PoweriZer pro bearing install Pt. 1

[MKudlock]

For this mod, you will need:

bearings (http://www.vxb.com/page/bearings/PROD/8mm/Kit7472)
Propane torch
thermometer
torque wrench (0-100 ft/lbs)
flathead screwdriver
superglue
loctite(optional)
assorted wrenches
Risers (duh)

First, remove the knee bar, calf pad and plastic knee bar brackets.  If you are unable to do this without a "kneebar removal" tutorial, then this bearing install is way over your head.



Then remove the upper spring mount bolt, nut, and two large flat washers.  



Pull spring away from riser frame, two small flast washers will either fall out or will be fused to the bearings.  Remove them and place them with the upper spring mount bolt, nut, and washers.  



You could leave the spring attached to the riser frame or romove it at the "knee" joint.  I highly suggest removing it.  

Now you can see how the bearing is cocked in the bore, not good.  



Use a propane torch and heat the tube at the end of the frame where the bearings sit.



Heat to approx. 180 degrees Farenheit when measured between the knee bar mounting brackets.



Use a screwdriver or other suitable tool and work the bearing out of the bore.
Carefull, it will be HOT!!!  Patience is a virtue.



Remove the bearing spacer.  It will be HOT as well! Save this spacer, we'll need it later.  



Here's a good shot of just how bad the cocked bearing was.  Only seven balls remain and the cage is nowhere to be found.  



Here is a method of cooling the frame without shocking/stressing the metal.  Run cold water over the frame at the end farthest from the bearing bore.  This will slowly draw the heat out.   (I've got some dishes to do)



Do this until the bearing bore reaches room temp at ~75 degrees F.

 

My bearing bores had alot of burrs, high metal, and burned remains of lube. I used a rotary tool with a sanding bit to lightly remove any foregin material or high metal.  



Here they are!  The bearings came in individually wrapped pockets to seal in the freshness. Ah...Fresh!

 

Use the propane torch and heat the bearing bores to 140 degrees F when measured between the kneebar mounting brackets.

 

Push the room temp. bearing into the heated bore and tap lightly with the handle of a screw driver or a soft faced hammer to ensure it is seated squarely in the bore.  



Insert the spacer previously removed into the bore.  !!!This is important!!! Failure to install the spacer will cause immidiate bearing failure upon final assembly!!



Install the second bearing while the frame is still hot.  The machining on the poweriZer frames is a little sub-par on quality.  One bearing may go in farther than the other, that's ok just so long as they're square and not cocked.  

Bend your upper spring mount bracket as shown.

 

If it's hard to see, here's an exagerated drawing.

 

Bend them so they will clear the wider bearings while still having the bolt holes sit as flat to the bearings as possible.  

The hard work is done.  Time to start putting them together.  Install one large flat washer onto the mount bolt and insert thru one side of the mount bracket.  



Place one of the smaller flat washers onto the bolt with the smooth(er) side toward the newly installed berings.



Slide the bracket over the bearings and slide the bolt thru both bearing and the inner spacer.  You did remember the spacer, right?  



Before sliding the bolt thru the other side of the spring mount bracket, slide the other small flat washer into the space between the bearing and bracket with the smooth(er) side toward the bearing.



Slide the bolt thru the small washer and thru the other side of the bracket.  Install the last large flat  washer onto the bolt.  

Since the bearings space everything out, the locking feature of the nuts will be inneffective. Put some blue loctite or superglue onto the threads of the bolt and install the locknut and torque to 8 ft/lbs.  Place enough superglue in the end of the nut to fill the cavity and let dry.  This will act as an indicator to tell you if the bolt is starting to loosen.  The dried superglue will go from clear to hazy if the bolt starts to back out.  Reinstall kneebar and you're halfway done!!  Do the exact same thing for the other riser and get out and enjoy the smoothness!!

[Athoul]

Very Nice tutorial, little to complicated for some of us but good none the less. 
You will have to tell us how well it works when you get some bocking done.

[Sprog]

Looks good, a little complicated in some areas but I think I understood most of it... Once you've done the other ones, we need a comparison against the original bearings

[English-tailor]

That was a very well put together tutorial. I dont think I will be doing it though ( I dont have a propane torch) but for anybody thats that way inclined I am sure it will be invaluable.

