"Thumper" is down for the count (temporarily)

[KilroyCD]

I had something happen to me today that was a real bummer. I was riding "Thumper" in to work this morning, and was literally halfway into my 13 mile ride when I approached a stop sign. I had been cruising along at 30mph the whole way, and when I left off the throttle and pulled the clutch and brake levers in, all heck broke loose! It sounded like ball bearings were thrashing around in the crankcase! I hit the kill switch and quickly pulled off the side of the road. I went to wheel the bike into a parking lot, and despite pulling both the clutch lever and compression release, I still had to pick up the back end to wheel it there. I called in to work and had them despatch my boss in the pickup to "effect a rescue", so to speak (that was embarassing). In the meantime, I started to try to find out what was wrong. I pulled the belt cover off and turned the flywheel. Everything felt normal. I turned the clutch pulley. That didn't feel at all right. So I looked things over, and lo and behold, the clutch pulley bearing had literally disintegrated! My clutch pulley was no longer even close to being square with the belt, it was toed inwards about 10 degrees and downwards about 10 degrees as well. The angle was totally cattywhompus! The ball bearings I heard and thought were thrashing around in the crankcase were actually thrashing around the belt cover! After getting to work and unloading Thumper from the back of the pickup, I was able to get the engine started, and to my relief it purred like a kitten. Unfortunately, my boss rode me about it all day (good naturedly, though), calling the bike a "Fizzer".
"Thumper" is back home now, and fortunately my brother Jim had converted his Whizzer to an auto-clutch, so he had a spare clutch pulley and bearing that he brought over this evening. Maybe tomorrow after the inaugural EZM rides with "Bluebird", I'll get to work on "Thumper" to get him back on the road.
Has anyone else ever had a clutch pulley bearing explode like that?

 

[Hal the Elder]

Sorry to hear that, Chris...

...I'm waiting to hear the discussion on the breakdown.

HAL

 

[bill green]

Hi Chris I had one (new) make bad noise and replaces bearings with skf sealed bearings..Bill

 

[jbcruisin]

cattywhompus?

cattywhompus? Wow how did you know how to spell that? I know the word but never saw it written. Hope you get back on the road soon.

 

[KilroyCD]

cattywhompus? Wow how did you know how to spell that?

Huked on fonix wurked for me!

 

[KilroyCD]

I've been working on a vintage bicycle restoration for the past week, so while literally watching paint dry I decided to pull "Thumper" out and address the clutch bearing problem. Once I got the belt cover off I started to closely assess what was wrong. I soon discovered that the cattywhompus angle of the clutch pulley was not caused by the failure of the bearing, but of the loosening of the nut that holds the clutch arm. As a result, it was quite loose. The noise I heard (that sounding like ball bearings thrashing around) was actually the pulley contacting the plate for my belt tensioner. I took the belts off, lined everything up, tightened everything back up again and put the belts back on. Lo and behold, everything worked! Instead of watching paint dry, I put a couple miles on "Thumper". :helmet:

Now back to more painting...

 

[jbcruisin]

If I remember right you have the slip clutch & Jim has the auto clutch. My auto clutch blew (is that a word?) & I put my slip clutch back on a few weeks ago. It works okay & I might just leave it on.

 

[KilroyCD]

If I remember right you have the slip clutch & Jim has the auto clutch. My auto clutch blew (is that a word?) & I put my slip clutch back on a few weeks ago. It works okay & I might just leave it on.

Jay, I think Jim is starting to have the same thoughts, as he hasn't been able to get his auto clutch dialed in properly yet.
I really like having the slip clutch, but need to tighten my "singing belt". When the clutch is pulled in, it sings like Beverly Sills.

 

[Hal the Elder]

I hope not...

Beverly Sills passed away on July 2, 2007.

Hal

 

[Quenton Guenther]

Hi Guys,

Just wanted to let you know I put several auto clutches through some serious tests over the last several days. I made a special version of the 3rd Mel. clutch for my 20" Sportsman racer and it worked much better than expected. 66 MPH on the street [in a 55 MPH zone] and 64 MPH on the Roller Road. The special Whizzer clutch used for the Dirt Drags did change to a bright blue color near the end of the event but still connected very well [yes, Jay it still pulls wheelies]. I will attach a picture of Gerd Lowack's 3rd Mel. clutch mounted & supported like it should be.

Have fun,