Belt drive

Less vibration

All Shovelhead and other models topics
Post Reply
Frazier
Posts: 87
Joined: Thu Nov 17, 2016 4:42 am
Bikes: Panhead
Location: So calif
Been thanked: 9 times

Belt drive

#1

Post by Frazier »

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
Site sponsor
Site sponsor
Posts: 1816
Joined: Tue Oct 31, 2017 1:00 pm
Bikes: 1950 Panhead, Resto-Mod
1968 90", 5 Speed Shovelhead,
1984 Custom Built Evo 100" Bagger
Location: Knoxville, Tennessee
Has thanked: 824 times
Been thanked: 698 times

Re: Belt drive

#2

Post by RooDog »

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
Posts: 87
Joined: Thu Nov 17, 2016 4:42 am
Bikes: Panhead
Location: So calif
Been thanked: 9 times

Re: Belt drive

#3

Post by Frazier »

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
Site sponsor
Site sponsor
Posts: 1816
Joined: Tue Oct 31, 2017 1:00 pm
Bikes: 1950 Panhead, Resto-Mod
1968 90", 5 Speed Shovelhead,
1984 Custom Built Evo 100" Bagger
Location: Knoxville, Tennessee
Has thanked: 824 times
Been thanked: 698 times

Re: Belt drive

#4

Post by RooDog »

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

Andygears
Posts: 795
Joined: Tue Feb 05, 2013 12:25 am
Bikes: 1950 panhead, 1999 FLHTCI, 1987 FLHTC custom
Location: Daytona Beach
Has thanked: 114 times
Been thanked: 214 times

Re: Belt drive

#5

Post by Andygears »

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
Posts: 35
Joined: Sat Jul 23, 2011 7:43 pm
Bikes: 05 bonneville 79 flh 38ul 69 trail 90
Location: Nevada
Been thanked: 4 times

Re: Belt drive

#6

Post by 38ulh »

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
Posts: 87
Joined: Thu Nov 17, 2016 4:42 am
Bikes: Panhead
Location: So calif
Been thanked: 9 times

Re: Belt drive

#7

Post by Frazier »

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
Posts: 87
Joined: Thu Nov 17, 2016 4:42 am
Bikes: Panhead
Location: So calif
Been thanked: 9 times

Re: Belt drive

#8

Post by Frazier »

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
Posts: 87
Joined: Thu Nov 17, 2016 4:42 am
Bikes: Panhead
Location: So calif
Been thanked: 9 times

Re: Belt drive

#9

Post by Frazier »

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 !

RooDog
Site sponsor
Site sponsor
Posts: 1816
Joined: Tue Oct 31, 2017 1:00 pm
Bikes: 1950 Panhead, Resto-Mod
1968 90", 5 Speed Shovelhead,
1984 Custom Built Evo 100" Bagger
Location: Knoxville, Tennessee
Has thanked: 824 times
Been thanked: 698 times

Re: Belt drive

#10

Post by RooDog »

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....
October 20, 2016.05.jpg
You do not have the required permissions to view the files attached to this post.

Frazier
Posts: 87
Joined: Thu Nov 17, 2016 4:42 am
Bikes: Panhead
Location: So calif
Been thanked: 9 times

Re: Belt drive

#11

Post by Frazier »

Nice looking stable of bikes you have there RooDog

RooDog
Site sponsor
Site sponsor
Posts: 1816
Joined: Tue Oct 31, 2017 1:00 pm
Bikes: 1950 Panhead, Resto-Mod
1968 90", 5 Speed Shovelhead,
1984 Custom Built Evo 100" Bagger
Location: Knoxville, Tennessee
Has thanked: 824 times
Been thanked: 698 times

Re: Belt drive

#12

Post by RooDog »

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....

Post Reply

Return to “Shovelhead”