[`esco]

Are you going to make an tutorial of how to attach these bearings below the footplate and at the other end of the controlbar too?

[`esco]

where's your drawing?

[tfd]

if there's any uk bockers who want this mod done but don't want to take on all that work, get the bearings and drop me a line, it really isn't that hard to do, and i'd gladly sort it for ya
piece of piss, i got everything needed in my workshop except the bearings..
tfd...

[MKudlock]

Yeah, it's a little more in-depth than taping the spring but the results were worth it.  I tried them out with the stock plastic "knee" bushings and a sort of "rockiness/bumpiness" I never really noticed before was gone.  They were all around smoother and more pleasant to be on.

The knee bushigs are gonna be even more in-depth than this.  I'm having to fabricate some spacers because no one makes them in the size I need.  If people have better luck finding the correct size spacer, the knee joint won't turn out to be too bad.  At least there's no need for the torch, the bearings are the perfect size to just push into the boars.

[MKudlock]

That would probably work, but this is a little more plug-and-play than fabbing up a whole new bracket (but not by much  )

[bathsheba]

I was able to get the top bearings out of my 'Rizers without heat or violence.  These have to be the cheapest bearings on the planet, I never saw anything so crappy.  Only 7 balls (judging by the cage, this is all they're designed to have), not sealed, the cage appears to be made of tinfoil (three out of four are completely shredded), and two of the races are cracked right through.  Needless to say all are completely frozen.

I hope some manufacturers are reading this.  Hello?  I wouldn't have minded paying $453.50 instead of $450 for some bearings that are actually able to deal with the load. 

Anyway, now I'm afraid to look in the 'Risers...I'll wait till the package from VXB gets here and I can put the Rizers back in commission.  Don't wanna be without at least one set working!

With the top joint open I can see better which joints have most play.  The top joint was definitely the worst.  The next worst is the midfoot joint, the other two appear fairly solid.  Well, one at a time.

[MKudlock]

UPDATE TIME!!!

The bearings are fantastic.  No problems.

EXCEPT- the torque I previously mentioned, 28 ft/lbs, is too high.  I found this out durring one of my heavy inspections.  This torque actually started to push the bearing ID into the surface of the internal spacer.  Not what I intended.  Rather, torque it to about 8 ft/lbs.  Sorry for the confusion.

About Bearing install pt. 2:  This ended up being WAY tougher than I anticipated.  I actually broke several of the new bearings while still in the "trial and error"  phase.  The bearings are in and performing excellently!  no wobbles, no bearing related squeaks, just a more solid, pleasant, bocking experience.  The install would require the fabrication of a custom spacer.  I made the spacer from a hardware store steel roll pin and carefuly ground and machined it to fit.  This was a very intense operation. Keep in mind, I call the above operation child's play, so the knee joint scores a perfect 10 on the "this is too hard, let's get drunk!" scale.

If anyone would be interested, I've been talking with some local prototyping shops about making a bearing install kit.  It would include the bearings, new hardware, and the machined spacer.  Anyone game?

[petterekman]

(A great tutorial)

Wow!
MKudlock, you rock! I don't mind mucking about with mechanics, and I could definately see this being done if mine start to break. Don't have a torch or IR-thermometer, but that can probably be sorted out...

A bearing install kit? Sounds interesting!

[tfd]

kevin, stage one of this operation is really easy to do matey, if you get the bearings i'll do it here for you, i got everything needed here
get the bearings you slaaaag... luv ya really
tfd..

[MKudlock]

No welding or other metalwork involved, just warming up that little bearing tube.  once you see it being done, you'll be like "Damn...I could have done that!"

[bathsheba]

Not much time for bocking at present, but I took my Rizers with new top bearings out for a bit.  It's a noticeable improvement.  First, the fix got rid of a lot (though not all) of the play in the joints. 

Second, the motion is so much smoother that it feels like different springs...they're not exactly softer, but they travel the top inch or two of their range much more readily, so everything feels easier.  It doesn't make much difference for hard jumps, but walking and running are way smoother...this is definitely how they're supposed to work.