[MikeD]

Hey, been searching b/c I know this must have been discussed...but couldn't find much. So, what is the clunk that my Firefly (SPV model) is making about an inch into its travel? Noticed it today for the first time...rode with it yesterday around town, locked down, without anything wierd happening. The clunk seems like top-out at first, but I don't think that's it. Happens on both compression and rebound, as best I can tell (was riding all day and didn't bother to take a long assessment of it so long as I could still ride it.)

Seems to have lost some small bump performance recently, even with the air pressure at minimum. Then that seemed to clear up and the clunk started.

Any suggestions or insight? I'll be tearing it down this week, but wanted some background if any was to be had.

MD

 

[DHracer1067]

i thought i heard something about the clunk before. like it was some spv valve opening but i really have no clue. but that might be what it is.

 

[WheelieMan]

Im pretty sure it has something to do with the travel adjustment, ive heard of numerous people with the same problem, although i have yet to hear how it was fixed.

 

[BMXman]

Mike mine also started to make the same noise but it still works fine...so I'm inlcined to leave it be....D

 

[DHblur]

My slider plus makes the same sound if there isn't enough air in the fork. I would see that as your first source of trouble.

 

[James | Go-Ride]

Definitely check your air pressure, we've had a number of Breakout Plus forks with a similar problem if the air pressure is under about 55 PSI.

 

[MikeD]

Hm. Maybe there's a chance I set the air pressure with the fork locked down...would that affect the fork? (I'd imagine not...the air chamber is the same size regardless of position in the travel/lockdown, right? I have yet to take one apart and see how it really works, though.)

But 55 PSI? It *should* be able to go to 30 PSI min, correct?

 

[Gumby]

My firefly has been back twice already for various things.
The clunk was on the last send in. It keeps losing small bump compliance.
It's had stiction problems too. We'll see if they fixed it this time.
It's a shame really because it felt absolutely marvelous when it was new.
I'm picking it up today. I'll post the list of fixes they did.

-Bruce

 

[punkassean]

I have had a top-out clunk the past few rides coming off of lips after pre-loading etc. I was thinking that since I was running the min. SPV PSI that maybe some air leaked over time causing the clunk. hmmm I will check later.

 

[Gumby]

1st ride on freshly serviced fork:
Clunk gone,
No more stiction.
Much plusher. I forgot what it felt like new.
I've really like my bike again.

I was starting to get hand pains from the jarring. I was starting to think that my frame was crap because it had so much brake jack. I couldn't hold a line in a bumpy turn.

It was the friggin fork !!!

So, here's the service list:
- Sher FFL 130 TA MBRY A.M - I've no idea what that is.
- replaced rebound SPV assy
- semi bath was dry. - this is odd because they had the fork in not 3 months ago.

-Bruce

 

[MikeD]

-Sherman Firefly ThruAxle MBRY (is that a name?) AM (time recieved, maybe?)

If I need a new SPV assembly already, that's not encouraging.

 

[Gumby]

Actually it's SHER FFL 130 TA MBRY A/M

The compression dampening knob feels different too. Perhaps it's the compression dampening cartridge for the through axle firefly.

 

[punkassean]

Perhaps I shall send mine in after Vheeeestler...It does feel "dry" I keep putting tri-flow around the dust wipers...

 

[Gumby]

HaHa, I did the same thing out of desparation.
I think that if you're not seeing oil on the stanctions after a ride, it's dry.

I'd check _before_ whistler, you'll have a much better time.

 

[punkassean]

What can I do to check, I am leaving at the crack friday...so I can't send it in exactly?

 

[MikeD]

Haven't looked at the SPV schematics yet, but taking apart a TPC+ fork is simple, and all you do to re-lube is add a small, given amount of motor oil to the leg...it sloshes around and lubes the inners as the fork moves. All you should need to do is download the manuals from Manitou's website and buy the oil; the process should take 20 minutes max.

MD

 

[punkassean]

I am in the same boat, having worked on TPC+ but not SPV, I will see if I can check it out. Thanks!

 

[Gumby]

Try this:

http://www.answerproducts.com/guides/Forks/2004/2004 Sherman Service Manual.pdf?cvar1=7/7/2004+10:57:23+AM

 

[punkassean]

Sweet Thanks!

 

[punkassean]

I have had a top-out clunk the past few rides coming off of lips after pre-loading etc. I was thinking that since I was running the min. SPV PSI that maybe some air leaked over time causing the clunk. hmmm I will check later.

