My next project

[Edward]

Finally got some free time to get the old clutch off and the nifty new one put on. Some washers , long small bolts, and a steering wheel puller helped get the thing off. Put the new one on and ... same thing happens. Lots of ear shattering noise and no forward motion. Phone the techs at PBU and adjusted the clutch. Still nothing so, clutch and bell assembly come off and got shipped back to Cali. I'm inclined to think maybe the bell is machined too large and the arms can't extend to the gripping point, only time will tell. Maybe I'll get a ride in before the snow comes.

 

[5-7HEAVEN]

Edward, it's not the clutch. ya need more gearing. that's why the engine's screaming, and your bike is crawling.

if ya can't go any smaller on the engine sprocket, ya gotta go bigger on the rear sprocket. 6-tooth on the front, 90-tooth on the rear. 7t/105t, 8t/120t.

UNLESS...you install a 78mm STATON gear reduction box($129). with 3.11:1, then the ratio is 6t/29t, 7t/34t, 8t/39t, 9t/43t,10t/48t, etc.

using your existing 47t rear sprocket, install the STATON gearbox and change engine sprocket to 9t. that compares to happy time engine and 39t rear sprocket.

JMO, 9t/47t would be an excellent combination, at 16.24:1 gear ratio.(my DAHON/STATON gear chain is presently geared at 16.67. it's similar to happy time engine with 40t rear sprocket. a LOT of low end/midrange power.)

right now, you're probably at 6.71:1 or 7.83:1.

WAY off!

Myron

 

[5-7HEAVEN]

Edward, at 6.71:1 gearing with approximately 5.5' tire patch, at 15mph, the engine is idling at 1600rpm. at 30mph, engine barely awakening at 3200rpm. at 8700rpm, theoretical speed is 81mph. at 10,000rpm, it's 93.5mph.

with my 20" DAHON at 16.67 gear ratio and 5.083' tire patch, at 15mph, engine is alive at 4300rpm. at 30mph, engine is slightly over my engine's maximum power at 8700rpm. at 81mph, theoretical rpm would be 23,400rpm.

with 9t/47t combo, 3.11 reduction box(16.24:1) and 5.5' tire patch, at 15mph, your engine would rev at 3900rpm. at 30mph, engine is alive at 7800rpm. at 8700rpm, estimated speed is 33.5mph. at 10,000rpm, calculated speed is 38.5mph.

with 10t/47t combo, reduction box(14.62:1) and 5.5' patch, at 15mph, engine speed is 3500rpm. at 30mph, it's 7000rpm. at 8700rpm, calculated speed of 37mph. at 10,000rpm, bicycle speeds of 43mph.

i guesstimated on your tire patch(rear wheel circumference), but estimations should be in the ballpark. if it's larger than 5.5, that's even more reason that your engine falls flat on its face.

Myron

 

[DougC]

I've clicked that first link three different times in a 24 hour period, and it always says "account temporarily disabled". Does it work at all?
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