Replacement Fork?

[bret]

Hello,

I have a replacement fork from Cruzbike.

My Quest appears to be an early v1 with suspension in the fork, but disk brakes. However, the replacement fork has both disk caliper mountings and posts for V brakes?
20171130_fork.jpg

The bearing surface at the fork crown looks a bit odd to me:
20171130_forkrace.jpg

Also, this alarms me:

Also note that the bushings in the fork-chainstay joint are nearly impossible to get out of the old fork. @Robert Holler knew this and gave me new bushings when I bought my fork. If you don't have those, I wouldn't bet on success.

The fork came with no separate bushings, and the openings are just machined aluminum. Should I get some bushings before I take it all apart?
20171130_forkbushing.jpg

Thanks for any information.

Regards,
Bret

 

[Rampa]

That looks normal. That is not the bearing surface. You would install the lower bearing-race of your headset on there.

Canti studs can be removed. They have flats at their base to put a wrench on. At least, all the the ones I've ever seen. The replacement fork needs to work with either type of breaks to accommodate all users.

 

[bret]

Does anyone know about the bushings?

 

[billyk]

I'm in Australia right now (work trip, no riding), so I can't post a photo, but there definitely are brass bushings at the joint at the bottom of the fork where it connects to the chainstay. This was on my original Q2 (suspension fork) and also on the new fork, which I think is for the Q100 and Q3. The bushings have a flange to provide a flat surface for the head of the bolt to seat on.

I don't think that joint would be tight without them, and that would be a very bad thing. I'll post a photo next week, or maybe someone like @Robert Holler, who really knows, would weigh in. He sold me the fork in his shop in Portland, and gave me the bushing set because he said I'd have a hard time getting them out of the old fork.

By the way the new unsuspended fork makes the bike feel much "tighter", definitely an upgrade. And I don't notice the absence of suspension, surprisingly.

 

[bret]

The brass bushings have been transferred, but they are not simple. My machine is a very early v1, perhaps even a prototype, so others may encounter different versions when they try the same. I went to a local electric bike shop, as I knew they were used to doing odd conversions.

Each bushing is 3 pieces:
One tube which goes through the center and provides the contact for the fixing bolt. It's length spans the full width of the fork blades plus the 'washers' formed by the outside flanges of the other two pieces (below) it goes through. It does not contact the aluminum fork at any point.
Two symmetric halves, one of each going in from each side. These provide a face on the surfaces of the fork blade (like a washer between the fork blade and the chainstay) and also a half-tube protruding into the hole in the fork blade. The 'one' piece mentioned above is slid through these 'half-tubes' and covers the joint between them.

We cleaned off the exterior and noticed the seam between the inner tube and what appeared to be an outer washer, supported the fork blade, and sized a punch and tapped it lightly to drift the center piece out. One entire side came out with the inner tube and then it became obvious what the set-up was.

For the second one, the inner tube came out alone, leaving the two washer/tubes installed with very little purchase to move them. Judicious tapping with a drift edge (the shop's 'magic screwdriver' was put into play here) eased one side out, allowing a full size punch access to the inner edge of the remaining one.

Given the generally static nature of the load, it seems at first like over-design, but I don't know if it was continued later. Aluminum can be soft, and it galls easily, so something may be required anyway. Precision is useful for this application, and it's not a joint I'd expect to dismantle often either.

The canti-lever brake studs unscrewed, leaving unsightly large threaded sockets. I'll find a cap or something. The head set bearings seem to have seated properly in the new fork.

No, we did not take pictures.

 

[billyk]

it's not a joint I'd expect to dismantle often either.

Right, but if you start hearing an odd creaking, especially when applying pedal force, consider this joint. I struggled for weeks with a creak I hated, and finally fixed it by taking this joint apart and greasing it with Phil Wood.

The fact is that these bikes we love have frames made of several bolted-together struts, rather than the welds of DF bikes. Where the rear triangle of a DF bike is one welded piece, the front triangle of my Quest is at least three (depending on how you count the boom slider). All these joints require occasional attention (grease).

 

[billyk]

Might as well mention that should you be replacing or removing your fork, this joint is the first one to align and tighten.

The reason is that the two "flanges" of the chainstay (orange in the photo) must be precisely aligned with the fork/bushing assembly that fits between them. If you don't let the fork turn freely (relative to the chainstay) while doing this, you won't be able to align these pieces to fit them together.

The photo shows the left-side flanges, with the fork/bushings fitting tightly between them.

I suppose it hardly needs saying that I did not do this in the correct order the first time. "Experience is a hard teacher. The test comes before the lesson".