UPDATE*

My friends Slider+ started making "the SPV clunk" while we were up at Whistler, so I pulled it apart to inspect for damage, Nothing was broken and the oil was super clean and full. I did notice that the bushings were really sloppy which kinda sucks for a virtually brand new fork. I cleaned out the lowers and greased the foam wipers and put 15cc of oil in each lower before buttoning everything back up. After charging the SPV chamber to 60psi we took it out for a test ride. The clunk was still there but the fork was much more plush and buttery and the clunk seemed to be less noticeable. Feeling his freshly lubed fork prompted me to pull my lowers off and grease/lube my lowers. After servicing my fork, it too felt super plush initially (almost 888 plush!) but the clunk I have noticed from time to time now seemed more prevalent. I learned from this that Shermans need to be periodically (read frequently) lubed in order to feel incredibly plush but I still don't know what causes the dreaded clunk and why it seems to come and go for no apparent reason? Has anybody else figured anything out? Also the Manitou service manual doesn't ever actually say the proper oil-level for the SPV Shermans, does anybody know what it is? I had to use my fork as reference to fill my buddies...My last new thought regarding the Sherman line is this, in the owners manual it is stated that the exposed stanchion needs to be the full fork travel plus 20mm in order to prevent the reverse arch from contacting the downtube on full compression. This makes me wonder why the slider (lowers) aren't 20mm taller with 20mm more bushing overlap. It seems as though this would help with the somewhat sloppy feel of the bushings and further increase rigidity. Anybody???

 

[Langer]

I have a 03 Slider + and talked to my LBS today about air pressure. They said the higher the air pressure the less spv lockout. The air supposedly raises some valve to make it more plush. I pumped my fork up to 100 psi max and my fork feels less sticky(spv) and more buttery smooth. I have noticed in the past when my air pressure was under 30psi it clunked similiar to what has been posted. Hope this helps.

 

[WheelieMan]

UPDATE*

My friends Slider+ started making "the SPV clunk" while we were up at Whistler, so I pulled it apart to inspect for damage, Nothing was broken and the oil was super clean and full. I did notice that the bushings were really sloppy which kinda sucks for a virtually brand new fork. I cleaned out the lowers and greased the foam wipers and put 15cc of oil in each lower before buttoning everything back up. After charging the SPV chamber to 60psi we took it out for a test ride. The clunk was still there but the fork was much more plush and buttery and the clunk seemed to be less noticeable. Feeling his freshly lubed fork prompted me to pull my lowers off and grease/lube my lowers. After servicing my fork, it too felt super plush initially (almost 888 plush!) but the clunk I have noticed from time to time now seemed more prevalent. I learned from this that Shermans need to be periodically (read frequently) lubed in order to feel incredibly plush but I still don't know what causes the dreaded clunk and why it seems to come and go for no apparent reason? Has anybody else figured anything out? Also the Manitou service manual doesn't ever actually say the proper oil-level for the SPV Shermans, does anybody know what it is? I had to use my fork as reference to fill my buddies...My last new thought regarding the Sherman line is this, in the owners manual it is stated that the exposed stanchion needs to be the full fork travel plus 20mm in order to prevent the reverse arch from contacting the downtube on full compression. This makes me wonder why the slider (lowers) aren't 20mm taller with 20mm more bushing overlap. It seems as though this would help with the somewhat sloppy feel of the bushings and further increase rigidity. Anybody???

Sorry I cant help you with the SPV clunk, but you answered your own question about the stanchion overlap. The lowers cant be any longer because of just that, the reverse arch would hit the downtube. And remember, the sherman lowers extend beyond the axle, so just because shermans have more exposed stanchion than other forks doesnt mean they will have less bushing overlap, or at least thats my thinking...

 

[punkassean]

Sorry I cant help you with the SPV clunk, but you answered your own question about the stanchion overlap. The lowers cant be any longer because of just that, the reverse arch would hit the downtube. And remember, the sherman lowers extend beyond the axle, so just because shermans have more exposed stanchion than other forks doesnt mean they will have less bushing overlap, or at least thats my thinking...

I don't think I was clear enough...what I meant was, why not have the RA stay where it is (in relation to the axle position) but have the actual sliders come up an additional 20mm (closer to the top of the RA)? Now do you see what I mean?

 

[WheelieMan]

I don't think I was clear enough...what I meant was, why not have the RA stay where it is (in relation to the axle position) but have the actual sliders come up an additional 20mm (closer to the top of the RA)? Now do you see what I mean?

Oh, I gotcha, yes that makes sense now. Im not sure why they dont lengthen the lowers. Probably because it saves weight to have them down so low. So are shermans known to have bushing problems? I was just out riding my 03 slider and my fork feels kinda notchy when applying the front brake and moving the bike back and forth. It could be that my headset is loose, but it doesnt appear to be.

