Suspension and brake lever feel questions for HP4

[towers040]

Shock is all fitted and torqued up

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[towers040]

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[stuartb]

What a great idea with those axle stands mate !..

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[SSR Suspension]

My understanding of Kashima is that it's for aluminium tubes only as found on mountain bikes. Also, splitting the lowers from the stanchions on USD forks gnarls the threads, best to upgrade the forks.

If somebody is removing stanchions and mauling threads A) They are not using the right tools and process B) They have no clue what they are doing and they should not attempt to do the task!
Removing stanchions DOES NOT maul the threads!!!

Kashima is used in Factory MX Fork slide tubes and shock bodies as they are Alloy. It CAN ONLY be done in Japan as it is a proprietory process owned by the Miyaki Co. and it CAN ONLY be applied to Alloy, Mountain bike stanchions are alloy and not steel like motorcycles.

 

[maubenga]

Who said mauling? I used an engineering term gnarl!
I can't see how you can remove the lowers without using a considerable amount of heat to break the grip of the thread lock.

 

[stuartb]

From what I've read/looked into, heat is essential when removing the lowers from the sliders... I was going to buy a set of sliders for my ZX and done a fair bit of hunting around the web for "how to" tips...seemed to be normal procedure to get a good bit of heat into the bottoms.

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[maubenga]

I was asked by a friend if I could look into this process, so I split a spare set of bent KYB forks.
Knowing that heat would be required to break the thread-lock, I gently applied it evenly until I could free the thread. I immediately noticed the damage to the part of the thread where the thread-lock was. I then applied more heat to the other leg so that it would be easier to split and the damage was the same.
Worried about the amount of heat that was required, I did a little research and found that the cast metal they use has a relatively low melting point of just above 600?C. Due to its various compounds (Silicon, copper, magnesium, iron, zinc, manganese, titanium, nickel, tin and aluminium), it starts to alter at much lower temperatures. At around 150?C the metal is subject to what is called ?thermal ageing? where the natural process of degradation is suddenly accelerated, and at 250?C it starts to deform. The thread-lock compound used by the suspension manufactures requires a minimum of 250?C to break the hold.
After I conveyed my concerns with safety my friend told me to dispose of the parts as it was not worth the risk of them snapping.
Do you now see my concern?

 

[stuartb]

100% mate, couple of videos I watched seemed to work OK but heat on a critical component makes me feel uncomfortable I decided against it after some chat with SSR on here.. mine were only aesthetically affected with DLC wearing off.

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[maubenga]

So SSR advised you against it but they do it anyway?

 

[towers040]

I spoke to multiple different suspension specialists before i decided to get the forks done and they all agreed it could be done and my forks would be fine

 

[stuartb]

So SSR advised you against it but they do it anyway?

No mate, the decision was mine, I don't have the select equipment to do it without resorting to heat.

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[maubenga]

There are no special tools other than a tube clamp and heat. The only way to separate them is with heat, the question is: Should they be refitted after they've been heated to that degree?

 

[JamieMac]

There are no special tools other than a tube clamp and heat. The only way to separate them is with heat, the question is: Should they be refitted after they've been heated to that degree?

From doing it to all my bikes and doing a minimum of 50,000 miles on each, no problem at all with any of them. The biggest pain is getting the locking pin out if they have them. That's what can damage the internal threads.

 

[maubenga]

I've fired off some emails to reputable suspension manufacturers to see what they say. I've seen aluminium knuckles on cars deform once heated to the same temperature. I didn't have any issues with the grub screws, it seems to be thread-lock related as that's where all the damage was.

 

[SSR Suspension]

I have personally never had any issues with removing tubes and have lost count how many I have swapped or removed for coatings, nor has any other suspension guy that I know. We certainly do not heat the foot though, and it does not take as much heat as what you believe, but you do need adequate torque.

When i worked for Ohlins in BSB we would use mapgas in the truck when doing teams forks but you don't need a huge amount of heat.

Where did you get the information about the loctite used by the OEM suspension companies, ive attended Factory training with Kayaba and we were told to use mapgas to break down the loctite when removing tubes.

Aftermarket race forks have very very little loctite if any (some of the stuff i have worked on at Ohlins had none), its a secondary safety next to torque at the end of the day its a threaded pipe into a tapped hole which is basic engineering.

Kayaba, Showa, Sachs are the primary companies that supply manufacturers with suspension Kayaba and Showa also produce Factory spec Off Road suspension as well as OEM manufacturer suspension.

Not all forks use grub screws, they dont really serve any purpose and for the most part most brands use a loctite to secure the steel stanchions in the feet. To note, MX and offroad forks tend not to use loctite or grub screws at all! They are very easy to remove.

I use loctite 2701 when reinstalling tubes as well as torquing the tubes, i have a special insert for my clamp tool which all K-Tech service centres would have purchased from their dealer tooling catalogue. We torque the tubes when we reinstall them. You'd be very unlucky if a tube unscrewed itself, as i said offroad bikes have no loctite nor grub screw and them bikes take far greater impacts than any road bike takes and never has a fork unscrewed itself.

 

[SSR Suspension]

Generically all loctite has the same breakaway temperature, the tube clamps we use have a width of 2ft, so there is plenty of breakaway torque. There is a little trick that a few of us use to help the process, i generally am of the mantra the turtle beats the hare when removing tubes, i have used a laser thermo gun to see how hot the tube has become before now, out of interest. I did not see any extreme temperatures registered on the cast alloy foot nor the steel tube, I do not know the specific spec of the loctite used by oem other than equivalent to 2701.

Ref the other user who asked me about removing tubes I did not advise him against it, his DLC coating was wearing. Which it will after all it is only a coating and after some 15 years of use you would expect some wear, after all PVD coatings for the most part are aesthetic, yes they do have a benefit of reduced stiction which aids the forks action but the rider would never ever feel that. I advised that the wearing of the coating would have no adverse affect on the working of the fork...

As for special tools, the clamp tool is a special tool. You can buy a cheap tool which can be used on some tubes but it is nowhere near as good as a proper clamp tool, but the Ohlins/K-Tech tool can not be purchased by the public.

 

[SSR Suspension]

 

[maubenga]

I?m aware how Ohlins remove their knuckles as I?ve seen it done. I wouldn't know what alloy they?re using as my findings relate to the cast alloy used by the Japanese.
Most of the manufacturers use green thread-lock. Loctite states in their technical data sheets ?Apply localized heat to the assembly to approximately 250?C. Disassemble while hot?.
I?ve not had any issues with grub screws.
I received a few replies from some manufactures. K-Tech basically avoided the question, which did not surprise me. Race Tech were helpful, they mentioned that the gnarling occurs if too little heat is applied which is more common than over heating.
Also, I do not have permission to access the image in your last post.

 

[scooby]

View attachment 5799

can you see it now?

 

[maubenga]

Is states 'may not have sufficient privileges to access this page'.