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Icebiker
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Discussion Starter · #1 ·
I posted this also in the Shock forum, but doing so here to ask fellow Trigger 29er owners. My 1 year old Fox DYAD was having the problems outlined in the following threads:

http://forums.mtbr.com/cannondale/fox-dyad-rt2-problem-775548-2.html

http://forums.mtbr.com/cannondale/fox-dyad-rt2-problems-904853.html


So after trying the various tips recommended in the first thread with no luck, I sent it in to Fox. I've re-installed it, and the "gap" issue is gone, however the initial shock stroke (in either long or short travel modes) feels notchy. As if the shock shaft encounters some resistance when your first push down on the bike.

Once the shock has gotten past that initial "notch", the rest of the travel (e.g. while riding) feels fine. I don't recall having this when the shock was new, but then again I wasn't focusing on it at the time.

Do any of you Trigger 29er owners have this "notch-in-initial-shock- stroke" issue and is it normal?

If not, I may send it back to Fox since the recent repair should still be covered.

Thanks
 

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Hi Bugeye
Mine is being looked at by Mojo who are the Fox people in the uk. When returned I will let you know how it feels.
 

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Had a very interesting conversation with a technician at mojo here in the UK. Basically he bench tested my shock and checked for leaked etc. Couldn't find a problem. Also he said that the piston is now going in all the way. He has replaced the bushings etc that were worn (which could have caused the creaking noises). I am waiting to put it on to see if it is fine.

He mentioned that all Dyads are not fully serviceable and that they can rebuild anything in the shock and doesn't understand where the myth has come from about some seals not being serviceable. He also mentioned that so ermines the piston just doesn't go all the way in on some shocks even after a total rebuild and providing the sag is correct and it bench tests ok then there is not too much to worry about.
 

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Contact Fox and get it sent back, the shock should not be notchy at all at any stage in the travel.

I sent my Dyad to Mojo UK in Jan this year for a service and when it was returned it was making a knocking sound as it rebounded, i sent it back to them and they replaced the whole unit under warranty. So it is not unheard of that they are returned not functioning correctly after being serviced..
 

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Chick0, mine is back tomorrow so I will check it out. Interestingly Mojo said they have now in stock replacement shocks from Fox should they need them. One can only think the only reason they would need them was if they can't be repaired and they had problems in the past. This is of course only speculation.
 

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Here is a quick video of the knocking sound the shock was making after it was returned from its first service.

I will add that the Fox service centre Mojo in the UK pick up and replaced the whole shock in super fast time (48 hours).




For some reason the in-bedded video is on its side, to see it the correct way click the link below ;)
https://www.youtube.com/watch?v=4gnaW7QWTx8
 

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Icebiker
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Discussion Starter · #8 ·
Thanks guys, I'm going to call Fox tomorrow. Will report back with the outcome.
Spoke to Fox today. Fox agreed notchy isn't normal, but suggested the seals may be a tad dry since the shock hasn't been cycled much yet. Since trails around here have been too soggy to ride, I haven't ridden the bike yet any further than around my driveway. Once I put some real dirt miles on it, I'll recheck. The overhauled shock is under 90 day warranty, so I can always send it in for a rebuild/replace. Will keep you posted. Note: mine doesn't make the noise in chick0's vid.
 

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Ok, my shock is back. Pumped up with the piston firmly wedged into the cylinder. With great difficulty I put the shock back on the bike because the shock eye to eye with the piston fully retracted is less than the gap left when the linkages are fully expanded. 2 people had to push the linkages to be able to get the shock mount bolts through the wholes.
My point is that the eye to eye distance is so incredibly tight that the piston will inevitably pull out a mm or 2 to be able to fit. Once the linkages get a bit of trail use with grit, sand, mud etc then this distance will naturally get bigger due to lack of smooth running In the linkages.

Mine now runs smooth and noise free , but the piston is sticking out a mm or 2 because that was the only way I could get it in the gap.
 

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That's weird.
I've sent had my Dyad serviced recently and when I had to put it back in, it was pretty much effortless.
 

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Ok, my shock is back. Pumped up with the piston firmly wedged into the cylinder. With great difficulty I put the shock back on the bike because the shock eye to eye with the piston fully retracted is less than the gap left when the linkages are fully expanded. 2 people had to push the linkages to be able to get the shock mount bolts through the wholes.
My point is that the eye to eye distance is so incredibly tight that the piston will inevitably pull out a mm or 2 to be able to fit. Once the linkages get a bit of trail use with grit, sand, mud etc then this distance will naturally get bigger due to lack of smooth running In the linkages.

Mine now runs smooth and noise free , but the piston is sticking out a mm or 2 because that was the only way I could get it in the gap.
Sounds strange, are all your suspension pivots lined up correctly? It might be worth stripping down and rebuilding the whole rear end of bike.
 

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Icebiker
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Discussion Starter · #12 ·
^^^agree....Morgs, I think you have to re-look at your linkages...I installed mine super easily, no gaps, no pushing down on the bike....
 

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Have checked out my linkages and it seems that the only thing stopping the linkages from folding back on themselves and hitting the seat tube is this stopper coming from the rear stay and hitting the bottom bracket. Mine is touching with the piston sticking out maybe 2mm. When I put the shock back on I couldn't increase the eye to eye distance because it seemed this stopper was stopping it.
 

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Yep but when unweighted the dyad doesn't show piston. I know this because it was fine when off the bike. The eye to eye is very tight on my bike which causes the piston to pop out
 

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So, you're saying that if you were to let all the air from the negative Dyad' chamber, it would still look like this?
If so, it's possible that the bike is not built properly. Check the rear pivots and try to find a cause.
 

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Interestingly when all the air is let out of the negative the piston is all the way in. I run the shock 290, 245. As soon as I get to around 200 on the negative, the piston just shows it's head. Once the shock is taken off the bike it looks fine which is what the Fox service guys based their assessment on.
 

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It's possible that you're losing a lot more pressure in the positive compared to the negative chamber after removing the pump, so the actual positive air pressure is lower than you believe it is, so "proper" negative pressure causes the piston to extend a bit.

Try pumping the positive about 60PSI more than the chart shows as that's about as much as you lose after removing the pump.
 

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It's possible that you're losing a lot more pressure in the positive compared to the negative chamber after removing the pump, so the actual positive air pressure is lower than you believe it is, so "proper" negative pressure causes the piston to extend a bit.

Try pumping the positive about 60PSI more than the chart shows as that's about as much as you lose after removing the pump.
Yes, this a common problem due the high pressures, air escapes with more force. I found that using the Scott high pressure shock pump helps this a bit, as it has a twin release mechanism.
 

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Have decided to use it over Easter and see what happens. Checked the pressures today. Positive 20 psi down which equates to the usual Cannondale pump connection loss, however negative wax 50psi down from usual.
I have the fault registered with fox even though they say they couldn't find anything wrong so if problem continues I will insist on them having another's look or new shock
 
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