 

[Matt D]

I just spoke with Manitou yesterday about the clunk that started on my Minute. I described a similar situation, and the tech thinks it's the SPV valve and is sending me a new one. I'll let you know if it does the trick. PM me in about a week if I forget to post the results.

I'd call the tech support line and tell them what's up and see what they can do.

My Slider+ has been working fine.

 

[punkassean]

If your headset is tight and you still feel "slop" then most likely your bushings are the cause. Place your index finger between the RA and the stanchion and then rock the bike back and forth (with the front brake applied) you will feel a squeeze on your finger when you rock the bike forward and it will relieve when you rock the bike back. The extra weight from a tiny bit more material would hardly overcome the positive of 20mm additional bushing overlap...

 

[punkassean]

I just spoke with Manitou yesterday about the clunk that started on my Minute. I described a similar situation, and the tech thinks it's the SPV valve and is sending me a new one. I'll let you know if it does the trick. PM me in about a week if I forget to post the results.

I'd call the tech support line and tell them what's up and see what they can do.

My Slider+ has been working fine.

I troubleshot the SPV assy. as per the service guide and it is functioning properly...

Please do let us know if this helps your fork.

 

[Matt D]

When I troubleshot the SPV valve it did not spring back quickly, rather it went kind of slow back to its resting position. Did yours do the same, or did it spring back right away?

 

[Rabie]

I have a 03 Slider + and talked to my LBS today about air pressure. They said the higher the air pressure the less spv lockout. The air supposedly raises some valve to make it more plush. I pumped my fork up to 100 psi max and my fork feels less sticky(spv) and more buttery smooth. I have noticed in the past when my air pressure was under 30psi it clunked similiar to what has been posted. Hope this helps.

I feel bad for your fork.

 

[WheelieMan]

If your headset is tight and you still feel "slop" then most likely your bushings are the cause. Place your index finger between the RA and the stanchion and then rock the bike back and forth (with the front brake applied) you will feel a squeeze on your finger when you rock the bike forward and it will relieve when you rock the bike back. The extra weight from a tiny bit more material would hardly overcome the positive of 20mm additional bushing overlap...

Ok, ill have to look at my fork a little more closely. If I do need to replace the bushings, how much is this going to cost? It doesnt make sense to me either why the lowers on shermans arent higher up, I guess manitou has their reasons.

 

[punkassean]

When I troubleshot the SPV valve it did not spring back quickly, rather it went kind of slow back to its resting position. Did yours do the same, or did it spring back right away?

It sprung back right away, it had fairly firm resistance.

 

[Gumby]

I feel bad for your fork.

I just read my manual for my 04 firefly and it said that _less_ pressure made it more plush. More = stiffer
I double checked it to make sure after reading your message.

FWIW, my seals suck too, lots of oil on legs after every ride.

-Bruce

 

[Langer]

I just read my manual for my 04 firefly and it said that _less_ pressure made it more plush. More = stiffer
I double checked it to make sure after reading your message.

FWIW, my seals suck too, lots of oil on legs after every ride.

-Bruce

Double checked message and have ridin on and it feels way better. I read the same thing in my manual and was suprised by the difference. MY SPV DOES NOT LOCK OUT WHEN THERE IS MORE AIR PRESSURE!

EDIT- Let me rephrase this, my spv seems like it doesnt lockout as much with higher pressure, but with the higher pressure the compression is a little stiffer. I also have my compression knob set with no compression. The only noises I have heard are when my air pressure was below 30psi. I will shut up now.

 

[bighitfsr]

Manitous manuals are a total shocker.
There is wrong information in older manuals and the instructions are generally just sketchy.

The manual that came with my TPC+ firefly had the wrong instructions for removing the fork lowers which resulted in me breaking the end off the rebound damper (manual says to remove when it should say turn clockwise/screw in further).

My LBS reckon the current manuals specifiy the wrong ammount of oil in the semi bath (should be only 6mls per leg not 15mls).

Anyway the semi bath lube does not provide all the lubrication for the forks internals. All shermans (TPC+ and SPV) use Prep M (the new golden stuff NOT the blue stuff). For this reason you will need to rebuild a sherman much more frequently than an open bath fork to replace the prep M. This is why the shermans feel so much smoother after a rebuild even though there is still plently of clean oil in the semi bath. My reccomendation is to rebuild the fork (clean lowers, regrease seals and bushings and replace the semi bath lube) when oil rings stop showing up on your stanchtion tubes. At this point the grease lubing the upper bushing and seals is running out. This is also the reason that shermans should have oil rings on the stanchions after every ride.

