mopeds


’tis the season

hello fellow readers, sorry for the lack of updates the past few weeks. Well I am back from Hawaii (1st trip there, so much fun!), and that moped rally in reno is happening this weekend. There should be 6 of us superteens there, so get ready for some crazy fun times.

yesterday we had a little fix-it bbq at my house, and in typical fashion we didn’t get all that much done. Well that’s a lie, Bret got his maxi running after some silly wiring snafu, and Tom got his sweet new variant sport going but it is really really loud and I don’t think my neighbors were all that excited about it.

My green derbi is still being a turd, and after 2 different carburetors and some cleaning I think its time for a 3rd. Hopefully I can get one from Tom tonight, then I can throw that on with the sweet ninja pipe I am borrowing, then it should be able to rip for prolonged periods. When it was running (for exactly 1 float bowl before dying), it was fast. The bored out cylinder, ninja and clutch springs (+TJT) along with a 20t front and super small 32t rear make this bike quick off the line with a predicted top speed over 45 (maybe more downhills!). So yea, I’m excited but not in that its not running now. If I can’t get it dialed I’ll just bring my boring old magnum

Sean is building what may qualify as the ugliest maxi ever. He got an old newport frame out of Matt’s yard (rusty, faded, ugly), is reusing his grungy 5-stars with custom (crusty) white-walled vm100s, some faded old red freespirit forks, some rad bicycle bars, and some random pug shocks. Power wise its solid, with his old athena kit, 21 phbg (he was gonna build an intake, but why do more work when you can just trade parts with Tom?), and a really really chromed out biturbo. All in all practical, ugly, and probably structurally questionable.

Sorry, no photos were taken because we were working super hard, or maybe we were just drinking beer. I’m not sure, but the sausages sure were tasty. See ya’ll in reno.



Matt’s Moped Madness

So I was moping the other day how I have 12 mopeds in my shed and they are pretty much all in a state of disrepair, but fortunately most are fairly straightforward projects and I have most of the pieces to get them done. The key element I currently lack is time to wrench.

Now on the other hand, super-cuperteen, mr. matto, has a lot of really big, mostly very scary projects. Matt came from building race cars and has been a life-time tinkerer (lego constructions consuming rooms, or so I’m told). His first moped was a Puch AD, but he quickly dropped that and built a mean old magnum.

You’ve seen it in old posts, but this bike really is impressive. It wasn’t quite so pretty when it first hit the streets back in 2008, but it was FAST. Remember back when Tommy hit 70 on his metra 80 magnum? That was back at the Mopedheads first rally, and Tommy was gps’d, but Matt was not. His motor has survived every rally since (except Seattle and SF where he rode Gerbi) and it has been right up there at 70 the whole time. The MB-5 wheels and forks make the bike a beast, but whatever, it goes. I wish I had some original photos of it with the simo and hero-gizmo tank and uncovered seat. Not nearly as nice, but still fast.

Like any builder progression is natural. We all got excited about Derbi motors a few years ago, and after I got my original variant, he put a wanted ad on MA and got a real nice flat reed motor for $100. He built it up and was out on the track at the 2nd polini cup. It was fast but it seized due to a pinched fuel line. He wanted something cooler so he grafted the motor and swingarm onto a Garelli SSXL frame with the help of one of our buddies, another dude into building cars. You’ve seen this bike and its been equally as rad. Its loud and its fast. Its also reliable, that is except for cracked seat mounts and just recently a blown seal.

Now his new projects continue the ingenuity. Another Gerbi, this time a piston-ported giladerbi has been made to fit another SSXL frame. Who would have know the mounts all align perfectly, just the cases need some trimming?


With the help of Tom and others, he is building a 50cc moby. He was going to go the whole GR1 route, but some creativity means a stock crank and cases pumping out 15+ hp. Its obviously early, but it has potential.

We all got into the mini-moped dirt-bikes a year ago, and he followed suit by picking up this rad pink magnumX frame. I don’t know what he wants to put on it, but I recall hearing about cheap monoshock swingarms and rad pitbike forks.

Also seen on the boards is his AR50. Much like the AR80, but with less displacement, this guy is rad. It has slicks, race-ready rear suspension and a cool custom seat. He showed me an English site that has big kits, CDIs and pipes, and how the power will far exceed that of an AR80. This is a blast to ride now, and it’ll be crazy with some more power.

Lastly is this death-trap he is constructing. I want to say its a honda frame and some big single cyliner 2 stroke. Apparently the motor will put out something like 30 horsepower and should weigh in less than 150 lbs. He has a cool fiberglass tank and other bits. I don’t support this, but its cool nonetheless.

Yep, Matt has a lot of bikes. All are rad and constantly pushing moped tech to new levels.



Derbi SL build pt2
January 9, 2011, 12:35 pm
Filed under: Projects | Tags: , , , , , , ,

Got the beast running today. We had some little troubles with a bad head gasket then the wrong base spacing, but we got it all dialed in and it fired right up. Runs like a beast! Pretty quick, especially for a 12.12 sha. I can’t wait to get something bigger on there. We have some minor things to do still, but basically its all there. Score!

