GSB's Whyte PRST-4 build

[Roxolid]

Re:

I bought a JW2 frame a while back purely on the engineering attraction, built up with what I had laying around it proved to be a great cross country bike.
When an illness made riding difficult I took it upon myself to do a full rebuild.
A bare metal repay in satin black, the forks were anodized black with the lower parts carbon wrapped.
The hard x-fusion shocks swapped out for a rock shox Sid dual air up front and a rock shox MC 3R with remote lock out on the rear. Race face carbon bars,seatpost and cranks, avid elixir cr brakes, floating discs, Sram XO shifters and mechs.
It's a good deal lighter than stock and the larger bodied air shocks give a much better ride.
It certainly draws attention,

 

[kneeslider]

Bit of an update on my PRST journey:-

In April of last year, some thieving scrotes stole my PRST-4 and my wife's PRST-1 from York, even when both were chained up. Then, cutting a very long story short, I spotted my PRST-4 for sale on Ebay in Middlesborough over a year later. Called the cops, and they went round and recovered it for me in quick time. The story was that the Ebay seller had bought it from a car boot sale in Middlesborough for £40 (Hmm) and then hadn't used it, so put it on Ebay.

The bike was completely unmessed with, the frame number was intact, and apart from two flat tyres was exactly as it was on the day it was stolen. I recognized it as being mine because I had put a couple of motorcycle track day stickers on the frame, which were still there. My wife's bike however is still out there somewhere.

In the meantime, to sate my appetite for weird transportation, I purchased a JW-4 from a Gumtree ad in Stoke, and rode around on that for a year or so. Comparing the two bikes is interesting. The PRST-4 is a medium frame size, and the JW-4 is a large. Both bikes are pretty much stock, but everything has been adjusted and fettled into optimum capability, however the PRST-4 seems to be the quicker of the two, obviously it has the better component choice, but who would have thought that the differences add up to a riding experience that is so much better?

I'm not so sure that the big grippers are a better solution than the more usual skewers of the JW-4, certainly for the rear wheel, I never seemed to get on with changing rear wheels out with the big grippers. You need one hand to hold the mech out of the way, another to hold the big gripper off the axle on the other side, and another hand to remove the wheel. Or maybe that's just me?

At just a tad under 6ft, I seem to fit both the large and the medium frames, but the smaller PRST-4 frame seems to be a lot more manageable, and less flex prone on tight technical stuff, so I prefer that one.

I guess that at the moment, I am in a quandary about whether to keep the JW or not. It's scruffier than the PRST-4, and sorting it out would make for a good project (Satin finish gold paint anyone?) Did GSB manage to reproduce any PRST-4 decals?

 

[saccades]

Love the PRST-4, good to know you got yours back.

 

[Mr Gudge]

Re:

Hi All PRST experts.
I have a 4 that i am about to attempt a spherical bearing change. Is there a step by step on the web anywhere so i don't fall into any holes with this service job

And FYI i have owned a PRST1 and a 4. Great bikes. Was always told to run the rear shock at the same psi pressure as my weight in pounds and the front at 75% of that. Always worked well for me.
I also flipped the stem, and ran a crud guard on the front wheel to increase the shock service time.

I'd appreciate your help with the bearing change.

Thanks D

 

[kneeslider]

Hello Mr Gudge.

Changing the spherical bearing isn't difficult. You need to undo the bolt through the spherical bearing, and remove it, then let the forks pivot away from the rest of the bike.

Undo the front shock lower nuts inside the Y shaped lower wishbone 8mm I think. You might need a longer reach socket to get to them, and you might need two of them to stop the threaded stud that the shock mounts to turning. Then use an allen key to undo the allen screws holding the lower wishbone to the frame, and remove the threaded stud that goes through the bearings.

You should now have the Y shaped piece free of the bike, containing the spherical bearing.

On the left side of the bearing, you should see a small hole, containing a grub screw? Undo this, and remove it.

Now, support the sides of the bearing housing and use an appropriately sized socket to press out the spherical bearing. Remember to only push on the outer part of the bearing, not the middle, otherwise you will ruin it.

Just reverse this procedure to fit it all back together again.

 

[Mr Gudge]

Re: prst 4

Thanks for that, I'll give it a go and report on my progress

 

[Lazyb5]

Re:

Hi, I'm sure the original manual said about bedding in the spherical bearing with non setting compound, can't remember what I used. I'll have a look when I get home to make sure I'm not talking out of my a...

 

[Mr Gudge]

Re: Prst4

I think I read that somewhere too. Bearing glue??? Not sure what that is, but would appreciate any advise

 

[Lazyb5]

Re:

Hope those 2 pages help, the bearing adhesive I used was Bondloc B641 Bearing Fit.

 

[Mr Gudge]

Rerst4

Thanks for that, it will be really helpful