MOPED ARMY

there is a BIG demand for sach front and rear sprockets.

i would take one in a munute

Hmmm...only 1 pic per post I guess...I 'll post a cople more...

Andrew

This is a pic of our 40 T rear sprocket made for the 9 hole bicycle

mount for motorized bikes (this the front view...dark circle is the "step up" so the sprocket can be flipped over to alter the sprockets relationship to the rear wheel to aid in chainline alignment...

I would take a 20tooth front sprocket for PUCH. Currently only custom made, from two sprockets. A solid , balanced, one piece sprocket would go over great for a lot of us. I can only imagine the speed it will deliver. I'll be a test pilot/subject!!. Thanks for the offer! Brent

Hi Brent,

Would love to make you up one but as I mentioned earlier, I would 'need a sample to go off of....If you Email me maybe we could set something up.....my Email is "andyinchville@earthlink.net"

PLEASE be sure to put in the subject section something refering to "Custom Sprockets" so it won't be accidentally deleted as spam.

Andrew

hmmmmm.... I think my friend louis could use something, since his rear wheel on his sachs isn't made to come off, maybe you could fab something...

i could deff use a custom rear sprocket and maby even a pulley if u can do that sort of thing, and a tip on your nice moped, the biturbo is doing nothing to add to your performance or if something, not very much, the header is way too long try making it a nice one sweeping motion and have it point backward, although you did do a nice job on the overall bike

Thanks for the comments on the bike....I tried the method you mentioned....having the pipe aimed to the back of the bike (looked pretty racy too but would have needed more fastening hardware / mounts to attach the unit to the bike...also, would have stuck back pretty far... but clearance issues ultimately prevented me from doing this (either the header pipe of the Bi Turbo unit itself would hit the cranks and prevent the bike from being pedaled....plus i had to find a mounting method that would work with nearly all bicycles should I market begin to manufacture this pipe set up to the motorized biking people (of course the actual production would have a nicer header made)....The longer header was used to lower the RPM which the power band comes on (my reading hear indicated the bi turbo is a mid/top end pipe...I had to lower the "kick in" rpm for our low revving....bike engines) and the engine goes "on the pipe"....The little 70 only like to go to about 5900 - 6000 RPM Max and even that feels a little fast for it...bike motors aren't as hi revving at all.....believe it or not I wanted to try to even make a longer header but it is close to optimal now....To make it longer, I would have to shorten the silencer which would lead to additional costs....probably not worth it for the little to be gained...I thought about looping the pipe too but haven't done that yet...I may try experimenting with some expansion chambers designed for the scooter people after awhile though.

Thanks for your comments!

Andrew

O.o too costly I would go to 1977 mopeds and buy one for $23 before I pay that much. sorry, but I don't think you are going to sell many because of the cost of labor and the fact that moped riders in general are cheap and spend as little as possible. Afterall, most moped riders have mopeds because of their cheap initial cost and their ability to get 150mpg. I am cheap and proud of it.

I think fifty would be very reasonable, but i have my doubts about durability. it takes about 5000 miles for a moped chain to wear a steel sprocket down to the point you probably shouldnt use it anymore. even quicker if the chain is too loose/tight, not lubed, etc. What process are you using for these? I assume laser cutting. Is the material heat treated before or after it is cut? Are the teeth beveled, or does it come straight out of the cutter? Would you be able to cut them in any other material? Could you produce a design i sent you using AutoCAD?

This is very cool, I think if you have some design templates laid out in autocad for the different hubs, and just add teeth to the array and redraw, you might really have something. Keep us posted.

i wouldnt worry about aluminum eating a chain anytime soon, i'd worry about it going the other way.

I read a little about the aerospace grade T651 7075 aluminum alloy, but I am no mettallurgist. It sounds like one of the hardest and most durable. Quoted below, it's described as 'considered high in strength", "fair machineability", and "low workability", which means to me it is more resistant to wear compared to the others which talk more about balance of strength with other factors, such as easier machineability and workability (not good when it comes to wear).

How well does it stand up to wear heat treated? What kind of mileage can we expect from these (have any of the bike guys worn one out yet)?

From http://www.aviationmetals.net/alumninum_rod_bar.html break>

"Alloy 7075 has been the standard workhorse 7XXX series alloy within the aerospace industry ever since. It was the first successful Al-Zn-Mg-Cu high strength alloy using the beneficial effects of the alloying addition of chromium to develop good stress-corrosion cracking resistance in sheet products. Although other 7XXX alloys have since been developed with improved specific properties, alloy 7075 remains the baseline with a good balance of properties required for aerospace applications. 7175 is more pure, however, it may not be suitable for all fracture toughness applications. This heat treatable alloy is considered high in strength. Corrosion resistance and machinability is fair. Rated low on workability and welded only by the resistance process. Heat treatable."

I'll just throw this out there...

I have CNC machine

and a bunch of 6061

I already have canned programs for most sizes of flat sprockets, i.e. no offset that fit the 4 on 66mm bolt circle common to sachs, grimeca mags, some garelli's and cimmatti's

E-Mail me for a price

chuck@lumenlab.com

Hi,

Look to the answer to the previous questions for some additional info on our sprockets....I think you might be interested in that...

Good Idea on advertising with 1977 Mopeds....I'll see if they'll let us do a banner there and of course we could always drop ship too.

Thanks for the lead and idea.

Andrew

HI,

A precision made 7075 T651 aluminum sprocket will outlast a poorly made steel sprocket....Of course in order to give a fair comparison, we would have to know the specifications of the steel that the aluminum sprocket would be compared against...there are actually many different grades of "steel" available each with differing strength and wear characteristics.....To further increase the durability of our sprocket they can be hard anodized as well....this would increase an already long wearing sprocket's life by a factor of 2 or more....Most of the sprockets we make out of this material are replaced not because they are worn out but because they are physically damaged or destroyed (we sell a lot to moto crossers and hard core 4 wheelers....rocks can play havoc with the teeth....steel or otherwise....he people at Motoredbikes.com haven't worn one out yet and I think there is one person doing a test on one there.....Something to note tho....to make any sprocket last, it is clenliness and lubrication are very important BUT also checking the chain for excessive stretch can also make a BIG difference in sprocket longevity.

Hope this helps.

Andrew

HI,

Love to see the patterns for the sprockets...

Andrew