Originally Posted by GMF
Not looking to criticize the effort, and projects with kids are always great, but all that work to put a 4lb marginal fork up front? You would be surprised how nice a steel fork with the correct geometry built just for that frame would ride.
But the *right* steel fork would cost more than the 1" WB suspension fork.
Good questions. Yeah, the expansion of metal is a little counter-intuitive. But if you think about what is happening the aluminum atoms are vibrating more at a higher temperature, causing a little more space between each atom. This happens throughout the material, even the ID where it does get bigger as a result of this extra atomic wiggle. Pretty neat stuff, really.
Originally Posted by Fillet-brazed
My position on the bike is definitely different than 18 years ago, but it is less Norba and more "have fun playing around". What I was feeling was with the big tires and ~80mm fork was that there was a lot of trail and the handling was slowing down more than i'd like. Taking some of the weight off the front wheel reduces the self-centering effect (and is better for my effed up back :-). So in this case, it works out well for me. If you were interested in maintaining a given riding position, you are absolutely right.
And i'll get in touch re: the ride :-) You can school me on pipeline again.
Oh, and 993rs, you are right. It was a lot of work for a marginal 3lb fork, but it was a cheap way to learn the feasibility of doing it on an awesome 3lb fork. I did used to have a TypeII fork (now owned by GOB), and rigid just isn't my thing with this bike. I'll happily pick up a late 80s fat (or whatever) and ride that rigid, but that isn't for my Phoenix. I'm not in the dirt enough to justify tons of bikes, though, so I just experiment with the ones I have.
Last edited by GMF; 02-11-2013 at 09:20 AM.
Reason: added replies
Originally Posted by yo-Nate-y
Scott did a fork with a 1" steerer for my '96 Slingshot and just finished one for my '98 Wojcik. Both forks let me run a disc up front and the AC lenghts were adjusted to run a 650b wheel.
I am sure Rock Lobster, IF etc would do something for similiar $.
I'm just wondering why those wiggling atoms wouldn't make the ID smaller on the crown. If the material that eventually touches the steerer tube expands doesn't that hole get smaller? I wonder if freezing both would allow for an easier fit since everything would be contracted. Does that make sense?
Originally Posted by GMF
I've never really played around with this beyond a freezer and a heat gun and don't know much about it, but it's interesting.
I know what you are saying, but think of the inner surface of the hole that I bored for the new steerer tube. If you make that diameter smaller, you are stuffing the same number of atoms into a smaller space, opposite of what the atomic-wiggle-phenomenon needs and does.
Originally Posted by Fillet-brazed
Another way to think about it. A flat plate would get longer if you heat it up. For arguments sake, say you started with a 10" long flat plate, and you got it really hot so it grew to 10.1". If you managed to roll that hot flat plate into a cylinder, both the ID and OD would be bigger, right (in fact the ID would be about .032" bigger... the amount that the flat plate increased in length due to heat divided by pi).
I think the crux of the question is in the above analogy, why does the flat plate length matter more than the thickness, and I don't have a great answer for you there (sounds like I have a little more research to do). I just know that I measured the fork crown both hot and cold and saw about a .002" to .003" increase in inside diameter when hot.
There are plenty of fork makers, but I emphasized *right* for a reason. If GMF doesn't want a rigid Type II, that's cool too.
Originally Posted by 993rs
Wow GMF, that's some mod. I admire the ingenuity.
I'll admit that I've largely steered away from this stuff in the past, wondering what the consequences might be. I've never really resolved what happens when two soft materials sheer against each other. Maybe it's good, maybe it's bad, but how do you know? If your headset starts to loosen up, that would be a bad sign. In the end, I often add a dowel pin.
I think it is worth considering that most modern forks use a swaging operation whereby the steerer is flared at the bottom to captivate the steerer. I think a lot of parts also rely on industrial adhesives, which help to reduce manufacturing tolerances and cost. The quill on a Ringle stem and the spider on Syncros tubular cranks come to mind.
