Clutch What size pulley for the driveline will i need?

[Philandra Chambliss]

Hello I am fro m motor bicycling forum seeking help from a different forum.


I have a Electra Amsterdam 3i with a 15 inch WHIZZER rear wheel sheave.


The bike is a 700c the base rim is a 622-20/ 700c x 20 which is equivalent to about 25 inches in actual measurements by tape.

I am running 700 x 38c tires and would like to know what size pulley I would need to equal 32.86 mph if I go with a manual direct style clutch.


Currently I am running a 3/4 1/2 inch clutch that is considered a 2.5 in size recently I was also told by 2 others on the other forum that the clutch will burn up....
So I'm looking to eliminate the clutch all together incase it may be true....


Here are some statistics and photos.


RPM: 3600/ 3HP

TORQUE FT LBS: 4.4

SHAFT SIZE/ TAPER: 3/4 N/A

Wheel status: 99.7% true

I was debating a 4 inch drive pulley but would like more accurate examples.

Hills are only a 20% concern.....

Top speed is about a 40%

Acceleration is about a 40%

Belt sizing speculation with the current 1/2 clutch up to a 4 inch pulley is about 68.9 inches to 70 inches.


Thanks

 

[machanic]

About a 2" pulley will do, crunching the numbers it comes out to a 1.68" dia. at 3600 engine rpm and a tire dia. of 7.15ft. And don't worry about the clutch prematurely burning out.

 

[5-7HEAVEN]

With a tire diameter of 27.3" and a 1.68" pulley, life is good.

With a 4" pulley, top speed at 3600 rpm @ 77mph,
the bike will not move an inch from a standing start,
and the clutch will self-destruct in a short time.

 

[Philandra Chambliss]

With a tire diameter of 27.3" and a 1.68" pulley, life is good.

With a 4" pulley, top speed at 3600 rpm @ 77mph,
the bike will not move an inch from a standing start,
and the clutch will self-destruct in a short time.

It's been awhile I've been driving my bike but I have this annoying ringing sound during engagement at low speed on it that turns into a tambourine sound under full load if you hold a tambourines clapper and shake it, that's what it sounds like.


"Chi chi Chi Chi Chi Chi...."

It's a JM CLONED MAX TORQUE clutch v belt drive A type brought through eBay but marked down on its actual price.


Inside the box was go kart supplies info...


It's top speed puts put 35mph and takes intermediate hills pretty well....



It's not burning out but I'm sure there's a problem some where I've moved on to paint til some other alignment issues are worked out

As you may noticed there is one side with a rods in it for alignment.

The other side needs the same to fix the offset issue.

Still need more work to the rack but clearance issues around. The nexus 3I have occurred debating getting rid of the nexus wheel set up.

 

[machanic]

With a tire diameter of 27.3" and a 1.68" pulley, life is good.

With a 4" pulley, top speed at 3600 rpm @ 77mph,
the bike will not move an inch from a standing start,
and the clutch will self-destruct in a short time.

The requested speed was 32.86MPH.

 

[machanic]

It's been awhile I've been driving my bike but I have this annoying ringing sound during engagement at low speed on it that turns into a tambourine sound under full load if you hold a tambourines clapper and shake it, that's what it sounds like.


"Chi chi Chi Chi Chi Chi...."

It's a JM CLONED MAX TORQUE clutch v belt drive A type brought through eBay but marked down on its actual price.


Inside the box was go kart supplies info...


It's top speed puts put 35mph and takes intermediate hills pretty well....



It's not burning out but I'm sure there's a problem some where I've moved on to paint til some other alignment issues are worked out

As you may noticed there is one side with a rods in it for alignment.

The other side needs the same to fix the offset issue.
View attachment 79484 View attachment 79485 View attachment 79486 View attachment 79487 View attachment 79488



Still need more work to the rack but clearance issues around. The nexus 3I have occurred debating getting rid of the nexus wheel set up.

View attachment 79489

You might not be reaching 3600 rpm with the current pulley ratio and lugging the engine which would cause odd noises. With the current pulley setup 35 MPH equates to 1615 engine rpm which would make the engine lug and the clutch ring like a bell.

 

[Philandra Chambliss]

You might not be reaching 3600 rpm with the current pulley ratio and lugging the engine which would cause odd noises. With the current pulley setup 35 MPH equates to 1615 engine rpm which would make the engine lug and the clutch ring like a bell.

So for that issue am I able to Change or upgrade to a new clutch with lower engagement lockup rpm? Some times it doesn't do it at all...

 

[Philandra Chambliss]

The requested speed was 32.86MPH.

The GPS indicates 35mph.

 

[machanic]

So for that issue am I able to Change or upgrade to a new clutch with lower engagement lockup rpm? Some times it doesn't do it at all...

You need a smaller pulley on the clutch, the ratio between the engine rpm and wheel rpm is to tall.

 

[5-7HEAVEN]

The requested speed was 32.86MPH.

Yes, I know.

From the looks of the picture, OP has a standard 3.2" OD pulley.
Gear ratio is 4.69:1.
62mph @ 3600rpm.

And that is why the clutch is rattling
like a tambourine.

Yes, this clutch will not live a normal life span.

OP needs to use a 2" pulley.
I doubt there's a smaller(than 2" pulley w/a 3/4" bore)available
at a reasonable price.
15" sheave/2" pulley = 7.5:1.
39mph@3600rpm.

Rpms will increase with governor removal and
cam change.