So from the top.

That's a 2000/2001 Xvert single crown you've got. There was no significant difference between the two years but if it's an OEM fork it could have different travel or springs.

Internally it's grease lubricated with the oil contained in the damper leg. It's the TPC/TPC+ compression damper which is a fantastic performer even by todays standards. The seals that can leak are the topcap/end-cap orings and the 1/2" oil seal in the damper end-cap.

The lower legs are lubricated by grease. There's a grease port in the back of each leg, but cleaning and manually lubing works great too. Slickoleum is perfect, the Prep M that manitou used to have is discontinued. Trying to convert it to oil bath will just mean a lifetime of dripping.

It's easy to to work on. The rebound knob pulls out, the lower leg bolts undo the normal way on these and the lowers just pull off. Any oil inside the lowers means the damper end-cap seal are leaking.

Replacement oil is ~15 cSt (Maxima 85-150 or Motorex 2.5wt) and the oil level is 90-100mm down from the top.

Wiper seals are the same as the current Manitou R7 and M30 forks.

 

Sweet! Thanks for such a complete reply. I don't think it's an OEM fork because the Trek VRX 300 came with a Manitou SX, so somebody must have upgraded it with the X-Vert. It's got a few other upgrades as well.

I'm assuming that I won't need much grease so should the 1oz tub of Slickoleum be fine, or will I need the bigger 10oz since it's supposed to be re-greased now and then? And how often do I need to re-grease?

Is the damper end-cap seal also the same as the M7 and M30? Or is it just the wiper seals that are the same?

I read that the Manitou Black is also very similar to the X-Vert and I read here about the procedure to service the fork. Is that about what I should be looking to do since the fork likely hasn't been serviced in a while? It just seems like a bunch of cleaning, greasing and changing oil. Shouldn't be very difficult.

Thanks again for the help.

 

Yes 1oz of slickoleum will be plenty. The damper end-cap seal is the same for all Manitou TPC forks (except the cartridge TPC+ and Dorado) since 1998. We have kits at Shockcraft.

The black is similar to the X-vert and some parts interchange, but the rebound shaft foot design changed which is a big difference in how you dismantle them. The X-vert has a foot bolt which unscrews the normal way (anticlockwise). The Black has a threaded rebound shaft which is unscrewed clockwise into the fork. Get that wrong and you break it.

Yes it's just cleaning, greasing, changing seals and changing oil.

 

Alright, sounds like I can handle that.

I thought I'd check the oil level in the damper according to your instructions here, and when I pulled the compression assembly out there was no oil in there at all. I assume this is very bad. I compressed the fork slightly and still didn't see any oil. I have a little 5w suspension oil but I don't know if it will be enough. Do you know approximately how much oil it takes to fill the damper? I don't want to have to wait till I can get more oil to ride it, that won't be till Monday at the earliest. But I can't ride it dry, and I don't want to waste what oil I've got if it won't fill the damper.

 

Riding the damper dry won't hurt it. But there's not much point in that unless it's your only bike.

Rough calc for oil volume. 23mm ID and 200mm long column of oil would be ~83cc. So not a lot. Whether that 5wt is a good idea depends on who makes it and how many cSt it is. 5wt oils can vary in viscosity by about double at riding temps. The 5wt rating defined at 100C.

 

It's Maxima V-Twin Fork Oil, 16.2 cSt @40°C according to the data sheet (pg 4). No specs listed for 100°C. I couldn't find any difference between it and the regular Maxima fork oil except that it has a different label on the bottle and it's a couple bucks cheaper. The regular Maxima fork oil is rated at 16.2 cSt @40°C and 4.41 cSt @100°C. The Maxima Racing oil you recommended is listed with the exact same numbers on the Maximausa site, so I'm guessing it should be ok? Keep in mind that this is South Florida. It's flat as a pancake here so there's nothing even close to high speed downhill runs.

If I can just pour some oil in and see how this bike handles the trail before getting into a rebuild/seal replacement I'd be seriously happy.

