Mike some good projects over the years. So, Mike agreed to paint my Grom, and yes, the stripes are painted. They are not vinyl, which differs from the original Interceptor.

The pearl white is fairly standard but Honda’s Candy Aleutian Blue ran $130 per pint. In hindsight, the exact OEM blue was probably not necessary. The blue from my Toyota Tundra would have worked just fine too.


The Interceptor decals were custom online from Do It Yourself decals. Just choose your font and color, they will arrive in a day or two. The miniature V4 lettering came from Xtreme Decals because I could not find the exact font. The red wings are standard Grom, mostly because I was lazy.


I had the seat re-upholstered in blue but the first iteration was too light. So, we dyed it a darker blue with good result. There was more I could have done but I had to call it quits sometime. The pipe should be “black chrome” instead of just black paint. Front Brembo brakes would have been cool rather than just the rear. I could have painted the rims two-tone silver and black to resemble the black painted aluminum wheels from the original bike. I stuck with the factory foot pegs because I did not like the aftermarket rear sets which are not aluminum. I should mill a pair from aluminum, if I don’t stop.

I think the theme worked out really well on this bike which begs the question, what to do next? One could do a Kawasaki Z125 as a first-year Ninja, the GPZ900R (the Top Gun bike) but it might be cooler to get a full race fairing and do one in Kawasaki green for a ZX7RR replica. [Editor’s Note: I vote Top Gun!]

The author’s finished product, the Honda VF125 Interceptor that Honda never built.

The little Gromster next to its biggest brother, the venerable VF1000F, and yes. I found the bigger VF in New Smyrna last week.

I liked it so well, I thought to enter my Grom-Interceptor in the Rat’s Hole bike build-off during Daytona bike week this year. I’ve never attended that show but they have a class for under 250cc. I guessed that class might be mostly for stretched Ruckuses [Editor’s Note: or is it Rucki?] and cafe tiddlers. There might be some old-school guys there who know race bike history, (or maybe Freddie Spencer with an autograph pen), but on both counts I was wrong.

So, for another $40 I paid the entry fee at the Rat’s Hole Custom Bike Show. There were only two bikes in my class. My competitor was an unrestored Schwinn Whizzer whose owner was trying to hawk. He sat there with a lawn chair and a cardboard sign saying “For Sale $2,000.” Heck, my paint job cost more than $2,000!

I did not know you could have “for sale” signs on your entry bike, but that’s a good way to get 10,000 eyeballs on your sale with a safe place to park to boot. Perhaps, that’s why this guy and his Schwinn won and I lost!

The owner’s loss came at the wheels of this bone stock Schwinn Whizzer. I think it was a real one and not a reproduction.

I came in second, which is another word for last. My loss came after the Judge’s opening show lecture about strict judging criteria: custom paint lines, panel fitment, workmanship etc., which in the end was all pretty much a joke given that I lost to a pre-assembled bike (or possibly one built from a kit some 60+ years earlier) with factory paint, patina and dry tires to boot!

In the end, build your bike because you want to, the way you want to. It may be a complete waste of money but you can enjoy it. Just don’t let anyone judge it or they might totally crap on your parade, as they almost did mine.

If you understand it, that’s all you need. I won’t be participating at the Rat’s Hole again, but there’s more in that story for another day!

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