Moped tires

[BruceBanner1983]

Let's get a no load full throttle tachometer reading off your engine. Until we know what kind of rpm you're actually working with its all a What If scenario. An 11\44 is also 4\1.

A 10\50 is a 5\1 reduction not 4.167\1.

My mistake, a 12t front and 50t rear is 4.167:1. My focus and concentration is sh!t today.

 

[Sidewinder Jerry]

My mistake, a 12t front and 50t rear is 4.167:1. My focus and concentration is sh!t today.

It comes down to this, in order for your 20" tires to do 55 mph, they have to be doing 925 rpm.

 

[Wrench]

It comes down to this, in order for your 20" tires to do 55 mph, they have to be doing 925 rpm.

925 RPMs ya mean it'll go 55 mph while at idle or the wheels have to rotate 925x per minute

 

[BruceBanner1983]

925 RPMs ya mean it'll go 55 mph while at idle or the wheels have to rotate 925x per minute

The tire itself has to spin 925 rpm.

 

[Wrench]

The tire itself has to spin 925 rpm.

I'm getting dizzzy trying to count that

 

[BruceBanner1983]

It comes down to this, in order for your 20" tires to do 55 mph, they have to be doing 925 rpm.

So I’m looking at possibly connecting my pedal chain to my transmission jack shaft, and I’m not sure but my pedal chainring is probably either 28t or 32t. I have a freewheel that if I can adapt it to my jack shaft is 24t. Then from jack shaft to rear wheel would be 12t-50t. So the pedal gearing ratio would be 28/32>24>12>50. I’m trying to figure out what gearing that would be, and how easy that would make it to pedal. The moped rims I bought were for a moped that doesn’t have a separate pedal chain, most likely a pedal freewheel clutch which is essentially what I’m attempting to do

 

[Chainlube]

So I’m looking at possibly connecting my pedal chain to my transmission jack shaft, and I’m not sure but my pedal chainring is probably either 28t or 32t. I have a freewheel that if I can adapt it to my jack shaft is 24t. Then from jack shaft to rear wheel would be 12t-50t. So the pedal gearing ratio would be 28/32>24>12>50. I’m trying to figure out what gearing that would be, and how easy that would make it to pedal. The moped rims I bought were for a moped that doesn’t have a separate pedal chain, most likely a pedal freewheel clutch which is essentially what I’m attempting to do

If you're putting a 20" wheel on a bike that was built for 26", then your pedals won't work. You might as well get a couple foot pegs.

 

[BruceBanner1983]

Well, I got the moped rims and I got 41M (319 lb load rating, 81mph speed rating) tires for them. I’m waiting on bearings to convert the rims to 10mm axles, but I got one of the tires on awhile.

 

[Chainlube]

Well, I got the moped rims and I got 41M (319 lb load rating, 81mph speed rating) tires for them. I’m waiting on bearings to convert the rims to 10mm axles, but I got one of the tires on awhile.

Does it fit in your dropouts?

 

[BruceBanner1983]

Does it fit in your dropouts?

I won’t have to spread her legs to get the wheels in the frame, but the axles it came with are too big for my dropouts. Front is a motorcycle fork with 10mm dropouts and the rear can take a 10mm axle but the axles it came with won’t fit front or rear. I don’t want to modify my dropouts, so I took the bearings out of one of the hubs (same size on both wheels), measured them and went on eBay and found high speed engine bearings that are the same OD and width as the ones I took out, with a 10mm ID and they were only $25 for 4 of them, they’re rated to over 20k rpms so I think they’ll be fine for my wheels lol. Might never have to change them again haha.