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Discussion Starter · #1 · (Edited)
Edit: This thread is about the standard Mojo.

Third edit: I am leaving the post below as is... But: The only lasting critic I have on the MRP guide for the Mojo is the lack of documentation. I could have sakved myself a bit of tinkering if the documentation would have been clear. Anyway... Now I am running the MRP guide as actually intended by Ibis, including adaptor (second edit). Doing some work with BB spacers ultimately solved all issues. My McGuiver solution isn't really needed. But maybe it is inspiration for retrofitting other guides.

Oh - and a 1x9 with a 32 in the front and a 11-34 in the back works. But it is hard at times. :)

Second edit: What I describe below as the HD axle bolt is actually the official retrofit adapter. I didn't know/understand when Ibis support talked to me.

So finally I've had enough of chain suck and the chain guard rotating. Coughed up the money and ordered the HD chain guide. Friendly Mojo support called me and informed me I would also need the HD axle bolt. Shelled out another $14... Stuff arrived tinkering started.

Findings:

1) Using the prescribed way to retrofit the chain guide has drawbacks: The axle bolt needs to be shortened using a lathe (who got one?). The HD axle bolt does not cover the bearings (drive side), so 2 oddly specked washers/shims would be needed (beyond what ACE stocks).

I spend some time looking at this and now start to realize why Ibis has not come up with a solution. This is complex for any given frame and crank combination. If Mojo frames have slight variations per model year and to allow for different bottom brackets and cranks probably quite some custom washers and shims need to be part of a retrofit package.

2) There seems to be a simpler solution: On my Mojo the axle and both bolts are hollow. A M6 bolt fits nicely in. So my personal solution is to leave the standard Mojo pivot axle in and fix the chain guide plate using a M6 bolt plus some washers.

See the photos.

Now, this is certainly not the perfect solution. But maybe the right direction and perhaps somebody more talented can refine it.

However, if this is dead wrong and dangerous... let me know.
 

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can't wait to hear if this works! The chainsuck is pathetic on these bikes!

Dbug should change his siggy from:

"Those who know, ride a mojo"

to

"Those who know, ride a mojo, unless its raining or muddy or anything wet, and then you ride something else."
 

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I have read a couple of reviews hat suggest that chain such is bad on Ibis bikes? I wonder if the chain suck has more to do with component spec? I just received my HD with the XT build and have ridden through some pretty ugly mud with no hint of chain suck? For sure my specialized enduro would not have last five minutes in those conditions without totally seizing up. I'am running sram on the enduro?
 

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Discussion Starter · #4 ·
RNBN said:
I have read a couple of reviews hat suggest that chain such is bad on Ibis bikes? I wonder if the chain suck has more to do with component spec? I just received my HD with the XT build and have ridden through some pretty ugly mud with no hint of chain suck? For sure my specialized enduro would not have last five minutes in those conditions without totally seizing up. I'am running sram on the enduro?
I don't think this is component related. But if it is... Ibis hasn't published a recommended component list.

I believe the chain suck problem is caused by a a combination of dirt, suspension movement and shifting. Dirt seems to be a pre-condition. Doesn't matter if it is mud or dust. The chain rings (or the chain) get a bit sticky either way. Chain suck happens if during shifting from middle ring to granny the suspension decompresses. Chain tension slacks through shifting and decompressing suspension. The slightly sticky chain gets drawn up by the chain ring, the small bump (on the backend of which the suspension decompresses) might help to send the chain up... The Narrow gap between the low chain stay and the chain rings traps the chain. Damage done.

Hans did a great write-up on how to shift smarter to reduce the chances to have a chain suck. I am pretty confident that he is right on the mark.

Also, the issue might very well be Mojo SL/standard specific. If my theory is close to reality then a slight change in bike geometry (e.g. less narrow gap between chain rings and chain stay) or suspension design (causing a change in timing of suspension move) could actually solve the issue. So far I haven't seen a HD owner report chain suck.

My contraption above primarily addresses the issue of a rotating chain guard. That was far more of an issue as I want to ride technical trails and need to rely on the guard. Trying to be smart about not hitting the guard defies the purpose - the way I ride.

I am planning to check if I can change this setup to a dual chain ring. Stay tuned.
 

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Sorry Kaba I miss read your post.
HD chain guide, HD axle bolts, I thought you were talking about the Ibis HD. I hope you are right about the HD not having chain suck issues.
With my enduro I ended up not riding or finding an alternate location if there was a chance of any amount of mud. It really was that bad.
 

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Kaba Klaus said:
Also, the issue might very well be Mojo SL/standard specific. If my theory is close to reality then a slight change in bike geometry (e.g. less narrow gap between chain rings and chain stay) or suspension design (causing a change in timing of suspension move) could actually solve the issue. So far I haven't seen a HD owner report chain suck.
I have both bikes. Never had chainsuck with the HD, get it occasionally on the Mojo. Both have the exact same cranks, rings, chains, cassette, and ders. I am with you on getting a bigger gap between the chainring and chainstay for the SL.

2 things reduced chainsuck on my Mojo.
1. made an adjustment to the bashguard. Ground off a piece the chain was catching on.
2. moved the chainguide farther away from the chainstay. I have to do this during a ride if I go over a log and the guide hits it and rotates.

redmr2_man said:
Dbug should change his siggy from:

"Those who know, ride a mojo"

to

"Those who know, ride a mojo, unless its raining or muddy or anything wet, and then you ride your HD."
fixed!
 

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I ride an Enduro sl and am currently rtesearching getting a mojo hd.

These reports of chainsuck really confuse me - I have never (never) had chainsuck with my Enduro SL, and being in the UK it's very wet and VERY muddy nearly all the time, running 2x9, e13 chainguide and bash.
 

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Kaba Klaus said:
I am planning to check if I can change this setup to a dual chain ring. Stay tuned.
I'm excitedly waiting to hear your results on this. I ride an SL and am planning a trip through the muddy Kenai Penninsula and then up into the interior of Alaska at the end of this summer; I'm hoping to have a resolution to the chainsuck issue by then. I currently run Shimano's Saint dual chainrings w/bashguard. I've never had to use a chain guide before, so I'm not sure what my options are with the Saint setup. I DO NOT want to give up my dual ring for a single, or my bashguard as I love to use it, so a solution that allows a setup with a dual chainring would be ideal, I had hopes for the Ibis anti-chainsuck device but it sounds like that's been a bust.
 

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Steve.E said:
I ride an Enduro sl and am currently rtesearching getting a mojo hd.

These reports of chainsuck really confuse me - I have never (never) had chainsuck with my Enduro SL, and being in the UK it's very wet and VERY muddy nearly all the time, running 2x9, e13 chainguide and bash.
where are you reading that? everything I've seen, says the hd is chainsuck free.

this thread is about the classic / sl
 
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