q-matic final drivve questions

jared8783

jared8783

New Member
what is the largest sprocket i can put on the rear tire and still hit 30mph with the motor all the way wound out
im gettin tired of hills and wind affecting my speed and 30 mph is the top speed i really need
i know i know the poor little engine will wear faster if i always keep it wound out
well thats a compromise i am willing to make

and another question as well
i am interested in the belt drive setup since the frame i chose has some chain rub issues
so i am wondering if that there is anyone out there who would be willing to sell me a clutch with the pully pressed onto it already
or preferebly to save me some money just sell me the clutch bell with the pully pressed onto it

thanks
jared
 
Hi Jarred,


You can run rear sprockets from 56 tooth [stock] to 72 tooth.

Here are the numbers.......
56 tooth 15.48 X 1 6000 RPM = 30 MPG
60 tooth 16.56 X 1 6500 Rpm = 30 MPH
62 tooth 17.11 X 1 6800 RPM = 30 MPH
66 tooth 18.21 X 1 7200 RPM = 30 MPH
72 tooth 19.87 X 1 7800 RPM = 30 MPH [redline, dangerous]


Max Torque has been making a special clutch for us with a 2.5" pulley, making the rear ratio 6.31 X 1 [total overall ratio 17.44 X 1] and 30 MPH @ 6800 RPMs. The cost is approx $50.00 more than the normal EZM clutch.

If you are having problems with chain clearance, the rear belt drive will be even more problematic. The wheel sheeve is 15" and makes the belt ride much more forward and hit the frame in a more narrow spot. In fact most Whizzer kits with the rear belt drive normally require "crimping" the frame in 2 locations to clear the belt path.

You can also try using a 3VX series belt on the primary. It will require cutting the groove deeper in the front drive pulley to allow the belt to ride without bottoming out. The pulley groove must be cut to 13 MM to clear [approx .080"].
The 3VX series will change the primary ratio from 2.76 X 1 to 2.935 X 1.

Using the 3VX and the stock 56 tooth sprocket will deliver 16.43 X 1 [30 MPH @ 6500]
a 60 tooth will = 17.61 X 1 [30 MPH @ 6900], 62 tooth = 7200 RPMs @ 30 MPH, 66 tooth = 30 MPH @ 7600 [near redline]

Hope this information helps.

Have fun,
 
here is a pic of where i have the chain rub issues (fyi that sprocket in the pic is a 44 tooth and i curently run a 56 tooth)
i think that is called a chain stay (correct me if i am wrong)
i sometimes have problems with it hitting the bottom one as well
so if i go with a bigger sprocket it would make the problem worse

i dont know exactly where you say the belt often rubs
but frame crimping is out of the question as far as i am concerned due to it being an alluminum alloy

i was think maybe the belt would clear those bars ( chain stays? someone please tell me if i got the name of those right) both over top and under
what do you guys think?
and i do currently have 12 gauge spokes

its getting cold here in Indiana so i have now got all of fall and winter to figure this thing out

thanks
jared
 

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It looks like you have a MM hub adapter is it possible to move it in toward the spokes a little and still clear the tire,(arrow = seat stay)
 
well after looking at it closer i have determined that i CAN NOT run a larger sprocket and definetly not a belt setup with out the final drive becoming worse up top (rubbing that is)

unless anyone has any bright ideas
and i am not willing to run some kind of tensioner that re-routes the chain to keep it from rubbing (only solution i see in sight for this frame)
i only see that as turning into some kind of a hassle and more parts to worry about

i am a firm believer is K.I.S.S. (keep it simple stupid)

so i am probably going to end up getting me a new frame and frame only
it must have v-brake mounts and accept 26x2.125 tires and a 3 piece crank
and preferebly aluminum and preferebly accepts safe fenders

ill probable be snooping around the threads trying to figure out a good alluminum frame to use
i have been having motor mount issues with this frame as well and am just fed up and ready to get rid of this frame


if anyone wants to suggest a nice frame to use that would be cool

thanks
jared
 
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These are really nice aluminum framed bikes that cost $119 for the blue and $150 for the black one...complete bikes. A that price you can ditch the parts and just use the frame....a sturdy, easy frame to build on.




 
Hi Jarred,


Why not try adding a thick washer on each side of the axle [between the frame and the hub] to "force" the frame outward. You can also try to move the entire motor slightly to the right to move the chain away from the frame.

The belt drive will only make your clearance problems worse, because the belt sheeve will be 7.5" from the center of the hub and the frame will have less clearance at that location.

When it gets too cold to ride you can send me your front pulley and I will cut it to accept the notched 3VX automotive belt, no charge. You just pay for shipping and we will do the work for free. The unit will run a 3/8" FHP belt without modifying the drive pulley, but the HD belt is the way to go.

Have fun,
 
thanks for the offer Quenton I really do appreciate it

i dont want to force the frame to do anything since it is alluminum and that idea just worries me
and also the motor BARELY fits in there
i had a motor mount custom made and still there is only like a quarter inch clearance from the valve cover to the bar above it
which causes issues of its own blah blah blah

im just plain sick of the frame and ready to get one that is proven to work well with 4 strokes
but it is however a trek calypso and i already had the rear wheel converted over to 12 gauge spokes and got a manic mechanic sprocket adapter for it

so i have all the quality parts i need
therefore i am just looking for a frame

hey scotto
at that price I am almost scared to motorize
sturdy?
i would still like to look into it though
where did ya get em

if anyone knows of a really laid back alluminum beach cruiser frame that will work well let me know please

thanks
jared
 
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