DUDE! Where's my locking freewheel ??!!

[Nashville Kat]

As a former racer, and now that I've tried my motor bike out a little, the one thing I'd like to have (besides a quieter motor) is better peddling!

I'm on a motorized cruiser now, but thinking I may build up a road bike with some 27 or 700C wheels, and the one thing I don't like is the way the bike pedals now- The motor's weight really doesn't affect that much, but now the extra drag of the big sprocket, heavy 415 chain, and especially the turning of the shaft take a lot of "normal cycling" away from the already sluggish cruiser.

So I've figured out what we need: A LOCKING FREEWHEEL-

Switch a lever and the motor freewheel on the back wheel acts like the freewheel on the other side- it freewheels without the motor chain, sprocket or shaft turning with it-

but then throw the lever the other way, and the assembly LOCKS UP like a fixed cog- Fires up the motor, and you're off under power again!

I've seen freewheels advertised on e-bay, with double sided hubs, but i'm assuming that one then needs a pull start to get the motor going-

I enjoy shutting the motor on and off quite a bit- off on downhills or at intersections, and on again on longer stretches or up hills-

Can anybody build one of these please?

I just took delivery on a narrow sprocket and cruiser chain and a narrow 36 rear sprocket,so I'm hoping hat cuts down peddling drag some- but I wont be happy until the bike is peddling close to normal again!

anyway, stay safe and Happy Motoring!

TheHearpe.tripod.com

[Junster]

Kinda what's behind this guy.

HybriPed - Wiki - Welcome to MABers

[lordoflightaz]

Originally Posted by Junster

Kinda what's behind this guy.

HybriPed - Wiki - Welcome to MABers

Except that we don't want to stop to make the change over.

[happyvalley]

A MB that freewheels like the bike did before it was motorized, one that performs more like a motorized bicycle than a moped (without having to leave the seat).
Observing the number of bikes being built, it seems to many its not that big a thing.
To me it's been the holy grail and one of the contributing factors for abandoning the frame mounted Chinese engines.

[matt167]

if you could get enough current from the white wire going thru an automotive A/C clutch, that could work to lock it up.. it doesn't take much power to lock those clutches up, and they would hold strong enough for the engine power.. A/C pumps draw more power than these engines produce..

only problem is you would an external source of power to lock it up when you want to fire it up.. a battery of some sort would do

[Nashville Kat]

Electric switch, eh?

That's more than I was thinking- another cable.

but this one doesn't even have to be on the bars. (My Micargi 7 speed is too crowded, and I just got a dual brake lever I have yet to install). A small lever on the seat post or seat stay will do. I'm picturing a three-speed control sized thing. It just has to go "on and off".

The old three speed hubs had a rod through them somehow- I never worked on them much in the shops- all it would have to do is move a pin mechanism to let the freewheel spin free or be locked up-

Also, our fixed sprokets could be drastically cut in weight and improved if someone would put out a splined hub- a matching sprocket would fit over the spline, and then be locked with a simple reverse thread lockring- (everything has to be reverse thread on the left side, or the chain pull direction will lossen it. The freewheels I see advertised babble something about screwing it on reversed- so I'm wondering if the friggin thing could ever then come off? And they don't lock up- just always work in freewheel mode)

Anyway, a splined hub and sprocket andlockring would eliminate all the nine bolts, all the steel backing plates and all the rubber pieces, assuming the alignment is good. My Macargi muti-speed hub, while not threaded, is the EXACT diameter of the sprocket hole, and then also has a stop ridge on the inside, that stops the sprocket exactly the width of a rubber side. I only had to use one piece of rubber, and not a chain tensioner either- it all lines up perfectly, like the asian frame and hub are otherwise made for the motor-

I just found oout that a bottom bracket lockring can also double as a cog lockring- but I don't think it can be reverse threaded.

[matt167]

use a CE clamshell adaptor instead of the rag joint and 9 bolt sprocket. you should then be able to fabricate some system to make a locking free wheel..

[Nashville Kat]

Actually, the now-popular single-cog track flip-flop hubs and wheelsets are really good too-

A freewheel goes on one side and a fixed track cog- and lockring- go on the other-

the flanges for the track cog fit our motor bike sprockets perfectly, and the hub has a stop ridge to keep it out of the spokes-

the lockring would spin on the wrong way with normal threads, but maybe another cup or cone/washer could hold it all on-

the motor sprocket would be wedged securely-and supported by the same diameter hub- the all it needs is minimal leverage to drive it with the hub- I'm looking for large flane now- I think some small lightweight bolts could go through both the sprocket and hub-


They are mostly available in 700C for a road/track frame, but the hubs could be on a 26" rim- they're on e-bay under "bicycle wheelsets"

I bought an old Schwinn World traveler (for 5 dollars!) about two weeks back, I'm think of motoring-

I've painted it and put MX bars and stem- it has a nice alloy crank- and 27" wheels (too large an un-dyed flange in the back) so I'm maybe gonna get some fixed gear trackie wheels-

I'm thinking a lightweight 48cc, with narrow chain and lightweight 36 sprocket I have already- Keep the whole thing as light as possible- maybe 36 lbs or so- and the narrow wheels ought to really roll!!!

One word about road frames- BEWARE of the narrow bottom brackets and 3 piece axles-

the World Traveler is not a true racing frame, but still lightweight and sturdy, normal size tubes, and it looks like the 80 on my cruiser might clear the cranks- (a nice alloy Sugino 3 piece setup)

but I've already bought a wide 135mmm spindle at Sick Bike Parts that I KNOW will clear-
and I guess the 48cc's are a little more narrow-

Say, does anyone have accurate measurements of the width of the different engines (all 2 and 4 stroke) they could share here?

[NEAT TIMES]

Nashville Kat, I Don`t Think This Is What You Are After But; I Had A Left Hand Thread Die Made To Cut Left Hand Threads On My Bicyle Hubs. Then I Can Screw On A Left Hand Freewheel Adapter Or a Complete Sprocket. Ron .. .. . What you are trying to achive would be great for sure! The 3rd and 4th pics are right hand thread and right side drive

[Nashville Kat]

Hey Neat,

Yeah, that's a start. You had die MADE?

I'm annoyed at standard road hubs, and have wondered if the left side could be cut down to the same diameter as the threaded side, and then even died like this- they seem to have as much clearance off the bearings as the freewheel side-

Do the manufacturers fear the motor sprocket?

I've been trying to track down some hubs like my Micargi multi speed rear- it's not threaded but already the correct diameter otherwise- a lockring would be nice- but it's a little bit cheap- steel with pressed on bearing races- so now i'm trying to get a line on some large dflange trak flip-flop-

the thread is right-handed, but the sprocket fits over it snugly-

Obviously I'm sort of a cycling purist and much concerned with weight- I think thats the main strength of a motorized bicycle compared to a scooter- Even a small 50cc scooter weighs in at about 200 lbs, while I can lug the bike up the stairs if need be, and I can tear it down and put it in the car or on a rack- plus most of the parts are quickly available at a bike shop.

Your allen bolt sprocket fasteners are interesting- what are they driven into?

also, how do you post these attached thumbnails- they're great!