Thanks for the comments. Initially, I did try to use an adhesive, but it sloughed right off the cold steerer, and immediately set in the hot crown, so it just got in the way. One of the nice things about using the RST steerer is that it does have a flange on the bottom which you can just barely see in the 2nd to last picture. It also has vertical knurling to help hold it rotationally. I do not think it will pull through.
Originally Posted by DoubleCentury
The two failure modes I envision practically happening is the press fit was not sufficient for how hard (sorry... "hard") i ride and the crown looses up and can wobble back and forth acting like a loose headset. The other one is clearly the steerer being able to spin. Neither are catastrophic (but not desirable) and I bet I would be able to gently ride out of whatever situation. I've been surprised before, though.
I'll take the phrasing of "ingenuity" as a compliment ;-)
This weekend I got my dremel on and replaced the bearings on the front New Paradigm hub that had loosened up and were on their way out. After 17ish years of use, time was due. They rolled fine, it was just the play that was bugging me. Unfortunately, most things that could have gone wrong, did.
The first thing I had to do was split the metal rings outboard of the bearing. These were siezed to the axle with no real good way of getting any purchase on them. Remove one side and tap, tAp, TAP... out the axle.
Of course, the cone came with. Not much holding the cone in on an angular contact bearing.
Bearing one with no cone in there any more = hassle for removing outer race.
This bearing seemed like the one going bad (didn't grease guard enough, i guess)
The inner race popped out of both bearings, leaving me with the split and pound method of bearing removal.
...which i did:
I like my dremel a lot and it can really help me out in situations like this. Eventually got everything out and cleaned up the inside of the shell.
Then in goes the grease guard seal backer
Then the grease guard seal
Fortunately, Enduro is still providing a source for these inch-based bearings
I guess orange seals are cooler?
But of course, remove the inner seal to work with the grease guard (after I get some appropriate grease)
And finally, installed. A few times there I thought i completely messed up, but in the end it pulled through
I've decided i'm not a huge fan of micro-shims for setting bearing pre-load, but it seems like they work in the long run. There is the slightly tiniest of play in the front wheel (between shim thicknesses), but it rolls really well and is an improvement.
This gave up the "FCAC" bearings, but got the ceramic instead. I hope it will be an upgrade and last a while.
...slowly making improvements....
I love your detailed posts of how you do things. Very informative and fun to read. I know it's a lot of effort to keep stopping and taking a picture but know that it's appreciated! Glad you got your wheel back together.
When I do projects I'm too excited/worried about the next step to worry about stopping to take photos. Nice work DC.
Originally Posted by girlonbike
Thanks for the comments, guys. This was a relatively straight forward project, although i didn't document the times i sat there thinking "WTF?". I'm also glad the carnage to the hub was minimal and largely hidden (grind marks in the bearing bore, etc.). There are a couple new dings from when i was tapping out the split race, but overall pretty subtle damage, er... patina. Gives me a good sense of what i'm in for when i locate that XTR titanium freehub body and axle to swap in (with the 'ramics)
DL - Dirt this weekend? Phoenii on pipeline?
No pictures this time, but swapped in an M965 XTR titanium freehub body and Ti axle along with the ceramic cartridge bearing in the rear hub. The XTR freehub is a tiny bit (like .010" larger diameter and just took a little grinding down to fit). Learned from the front hub process and made a little outer bearing race puller with a washer and axle and made significantly fewer chips (can take pics later, if any interest) when the rear cartridge bearing also came apart...
Also swapped the 2.4 tires with some 2.1s (works better with the narrow rims, i think), improved the cable routing of the toggle came = mo power, and was given a marzocchi marathon that may be getting the same steerer swap treatment to improve the front end of the phoenix.
Retro Sea Otter
Been pretty busy so haven't been on mtbr a ton, but recently the Sea Otter Classic came through my neck of the woods (not sure if you've heard of it?), and I tried my first MTB race in about... 20 years. Entered Cat 3 middle aged, and tuned up the Phoenix.
It went pretty well - 4th out of 61 riders on an old school bike. She did well and it was fun. #2100 representing. May have to cat up for the local races :-)
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