Eliminate the Compensator

[Twistedtwincam]

Jan 2023 purchased a Dyna Fat Bob, non molested and less than four thousand miles.

Less then one thousand miles the flywheels my riding style caused the flywheels to drastically shift, vibration was so bad the tail lamp fell off!

I say my fault cause my other bikes are V-rods and ZX14!

So I rebuilt it using S&S wheels, 79cc Super Stock heads, 106 cylinders, fueling 574 camshafts plate &oil pump, S&S 2-1-2 Exhaust, Hayden M6, Fuel-Moto clutch lock up. Quick shifter, Had fuel Moto write the base map, and our local tuner finished it, Amazing to FM cause the Tuner said that base map was 98.9 percent spot on.
 
I now have 900 miles and the factory compensator is failing ( was hoping for a few thousand miles ) bike was equipped with pre SE style, In no way thrashing HD since they build parts to cope with maybe 60 horsepower!

 I really do not want to spend SE $400, MOW $700, Baker $900.
Taking into consideration it's a Friday night Hot Rod, Looking at a Vulcanworks 34 sprocket.

They also make a 32 and the gearing change interests me, considering only use sixth gear at or above 85mph don't like how the bike feels at RPMs below 2700.

I understand both sides of the fence to compensate or eliminate and accept what ever happens down stream and will go with a baker grudgebox and a billet clutch basket.

But what I'm looking for is feedback on dropping to 32?

Thanks for reading my long novel and appreciate advice.
Jeff

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[hrdtail78]

that base map was 98.9 percent spot on.
 

I'd be very happy if my finished tunes were this spot on.

If you have already shifted a flywheel and ruined a comp in 900 miles.  I would not recommend going to a solid or raising the leverage on your crank.  I would suggest looking to retrofit a slipper clutch when doing clutch hub change.

[Twistedtwincam]

that base map was 98.9 percent spot on.
 

I'd be very happy if my finished tunes were this spot on.

If you have already shifted a flywheel and ruined a comp in 900 miles.  I would not recommend going to a solid or raising the leverage on your crank.  I would suggest looking to retrofit a slipper clutch when doing clutch hub change.

Thank you for the Advice hrdtail78!


Just glad four hours of dyno time at $175 wasn't required

[hattitude]

Jan 2023 purchased a Dyna Fat Bob, non molested and less than four thousand miles.


So I rebuilt it using S&S wheels, 79cc Super Stock heads, 106 cylinders, fueling 574 camshafts plate &oil pump, S&S 2-1-2 Exhaust, Hayden M6, Fuel-Moto clutch lock up. Quick shifter, Had fuel Moto write the base map, and our local tuner finished it, Amazing to FM cause the Tuner said that base map was 98.9 percent spot on.
 
I now have 900 miles and the factory compensator is failing ( was hoping for a few thousand miles ) bike was equipped with pre SE style, In no way thrashing HD since they build parts to cope with maybe 60 horsepower!

Looking at a Vulcanworks 34 sprocket.

They also make a 32 and the gearing change interests me, considering only use sixth gear at or above 85mph don't like how the bike feels at RPMs below 2700.


But what I'm looking for is feedback on dropping to 32?

Thanks for reading my long novel and appreciate advice.
Jeff

I put the Vulcan 32T sprocket on my '16 Ultra Classic with a 124" S&S Crate engine (135HP/151TQ) from FuelMoto.  Mine is a Twin Cam application, not an M8, so not sure how/if my experience will translate to your situation.

I am on occasion a "spirited" rider, but I am not as hard on my bikes as you seem to be.

I switched to the solid sprocket @ 32T, just to see what it would be like. That was in 2020, and I am still running it.

It is a little noisier than a compensated engine gear at low speed, low torque situations, but nothing I find offensive. It has been awhile since I checked my primary chain tension, so maybe I should do that...

I like the gearing change. It only added about 250 rpm at an 70mph cruise. I am cruising mostly at 2.9k - 3.3K around here on the SoCal freeways. For comparison, my '16 Dyna (Low Rider) seems to be about 2.7K to 3.0K at the same speeds.

