Proglide rear shocks questiions

[Easyrider]

I've been on a tear reviving my 1997 Proglide that's sadly spent too much time sitting around in the garage for a long time. I purchased it new so no one has ever put a wrench on it other than me. This bike has been a fun, attention getting bar hopper for a long time. The issue I am asking about could have a lot to do with my old age and the ravages of riding a rigid frame panhead and dirt bikes in my younger years. But the Big Dog's ride is REALLY stiff so I feel I need to look into it some.

I recently went over a small pothole and it bottomed out HARD. Loud clunk. This bike is not a low rider so I don't know what hit what but I decided I needed to take a deep dive into the state of the rear shocks. I contacted Progressive and their "expert" seems to know less about their shocks than I do. And I don't know jack.

What I do know is that what's on there is a 412 series Progressive Suspension shock set. They look to be exactly the same as what's listed in my HD parts list for a 1997 FXR/FXWG. The adjustment ring is on the bottom of the shock and uses a 5 position cam scheme. I do not currently have an adjustment tool for them but will order one soon.

The HD service manual strongly cautions to NOT adjust the shocks from max to minimum settings as this can cause serious problems and damage something... something to do with the swing arm as I recall. This makes no sense to me. Perhaps someone a lot smarter than me on here can fill me in? You should be able to adjust back and forth to all five cam settings indiscriminately right? So long as both shocks are adjusted to the same setting of course.

When I get on the bike, the spring compresses an inch or two. If I jump up and down the rear end bounces slightly but it's VERY stiff. I weigh 220# so not a little guy. There's really no way to test the dampener. My experience with shocks is that when the dampener goes bad the rod just slides up and down offering no resistance. If there is a problem with the dampener in my case, it's that one or both of the rods are frozen in place. The Progressive "expert" offered zero help on figuring out if these shocks are bad/worn out.

I thought I'd start by adjusting the shocks to their minimum preload and getting a baseline on how it rides at that setting. Perhaps someone here knows but I'm guessing a 220# rider who rarely rides two-up would be around the middle shock cam setting.

What's confusing me is that it rides like the shocks have way too much preload. But the bike is bottoming out when it hits a tiny pothole which suggests not enough preload. Hoping to get some wisdom from the smart folks on here. Thanks in advance!

 

[Mickmorris]

I've been on a tear reviving my 1997 Proglide that's sadly spent too much time sitting around in the garage for a long time. I purchased it new so no one has ever put a wrench on it other than me. This bike has been a fun, attention getting bar hopper for a long time. The issue I am asking about could have a lot to do with my old age and the ravages of riding a rigid frame panhead and dirt bikes in my younger years. But the Big Dog's ride is REALLY stiff so I feel I need to look into it some.

I recently went over a small pothole and it bottomed out HARD. Loud clunk. This bike is not a low rider so I don't know what hit what but I decided I needed to take a deep dive into the state of the rear shocks. I contacted Progressive and their "expert" seems to know less about their shocks than I do. And I don't know jack.

What I do know is that what's on there is a 412 series Progressive Suspension shock set. They look to be exactly the same as what's listed in my HD parts list for a 1997 FXR/FXWG. The adjustment ring is on the bottom of the shock and uses a 5 position cam scheme. I do not currently have an adjustment tool for them but will order one soon.

The HD service manual strongly cautions to NOT adjust the shocks from max to minimum settings as this can cause serious problems and damage something... something to do with the swing arm as I recall. This makes no sense to me. Perhaps someone a lot smarter than me on here can fill me in? You should be able to adjust back and forth to all five cam settings indiscriminately right? So long as both shocks are adjusted to the same setting of course.

When I get on the bike, the spring compresses an inch or two. If I jump up and down the rear end bounces slightly but it's VERY stiff. I weigh 220# so not a little guy. There's really no way to test the dampener. My experience with shocks is that when the dampener goes bad the rod just slides up and down offering no resistance. If there is a problem with the dampener in my case, it's that one or both of the rods are frozen in place. The Progressive "expert" offered zero help on figuring out if these shocks are bad/worn out.

I thought I'd start by adjusting the shocks to their minimum preload and getting a baseline on how it rides at that setting. Perhaps someone here knows but I'm guessing a 220# rider who rarely rides two-up would be around the middle shock cam setting.

What's confusing me is that it rides like the shocks have way too much preload. But the bike is bottoming out when it hits a tiny pothole which suggests not enough preload. Hoping to get some wisdom from the smart folks on here. Thanks in advance!

Ok so where is your preload set now? Has it always been set as it is now? No adjustments ever? If you are bottoming out you are correct in assuming it would not be enough preload. But if the preload was never correctly set to begin with you may have over time damaged the swingarm bushings and/or the swingarm pivot bolt. They do go bad. Ask me how I know…Anyway if you do as you suggested to yourself and set the preload to the minimum and see where that puts you under load then work your way up to the max preload you should find your ideal preload. I’m curious to know what you mean by it feels like the shocks have way to much preload?

 

[Easyrider]

Thanks for the response! You brought up the point that I mentioned seeing in the HD service manual that I don't understand: damaging the swingarm assembly by incorrectly adjusting the shock preload. For my own education, what "incorrect" setting would cause the damage you and the service manual cause?

