40 series is BIG :o

[FNTPuck]

NT carb for scale.

 

[Spare_Parts]

I have seen smaller primarys on Harleys!

 

[FNTPuck]

I have seen smaller primarys on Harleys!

Go big or go home .

Selling my moped wheels and going with dirtbike hoops, 10ga spokes, an enduro front hub+brake, and a motobecane rear moped hub (its about the only dual sprocket hub that will let me keep pedals besides the generic Leleu). 21" front, 18" rear. This will give me right about 26" diameter for the rear wheel, 27in for the front, and DOT motorcycle tires front and back. Heavier and slower than the smaller 23.5-24" moped wheel OD, but waaayyy stronger and will let me put a real tire on the back for the nasty acceleration this bike will have. I thought about the ghettobike rear hub but couldn't bring myself to drop that much cash on a rear hub that is still a smaller bicycle style vs a thicker casting moped hub.

Looking to take the title of fastest 1/8th and 1/4 mile motorized bike. Might add a removable wheelie bar for the strip.

As the build gets closer I will eventually start posting pictures in a build thread.

 

[Will'smotobikes19]

Is this for the 300cc Briggs or whatever you were talking about?

 

[FNTPuck]

Is this for the 300cc Briggs or whatever you were talking about?

Ya, the 305 Briggs bike.

Getting close to being done, just need to order the 18" dirt bike hoop and measure the spoke length for the rear wheel, then widen or replace the rear end with a stronger setup that can clear the ~4" rear tire. Still need a few other little things to get it moving like rear brake plate for the Moby hub, puch sprocket, some brake cables, levers, etc. but most of it is finished. I replaced the head tube with a larger chromoly one, boxed the front end, and mounted the Kawasaki fork to it a few days ago and the front wheel and axle will be in next week to finish up the front half.

Then its little things like gas tank, better seat, different handlebars, etc. Once its dialed in, I can move on to performance parts and upgrade valve springs, port the head, and plumb the nitrous.

 

[Deleted member 26224]

If your moped rear hub is this one

Motobecane AV88 Rear Wheel Hub - 1977 Mopeds

This is a huge rear hub for old timey Motobecane mopeds.

m.1977mopeds.com

Then it’s a bad choice. And 1977 mopeds will give you a huge headache. You can get the same hub from mbrebel but it’s much more expensive, closer to the price of the bare damgood hub. Also it has a 10mm rear axle and small bearings, and the drum brake is awful.

A better option? Don’t look at me man. Mopeds are the only vehicles you’ll find a sprocket, brake, and freewheel as stock.

I have this pitbike rear wheel with sealed bearings for a 14 or 15mm axle, the rim looks like a 14x1.85 and came stock with a 90/100 dirt tire. You can have it for the price of shipping. I would get a freewheel hub, chop off most of it, drill some holes in the spike flange and make an adapter to bolt to the disc side. Also can try finding a junk hub motor and cut up the side cover with freewheel on it to make an adapter. Short of that I dunno.

 

[JerboaJohn]

about the ghetto hub, yeah it's pricey but it's not hollow and it's heavy, being solid, only drilled for the axle. and incut for 202 bearings

 

[JerboaJohn]

yeah I remember those mopeds from mid 70's were sucky but for lots reasons. then in 81 they started to actually get good. tho I can't remem anything specific from 76, 77

 

[FNTPuck]

If your moped rear hub is this one

Motobecane AV88 Rear Wheel Hub - 1977 Mopeds

This is a huge rear hub for old timey Motobecane mopeds.

m.1977mopeds.com

Then it’s a bad choice. And 1977 mopeds will give you a huge headache. You can get the same hub from mbrebel but it’s much more expensive, closer to the price of the bare damgood hub. Also it has a 10mm rear axle and small bearings, and the drum brake is awful.

A better option? Don’t look at me man. Mopeds are the only vehicles you’ll find a sprocket, brake, and freewheel as stock.

I have this pitbike rear wheel with sealed bearings for a 14 or 15mm axle, the rim looks like a 14x1.85 and came stock with a 90/100 dirt tire. You can have it for the price of shipping. I would get a freewheel hub, chop off most of it, drill some holes in the spike flange and make an adapter to bolt to the disc side. Also can try finding a junk hub motor and cut up the side cover with freewheel on it to make an adapter. Short of that I dunno.

I already have the complete 17" spoked Motobecane wheels since I was going to use them both, but changed plans and now only going to use the hub for the rear laced to an 18" dirtbike hoop with 10ga spokes. Selling the front wheel complete along with the rear hoop/spokes/sprocket, brand new MC11 tires on both.

Hard to tell with brake plate on and no view of the freewheel side if it is that exact hub. There are two versions of the 80mm hub that came on MBs (and also a third less common smaller 70mm version), there is the Motobecane one with flat freewheel side with "M" logo and short little supports inside and there is also thicker internal support Leleu one with tapered freewheel side and the internal supports go across more of the wheel. They both have sealed bearings, but small 10mm axles. You can upgrade them to 12mm with larger bearings easily and drill out the brake plate to run a sealed 12mm axle kit. Also there are a lot of chinese knockoff Leleu ones floating around like what mopeddivision sells (but at least they label them Leleu STYLE and dont pretend they are authentic). Like most knockoff parts they will not be as strong as a real hub.

Where do you see failures so I can see where the issue is? Any links to a broken one? In my research I found Morini guys race with these hubs and 15-20 hp beasts, and there are two successful predator 212 builds I know of using them (Scott and Kurt both have sick 212 builds with this rear hub). I have not seen one single failure of a Motobecane rear hub on a motorized bicycle nor moped, but that is just from searching the internet - I have built and raced a lot of motorcycles and motorized bikes but don't have much history with mopeds. My front end is not using moped parts FWIW, its the complete front end from a Kawasaki Enduro - forks, triple trees, hub, hoop, and spokes. Head tube was also replaced with a thicker and larger chromoly mountainbiking tube to replace the thin cruiser head tube.

Thanks for the offer on the wheel! I need a much taller tire than a 14" though. At least a 17" to get a minimum of 23+" OD.

I've got a complete '92 A35 Tomos as well that I might take the front end off of to put on my 2stroke but I kinda don't want to take it apart since they are kind of rare around here. Also, its a 16" mag wheel and I prefer spokes. If I do, I will probably upgrade the clutch, put a big bore kit on the motor, and throw it on a Dyno cruiser. Should do 75ish.

 

[FNTPuck]

about the ghetto hub, yeah it's pricey but it's not hollow and it's heavy, being solid, only drilled for the axle. and incut for 202 bearings

Yea, I would get the ghettobike hub over the DAM good one if I was gonna drop a bunch on a hub.