 

Yes that maxima will be perfect. Just be careful it doesn't leak out somewhere else after you pour it in!

 

You just had to say that! That's exactly what I ended up with.

Above, you said that the correct level is 90-100mm from the top, but I measured and it seemed that 100mm down from the top is where there's some hat/valve/washer lookin thing so I followed your other instructions on the Fork FAQ on your site about how to get the oil level to about 5cm above the top compression piston. I got it to about 5.5 but then the fork would only compress about an inch where it felt like it hit a stop. I leaned on it and it slowly went down some, but it started dripping a lot of oil on the floor. When I took my weight off of it, the wiper seal popped off so I figured I must have done something wrong...

I drained most of the oil out of it and now there's more travel, but it still feels like it hits a stop. Before I put oil in it I couldn't hit any sort of stop by leaning on it. I'm guessing that the fork has oil in some place that's not supposed to have oil and I probably need to completely disassemble the fork to remedy the issue.

But I need a longer hex wrench for that because my bits are too short to reach the one on the bottom of the fork. To the hardware store Batman! So what did I do wrong?

 

You just had to say that! That's exactly what I ended up with.

Above, you said that the correct level is 90-100mm from the top, but I measured and it seemed that 100mm down from the top is where there's some hat/valve/washer lookin thing so I followed your other instructions on the Fork FAQ on your site about how to get the oil level to about 5cm above the top compression piston. I got it to about 5.5 but then the fork would only compress about an inch where it felt like it hit a stop. I leaned on it and it slowly went down some, but it started dripping a lot of oil on the floor. When I took my weight off of it, the wiper seal popped off so I figured I must have done something wrong...

I drained most of the oil out of it and now there's more travel, but it still feels like it hits a stop. Before I put oil in it I couldn't hit any sort of stop by leaning on it. I'm guessing that the fork has oil in some place that's not supposed to have oil and I probably need to completely disassemble the fork to remedy the issue.

But I need a longer hex wrench for that because my bits are too short to reach the one on the bottom of the fork. To the hardware store Batman! So what did I do wrong?

The 5cm only works for the dual crown forks where they have a big air space. The single crown ones had a much smaller window.

The oil level needs to be high enough to cover all the pistons and ports. But low enough that the fork still comrpesses fully.

Your lower seal is leaking and dumping all the oil into the lower legs where it doesn't belong.

Why do you need longer allen key bits? The foot bolts only need normal keys.

 

After disassembling the fork, it turns out that the place where I thought I needed a longer allen wrench is actually where the Damper Adjuster Knob is supposed to go. My knob seems to be missing. I thought that was where the compression rod screw was because I thought the little screw on the other leg was much too small to have such an important job. I printed out the fork schematic now to prevent further mix-ups.

The lower leg was indeed full of oil. After further disassembly I found that the shaft seal not only failed but was in many small pieces. It was also very brittle. The damper leg is also missing the O-ring that sits just above the rebound elastomers. At least there's supposed to be one there according to the schematic, but it's outside of the little dotted line so maybe it goes somewhere else.

I reassembled the fork without the shaft seal and filled it just to see if there would be a difference compared to before. I filled it properly this time using a measuring stick, but it felt just like before I started messing with it, without noticeable damping effect. I adjusted the compression knob to the max in both directions but I couldn't tell a difference there either. After a little bit of fiddling I could tell that the lower was filling with oil again because it would hit a hard stop that seemed to be rising slowly.

Even though the fluid is quickly draining into the lower leg, shouldn't there be noticeable compression damping at least in the first few minutes before there's a lot of fluid loss? Everything else appeared to be in good shape. Is there somewhere specific that I should look for other problems? I don't want to get a set of seals if there's something else causing a problem that could mean I need to replace the fork.

 

For a damper to work it must be able to trap oil and control the only escape paths. That doesn't happen if you've got a leak.

Fix the leak (replace that seal) and you'll be good.

 

Alright, I'm ordering the damper seal. I think the wipers are ok. No cracks or damage to either so I shouldn't need to replace them?