The shock preload adjustment is the same as it was when the Proglide left BDM. I do not have the adjusting tool (yet) so I have no idea how it is currently set. Nor do I know if the shocks have the standard or heavy duty springs in them.

Old bike but not ridden hard or roughly. The bushings could be worn out or just old. Damaged pivot bolt? Perhaps you can tell me more on what could be done wrong to cause that damage.

I've added pictures. The bushings look ok to me. Old but no cracks, etc. Note the open circular space in one are around the circumference of the bushings. I don't know what it's supposed to look like in there but it's possible that the bolts bent and the swingarm is sagging and not where it should be. Replacing those fasteners could be above my pay grade. Good call if that's what the problem is!

If the frame wasn't so high off the ground I'd guess that the frame was bottoming out but there's no way the frame rails are hitting the ground when going over such a small dip in the road. So I did suspect that the swingarm might be hitting something... but there is a LOT of preload in the shocks so that swingarm just isn't moving much. Hence why I am scratching my head.

 

[Easyrider]

Looking at this closer I saw a video of an upgrade that could be an expensive overkill since I only ride this bike around town. Doesn't look crazy complicated although I have no ability to press in and out bushings here. Just replacing the pivot bolts could be easy enough and perhaps the wheel and swingarm can stay on? I'll have to look at the service manual. But if it's bent pivot bolts that would explain a lot. Any way to confirm without actually removing the bolts? I like this upgrade as it eliminates the possibility of developing the death wobble. Probably close to $1k in parts and some skin off my knuckles. I don't have a hydraulic lift but my scissors jack and condor chock could be enough.

 

[Mickmorris]

Thanks for the response! You brought up the point that I mentioned seeing in the HD service manual that I don't understand: damaging the swingarm assembly by incorrectly adjusting the shock preload. For my own education, what "incorrect" setting would cause the damage you and the service manual cause?

The shock preload adjustment is the same as it was when the Proglide left BDM. I do not have the adjusting tool (yet) so I have no idea how it is currently set. Nor do I know if the shocks have the standard or heavy duty springs in them.

Old bike but not ridden hard or roughly. The bushings could be worn out or just old. Damaged pivot bolt? Perhaps you can tell me more on what could be done wrong to cause that damage.

I've added pictures. The bushings look ok to me. Old but no cracks, etc. Note the open circular space in one are around the circumference of the bushings. I don't know what it's supposed to look like in there but it's possible that the bolts bent and the swingarm is sagging and not where it should be. Replacing those fasteners could be above my pay grade. Good call if that's what the problem is!

If the frame wasn't so high off the ground I'd guess that the frame was bottoming out but there's no way the frame rails are hitting the ground when going over such a small dip in the road. So I did suspect that the swingarm might be hitting something... but there is a LOT of preload in the shocks so that swingarm just isn't moving much. Hence why I am scratching my head.

What you have pictured there is not the swingarm bushing. That’s just a rubber bushing that covers the pivot bolt. The bushings for the swingarm aren’t visible until you remove the swingarm.

 

[Mickmorris]

Looking at this closer I saw a video of an upgrade that could be an expensive overkill since I only ride this bike around town. Doesn't look crazy complicated although I have no ability to press in and out bushings here. Just replacing the pivot bolts could be easy enough and perhaps the wheel and swingarm can stay on? I'll have to look at the service manual. But if it's bent pivot bolts that would explain a lot. Any way to confirm without actually removing the bolts? I like this upgrade as it eliminates the possibility of developing the death wobble. Probably close to $1k in parts and some skin off my knuckles. I don't have a hydraulic lift but my scissors jack and condor chock could be enough.

It’s not a bad deal to do at home. Just take your time.

Looking at this closer I saw a video of an upgrade that could be an expensive overkill since I only ride this bike around town. Doesn't look crazy complicated although I have no ability to press in and out bushings here. Just replacing the pivot bolts could be easy enough and perhaps the wheel and swingarm can stay on? I'll have to look at the service manual. But if it's bent pivot bolts that would explain a lot. Any way to confirm without actually removing the bolts? I like this upgrade as it eliminates the possibility of developing the death wobble. Probably close to $1k in parts and some skin off my knuckles. I don't have a hydraulic lift but my scissors jack and condor chock could be enough.

Oh yeah. Those are nice he’s installing. Pay attention to the comments he is making about alignment with the transmission case.

 

[Easyrider]

Yeah, thinking more about it I thought maybe that was a dust cover or a bushing designed to just absorb lateral movement. Those bushings don't completely line up with the hole they butt up against. Don't know if they are supposed to. But if they are supposed to then that would be a clear clue that the pivot ends are bent. By a lot.

Wondering if I can change the bushings one at a time without having to remove the shaft and deal with getting everything re-aligned afterwards. The bike doesn't have a lot of miles on it (~23k) but it probably couldn't hurt to change the bushing just because.

Again I don't know if there is a way to tell if the pivot is bent without removing it completely, something I'd like to avoid having to do if at all possible. I'm not smart enough to understand how that shaft could get bent just with normal riding. The service manual said (vaguely) that incorrectly adjusting the shock preload could damage the swingarm..... if you can tell me how and why that would be great.