Sean got his new build fired up and its looking good. Obviously need some more little things, but hey, almost there and it sounds great.



Derbi SL Build Part 1

Matt and I started getting the SL all put together. We started with this:


Plans are to use the Rev mags, his green frame, my c-5 piston port motor with a bored stock cylinder, tjt, some pipe, treats cdi, dellorto sha, etc.

Of course in building any bike nothing is as ever as easy as it should be. For example, we had to mess with the forks because of course (as its a derbi) the brake hub tab on there differ for every year of production. Older bikes have smaller tabs higher up. These barely work with the rev hubs, and we determined it unsafe. Fortunately Matt has a set of never Variant Sport forks which have tabs that run much lower (to down closer to the axle), so we decided to use those.

If you’ve ever messed with derbi forks this picture should ring true. Gosh what a mess, and how it is NEVER easy to get those little rods in the hole (that’s what she said?). After much fandangeling, I got them in but turns out the wheel spacing is still wrong. So we sawzalled the tab in half on the fork arm to shimmy the wheel over, but even still its way off. So now we have to mod the hub plate to get that wheel centered so we can run a fender.

So its almost done and looking pretty cool. The big pirellis have about the same profile as a regular 2.25×17, so the little wheels don’t look too stupid (meaning big ‘ol fender gaps). We have to figure out the exhaust situation, find a carb, hook up the ignition, and get the front fender shored up. Exciting times. Oh yea, gotta find brake cables that work too.



Derbi Day

Today was a busy day getting all my derbi junk together.

Tony hooked it up with pretty much all the plastics, controls and other bits from the revolution, the complete revolution motor (which someone managed to strip in one of the swingarm bolts and cut off the head, extracted it wrong and drilled a new hole at an angle to hold it together, wonderful!), the revolution wheels with new 2.75 Pirelli ML75, Rev. shocks, the messy pyramid reed motor (missing clutch, variator, cylinder and head), and a ducati cdi stator and flywheel. Oh yea, also a spare new revolution crankshaft. So yea, quite the collection.


First order of business was comparing fitment of the revolution motor in the c5 frame. Obviously its going to take some work but its not too far. A fellow down in the LA area put a Flat-reed motor on his rd50 (same frame) and basically had to modify the kickstand/motor holder and add an upper bar to support the upper/front bolts on the case. I’ll be doing much of the same. The rear holes in the mount will need to be slightly modified but beyond that it should all fit very well.

Here is the frame with the original piston port and another with the start motor. Kickstart lines up perfectly!



To keep everything simple to work on I will have to drill out the stud holes in the cylinder and head to fit the funny c5 mini-studs and bolts. All easy. Much of this will be on hold until school is up in may. So yea, just getting excited about what is to come.

To keep things complicated I’m going to be putting together another derbi with the help of Matt who has a really spiffy green Variant frame. We are going to build it mostly as a loaner for friends or us when all our stuff is broken. The setup will be simple, piston port bottom, stock cylinder bored out to 60cc, homeot 4p, milled flat reed head, tjt, malossi clutch springs, 20×30 gearing, 19phbg, revolution mags, and so on.

Tom had this cylinder on his Variant a few years ago and hit a hair under 50 with an estoril with a janky header. So optimized it ought to be a pretty rad bike that is decently reliable and quick. I’m going to try and get most of it together tomorrow, but I gotta switch a water pump on the diesel first.

Lastly, here is the nasty pyramid reed. Crank actually turns pretty well but it sure is crusty.



derbi factory

Tom has a lot of derbis. Yesterday we BBQ’d and I saw most of them: Senda, GPR50, Revolution, C5 diablo, Variant SLE, Variant TT, and probably more. One was in boxes, others apart. Also a few frames designed for flat reed motors, including a hobbit and a grande. No pyramid reeds and I didn’t see a flat-reeder, but that doesn’t mean he doesn’t have one. Its a pretty sweet collection. Once my c5 is done we are going to wreck havoc.

update: now he has a laguna. Collection complete





In less exciting news, progress has been made with magnumX. The top end is on, intake there, carb and controls solid, so now the fun part of making a pipe fit. The only setup will not clear unless I want to pull off the pipe everytime I change the plug. No thanks, so I’m going to have to get crafty. I might play around with it thursday. I think sean is getting close on super tom, so mini-bruisers are going to be rolling soon. The cuperteens are also on lookout for a fleet of the coolest bikes ever. Check out The Stand for a preview.

Also, I didn’t go racing. It was hot, I was tired, and I didn’t think anyone would be there, so I skipped the 5 hours of driving and $50 race fee. Next time we are going to try and be there, hopefully others will show as well.



goodby derbi
January 7, 2010, 9:19 pm
Filed under: Uncategorized | Tags: , ,

on tuesday a squid came and took away my first derbi. It was a really fun bike, but I’m moving up to the c5, so it was time for it to go. I look forward to seeing its next incarnation. I’m sure it’ll be a blaster.

My diablo stuff was also taken to Motomatic for powder. The build is going slower than I had hoped, but thats not a huge deal. Its going to be a nice bike when done and I’m not going to rush it.