Use an air impact driver c/w a 3/4" BSW impact socket ( machine the socket feed in taper off so that you have maximum engagement) There is no need for any locking devices. This works when the nut has been tighten to 100 ft/lbs and blue loctite has been used.
PD: Primary Drive undo ESA PD7
- Thread starter paw99
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and a few fish suppers! Cheers, Stu.
Here in the U.S. a 1 5/16 inch socket, 3/4 inch drive, fits PD 7 very well. You can get a LOT of leverage with a 3/4 inch drive breaker bar or “T” handle. I just went through your problem.
Now I’m looking for the correct thread pattern (BSF, BSW, CEI ???) die to clean up some of the threads.
Now I’m looking for the correct thread pattern (BSF, BSW, CEI ???) die to clean up some of the threads.
Attachments
The captions on my photos didn’t come through.
1st photo: Plumbers abrasive tape on PD 3/2 to give strap wrench more bite.
2. Strap wrench on PD 3/2 over top of plumbers tape. Note handle of strap wrench on foot peg mount. No torque going through engine parts. If removing PD 7, turn strap wrench upside down.
3. Addition of “C” clamp onto strap wrench for additional holding power.
4. 1 5/16 inch socket and 3/4 inch drive ”T” handle on PD 7.
1st photo: Plumbers abrasive tape on PD 3/2 to give strap wrench more bite.
2. Strap wrench on PD 3/2 over top of plumbers tape. Note handle of strap wrench on foot peg mount. No torque going through engine parts. If removing PD 7, turn strap wrench upside down.
3. Addition of “C” clamp onto strap wrench for additional holding power.
4. 1 5/16 inch socket and 3/4 inch drive ”T” handle on PD 7.
A piece of 3/16 or 1/4 in Aluminum flat bar the width of the sprocket teeth and then put between the 2 sprockets so that they jam one to the other. Then the 3/4 drive 1 5/16 (not forgetting to face the business end of the socket as described by others to get a full bite on the nut. Tightening will drive the cush drive springs to coil bound, and loosening with the alloy in the other way around, will also drive the springs to coil bound. Done well over 100K miles on a couple of bikes using this method. Touch wood never had one come loose. No locktite.
Know Thy Beast should be in your library 3/4 in dia 20 tpi bsf threads (ie 55 degree)
Know Thy Beast should be in your library 3/4 in dia 20 tpi bsf threads (ie 55 degree)
I have experienced the ESA nut coming loose in use. I am also aware that using any form of impact driver in the nut WILL apply a twisting moment the the mainshaft/flywheel interference fit and there is a risk, all be it small, that the mainshaft may turn in the flywheel - not something any one would want.
So some form of chain whip on the teeth of the sprocket along with a solid socket that has had its face squared off to give maximum contact/bite with the nut and a long breaker bar is in my opinion the safest way of removing or replacing the ESA nut.
As to preventing it from loosening off in use, I drilled a series of small holes around the periphery of PD5 which is keyed onto the mainshaft, so should NOT move with the ESA, and modified the top hat to take lock wire as shown in the photo. No need for any form of thread locker. So far 30,000 miles without any subsequent issues.
Martyn
So some form of chain whip on the teeth of the sprocket along with a solid socket that has had its face squared off to give maximum contact/bite with the nut and a long breaker bar is in my opinion the safest way of removing or replacing the ESA nut.
As to preventing it from loosening off in use, I drilled a series of small holes around the periphery of PD5 which is keyed onto the mainshaft, so should NOT move with the ESA, and modified the top hat to take lock wire as shown in the photo. No need for any form of thread locker. So far 30,000 miles without any subsequent issues.
Martyn
I have KTB and refer to it frequently.
My problem is I want to buy a die to clean up the threads. When I go online looking for a BSF 3/4-20 die, I only find thread pitches of 10 or 12 for 3/4 inch BSF.
Poking around online I find CEI offered in 3/4-20, but is the thread profile correct?
Get a Thread file like this for 55deg. https://uni-thread.com/thread_restoring_file.php
Greg,
as seen in my other post, you need 3/4" x 20 TPI Cycle, which is 55 degree Whitworth form.
You'll probably have to source a die from the UK. Someone like Tracy tools.
Good luck,
Delboy.
