How to rebuild a "non-rebuildable" CRF150F rear shock..

[bajatrailrider]

Cr85 shock to 150 yes you can do it but not a cheap way to go. As after mods to fit you need change spring and revalve.  So just for starts 125$ plus for shock revalve 150 to 200$   Spring 120$ 

[r1superstar]

On ‎1‎/‎24‎/‎2018 at 11:04 AM, basmn said:

For what its worth.....if only the seal is leaking its worth taking it apart and freshing it up.... if you want high performance...well replace it. I simply drilled it to relieve the gas charge...removed washers from the stack. ( compression and rebound...more so the rebound as it was very slow....changed the oil and i was pleased with the out come...i only trail ride so it worked out just fine. If you want top notch suspension on a bike go buy a bike that has it...i did...a yz250fx..now this bike has suspension ???

What did you drill?  I have the shock apart, but can't get the clip out.  This shock is on an 07.

[Confederate]

You drill a hole where this schrader valve has been installed. You drill a small hole there while wearing safety glasses to release the nitro charge. Then you drill larger and tap to install valve so you can recharge it once back together.

[r1superstar]

5 minutes ago, Confederate said:

You drill a hole where this schrader valve has been installed. You drill a small hole there while wearing safety glasses to release the nitro charge. Then you drill larger and tap to install valve so you can recharge it once back together.

Ah, that's what I was thinking.  How much nitrogen psi should go back in?  And how much oil (oz)?  Thank you so much for the help!!!! 

[ricky racer]

On ‎1‎/‎28‎/‎2018 at 6:30 PM, bajatrailrider said:

Cr85 shock to 150 yes you can do it but not a cheap way to go. As after mods to fit you need change spring and revalve.  So just for starts 125$ plus for shock revalve 150 to 200$   Spring 120$ 

BUT now that the fox shock is no longer available its not bad. I just bought one for $80 shipped plus $129 gold valve do it yourself and a Cannon Racecraft custom spring $125 so $375 after oil and seal. Not bad for the performance I'm expecting! If I could buy a gold valve for my 89 xr600r shock I'm using currently I would keep it. But I've made it work the best you can and that's not good enough for me. Yes I can charge the shock myself with Nitrogen. Now to order up some xr400 forks to replace the xr600r forks on the bike now. Once again because you cant buy good valves for them  

Edited February 8, 2018 by ricky racer

[bajatrailrider]

8 minutes ago, ricky racer said:

BUT now that the fox shock is no longer available its not bad. I just bought one for $80 shipped plus $129 gold valve do it yourself and a Cannon Racecraft custom spring $125 so $375 after oil and seal. Not bad for the performance I'm expecting! If I could buy a gold valve for my 89 xr600r shock I'm using currently I would keep it. But I've made it work the best you can and that's not good enough for me. Yes I can charge the shock myself with Nitrogen. Now to order up some xr400 forks to replace the xr600r forks on the bike now. Once again because you cant buy good valves for them  

Looking forward to your shock mods cr85. It cost more for guys on 230 with stock battery. Remove battery tray mod air box put mini battery on top. Another 100$. Not bad.  For now I will stick to my fox and the other .4 crfs. With xr250r shocks. That mod is about 250$. Shock rebuild and cost of shock used. Keep us posted dig your mods rr 

Edited February 8, 2018 by bajatrailrider

[r1superstar]

Just finished changing the shock seal head.  The old one had the inner o-ring split in half.  I still need to install the Schrader valve and get it charged with nitrogen.  Thanks for all the help with this.

 

Just an F.Y.I.  As stated in a previous post, drill the shock very slowly.  Don't push too hard and et the drill bit do the work up until it punctures the shock.  Then back off and let the nitrogen escape.  I was afraid the shock was going to take off once punctured but it didn't.  Wear safety goggles, try not to inhale the nitrogen, and don't be scared.  

Edited February 10, 2018 by r1superstar
pics

[Hondagal]

On 1/24/2018 at 8:25 AM, firsthere said:

 Are you adding a scrader valve to refill the bladder?

How hard would it be to fit a cr85  shock on my my 2005 crf150f

[Hondagal]

1 minute ago, Hondagal said:

How hard would it be to fit a cr85  shock on my my 2005 crf150f

How do u take the bottom part of the shock absorber off that is above the shaft

[bajatrailrider]

10 minutes ago, Hondagal said:

How hard would it be to fit a cr85  shock on my my 2005 crf150f

Cost shock small battery  revalve spring  about 450$

[bajatrailrider]

You can get as new crf150f shock 50$ plus shipping. May cost more to fix yours.

