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Discussion Starter · #1 ·
Hi to all!

When the temperatures goes down to zero my nixon TPC+ 08 feels very harsh (not plush, rebound not so quick). I replace the oil in damper on 2.5wt Motul. My friend (a big Manitous fan) told me what i made mistake and i can damage damper. He's using 10wt all year long.

When i taken off the lowers there no oil in both legs. Also i find a lot of red high viscosity grease on shaft in left leg. May be this red grease makes harsh feel on cold?

Where is the truth?
 

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noMAD man
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Yeah, I even asked Manitou what kind of grease that red stuff was, and they said it was some kind of Motorex stuff. I agree with your observation. There's too much of it in the spring leg IMO, and it's extremely thick. I removed all that stuff when I did mine the first time, and oddly I just seviced mine again yesterday, so everything's fresh in my mind.

I use Slick Honey for greasing the 5" spring that's in that leg. I put a little on the air piston and the pushrods. I use some 15W-50 motor oil for the 3cc for the air piston with just a dash of PFTE. I use the same motor oil for the semi-bath in each leg. Frankly I think any multiviscosity motor oil does fine in the semi-bath.

I can't believe your friend runs 10wt oil inside the damper. The damping would be really slow if I did that to any of the TPC forks I've owned over the years. Manitou recommends 5wt. You can run 2.5wt suspension fluid, and it will not damage the TPC piston rings. If it works for you, it will be fine. I'm thinking your harshness was possibly due more to the lack of semi-bath oil in the forks. When that oil disappears and the fork hasn't been serviced for awhile, it gets sticky and harsh from my experience.
 

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Discussion Starter · #3 ·
TNC thanks for you reply.

My LBS have Manitou Prep-M grease. Would be this thing working like slick honey? The viscosity of oil influences only on speed of damping?

Thank you again.
 

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noMAD man
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Yes, Prep-M can be used in place of Slick Honey. Manitou seems to go back and forth between recommending Prep-M and some type of Motorex grease in different applications in their forks. After owning and servicing many TPC Manitou forks, I haven't found any performance difference in using different high quality bike greases...just don't use anything extremely thick IMO.

I'm sure you realize that the damper oil is extremely critical in what viscosity you use but not so much in the semi-bath oil. I think it's important to use multiviscosity motor oil as the semi-bath lubrication, as this keeps the fork stroking smoothly. The air piston has to be lubricated with a bit of grease/Prep-M and a small amount of oil poured on top of the piston after reinstalling it in the leg. Use decent amounts of the Prep-M grease in the bushing, coil spring, and pushrod areas.

Please let us know if you get any noise out of your fork after a complete service.
 

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I dig trails!
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The TPC system requires that the oil is displaced (pushed up or down) for damping and form movement. If the damper oil viscosity increases, I can see some harshness happening. But isn't the damper oil 2.5w already?

For the bath oil I was recommended that the motor oil be synthetic. Dunno if that makes a difference.

P
 

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noMAD man
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Mr.P said:
The TPC system requires that the oil is displaced (pushed up or down) for damping and form movement. If the damper oil viscosity increases, I can see some harshness happening. But isn't the damper oil 2.5w already?

For the bath oil I was recommended that the motor oil be synthetic. Dunno if that makes a difference.

P
MP, to insure I wasn't having a brian fart, I rechecked my current Nixon printout from Manitou's site, and it's definitely 5wt...Motorex fork oil for their specific recommendation. I've had and done TPC carts for so long that I thought maybe I was just going by autopilot, but apparently 5wt has always been the TPC cart recommendation. Not to say that can't be tweaked with other viscosities for personal tuning preference.

I will say this...my last service from the OEM oil was 5wt Bel-Ray, and my comp/rebound settings didn't change to achieve the same performance. This time I went with 5wt Golden Spectro, and I had to turn the rebound adjuster to full open to get the same results. It was one full turn in from fully open before. It works great, but there was a very subtle change between oils...which just points out that issue that often gets discussed here about the slight differences in brands.

I agree with the synthetic oil recommendation. I don't even have or use any non-synthetic motor oil anymore...for anything. The molecule design and manipulation in synthetic oil is just better and stays that way longer from everything I've read on the issue. You want a good argument...go to a hot rod or motorcycle forum and start discussing motor oils.:lol:
 
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