fall away??????
Grand HDF Member
Joined: Dec 2004
Posts: 4,513
Likes: 4
From: Midland, TX
RE: fall away??????
Fall away is how the handle bars fall from center to the left or right stop with the bike on a lift. It's used to determine the tightness of the steering head nut. If I'm not mistaken, most newer models use a torque value for the steering head nut rather than using the fall away method. I'm not certain how it is measured.
I believe this is correct, or I could be totally full of crap.
I believe this is correct, or I could be totally full of crap.
Seasoned HDF Member
Joined: Dec 2004
Posts: 7,934
Likes: 43
From: Bloomfield, NM
RE: fall away??????
Pat is right on this. Fall away is used to determine the adjustment on steering head bearings. If you get a shop manual you will find it explained in detail.
When you do the test, make sure that all cables, brake lines, and wiring have enough slack in them that you don't get a false reading from something binding.
Regards,
Bill
When you do the test, make sure that all cables, brake lines, and wiring have enough slack in them that you don't get a false reading from something binding.
Regards,
Bill
Road Warrior
Joined: Feb 2005
Posts: 1,679
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From:
RE: fall away??????
FYI... I found this in a Tech Column...
From: JB <>
Subject: Re: steering head bearings
Make up an alignment pointer with a hanger and figure out a way to prop it up so it is over the front of the fender (like shown in the FM). Then, measure the "drop away" points as described. Tighten the steering nut just enough to give you the correct setting (about 2" between drop away points).
Actually, even though that's the procedure described in the manual, there is a more accurate way. There was an article in Hot XL a few years back that described that procedure, I got in an argument about it with a friend (I defended the FM procedure, which was also the way taught at MMI), but when we measured after both procedures, turned out he was right.
This is how it's done on a Springer, and how it should be done on a Sporty.
[ul][*] Remove anything that binds when you swing the front wheel from lock to lock - clutch cable, etc. - I've even had to loosen the headlight at times. By the way, it' easier to just remove the left lever with cable attached than to take the cable out of adjustment and remove it from the lever.
[*] Remove caliper(s) and hang it/them so they don't hang up when you swing the front wheel. Lift the bike so it's level. Hang a plum bob from that little hole in the front fender.
[*] Slowly swing the front wheel from lock to lock and put a piece of tape on the floor following the path of the plum bob.
[*] Now balance the front wheel so it's pointing straight ahead. Notice that the procedure in the FM also seems to want you to do this but it's impossible without removing the caliper, especially if you only have one. The FM is also unclear as to where you start to "nudge" the wheel. At MMI, we were taught that you start at right lock, and that before you start, you swing the wheel back and forth slowly a few times to distribute the grease in the bearings, or your measurement will be way off. You should do this regardless of which procedure you follow.
[*] Anyway, once you have the tape on the floor, mark the center spot, the spot where the tip of the plum bob points when the wheel is pointing straight ahead. Now distribute the grease and then nudge the fender in one direction from that center point, and mark on the tape where it falls away.
[*] Then distribute the grease again, point the wheel straight ahead so the plum bob is pointing at your center mark, and nudge it in the other direction, again marking on the tape where it falls away.
[*] The distance from fallaway mark to fallaway mark should be 1"-2", preferably right in the middle at 1.5". If it isn't, you can follow the procedure in the manual for adjusting it. [/ul]
Subject: Re: steering head bearings
Make up an alignment pointer with a hanger and figure out a way to prop it up so it is over the front of the fender (like shown in the FM). Then, measure the "drop away" points as described. Tighten the steering nut just enough to give you the correct setting (about 2" between drop away points).
Actually, even though that's the procedure described in the manual, there is a more accurate way. There was an article in Hot XL a few years back that described that procedure, I got in an argument about it with a friend (I defended the FM procedure, which was also the way taught at MMI), but when we measured after both procedures, turned out he was right.
This is how it's done on a Springer, and how it should be done on a Sporty.
[ul][*] Remove anything that binds when you swing the front wheel from lock to lock - clutch cable, etc. - I've even had to loosen the headlight at times. By the way, it' easier to just remove the left lever with cable attached than to take the cable out of adjustment and remove it from the lever.
[*] Remove caliper(s) and hang it/them so they don't hang up when you swing the front wheel. Lift the bike so it's level. Hang a plum bob from that little hole in the front fender.
[*] Slowly swing the front wheel from lock to lock and put a piece of tape on the floor following the path of the plum bob.
[*] Now balance the front wheel so it's pointing straight ahead. Notice that the procedure in the FM also seems to want you to do this but it's impossible without removing the caliper, especially if you only have one. The FM is also unclear as to where you start to "nudge" the wheel. At MMI, we were taught that you start at right lock, and that before you start, you swing the wheel back and forth slowly a few times to distribute the grease in the bearings, or your measurement will be way off. You should do this regardless of which procedure you follow.
[*] Anyway, once you have the tape on the floor, mark the center spot, the spot where the tip of the plum bob points when the wheel is pointing straight ahead. Now distribute the grease and then nudge the fender in one direction from that center point, and mark on the tape where it falls away.
[*] Then distribute the grease again, point the wheel straight ahead so the plum bob is pointing at your center mark, and nudge it in the other direction, again marking on the tape where it falls away.
