More Top End

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gilb
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More Top End

#1

Post by gilb »

This is a 53 Panhead with a enclosed belt drive. I have a 24 tooth trans sprocket and a 51 tooth rear sprocket, The engine sprocket is 39 and the clutch is 62. I think I calculated this before and have a ratio of 3.38. I feel comfortable at 55-60 mph with this but would like to get at least another 5mph at the top end. Would changing the trans sprocket to a 25 tooth accomplish this? Can you gain about 5mph per tooth, at the same rpm?

Thanks!
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Re: More Top End

#2

Post by VPH-D »

If you get much bigger with your gears, you're gonna have a hard time getting the bike moving without slipping the clutch...
VPH-D
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Re: More Top End

#3

Post by 65panhed »

The 25 tooth will also possibly chew into the clutch arm on the tranny. I run 25 tranny and 47 rear wheel and O-Ring chain and the arm has been chewed. I jus weld it up when I have to. My objective is to keep overall engine speed down and with the 4 3/4 arm I really need to watch the piston speeds.
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Re: More Top End

#4

Post by RUBONE »

Spin it faster...
Why is everyone so afraid of RPM. Engines work well and last long when spun into their sweet spot, and it isn't about loping...
Lugging an engine will kill it just as fast as over revving.
As for the 4-3/4 inch arm. I liked to bounce my 4-3/4 inch stroke off the 7K mark on the tach for shifting...
All this fear of piston speed, torque specs, highway RPM, has taken all the fun out of riding .
Ride it like you stole it and quit worrying. :roll:
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Re: More Top End

#5

Post by 65panhed »

Rubone...You obviously have more money than I do. I prefer not to mistreat my equipment.
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Re: More Top End

#6

Post by RUBONE »

Nope, very little money..
But my stuff doesn't break!
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Re: More Top End

#7

Post by bangkokbob »

Running standard everything except for belt drive.
ie 22 T front sprocket and sweet spot 65-70 MPH.
Thinking about going up to 23T when chains and sprocket need replace.
Maybe sweet spot 70-75 MPH.
Regards B.B.
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Re: More Top End

#8

Post by PanPal »

It is my understanding that the balance factor changes the sweet spot. These motors wind up just fine. They do like the RPMs. I wouldn't go too tall with the gearing either. You just loose all the balls your motor can provide for top end. No more fun in the mountains.
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Re: More Top End

#9

Post by 49bones »

RUBONE wrote:Spin it faster...
Why is everyone so afraid of RPM. Engines work well and last long when spun into their sweet spot, and it isn't about loping...
Lugging an engine will kill it just as fast as over revving.
As for the 4-3/4 inch arm. I liked to bounce my 4-3/4 inch stroke off the 7K mark on the tach for shifting...
All this fear of piston speed, torque specs, highway RPM, has taken all the fun out of riding .
Ride it like you stole it and quit worrying. :roll:

when i have gotten back home after a good trash out on mine its normally running better than ever. You don't have to baby them! Ride em.
gilb
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Re: More Top End

#10

Post by gilb »

OK, Thanks for all the response. My wife and I just did a 1600 mile trip and tried to keep it around 60 most of the way. The vibration just seems so intense when I hit 65 or 70, the wife gets upset as there is so much vibration on her footpegs and I notice it as well on the floorboards. I will try to see if I can find a sweet spot over the 70 mph.
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Re: More Top End

#11

Post by PanPal »

Check you motor mount bolts. Loose bolts don't help.
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Re: More Top End

#12

Post by 58flh »

Gilb-----I have been saying this to alot of guys!--As Rubone said--If your comfy at 55-60---Then Your motor (I believe is spinning low RPM)-Dont be afraid of 4000RPMS---This is where there INTENDED FACTORY DESIGN is meant for!.Doing 70mph at 3500Rpm--IS LUGGING!--NO GOOD ,Maybe it feels better to you ,But the motor Dont like it & You will actually end-up SERVICING your bike MORE!.I run a chain,24T-compensater/ 24T-Mixer-51Rear.I pass at 90MPH-Also I have no off-line issues!.Spin it & frequent OIL CHANGES/& weekly look over is all thats required to have a daily SUCESSFUL RUNNER!.I wouldnt give you bad or a STORY of INFO!.IM telling you from actual EXP.---Anybody Here that REALLY uses thier machines for DECADES,Become familier with every quirk the machines have!.I use to want lower RPM!--BUT MY POP said IF it were good for the design He would of changed it long ago!.I BUBBLETEST 1-Time a month!--sometimes nothing -other times a pinhole leak & a 1/2 turn on clamp its gone!--I just went from 2-kicks back to 1-kick!.The top-End on Pans is virtually indestructable!-(olny lack of oil can hurt them.And they dont lack!.Trust your skills man,that you no-doubt have & built a nice MOTOR/MIXER!---Let her spin----Check this out-(T-Monster wheels/Much heavier & there spinning & most important LASTING without damage--Even Strokers to 84-inch are totaly safe daily runners!).--Respectfully----Richie
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Re: More Top End

#13

Post by 1962FLH »

From what you are saying it sounds like the motivation for the Drivetrain ratio change is excessive vibration. Drivetrain ratio change does not make excessive vibration go away. Just forces you to put up with it at a different speed. Excessive vibration is not normal. Excessive vibration will break motor mounts and frames and cause things to fall off. I would find and address the cause of the vibration before gearing up.

Good luck with it.

John
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Re: More Top End

#14

Post by VPH-D »

It just occurred to me that your speedo is about 10 mph off, because of your 24 tooth trans sprocket. You're not going 60 when the speedo says so...
VPH-D
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