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Push 11-6 heating issues

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Gemini2k05

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Discussion starter · #1 ·
Has anyone else experienced significant heating issues on their push on extended, intense descents? I’ve got one on three different bikes. And on the most recent one (transition spire) I’ve noticed this problem significantly. Less on the other ones, but probably because I haven’t taken those to a bike park yet. I know @GH28 has experienced the same issue.

I’ve been riding around Chamonix/Portes du Soleil all week, and it is heating up quite badly and getting significant fade. Reduction in rebound and compression damping was very noticeable after the second lap. Between runs it was unable to cool sufficiently so it was getting hotter and hotter on subsequent runs. I have to stop at points and let it cool and spray it with my water bottle. I’m concerned that I’m significantly reducing the service life of the oil in there as well with intense, repeatEd thermal cycles.

However this is basically a corner case for a use application. The runs at morzine were 1500 ft, and 2500 ft at Les Houches, probably average grade around 25%+ and fast, plus I’m 210lbs. Problem is the lift only took 4.5 minutes to get up that 1500 ft. I guess a good problem to have normally, But I think if you were doing a lot of aggressive lift riding or big runs I’d recommend a different shock. I’m still going to keep it because usually I wouldn’t be doing stuff like this on this bike. But I might get like a dhx2 for park days.

These are the trails I was riding for reference.
 
#3 ·
For a start fark yes to Chamonix and Portes du Soleil. I was there 12 years ago and it was rocking back then. Oh yeah.

I've never had any problems with my 11-6. It's not the latest model.

Earlier this year I did an epic 22000 vert meters of descending in 9 days with predominantly 20-30min intense runs back to back. Zero issues.

There might be something wrong with yours.
 
#4 ·
I was in Morzine a few weeks ago and it was 35c + every day. my Ohlins shock got hot to touch but never felt like it faded. how many hours have you got on the shock - maybe the oils toast or the oil in the shock is not very good?
 
#5 ·
PUSH not rated for use in 'yurp, 1000' flow trails only please. :LOL:

All shocks get hot with extended DH use, the Spire has a lower leverage in general and therefore the shock moves faster and creates more damping than say a DH bike with 30% progression which relies on the spring more for support and has a lower shaft speed in general.

If PUSH is in the "more damping, lower spring rate" camp that is popular these days, makes even more sense.
 
#6 ·
My last gen 11-6 performs like a champ. Best shock I have had. Never a heating issue or any other problems or concerns. I dropped down one spring rate from what was suggested, but apart from that, I’m deep into season 3 of some serious fun with it. I would note that it’s been serviced regularly - I have sent it in for servicing every winter.
 
Discussion starter · #7 ·
Maybe there is something wrong with it? I don’t have a thermocouple so can’t say what temp it reaches, but definitely too hot to touch, but lower than 100C because water doesn’t boil on it. I’m sitting in the Verbier parking lot right now, just finished ~20k ft descending day, it was getting very pogo-sticky at the bottom of the IXS race trail each run.

Definitely affecting performance. I’m losing a significant amount of rebound damping, very noticeable.

I don’t have much time on it. Maybe…10 rides before this trip? Less than 100k ft of descending for sure. Could it be a frame alignment issue? 🤷‍♂️🤷‍♂️
 
#8 ·
Gemini2k05 said:
Maybe there is something wrong with it? I don’t have a thermocouple so can’t say what temp it reaches, but definitely too hot to touch, but lower than 100C because water doesn’t boil on it. I’m sitting in the Verbier parking lot right now, just finished ~20k ft descending day, it was getting very pogo-sticky at the bottom of the IXS race trail each run.

Definitely affecting performance. I’m losing a significant amount of rebound damping, very noticeable.

I don’t have much time on it. Maybe…10 rides before this trip? Less than 100k ft of descending for sure. Could it be a frame alignment issue? 🤷‍♂️🤷‍♂️
Click to expand...
How about asking PUSH directly? They are very responsive and are far better able to troubleshoot than anyone else on this forum.
I rode Verbier a few years ago with an 11.6 equipped Nomad. The shock is supposed to get warm with use but I've never had performance degradation, under any condition
 
#9 ·
My Manitou McCoud overheats and loses damping pretty easy on big descents...but it's an XC shock, have noticed a little change on others. You can buy a small cheap infra-red temp gauge to determine the temp change on the body/res.
 
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#11 ·
Heat is normal. How hot is the question. You have to adjust the shock for the temperature. I would say anything under 150f is within spec. At least it's not air or your spring rate would go thru the roof.
 
#13 ·
All shocks heat. The damper turns motion energy into heat and the ambient air takes it away. The more energy you're putting into a shock the hotter it will get.
But shocks shouldn't get out of control as they heat.

Your oil will basically halve in viscosity every 20C. From ambient to 40C it's half it's original viscosity. From 40 to 60C it will roughly halve again. With a well tuned shim stack shock this isn't a problem as the shims react to pressure and viscosity has only little effects.
If you have a shock relying on a lot of open adjusters (or with a lot internal leakage relying on thicker oil to control) then it can start to get out of control as it heats.

@Jayem experince with the McLeod heating and speeding up is one I've also experienced. That's a lightweight shock with ~25cc total oil inside. Even in that case I was able to get the shock stable in the ~20-50C range by using a higher VI (viscosity index, original oil was VI150, new oil was VI405) oil and reshimming the rebound so it used shiims more and the free-bleed less.
 
Discussion starter · #14 ·
The Squeaky Wheel said:
How about asking PUSH directly? They are very responsive and are far better able to troubleshoot than anyone else on this forum.
I rode Verbier a few years ago with an 11.6 equipped Nomad. The shock is supposed to get warm with use but I've never had performance degradation, under any condition
Click to expand...
Yeah of course I will talk to them. Just wanted to see if there were any known issues “out there” first or if I was experiencing something unique (along with @GH28). Seems odd the 2 of us would experience the exact same thing and no one else experiencing anything like it. Oh well, we’ll see what they say.
 
#15 ·
I had an issue with the rebound circuit making my 11.6 erratic and rough during a ride. Sometimes the rebound would be super slow and then speed up wihout touching anything. This happened on multiple occasions so I contacted Push. Darren gave an explanation regarding the rebound needle sticking due to it being forced at either end of its adjustment and the o ring on the adjuster letting in air causing the erratic behaviour. I got the shock stripped and discovered the real reason which was poor machining tolerances causing the needle to stick. In the end I didn't keep this shock long, even after a retune it just felt off but that's another story. Hopefully you have a good one and a service/change of oil fixes it.
 
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Gemini2k05
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