This is AWESOME! love the build idea man.
Btw, what tires are those?
This is a discussion on Junkyard Grom Offroad Build within the Grom Builds forums, part of the Honda Grom Forums category; A few weeks ago I stumbled across a guy on Craigslist with a totaled Grom. His frame was garbage and I wasn't looking for another ...
A few weeks ago I stumbled across a guy on Craigslist with a totaled Grom. His frame was garbage and I wasn't looking for another Grom so I bought the front end (wheel, tire, front brake, forks, triple tree, front brake lever, bars) and the rear swing arm and rear wheel.
I'm going to use these parts and some other junk parts and add a $100 200cc pull-start lawn engine to make a mini bike for the Gambler 100 Mini Bike Rally next Spring. Sorry, I realize that might annoy some folks here to use salvage Grom parts for a frankenstein thrasher build but these are actually pretty decent parts for what I'm doing. And they were cheap!
Next step was to see what kind of frame I could drop the front forks into. All Balls Racing has a pretty good search feature to see what frames are compatible with your forks (https://www.allballsracing.com/forkconversion). Believe it or not, the Grom steering stem fits most of the old Honda CB frames. I found a guy with a 1972 Honda CB175 frame and I cut that in half. Then I put the Grom forks into that.
Today I welded the CB175 frame into a rusted and busted old mini bike frame.
The Grom rear swingarm doesn't fit into the mini bike frame yet unless I attach it to the very back (and that will make my wheelbase over a foot longer than the stock Grom wheelbase). I want to keep this thing small and nimble so I'll do some more cutting and welding on the minibike frame tomorrow.
More to come if anyone is interested.
I want to see this build. And now I want to go to that rally, but it's 2,500 miles away!
2014 Black Grom
2019 Red Monkey
Here's a shot with the chopped Honda frame welded to the old and nasty mini bike frame. I had to partially cut and bend the rear end to make room for the swingarm. I'll weld it back together later and add some more support.
The shock is probably overkill but it is adjustable and at least it won't bottom out on big drops like the stock Grom rear shock. Plus, the price was right (free).
I'm planning to chop the swingarm supports out of the old Honda frame and weld those onto the mini bike frame so I have a strong connection there. (It's just sitting there temporarily for now so I could get a rough idea of my wheelbase.)
We did it last year and it was a blast! 22 laps of 4.5 miles each. Not a whole lot of rules other than you have to ride a bike with a pull-start motor (like a lawn mower). There were about 120 bikes that started the race but only about 30 actually finished. Our team managed to finish but we were several hours behind the winning teams.
Very cool build. I'm surprised you didn't just buy a Grom frame which is cheap. This is way more adventurous for sure! But in the end you'll have a custom bike.
Good info on that All Balls search. I love finding tools like that.
Leaf Spring Mafia: http://www.instagram.com/LeafSpringMafia
I was also nervous that if I showed up with a Grom, it would be "too nice" and they wouldn't let me race. This race is a rolling collection of old, home-built mini bikes and shitty Chinese mini-bikes you can buy at Wallmart for $400. Most of these bikes don't even have headset bearings! Their front forks are attached to the frame with only a fat carriage bolt, some fender washers at top and bottom, and a lock washer and a nut. The smart riders put red lock-tite on everything but stuff still rattles apart.
Images taken from this article about the event: https://www.motorcyclecruiser.com/do...i-bike-enduro/
Last edited by kzam; 10-24-2019 at 03:01 PM.
This is what’s left of the old Honda CB frame. I want to use that center column to support my swingarm so I started by cutting it up.