[adnohguy]

Cost shock small battery  revalve spring  about 450$

2005 and older 150f is kick start and has no battery

[bajatrailrider]

Thank you adn so about 350.00 for cr85 shock to work

[r1superstar]

Update,

 

Installed the shock, rode the bike for two hours the other day. Everything works great!!!  I highly recommend this fix over buying an expensive aftermarket shock. Unless what you are looking for is more adjustability.  This bike is for the wife so the tocks shock will suffice.

[Robert Taylor1957]

This reinforces that many people should be allowed nowhere near suspension because they have the mechanical finesse of an elephant. Back in the 70s when Yamaha introduced De carbon type shocks there was very strictly controlled licensing and training for those carefully chosen to rebuild and service such units. Now several decades later aided and abetted by the internet and these accursed forums ( everything is ''correct'' on such media ) there are even more mechanically inept people ''having a go''. Suspension is a product that can seriously affect your safety and everyone elses in immediate vicinity if done badly. As a professional I witness such ''have a go'' ineptitude day in day out.

 

Vice grips on a shaft, really?  Maybe indeed the sweep area of the seal head will never get there but the jaw marks that broach through the chrome will accelerate the demise of the shaft as raw steel underneath the broached chrome is exposed to the elements in an area of the shock that accumulates dirt, grime and moisture. This part of the blind leading the blind speaks volumes on its own account. I really hope this ''authoritative expert'' doesn't work in the aircraft industry

 

Shaking my head in disgust I really don't have the appetite ( or time )to go through everything else that has been done badly and also NOT done. I make no apologies for stating the obvious and my contempt for such mechanical heresy.

[mixxer]

Geezus Robert....

Go take a midol or two ....

Is someone from this forum bothering you to fix something ??

Were you born knowing how to work on everything, or did you have to learn it like the mere mortals on this forum..

I can understand a heated debate... But I don't think anyone was bothering you to fix anything.   Or arguing with you about how to do it...

If you can't find some midol... I suggest pamprin and a mimosa....?

[r1superstar]

On ‎1‎/‎24‎/‎2019 at 1:05 AM, Robert Taylor1957 said:

This reinforces that many people should be allowed nowhere near suspension because they have the mechanical finesse of an elephant. Back in the 70s when Yamaha introduced De carbon type shocks there was very strictly controlled licensing and training for those carefully chosen to rebuild and service such units. Now several decades later aided and abetted by the internet and these accursed forums ( everything is ''correct'' on such media ) there are even more mechanically inept people ''having a go''. Suspension is a product that can seriously affect your safety and everyone elses in immediate vicinity if done badly. As a professional I witness such ''have a go'' ineptitude day in day out.

 

Vice grips on a shaft, really?  Maybe indeed the sweep area of the seal head will never get there but the jaw marks that broach through the chrome will accelerate the demise of the shaft as raw steel underneath the broached chrome is exposed to the elements in an area of the shock that accumulates dirt, grime and moisture. This part of the blind leading the blind speaks volumes on its own account. I really hope this ''authoritative expert'' doesn't work in the aircraft industry

 

Shaking my head in disgust I really don't have the appetite ( or time )to go through everything else that has been done badly and also NOT done. I make no apologies for stating the obvious and my contempt for such mechanical heresy.

 

LOL ^^^^

[Robert Taylor1957]

On ‎1‎/‎26‎/‎2019 at 3:22 AM, mixxer said:

Geezus Robert....

Go take a midol or two ....

Is someone from this forum bothering you to fix something ??

Were you born knowing how to work on everything, or did you have to learn it like the mere mortals on this forum..

I can understand a heated debate... But I don't think anyone was bothering you to fix anything.   Or arguing with you about how to do it...

If you can't find some midol... I suggest pamprin and a mimosa....?

I was only aware of this forum because a customer sent me a link. My background is I started as an aircraft engineer 45 years ago and for 35 years have been a suspension engineer with proper and formal training. And thence a huge level of experience, supplemented by a suspension dyno. I am a national distributor of 4 ''top of the tree'' suspension brands. Ethos is do the job properly  or not at all.

 

I don't take drugs, my only drug is hard work.

 

I make no apology whatsoever for my comments  including ''the blind leading the blind'' and with so many people only having ''enough knowledge to be dangerous'' this just reinforces my personal contempt of forums, especially when the subject in question places peoples safety at risk. Many of the comments on this thread are mindless and no less than ignorant, such as ''just play with the stack''. Also, ''how much air pressure?" Those that actually know something about pressurised shocks know that you do not pressurise with air along with all of its contaminants and moisture content.