About the fork lowers.
The reason 7 inch shermans and 5 inch shermans have the same lowers is that its too expensive to manufactuer different lowers for the different forks.
Also if they extended the lowers above where the seals are you'd increase the crown to axle length making the fork much taller. They could extend the lowers further below the axle but I cant see the need to do this. The lowers on shermans are extended more than the lowers on a boxxer or supert. So essentially 7 inch shermans have adequate overlap and 5 inch shermans have excessive overlap. When boxxers went from 150mm travel to 175mm the lowers didnt change, same deal with the shermans.

 

[Garrett]

Double checked message and have ridin on and it feels way better. I read the same thing in my manual and was suprised by the difference. MY SPV DOES NOT LOCK OUT WHEN THERE IS MORE AIR PRESSURE!

EDIT- Let me rephrase this, my spv seems like it doesnt lockout as much with higher pressure, but with the higher pressure the compression is a little stiffer. I also have my compression knob set with no compression. The only noises I have heard are when my air pressure was below 30psi. I will shut up now.

Just for the record...the minimum pressure you're supposed to have in the slider+ is 35psi, so it's no wonder you had problems with it when it was below 30.

 

[punkassean]

About the fork lowers.
The reason 7 inch shermans and 5 inch shermans have the same lowers is that its too expensive to manufactuer different lowers for the different forks. Also if they extended the lowers above where the seals are you'd increase the crown to axle length making the fork much taller. They could extend the lowers further below the axle but I cant see the need to do this. The lowers on shermans are extended more than the lowers on a boxxer or supert. So essentially 7 inch shermans have adequate overlap and 5 inch shermans have excessive overlap. When boxxers went from 150mm travel to 175mm the lowers didnt change, same deal with the shermans.

I still don't think you get what I am saying....I am not suggesting that Manitou make the axle to crown height any different, I am suggesting that they physically add material about 20mm above the existing dust wiper and relocate the dust wiper and upper bushing/seal up 20mm. The top of the Reverse Arch to axle height would remain the same as it is now. This would not make the fork any taller at all. It would however increase the bushing overlap. This change to the lower wouldn't affect 4",5" or 6" Shermans, they all could benefit from this change and it would have no negative side-affect. The shorter forks already have sufficient overlap but at 170mm there is a significant rocking back and forth between the stanchions and sliders even when the fork is brand new. I think this change would especially benefit the Breakout+ due to the extra loads placed on a 7" SC fork, in that application every extra mm. of overlap is greatly appreciated. Basically as far as I know you can never have too much overlap, it is usually a question of how much can you incorporate into the designs physical limitations...

I totally agree with you that Shermans need to have the lowers pulled off and lubed frequently to perform to their full potential and that the oil in the legs only needs to be changed rarely. Oh yeah and the manuals are more or less a rough outline but by no means a step by step guide. That's a shame because although there is only a small amount of info missing or incorrect, it happens to be the most crucial info (oil-levels, etc)

 

[Tarpon]

I've been looking through the Service Guide for the Shermans and it seems to be pretty complete. Oil heights are on the last few pages that have the fork diagrams and torque specs (it's one of the last items in the table). Do you guys really think that greasing the seals and bushings is necessary? The Guide only mentions greasing the spring and the o-ring on the SPV assembly (also the bushing ID to help get the installation tool in/out).

 

[punkassean]

I've been looking through the Service Guide for the Shermans and it seems to be pretty complete. Oil heights are on the last few pages that have the fork diagrams and torque specs (it's one of the last items in the table). Do you guys really think that greasing the seals and bushings is necessary? The Guide only mentions greasing the spring and the o-ring on the SPV assembly (also the bushing ID to help get the installation tool in/out).

When I printed out the manual, the field in the excel spreadsheet for the oil-height was incomplete (blank) and in the paragraph within the step-by-step instructions, there was an underscore ( _ ) where it should show the oil-height. Maybe they have updated it? Yes I really think greasing the foam-ring and adding oil to the lowers is needed for full performance. I know for sure my fork gets real sticky real fast without lube.

 

[Tarpon]

Could be that they updated it, check pages 27-30. I was not implying that no lube was needed, obviously, the 5/20 oil in the semi-bath is required. Anyway, thanks for the info; I'll be changing the oil in my Breakout for the first time soon.

 

[punkassean]

The semi-bath oil (15cc) in each lower leg and Prep-M grease on the foam rings and coil-spring (compression) assy. is also key to stiction free performance.

But what is the dampening oil level? That field is blank in my manual?