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  1. #1
    No Clue Crew
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    Manitou Tower Pro help request

    Howdy. Recently purchased a leftover '11 Manitou Tower Pro 120mm fork from Jenson for my new Yelli Screamy. I'd had an older Minute years ago and liked it well.

    Took the rig out for a maiden run on the typical choppy AZ chunk I normally ride. Had a couple of abnormal issues I'm looking for help on.

    First, the rebound on the right lower leg has no detents and only 180 degrees of motion. I'm running what appears to be full fast (knob turned clockwise from above/right side up). I'm about 205 pounds in gear. I put about 80psi into the air chamber, which is on the lower end of the recommendation for my weight. I ran the damper fully open.

    Sag was about right, but I got a bit of brake dive, so I dialed in one click of damping. Climbing was fine. However, on high-speed chunky descending, the fork was very rough and clunky sounding. So rough, it knocked my fingers off the brake levers a couple times. The clunking wasn't like a topout clunk that you can re-create by physically topping out the fork. It almost sounds like the spring rattling around inside.

    From the rebuild manual (which I admittedly skimmed through), it appears there's splash oil in the lowers and most of the oil is in the right (damper) leg. Is there no oil in the spring (left) leg? Can I check levels without dropping the lowers?

    There's nothing visibly loose and I can re-create the condition with typical neighborhood riding. Only on high-speed descents with multiple hits.

    Any insight or help? Thanks.

  2. #2
    dru
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    The fork is really easy to take apart. I have the Expert and it is essentially the same with the exception of the spring. The lowers come off by undoing the bolts on the bottom of each leg. Take the rebound dial off first. The spring should have only grease on it, no oil. All the dampening oil is in the right side damper unit.

    You can't check levels without pulling it apart. DOWNLOAD THE MANUAL......

    The fork has bugger all oil in the legs, which is why I checked mine about 2 days after I got it. The legs use 5w 40 synthetic motor oil. A quart will do you about 1,000,000 services.

    I don't know why your fork is noisy. I can hear the rebound on mine, but that's it.

    Drew
    occasional cyclist

  3. #3
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    I haven't used a Tower but did have a Minute 29er. Problem when I got it was a medium spring from the factory. Installed a x-firm(I'm 210 geared up) cured my brake dive and chatter problems. Did not have any noise. No clue on that.
    Keep the reports on the Yelli coming thinking about that for my next ride.

  4. #4
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    Thanks. I know how to take it apart, I was just unclear if I could check oil levels in the damper without dropping the lowers (I have another ride tomorrow and it's 120 degrees in my garage). The noise seriously sounds like the coil whapping around in there.

  5. #5
    dru
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    http://www.manitoumtb.com/assets/Ser...e%20Manual.pdf

    You can yank out the compression damper from the top I do beleive, (and check the oil level) without taking the fork apart, but not the rebound damper.

    Drew
    occasional cyclist

  6. #6
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    OK, did a second run on similar trails. Running the rebound full fast helped somewhat and the fork is super-supple on small bumps and while climbing. Again, though, at high-speed and multiple hits, the fork is extremely rough and clunky. My hands are sore today from the jarring and white-knuckling trying to control it at speed. For reference, I've ridden my SS with an older 100mm QR Reba on some of these same trails and the Reba is much more plush. And the Fox 36 on my Enduro is no comparison at all.

    I did yank the damper from the right leg. Oil level is a tiny bit low from the stated 87mm (some of which could've been lost from pulling the damper).

    If I understand the fork properly, it seems the issue I'm having is once the fork is past the "coil" stage of its travel and is into the air portion. Settings are full fast rebound, 80psi in air chamber and two clicks from full open on the compression damper side.

    Any ideas?

  7. #7
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    You should probably call Manitou, as their customer service is highly rated. At your weight I say you need a firm or x-firm spring.

  8. #8
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    The fork does have a break-in period. Also the fork needs the proper spring for your weight or you will be running too much main spring air pressure.

  9. #9
    Flaccid Member
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    Or buy a Marzocchi Micro Ti.
    "i'll brazilian when YOU do boy, right around the ol' rusty star. Actually, whole fruit bowl. Get on it!" NicoleB

  10. #10
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    Quote Originally Posted by RandyBoy View Post
    Or buy a Marzocchi Micro Ti.
    That's really help-full.

  11. #11
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    I understand the break-in period and the spring issue. None of those would explain the symptoms I'm experiencing. I'm with you on the air pressure, but I'm still at the low end of the scale for my weight. Guess I'll call Manitou tomorrow.

  12. #12
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    Hi Blatant, I have a Tower Pro 2012 model and feel it's great. I imagine the clunking is the ABS+ feature when engaged blowing past the platform. I removed the platform shims. The ABS+ dial no longer functions, on purpose, then by putting more oil on the Damper side I will slowly decrease air volume creating a more progressive feel with more bottom out resistance. The beauty of this fork is the ability to change the feel of the fork to tune it largely how you like it. I don't care about platform but don't like really linear forks.