 

On that CRF shock and many non rebuildable ones of its type there are radial indent grooves that hold in place an internal gas dividing piston as a stroke restrictor. NO, IT DOESNT HAVE A GAS BLADDER!!! Some of these travel restrictor rings are almost a complete plate with  small central hole drilled in them, this to afford a crude form of pressure balance

 

So yes you drill a hole to release nitrogen pressure but after drilling and tapping to install a gas charge nipple it leads to the following questions

 

1) How do you remove any residual tapping swarf from inside that chamber? There is always some, no matter how careful you are. That can then  find its way into the sealing o ring on the dividing gas piston. No one has asked this obvious question...…

2) How do you check the integrity of the gas piston o ring and piston ring on the dividing gas piston? Of course you cannot

3) How do you assemble in such a way that at full open position the piston is not topped out against the travel limiter ring? Conversely that it is not near to or bottomed out at the very top of the shock? The first scenario will lead to cavitation and the second scenario can under heavier bottoming loads actually blow the shock apart.

4) What gas pressure has been employed and does anyone on this accursed forum understand the gas pressures required for such a shock with no base valve or compression adjuster? Of course, gas pressure is primarily there to ''preload'' the oil so it doesn't cavitate through restrictive passages

 

The sad thing is some companies will ''rebuild'' these shocks knowing only too well about what I have articulated in point 1 above. But their attitude is why let ethics get in the way of profit?

 

Just like the aircraft industry there should be a level of regulation to protect people from their own ignorance.

[adnohguy]

I was only aware of this forum because a customer sent me a link. My background is I started as an aircraft engineer 45 years ago and for 35 years have been a suspension engineer with proper and formal training. And thence a huge level of experience, supplemented by a suspension dyno. I am a national distributor of 4 ''top of the tree'' suspension brands. Ethos is do the job properly  or not at all.
 
I don't take drugs, my only drug is hard work.
 
I make no apology whatsoever for my comments  including ''the blind leading the blind'' and with so many people only having ''enough knowledge to be dangerous'' this just reinforces my personal contempt of forums, especially when the subject in question places peoples safety at risk. Many of the comments on this thread are mindless and no less than ignorant, such as ''just play with the stack''. Also, ''how much air pressure?" Those that actually know something about pressurised shocks know that you do not pressurise with air along with all of its contaminants and moisture content.
 
On that CRF shock and many non rebuildable ones of its type there are radial indent grooves that hold in place an internal gas dividing piston as a stroke restrictor. NO, IT DOESNT HAVE A GAS BLADDER!!! Some of these travel restrictor rings are almost a complete plate with  small central hole drilled in them, this to afford a crude form of pressure balance
 
So yes you drill a hole to release nitrogen pressure but after drilling and tapping to install a gas charge nipple it leads to the following questions
 
1) How do you remove any residual tapping swarf from inside that chamber? There is always some, no matter how careful you are. That can then  find its way into the sealing o ring on the dividing gas piston. No one has asked this obvious question...…
2) How do you check the integrity of the gas piston o ring and piston ring on the dividing gas piston? Of course you cannot
3) How do you assemble in such a way that at full open position the piston is not topped out against the travel limiter ring? Conversely that it is not near to or bottomed out at the very top of the shock? The first scenario will lead to cavitation and the second scenario can under heavier bottoming loads actually blow the shock apart.
4) What gas pressure has been employed and does anyone on this accursed forum understand the gas pressures required for such a shock with no base valve or compression adjuster? Of course, gas pressure is primarily there to ''preload'' the oil so it doesn't cavitate through restrictive passages
 
The sad thing is some companies will ''rebuild'' these shocks knowing only too well about what I have articulated in point 1 above. But their attitude is why let ethics get in the way of profit?
 
Just like the aircraft industry there should be a level of regulation to protect people from their own ignorance.

So can any of us or at least us regulars on this forum start sending all of our shocks to you and expect excellent results?
What is your normal turn around time?
What is the warranty or adjustment period should any of us have any issues of problem?
What type of pricing can we expect?
I have two shocks right now that need your type of expertise.

You game?

[Robert Taylor1957]

2 hours ago, adnohguy said:

 

So can any of us or at least us regulars on this forum start sending all of our shocks to you and expect excellent results?
What is your normal turn around time?
What is the warranty or adjustment period should any of us have any issues of problem?
What type of pricing can we expect?
I have two shocks right now that need your type of expertise.

You game?

 

If you were up for substantial airfreight costs yes. But frankly I have more than enough work in my own market and have a philosophy of not parasiting into other markets, just for the sake of turnover and profit. We have quite a number of suspension units sold into our country from the USA , of course if something goes wrong the seller is conveniently ''protected'' by distance.  And stuff does go wrong and/or the unit is not set up and sprung properly. What would help to ''make America great again'' would be if a good number of your businesses didn't have a philosophy that includes selling their grandmothers for sixpence...

 

Note that in the case of the very shock type in this thread we would point blank refuse to rebuild one of these given that you cannot check the integrity of the gas piston seals or be sure of removing all tapping swarf. If you cant confidently warranty it don't do the job in the first place. It is for good reason such shocks are non rebuildable.