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I just acquired a Manitou Magnum 29+ 100mm travel fork that has IVA. Have not installed the fork but wonder if I should swap out the IVA for IRT? I have read once the IRT is tuned the performance is really good but this is on longer travel forks. Not sure the 100mm fork would benefit. Thanks.
 

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Yes, you can swap for the IRT. I run my magnum pro at 140mm and love the IRT once I got it tuned in. It wasnt really easy as small changes make a pretty big difference. But once it was there, its butter! Totally worth it on the longer travel. I cannot speak for the 100mm of travel though.

Why not give it a shot with the IVA first and if you are happy with how it feels, no reason to switch to IRT.
 

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From what I've seen online, You can put the IRT assembly on a Mattoc comp, but you have to make sure the threads are fine (0.8mm) And you have to do a piston swap. Mattoc IRT Upgrade Kit Fine Thread 2020+ (Manitou) | Shockcraft Not sure what that means or how to do it, but I might consider doing it on my new Mattoc comp. It's not reaching anywhere near full travel with the IVA on the highest air volume setting. Idk if I should resort to just taking parts off of the IVA assembly.
 

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From what I've seen online, You can put the IRT assembly on a Mattoc comp, but you have to make sure the threads are fine (0.8mm) And you have to do a piston swap. Mattoc IRT Upgrade Kit Fine Thread 2020+ (Manitou) | Shockcraft Not sure what that means or how to do it, but I might consider doing it on my new Mattoc comp. It's not reaching anywhere near full travel with the IVA on the highest air volume setting. Idk if I should resort to just taking parts off of the IVA assembly.
If you want more volume than IVA gives, just take the o-ring off the IVA piston. This brings more dead volume into play.
You can put the o-ring back whenever you want.
 

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If you want more volume than IVA gives, just take the o-ring off the IVA piston. This brings more dead volume into play.
You can put the o-ring back whenever you want.
Shh, don't tell, I was just about to release my volume maximizing top cap for $200.
 

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If you want more volume than IVA gives, just take the o-ring off the IVA piston. This brings more dead volume into play.
You can put the o-ring back whenever you want.
Hey so I went for a ride this morning and took out that o ring and I'm still getting only 80mm of travel. I have the 29/27.5+ 120mm comp version and when it was shipped to me it actually came as a 160 with 4 travel spacers included in the box, but very clearly said 120 on the fork so I took the fork apart (after making some tools) and realized there were already 2 spacers on this air spring and it didn't make sense why it measured160mm. It just wasn't matching with any of the charts I looked at. Is it possible I put the spacers in wrong? I added the 4 spacers to the same side that the other 2 spacers came on. Technically 2 spacers in the 29er version should be 120 according to the Mattoc chart, but it was very much 160mm of travel. In total I have six spacers in the fork now and my exposed stanchions do indeed measure 120mm. For reference, here are the charts that came with my fork, one is dated 2018 and the other I think 2017.
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Mine is 2021, I'm starting to think maybe the correct orientation is 4 spacers on the bottom of the piston or 3 and 3 on opposite ends like for the mastodon fork EXT 120. Also, its strange that they would send both of these with my Mattoc. They also sent me A chart for a magnum which I believe they don't even make anymore. Any insight would be appreciated
 

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Hey so I went for a ride this morning and took out that o ring and I'm still getting only 80mm of travel. I have the 29/27.5+ 120mm comp version and when it was shipped to me it actually came as a 160 with 4 travel spacers included in the box, but very clearly said 120 on the fork so I took the fork apart (after making some tools) and realized there were already 2 spacers on this air spring and it didn't make sense why it measured160mm. It just wasn't matching with any of the charts I looked at. Is it possible I put the spacers in wrong? I added the 4 spacers to the same side that the other 2 spacers came on. Technically 2 spacers in the 29er version should be 120 according to the Mattoc chart, but it was very much 160mm of travel. In total I have six spacers in the fork now and my exposed stanchions do indeed measure 120mm. For reference, here are the charts that came with my fork, one is dated 2018 and the other I think 2017.

Mine is 2021, I'm starting to think maybe the correct orientation is 4 spacers on the bottom of the piston or 3 and 3 on opposite ends like for the mastodon fork EXT 120. Also, its strange that they would send both of these with my Mattoc. They also sent me A chart for a magnum which I believe they don't even make anymore. Any insight would be appreciated
Okay. You've got the 27+/29". That started as a Magnum and then became a Mattoc. It normally ships at 120mm travel, can do 140mm travel with two spacers removed from inside the stanchion and can do 150mm with some custom mods.
It cannot do 160mm. Only the 27" forks can do that.

Mastodon is a different fork. Don't look at that spacer sheet, it won't help you.

Take the lower legs off and measure the exposed air shaft from end-cap to bottom of the rubber bumper and that's your max travel.
While you're in there check the damper side shaft strokes all the way home. If it doesn't you can have too much oil in the damper.
 

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Okay. You've got the 27+/29". That started as a Magnum and then became a Mattoc. It normally ships at 120mm travel, can do 140mm travel with two spacers removed from inside the stanchion and can do 150mm with some custom mods.
It cannot do 160mm. Only the 27" forks can do that.

Mastodon is a different fork. Don't look at that spacer sheet, it won't help you.

Take the lower legs off and measure the exposed air shaft from end-cap to bottom of the rubber bumper and that's your max travel.
While you're in there check the damper side shaft strokes all the way home. If it doesn't you can have too much oil in the damper.
Ok I'll definitely check that. Is it possible for a fork to have 120mm of travel but have an exposed stanchion of 160mm? Because that's basically what mine was like when I got it. I do remember that the stanchion tubes looked really long when I opened it. Could it be mis-manufactured? To me it's starting to look like they put the lowers and air spring from a mattoc 29 onto an upper leg assembly from a 27.5 boost fork. That would explain 120mm of travel with 160mm of exposed stanchion when the fork has 2 spacers. But I can't be sure.
 

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Ok I'll definitely check that. Is it possible for a fork to have 120mm of travel but have an exposed stanchion of 160mm? Because that's basically what mine was like when I got it. I do remember that the stanchion tubes looked really long when I opened it. Could it be mis-manufactured? To me it's starting to look like they put the lowers and air spring from a mattoc 29 onto an upper leg assembly from a 27.5 boost fork. That would explain 120mm of travel with 160mm of exposed stanchion when the fork has 2 spacers. But I can't be sure.
Exposed stanchion is not travel. These forks don't use all the stanchion and the crown is tapered so extends further down the inside than the outside.

You need to measure the shaft inside if you're changing travel.
 

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Exposed stanchion is not travel. These forks don't use all the stanchion and the crown is tapered so extends further down the inside than the outside.

You need to measure the shaft inside if you're changing travel.
That makes sense. But is that normal for a fork to have 160mm of stanchion exposed but 120mm of travel? That's just strange to me. It raises the front end way too much. I've just never seen a fork that just leaves 40mm of stanchion not used like that.
 

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That makes sense. But is that normal for a fork to have 160mm of stanchion exposed but 120mm of travel? That's just strange to me. It raises the front end way too much. I've just never seen a fork that just leaves 40mm of stanchion not used like that.
You need to measure the exposed shaft inside.
 

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Having a 27+ Magnum, I would like to know how I can increase the travel to 150 mm with a custom mod

Exposed stanchion is not travel. These forks don't use all the stanchion and the crown is tapered so extends further down the inside than the outside.

You need to measure the shaft inside if you're changing travel.
 
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