[mojo_man]

So the first ride (outside the house)with the ACSD attached and I have to tell you it is not fit for purpose.

In my local sandy crud I had one incident of chain suck and it bent the end and rendered it useless. To add insult to injury it looks like it forced the device up into the bottom of the rear triangle. I haven’t checked for damage yet and I’m knackered. Photos to follow once I can summons the energy.

 

[pachaven]

Bummer:madman:

 

[Internal14]

So the first ride (outside the house)with the ACSD attached and I have to tell you it is not fit for purpose.

In my local sandy crud I had one incident of chain suck and it bent the end and rendered it useless. To add insult to injury it looks like it forced the device up into the bottom of the rear triangle. I haven't checked for damage yet and I'm knackered. Photos to follow once I can summons the energy.

Yeah, without that thing being bolt against the frame in some way, there is no way that the BB cup pressure will keep it from moving. And grossly, it moves a sharp angled aluminum piece into the bottom of the swingarm.

Why didn't IBIS put on ISCG tabs again?? Put a warning on the frame, :Not to be used in conjunction with a fixed bashgaurd. Only for chainsuck device." I guess they didn't originally think chainsuck was going to be an issue since it's been pretty much a moot point on most bikes the past ten years.

Maybe once we all buy enough Mojo's they'll be able to afford another mold and then we can get tabs.

There's got to be a fix for this issue....somewhere.:madman:

 

[Yerma]

mojo man can you post some pictures?

Of the post chain suck ACSD.

So the first ride (outside the house)with the ACSD attached and I have to tell you it is not fit for purpose.

In my local sandy crud I had one incident of chain suck and it bent the end and rendered it useless. To add insult to injury it looks like it forced the device up into the bottom of the rear triangle. I haven't checked for damage yet and I'm knackered. Photos to follow once I can summons the energy.

 

[mojo_man]

FAIL!

I still haven’t assessed the damage if there is any as I will be removing the ACSD tonight.

As you can see in doing its job it has moved back dug into the frame only saved by fishboys frameskin.

 

[Yerma]

What happened?

Can you figure out what actually happened? Did the chain wedge between the pucks and the chainring?

 

[mojo_man]

About 5 miles into the ride there was a big clunk and the chain wouldn’t move so a quick back pedal and carried on. Didn’t happen again all ride.

There was enough force to move the device round. The issue is that as you are sat on the bike the rear triangle pivots away from the ACSD so when it moved round on the BB and the bike un-weighted the suspension would of force the two parts into each other (again and again and again....)

For you reference it was a brand new Shimano Yumeya chain, 11 month old XTR cranks, 2 month old cassette which were all spotless (before the ride)

 

[shiny]

Have you sent any feedback to Ibis on the ASDC? Hope it has not done any damage when it hit the swing arm.

 

[antipatterns]

Installation instructions

Thanks for the pics, and yes, please update us on effectiveness. Seems odd that there are no installation positioning instructions.

Installation instructions:
http://www.acecosportgroup.com/docs/k-edge_dirt_acs_instructions.pdf

I'm running a double (22/36) with just the inner 'puck' and so far it's working out
fine. But I only get occasional suck so it's hard to know for sure that it's doing
it's job.

I also used carbon installation friction paste when I installed it to help prevent
rotation... who knows if that was a good idea or not.

It seems amazing that the chain could hit mojomans hard enough to rotate
it up into the rear triangle like that... The puck sits so close to the teeth that
I just don't see how the chain could put any amount of force into twisting it.
Now he's got me worried that it's going to do more harm than good.

 

[Yerma]

Very poor design.

So... I've been riding MTB's since 1980 and I've wrenched my bikes for most of this time. From a first generation Stumpjumper to my current Ibis, I've had some incidents of chain suck on every MTB I've owned. I keep my drive train in good shape. New chains every 6 months or so, and new inner and middle every year. Lots of lube and wiping down the gunk as needed. My Mojo has not been any worse than other designs but as we all know, in the winter if you live in a wet area with mud and run a triple up front- you will eventually get chain suck. So I was excited to see the ACSD on the Ibis site. I'd just come back from a sticky mud ride with 3 or 4 incidents of chain suck and I figured it would be an effective solution for winter riding. I read mojoman's post about his problems and was concerned but when my ACSD arrived Tuesday, I mounted it up. As pointed out by others Ibis doesn't waste any paper with mounting instructions so I used the online PDF. It's a very straight forward process, double check the order of cup, ACSD and spacer, degrease the faces and (in my case) torque a bit past spec to insure the device won't rotate on it's own. Set the chain pucks close and double check the clearance. The online directions are actually from a Tomac bike so you need to rotate the ACSD closer to the swing arm than shown. The trails in WNC are pretty muddy right now and we've been avoiding the worst ones as not to impact them too much. Today we rode muddy double track and a short single track that had areas of soft sticky mud- a great test for the ACSD. Within a 1/4 mile on the first climb in my small ring I felt the chain catch for a brief second and then release. The drivetrain was under full load, seated and climbing. Remembering Mojoman's experience I stopped to check things out. Sure enough, the ACSD had been forced clockwise into the swing arm. I spent the next 5 minutes trying to wedge a tire lever in between the ACSD and the swing arm to pry it away so I could continue with the ride. I finally succeeded and double checked the clearance between the chainring teeth and it looked fine. Less than 20 meters up the trail it happened again. This time it had shoved the ACSD hard into the swing arm. I realized I'd be walking the rest of the uphill if I tried the same again so I removed the pucks, pried the ACSD arm away and muscled the bike up the climb in the middle ring. If my and Mojoman's experiences are any indication, the design is a failure for anything but the lightest chain suck. With heavier mud the chain sticks to the teeth and begins to wedge the puck away from the ring, forcing the whole armature back into the chain stay. I hope the folks at Ibis stop selling this. It's a poor design and I'll be sending mine back. (edit:yerma)

 

[Coloradoxj13]

Anyone want to buy an unopened ACSD?