    I would recommend the heavy spring kit. Swap this out( disc side lower leg). Make sure the coil has grease on it. Also make sure there is 16 cc semi bath oil in both lower legs. You need 10wt 40 oil. I believe Moterola is the brand they recommend.

    By swapping the coil, you can then reduce air pressure. At least I did. Running the same pressure as the stock spring felt very harsh. I dropped 20 PSI, the fork dives alot less and is still super supple. Simple terminology, sag or the initial part of travel is dictated by the coil part of the MARS system. Mid stroke and top out is by the ABS+ including oil levels and shim stacks. High velocity is set at the factory but is effected by tuning, just to a lesser degree.

    The other theory I came up with for the clunking is that the Air pressure used is too high in relation to the stock spring. Remember they work in sequence. To create an even spring rate the air pressure can't exceed the coils intended load. The variance you have may be enough to create a uneven spring rate. (not the technical term)

    Manitou is in fact an excellent resource. The website has alot of tech manuals. I definately recommend playing with the internals. It is alot of fun and very educational.

    Hope this helps.

  13. #13
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    Thanks for the helpful post. I've got a call into Manitou tech right now, just awaiting a callback. To be clear, the sound isn't exactly a "clunk" (not like a topout clunk), but more like a clacking/rattling; this happens no matter what position the ABS is in, even when completely open.

    I like the stiffness and small-bump compliance of the fork. If I could get the bigger-hit/high-speed performance dialed, I'll be stoked.

  14. #14
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    I'm 206 LBS 6'2" I like the stock spring because it is ultra supple. I do however run the heavy spring as it losses very little small bump and allows me to run no platform.

    High velocity as in how violently the fork is forced through it's travel, nothing to do with speed. This is where shim stacks will have to come into play.

    The clacking sounds like a Manitou question. Definately outside my limited knowledge base.

  15. #15
    Trail Tire TV on blogger
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    Quote Originally Posted by cgcharlie View Post
    I haven't used a Tower but did have a Minute 29er. Problem when I got it was a medium spring from the factory. Installed a x-firm(I'm 210 geared up) cured my brake dive and chatter problems. Did not have any noise. No clue on that.
    Keep the reports on the Yelli coming thinking about that for my next ride.
    Tower's need to proper spring just like the Minutes did (basically the same fork)

    Blatant, you should be using the Firm at least at your weight if not he X-firm spring kit, it should cure 90%, if not 100% of your issues. But the Manitou tech's will probably tell you that....


    really wish they sold it in a variety of spring kits, or at least the Firm as the medium doesn't really seem to be the best for the larger variety of people.. once you get the right spring setup you'll love the fork though!!
    Going to try and bring Trail Tire TV back. go take a look... http://trailtiretv.blogspot.com/

  16. #16
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    here's a thread on the whole Manitou tower and spring issues... it's quite LONG.. but worth the read if you can spare the time as the guy gives lots of details and info about the process and working with Manitou

    Manitou Tower Pro Fork for Clydesdales - Techical
    Going to try and bring Trail Tire TV back. go take a look... http://trailtiretv.blogspot.com/

  17. #17
    mtboaxaca
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    2011 Tower pro 29er 140mm

    I have less than 10 rides on this fork since new. I can set the air pressure and it lasts for about 3 hours, it leaks somewhere? I opened the air fill top cap and cleaned/lubed it. Checked the air fill valve its tight. Inside below the cap there is a floating alum. sleeve that I cleaned and lubed. Aired up I sprayed the top cap area w/soapy water, no leaks. Anyone else had the same problem?

  18. #18
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    Quote Originally Posted by MTBOaxaca View Post
    I have less than 10 rides on this fork since new. I can set the air pressure and it lasts for about 3 hours, it leaks somewhere? I opened the air fill top cap and cleaned/lubed it. Checked the air fill valve its tight. Inside below the cap there is a floating alum. sleeve that I cleaned and lubed. Aired up I sprayed the top cap area w/soapy water, no leaks. Anyone else had the same problem?
    Never heard of any issues w/ air loss. If the floating piston leaks air will enter into the lowers. I'd imagine if you removed the spring rod bolt (from the lowers) you might get air release. If that were the case i'd replace the floating piston o-ring and make sure the inside of the stanchion isn't damaged. You can also call Manitou they are quite receptive.

  19. #19
    Trail Tire TV on blogger
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    Quote Originally Posted by keen View Post
    Never heard of any issues w/ air loss. If the floating piston leaks air will enter into the lowers. I'd imagine if you removed the spring rod bolt (from the lowers) you might get air release. If that were the case i'd replace the floating piston o-ring and make sure the inside of the stanchion isn't damaged. You can also call Manitou they are quite receptive.
    everything he said... I emailed them and had a response within 24 hour
    Going to try and bring Trail Tire TV back. go take a look... http://trailtiretv.blogspot.com/

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