Belt drive

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Frazier
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Belt drive

#1

Post by Frazier » Thu Apr 25, 2019 3:43 pm

Put a belt drive on the shovelhead and took it for the first test ride , its like a different motorcycle ! Before i wouldnt take it over 62 mph the vibration was so bad i thought id brake it or the motor would blow up or something , now its smooth through all the rpm ranges and i actually had it up to 75 mph with no problems ! Big difference !!



RooDog
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Re: Belt drive

#2

Post by RooDog » Fri Apr 26, 2019 4:55 pm

Sounds to me like you have another issue not related to the belt drive. My 90", '68 Shovelhead, 5 speed, in a OEM swing arm frame is good for 70-80 MPH all day long, until it developed a buzzy vibration. While I had it down for some paint work I discovered the top engine mount, the laminated section of frame hanging down from the backbone, had cracked. And that was the source of my new found vibrations. If I were you I would be check all of your engine and transmission mounting points both for fastener tightness and structural integrity. There could very well be something in need of fixing....
....RooDog....

Frazier
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Re: Belt drive

#3

Post by Frazier » Fri Apr 26, 2019 11:21 pm

Good idea , i will check all those fasteners this evening , also the primary chain was so wore out the owner before me turned the primary adjuster over to get more adjustment , also the engine sprocket was a solid mount 22 tooth and the new belt drive is a better drive ratio with the 24 tooth trans and 48 tooth wheel sprocket

RooDog
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Re: Belt drive

#4

Post by RooDog » Sat Apr 27, 2019 12:17 am

Good numbers on the toot counts. I find old Harleys were typically geared too low for the real world.
...RooDog...

Andygears
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Re: Belt drive

#5

Post by Andygears » Sat Apr 27, 2019 1:28 pm

A really bad primary chain with a solid front sprocket can make a lot of vibration, which will loosen everything, mounting bolts and worse, frame welds! RooDog is right, spend some time going over everything and making sure stuff is tight & look over the bottom of the seat post tube to see if a "typical" crack has started there. Rear chain and sprockets not to be ignored.

Andygears

38ulh
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Re: Belt drive

#6

Post by 38ulh » Fri May 10, 2019 11:57 pm

I'm curious about your belt drive. Who made it, is it in a stock aluminum primary, does it require an idler? I ask all these questions because I had an inclosed Primo many years ago, I like belt drives but I always thought that Primo was wearing itself out from the back side of the belt by slapping the inside of the primary. I don't think I'd like an idler either. I didn't keep the primo long enough to wear out or break a belt. I've often considered trying another belt drive on my shovel.

Frazier
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Re: Belt drive

#7

Post by Frazier » Mon May 13, 2019 1:16 am

Its a BDL 11 mm belt drive in a stock shovel with swingarm frame and aluminum primary and yes there is a belt adjuster , there has to be with this setup cause with the aluminum inner primary the trans is non adjustable

Frazier
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Re: Belt drive

#8

Post by Frazier » Mon May 13, 2019 1:19 am

Yes Roo Dog finally getting around to working on the shovel and so far ive found a loose top motor mount , gonna check the motor mount bolts next , Thanks

Frazier
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Re: Belt drive

#9

Post by Frazier » Fri Jun 07, 2019 2:35 pm

Tightened up the top motormount and put 150 miles on her and shes running even smoother , also put a new one way crank breather on from V-twin and that seamed to stop the oil leaks in the top rocker box gasket and rear lifter base gaskets !

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Re: Belt drive

#10

Post by RooDog » Fri Jun 07, 2019 3:38 pm

I love it when a plans comes together.
I scored a new Karata belt drive from their eBay outlet vendor to use on my 90", 5 Speed '68 FL. I hope it turns out as well as yours did, the bike is currently down from the frame repair and new paint, but it will be back up and burning up the roads maybe next season. My Panny is finished, and my Big Red Evo is doing just fine, so there's no rush on the Shovel....
Best Regards.....RooDog....
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Frazier
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Re: Belt drive

#11

Post by Frazier » Fri Jun 07, 2019 5:05 pm

Nice looking stable of bikes you have there RooDog

RooDog
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Re: Belt drive

#12

Post by RooDog » Fri Jun 07, 2019 5:19 pm

Frazier wrote:
Fri Jun 07, 2019 5:05 pm
Nice looking stable of bikes you have there RooDog
Thank You, Sir.
That Panny's been in the family since 1967 and this is its last revision from me, somebody else can do it the next time....
The bagger has been a cub bike for the last 15 years, for road runs and parties, now it's just for fun and around town....
....RooDog....

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