It does require a different primary chain tensioner in my application. The Vulcan kit supplied a manual tensioner with a thicker tensioner pad than the OEM tensioner pad, to be able to run the OEM chain with the smaller sprocket. I'm not sure I like the extra angle to the chain, but doubt it causes any serious issues. Some solid 32T front sprockets use a "shoe" that snaps onto the OEM tensioner. That didn't appeal to me for whatever reason. I don't need to upgrade my clutch basket because of my mostly casual riding style. If I do, I will probably go to a 49t basket. That should get approximately the same gearing change, but I'd be able to run a better fitting primary chain and use the OEM primary chain tensioner..

Here is a pic of the 32T sprocket installed with the included manual primary chain tensioner.

[Twistedtwincam]

Jan 2023 purchased a Dyna Fat Bob, non molested and less than four thousand miles.


So I rebuilt it using S&S wheels, 79cc Super Stock heads, 106 cylinders, fueling 574 camshafts plate &oil pump, S&S 2-1-2 Exhaust, Hayden M6, Fuel-Moto clutch lock up. Quick shifter, Had fuel Moto write the base map, and our local tuner finished it, Amazing to FM cause the Tuner said that base map was 98.9 percent spot on.
 
I now have 900 miles and the factory compensator is failing ( was hoping for a few thousand miles ) bike was equipped with pre SE style, In no way thrashing HD since they build parts to cope with maybe 60 horsepower!

Looking at a Vulcanworks 34 sprocket.

They also make a 32 and the gearing change interests me, considering only use sixth gear at or above 85mph don't like how the bike feels at RPMs below 2700.


But what I'm looking for is feedback on dropping to 32?

Thanks for reading my long novel and appreciate advice.
Jeff

I put the Vulcan 32T sprocket on my '16 Ultra Classic with a 124" S&S Crate engine (135HP/151TQ) from FuelMoto.  Mine is a Twin Cam application, not an M8, so not sure how/if my experience will translate to your situation.

I am on occasion a "spirited" rider, but I am not as hard on my bikes as you seem to be.

I switched to the solid sprocket @ 32T, just to see what it would be like. That was in 2020, and I am still running it.

It is a little noisier than a compensated engine gear at low speed, low torque situations, but nothing I find offensive. It has been awhile since I checked my primary chain tension, so maybe I should do that...

I like the gearing change. It only added about 250 rpm at an 70mph cruise. I am cruising mostly at 2.9k - 3.3K around here on the SoCal freeways. For comparison, my '16 Dyna (Low Rider) seems to be about 2.7K to 3.0K at the same speeds.

It does require a different primary chain tensioner in my application. The Vulcan kit supplied a manual tensioner with a thicker tensioner pad than the OEM tensioner pad, to be able to run the OEM chain with the smaller sprocket. I'm not sure I like the extra angle to the chain, but doubt it causes any serious issues. Some solid 32T front sprockets use a "shoe" that snaps onto the OEM tensioner. That didn't appeal to me for whatever reason. I don't need to upgrade my clutch basket because of my mostly casual riding style. If I do, I will probably go to a 49t basket. That should get approximately the same gearing change, but I'd be able to run a better fitting primary chain and use the OEM primary chain tensioner..

Here is a pic of the 32T sprocket installed with the included manual primary chain tensioner.

[Twistedtwincam]

Thanks for sharing the details on the gearing, exactly what I needed!

Mine is a Twin Cam originally 96 - now 106  my Torque and HP numbers are no where near yours, but in the mid 120s respectively for both HP-Torq

Don't think beat my bikes to death they are very well maintained, Not a drop clutch burn out type of rider, more of a straight line wind it out little past peak power and shift kind of rider!

Agree with everything you wrote, The gearing information was spot on and going to benefit from that!

Thanks and ride safe
Jeff

[Mad-Max]

I'm running the 32T in my 2009 ultra puts 120hp down, ya its a bit noisier but I enjoy it and now I use 6th gear a lot more.

[Twistedtwincam]

Now have the parts to make the parts swap from the 34 to a 30 used my draggy to make a baseline run, instead of waiting for my Local track to open next month.

We have used the draggy on the drag bike in the past during testing down in Mexico, one time I installed in and made some runs comparing accuracy and it's always been within .02-seconds from my time slips.

The retest will use the same section of highway with the same slight grade for the comparison.

Made four runs this was the best with the least wheel spin compared to the other three, road was cold and even with thirty pounds of air in the rear, had to come out of the hole soft not to break traction.

[Twistedtwincam]

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