Pace rc31 questions about safety and bonding - pics up

[ishaw]

I've just acquired a nice set of pace rc31 xc forks, the ones with the silver crown and drop outs, and yellow and white decals. I have a couple of questions:

1. I want to run v brakes but it has no mounts. Are there any differences in the leg diameters between my set, and the all black later versions of the fork.

2. There are two torque screws on the back, at the top of the legs. What are these for?

3. Should the leg top caps be flush with the crown, or slightly recessed.

I think that's all for now.

Cheers

 

[cce]

1) no

the other two, i cant help with.

 

[Piers]

2) To make you wonder should you disregard the warning sticker/manual that says DO NOT UNDO THESE.
3) Think mine are flush.

 

[ishaw]

Thanks, so the screws, what purpose do they serve then?

And my caps are recessed a few mms, should I worry about this? I only ask as at the top and bottom of each leg I can feel a lip/recess where the shiny lacquer stops. Should I worry about this in relation to the bonding, or is this just simply how they come? I can take some pics if it helps as they are mint in every respect and I just want reassurance they are ok to ride.

 

[ishaw]

A few pics to show you what I'm concerned about. Not so much the recessed top caps, but the gap between the crown and the leg.

 

[cce]

hmm, that first pic doesnt look so hot.

there have been reports of them coming unbonded.

 

[ishaw]

Been doing a lot of googling and staring at images and it seems that some of the fork pics I've seen have a rubber o-ring style thing at the top.

Be interested in anyone else's pics or info on their own forks in this area.

The recessed top caps seem to be standard on this model from the pics I've seen, so that's one mystery solved.

The bolt ad how the forks are asseembles are also a little less of a mystery now too, thanks to bikemagic:

At the top end, small butted steel stanchions are heat shrunk into the hollow CNC’d crown. The carbon legs are then bonded onto these spigots with a small elastomer ring between top edge of carbon and bottom edge of crown to allow movement without chafing and provide a little extra damping of the whole structure. The 420mm leg length (dropout / axle to bottom headset race) is designed to mimic a medium travel ssupension fork and keeps modern bike geometry happy. There’s also a small screw blocking the ‘glue hole’ which we have to say looks like an MFI kitchen cast off, but luckily it’s hardly noticeable once on the bike. Before you ask, every second phrase of the instruction manual (yes we did read it) says “don’t even think of adjusting or removing the screw”.

So, should I simply find myself a rubber ring to plug the gap? Seems as though a little movement is part of the design??

 

[Rampage]

You might be able to slide a small o-ring over the dropouts and up the leg to cover it.
Hea you got a capture of the crown?
Give me a few minutes and I'll take a picture of mine.....

 

[justbackdated]

Hi Ian,

The later black hinged type brake mounts and the earlier silver bolted type will fit any RC31, all the carbons are the same[or very similar] diameter.

The torx screws were fitted as a 'belt and braces' security method to the earlier RC31s, this being a feature that was thought redundant and was dropped from the later production. The carbons are fitted onto short steel tube 'spigots' which were pressed into the crown in a similar manner to the stanchions on the sus forks. There is an upper and lower bushing between the two, the gap between these is filled with glue by pumping it in the holes at front and back of the carbon, the screw was fitted in the back hole and the front hole filled with wax and the decal put over it.

The gap at the top was filled with a foam seal about 2mm deep. The reason for this was partly to fill an uneven gap due to tolerance difficulties[!] and to insulate the carbon from the crown to prevent creaking.

I have seen a few forks with unbonded carbons but it is very rare, if you take out the screw and can twist the carbon then it is unbonded!! It is possible for the disc side dropout to become unbonded due to heat from the brake destroying the bond but again I have seen very few occurrences.

The top caps should be flush[I've pressed enough of those in!!] but if pushed will go in below the crown as there is no stop as such.

 

[Rampage]

These are mine, they have a silver crown despite the picture.
The second picture is the brake mounts.