Belt tension with lighter than stock rider.... - Harley Forum

03fxst · #1 06-12-2009, 07:13 PM

Hey guys
I've been chasing down a belt rubbing issue. Slight rub when we are two up that seems to go away after riding a bit. Think I've nailed it to the belt guard which seems to have shifted slightly and the top of the belt is rubbing the grove in the guard where it is slotted to go around the swing arm.
In the process I checked the belt tension and it seems a tad off. Book says 5/16ths to 3/8ths. It is showing close to one half inch of free play cold using the Harley tool. Trouble is the reading in the book is for tension with weight of the rider on bike. My wife is sitting on the bike for the test and she is 30 pounds lighter. Should I still adjust it down to 3/8's. Is there a formula for testing it with no one in the saddle?
On the guard I will shim that away from the belt to stop the rubbing. I believe the culprit was s small rubber bushing that either fell off or I forgot to put back on the last time I removed the guard late last year.

Still tweaking...
03FXST

frisco-rigid · #2 06-12-2009, 11:53 PM

Hi Buddy

Gee, if this were my issue I'd put my LiL Suction Cup in the seat along with 30 Lbs. of something and adjust it to the 5/16",, that way when you're riding together you'll know it'll loosen to no more than 3/8" hopefully..

OR----perhaps

Get your bud that weighs as much as you and Sweet Pie together and adjust it to 3/8",,,, then when riding alone it'll hopefully Tighten no more than the 5/16" setting..

OR-----
Start that rigid frame sickle you know you're gonna build eventually,,,,, don't fight it Pal,,,,, you know you want to................................................ .....!!

unclepsycho · #3 06-13-2009, 12:00 AM

I adjust mine without a rider...
is that why I get a wierd howling sound right after each tire change??? it eventually goes away, but the belt makes noise for the first 200 or more miles.
I only "eyeball" it without the Harley tool......

03fxst · #4 06-13-2009, 08:44 AM

Hey Unc
I don't trust my eyeball enough to go that route. Although I read that without a rider you can do a twist check. If the belt won't turn thirty degrees it is too tight if it twists more than 45 it is too loose. Me, I'll tweak with the tool.
Frisco, I have a thirty pound bag of traction sand in the garage (it is Canada) but she is nervous just holding the bike itself up. If she sits on it leaned over on the kickstand with the sand on the back is the tension range the same or must the bike be in an upright riding position.
As for my bud, he weighs thirty pounds more than the two of us combined so the problem is the same.

As for building my own scoot....I fear that psychosis is reaching a critical stage and a frame will arrive in my garage when I least expect...I try to fight it but I grow weak.

Dreaming of a bobber of my very own making..
03FXST

frisco-rigid · #5 06-13-2009, 08:36 PM

I'm sure she can do it..

03fxst · #6 06-13-2009, 10:31 PM

I set it slightly tighter than spec with just her weight. Less than a sixteenth on the snug side. Did the twist test and all seemed fine. Put the belt guard back on took a run and it was perfect solo and later two up. No belt rubbing, no problem.

Gotta love a tweak that works
03FXST

unclepsycho · #7 06-13-2009, 11:06 PM

Thanks for the follow up..... it's good to know when things work out right.

Gas Man · #8 06-14-2009, 04:06 PM

Remember... the more weight added to the bike the tighter the belt will get. So I say run it slightly loose.

frisco-rigid · #9 06-15-2009, 02:39 AM

Hmmmm

OK, let's see a show of hands---- with how many of you does your belt Tighten Up as you add weight..??

Don't listen to him 03,,, as you already know they loosen as weight is added..

He's real good with Valve stem photos though..

HarleyCruiser · #10 06-15-2009, 04:22 PM

Leave it to Frisco, to challenge the mind.
Since the arch of the axel is shorter than the arch of the belt I thought the tire was closer with no weight, as it would be lower than the horizontal plain of the trans pulley, would tighten up until horizontal then loosen up as it arched in higher.
Guess it would depend if the bike was lowered or raised or stock, Don’t know.
It would be pretty easy to tell on a bike with straight rear trailing arm.
Put a straight edge on the trailing arm and see if it was higher than the rear trans pulley center.
Hard to tell on my Softail.
For what it is worth I do mine without any weight at all.
The HD dealer where I bought my bike uses the twist the belt method.
Something about if you do it enough "you know how tight is tight."

Quote:

Originally Posted by frisco-rigid

Hmmmm

OK, let's see a show of hands---- with how many of you does your belt Tighten Up as you add weight..??

Don't listen to him 03,,, as you already know they loosen as weight is added..

He's real good with Valve stem photos though..