 

[getbusyliving]

I hope the folks at Ibis stop selling this. It's a poor design and I for one will be requesting a full refund.

Thanks for the post. Bummer. Looks like we have multiple fairly major thumbs down on this, with zero thumbs up so far...

 

[hanssc]

So... I've been riding MTB's since 1980 and I've wrenched my bikes for most of this time. From a first generation Stumpjumper to my current Ibis, I've had some incidents of chain suck on every MTB I've owned. I keep my drive train in good shape. New chains every 6 months or so, and new inner and middle every year. Lots of lube and wiping down the gunk as needed. My Mojo has not been any worse than other designs but as we all know, in the winter if you live in a wet area with mud and run a triple up front- you will eventually get chain suck. So I was excited to see the ACSD on the Ibis site. I'd just come back from a sticky mud ride with 3 or 4 incidents of chain suck and I figured it would be an effective solution for winter riding. I read mojoman's post about his problems and was concerned but when my ACSD arrived Tuesday, I mounted it up. As pointed out by others Ibis doesn't waste any paper with mounting instructions so I used the online PDF. It's a very straight forward process, double check the order of cup, ACSD and spacer, degrease the faces and (in my case) torque a bit past spec to insure the device won't rotate on it's own. Set the chain pucks close and double check the clearance. The online directions are actually from a Tomac bike so you need to rotate the ACSD closer to the swing arm than shown. The trails in WNC are pretty muddy right now and we've been avoiding the worst ones as not to impact them too much. Today we rode muddy double track and a short single track that had areas of soft sticky mud- a great test for the ACSD. Within a 1/4 mile on the first climb in my small ring I felt the chain catch for a brief second and then release. The drivetrain was under full load, seated and climbing. Remembering Mojoman's experience I stopped to check things out. Sure enough, the ACSD had been forced clockwise into the swing arm. I spent the next 5 minutes trying to wedge a tire lever in between the ACSD and the swing arm to pry it away so I could continue with the ride. I finally succeeded and double checked the clearance between the chainring teeth and it looked fine. Less than 20 meters up the trail it happened again. This time it had shoved the ACSD hard into the swing arm. I realized I'd be walking the rest of the uphill if I tried the same again so I removed the pucks, pried the ACSD arm away and muscled the bike up the climb in the middle ring. If my and Mojoman's experiences are any indication, the design is a failure for anything but the lightest chain suck. With heavier mud the chain sticks to the teeth and begins to wedge the puck away from the ring, forcing the whole armature back into the chain stay. I hope the folks at Ibis stop selling this. It's a poor design and I for one will be requesting a full refund.

Hi guys, just letting you know we tested it here with good results, but not all mud is created equal and we're taking these comments seriously. No problem getting a refund if it doesn't work out for you. We'll stop selling it if it seems lame overall. We welcome the feedback. Also, please realize this is not our design, just a new product that we're offering.

H

 

[Yerma]

Yea, this time of year in WNC it's messy and I had high hopes for the ACSD. I may switch to a single front ring & bash guard for the winter. I hate to lose the 22 for the long climbs around here though. I want to point out that Ibis has been great (like always) and quickly responded to my feedback to them. As Hans points out it's a non Ibis design and it certainly may help in some locals.

 

[adumesny]

Hi guys, just letting you know we tested it here with good results, but not all mud is created equal and we're taking these comments seriously. No problem getting a refund if it doesn't work out for you. We'll stop selling it if it seems lame overall. We welcome the feedback. Also, please realize this is not our design, just a new product that we're offering.
H

As always Ibis is straight forward and honest about things... refreshing and much welcome these days.

 

[Relayden]

For you reference it was a brand new Shimano Yumeya chain, 11 month old XTR cranks, 2 month old cassette which were all spotless (before the ride)

New chain (10 speed?) with 11 month old chainrings, not helping the situation...

 

[getbusyliving]

In case any of you missed this, a good chainsuck writeup from Ibis. Perhaps more effective than a ACSD is "ACSA" (anti-chain suck advice): http://forums.mtbr.com/showthread.php?p=7735626

 

[mojo_man]

New chain (10 speed?) with 11 month old chainrings, not helping the situation...

Its not a 10 speed chain, and I would think that XTR chainrings would last more that 11 months based on the amount I ride.

 

[Fixed]

device

Dang, hoping this might work for me, too.

I have a device on mine that is about 5 years old, with a steel plate that replaces a spacer with a triangular plastic thing bolted on, which in theory, should pry the chain away from the ring.

But, I think everyone making these things underestimates the forces involved. The chain and chainring yanks on the device and rotates it around the bottom bracket, then, if that's not enough, the force bends and mangles the device, too. Think about it, if you are standing hard on the pedals and weigh 170 pounds, there is a whole lot of torque involved.

A solution is going to require a device with some kind of mechanism that will prevent rotation, and it's going to have to be extremely tough and stiff. Might have to involve some kind of roller instead of a fixed friction device to pry the chain away.

 

[redmr2_man]

new chainrings (truvativ on noir crankset), new chain (sram 991), new cassette (sram 990).

I still haven't had one successful wet ride in northern california. Pathetic.