[*] The distance from fallaway mark to fallaway mark should be 1"-2", preferably right in the middle at 1.5". If it isn't, you can follow the procedure in the manual for adjusting it. [/ul]
Seasoned HDF Member
Joined: Dec 2004
Posts: 11,068
Likes: 1,470
From: Texas! Ya mean there's someplace else?
RE: fall away??????
I use this instead of the mumbo-jumbo fall away method. Got it from an old HD mech off another board.
Jack the front end of the bike off the ground. Tighten the adjusting nut until the front end is hard to turn. Next turn the handlebars back and forth, from stop to stop, through several cycles. Notice the front end becomes easier to turn. Back off the adjusting nut to a slightly loose fit, then tighten to about 9 ft-lbs torque. If the front end still wobbles after this (tire pressure good and tire in good condition, with no cupping, etc.) and the wobble occurs during deceleration, tighten the adjusting nut a bit more.
If you get a shimmy and more tightening does nothing to help, then suspect that the steering head bearings have shifted and the races are no longer parallel to the axis of the steering head. This is not unusual in HD bikes as they are relatively heavy. Modern bike head bearings tend to shift back and forth in the frame, especially on the heavier bikes, and this causes the bearings to become non-parallel. Any free play in the head bearings will compound this situation. This sets up torque forces that constantly try to correct themselves resulting in a shimmy, or head shake. The cause is not looseness; the bearings have shifted, and things ain't parallel. Pull the front end off and try to reseat the races in the frame neck.
Check the head bearings frequently IAW the service manual. Since these bearings do not move around like those on an axle, they tend to stay in one spot in relation to the race. Therefore every blow on the front end from road conditions tends to flatten the individual rollers or ***** ever so slightly. Over a period of time these flat spots can cause a condition whereby you point the forks straight ahead, and they tend to fall back onto the flat spot, causing a weave as you go down the road. If tightening the preload does nothing to correct the situation, suspect flat spots in the neck bearings.
Alpha Samuel (from MSN Harley Tech Tip Message Board)
Jack the front end of the bike off the ground. Tighten the adjusting nut until the front end is hard to turn. Next turn the handlebars back and forth, from stop to stop, through several cycles. Notice the front end becomes easier to turn. Back off the adjusting nut to a slightly loose fit, then tighten to about 9 ft-lbs torque. If the front end still wobbles after this (tire pressure good and tire in good condition, with no cupping, etc.) and the wobble occurs during deceleration, tighten the adjusting nut a bit more.
If you get a shimmy and more tightening does nothing to help, then suspect that the steering head bearings have shifted and the races are no longer parallel to the axis of the steering head. This is not unusual in HD bikes as they are relatively heavy. Modern bike head bearings tend to shift back and forth in the frame, especially on the heavier bikes, and this causes the bearings to become non-parallel. Any free play in the head bearings will compound this situation. This sets up torque forces that constantly try to correct themselves resulting in a shimmy, or head shake. The cause is not looseness; the bearings have shifted, and things ain't parallel. Pull the front end off and try to reseat the races in the frame neck.
Check the head bearings frequently IAW the service manual. Since these bearings do not move around like those on an axle, they tend to stay in one spot in relation to the race. Therefore every blow on the front end from road conditions tends to flatten the individual rollers or ***** ever so slightly. Over a period of time these flat spots can cause a condition whereby you point the forks straight ahead, and they tend to fall back onto the flat spot, causing a weave as you go down the road. If tightening the preload does nothing to correct the situation, suspect flat spots in the neck bearings.
Alpha Samuel (from MSN Harley Tech Tip Message Board)
6th Gear
Joined: Mar 2006
Posts: 11
Likes: 0
Springer Head Bearing Adjustment
This is exactly what I was looking for. My new Springer has a little over 500 miles and the manual says that it is time to check the play. I have a couple of questions:
-- How important is it check this? Steers straight with no clunking or slop when holding the front brake and rocking the fork around now. Jacking it up and disconnecting everything just to check things seems like a violation of "If it ain't broke, don't fix it"
-- Is this one of those things that you check (and possibly adjust once) between 500 and 1,000 miles once it has seated a bit, but never needs adjustment again?
-- The shop manual references a special Springer Head Bearing Adjustment Tool (Part # HD-47255) that allows you to make the adjustments without having to remove bars, riser, or triple tree. Dealer says it is a Special Order Item that costs $49.95 and will take 4 to 5 weeks to get. Seems pretty expensive for something that looks like a $8 to 10 spanner wrench. Is anyone familar with this tool? Is it worth it? Anybody make an aftermarket version that you are aware of? Dealer said only place he could find it was Kent Moore (aka HD).
Thanks,
--Bill
-- How important is it check this? Steers straight with no clunking or slop when holding the front brake and rocking the fork around now. Jacking it up and disconnecting everything just to check things seems like a violation of "If it ain't broke, don't fix it"
-- Is this one of those things that you check (and possibly adjust once) between 500 and 1,000 miles once it has seated a bit, but never needs adjustment again?
-- The shop manual references a special Springer Head Bearing Adjustment Tool (Part # HD-47255) that allows you to make the adjustments without having to remove bars, riser, or triple tree. Dealer says it is a Special Order Item that costs $49.95 and will take 4 to 5 weeks to get. Seems pretty expensive for something that looks like a $8 to 10 spanner wrench. Is anyone familar with this tool? Is it worth it? Anybody make an aftermarket version that you are aware of? Dealer said only place he could find it was Kent Moore (aka HD).
Thanks,
--Bill
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