Also, I'm trying to find a replacement rebound knob since mine didn't come with one. Can I use a knob from a different fork, like a Mars or something? I tried an allen wrench to adjust it, but it's either a half size, or it's not metric.

By the way, thanks a million for all your help. I'd be guessing in the dark without your advice.

 

Rebound is 3/16" hex which is ~4.8mm.

The knobs from any SX or Xvert 97 to 2002 will work but they're extremely hard to find. I can machine up new aluminium knobs but not cheap.

 

After more than a month I finally got the damper seal ordered and got it installed today. All went well except I lost the little ball bearing that made the rebound adjuster click. No biggie, I can count turns. The rebound adjustment works well and there's a definite difference between max and minimum. The damping adjustment, on the other hand, doesn't seem to do anything. There seems to be no discernible difference with the TPC knob all the way clockwise, or all the way counter clockwise. However, the fork is damping now because it doesn't have that boingy boingy free spring feel anymore. I'm also slightly concerned because when I put a 3/16" hex in the bottom of the fork to adjust the rebound, it always comes out wet. I'm hoping that's just leftovers from all the leakage before. Any ideas?

 

The ball bearing is 1/8" so easy to replace. I'd monitor the wetness on the rebound screw and see if it gets better or worse. Those rebound shafts can be stripped and orings inside replaced if required.

The low speed rebound adjustment on those is subtle. You likely won't feel it pushing on the fork, but riding through g-outs you should feel the difference. You'd need to machine new compression pistons with oring seals and a slight dish in the face so the shims seal better to get a significant change in compression feel by just pushing on the fork.

Funnily enough Manitou did just that with their ABS+ compression damper.

 

It's been almost two months and I thought I'd give an update. The rebound adjustment is indeed subtle, but the compression adjustment doesn't appear to do much, if anything (at least not that I can tell). However, I have absolutely no complaints because it performs very well for my (lack of) skill level, and I feel like I can push it as hard I want without damaging it.

In fact, I like it so much that I'm trying to find another one, or something similar, for my friends bike. He's got original Suntour parts on his Mongoose Otereo and they have disintegrated and given up on life over the last few months while my Manitou quite happily eats up whatever I roll it over.

Thanks again for all the help and guidance.

 

Back for another update and a question or two.

This fork now resides on another bike after I broke the Trek. I've been hammering the heck out of it and It takes punishment well. I've never bottomed it as far as I can tell, and it only weeps oil very slightly at the top cap where you add oil. However, on the crest of some small sharp trail features, the front wheel has a tendency to pop up much more than I'd like even though I've got the rebound turned up all the way. It also feels a little stiff over rock gardens.

The damper adjustment on top still doesn't seem to do anything at all. When it's turned fully clockwise, or fully counter-clockwise it rides the same. I'm guessing this is related to why it feels stiff? Or is the tune of this damper such that the adjustments can only be felt on big hits and drops? Any suggestions on what I can do to get it to ride a little softer, yet not pop on sharp crests?

 

Lots of good information on this thread; thanks. Just picked up a 1998 Specialized Ground Control FSR with the same X-Vert fork. Looking at it they changed out a couple different items as well. I've been out of the loop for a long time. I did find a manual for the fork:
http://www.spoke-n-word-cycles.com/.../TechnicalDocuments/Manitou/Manitou 2001/Manitou 2001 X-Vert Service Manual.pdf

Anyone know of a video help out with basic maintenance. The fork isn't leaking, but have no idea the last it was serviced.

Thanks

 

They're pretty simple. Lower legs are grease (use slickoleum), undo the bottom two bolts and they slide off. Manual has the oil height for the damper, use 15cSt oil. If there is oil in the lower leg then you need to replace the damper seal in the end-cap around the shaft. I have kits for that.

 

Ohh, those late 90's early 00' Manitou forks are good.
Still got an X-Vert Air 120mm laying around. No bleeding the lowers with a zip tie BS back in those days. Those are all new features on expensive forks. LOL