I’ve seen CF road bike rims out there so I know it’s been done and apparently perform well but not sure how scaling it up from typical 26" road bike rims to 36’er sized rims would affect it. I know it’s not going to really be ‘cost effective’ to make one at all but what are your guys’ opinions on it? Do you think it would work?
I have a spare 36 UDC rim and I am wondering about moulding it to make a CF rim. My concerns are:
Is the shape right?
If I mould an airfoil instead how will the spokes fit and how do I make a double walled rim?
you could make a double wall by laying the main rim, then inserting a shaped foam core and laying the second layer over the top of it. The foam can then be melted out with acetone. I was also thinking about the possibility of moulding a CF rim off a stock one, i think it would take some fairly serous reinforcement aroud the spoke holes to stop the nipples being drawn through, possibly a metallic strip runnign around the inside of the rim.
Making only the rim in CF would not yield much weight loss. Instead mould rim, spokes and hub into one. Then add saddle base and seat post in CF and you have to hold on to the uni so it won’t blow away in the wind.
But the big benefits are only present when using tubulars. Clichers tend to use hybrid solutions or have restrictions on air pressure. Keep in mind though that thats like <7bar, which sucks för roadbikes IMHO, but may not matter for unis.
The only problem i’d see, is for it to ne structurally sound, it’d have to weigh a little more, and be a little bigger. CF isnt THAT strong really, you scratch it, it loses it’s strength a lot, it can crack easy. I’d end up seeing your nipples ripping out of the holes.
use mag, or Ti, they’re already made in bike rims, and probably dont cost AS much as CF. It’d still be really cool to even see a mass produced, and sorta cheapish CF rim in production, and selling.
As compared to current rims. CF bike wheels are notably more stiff and less forgiving than regular bike wheels. That is half the reason people like them (the other half being weight.) I think a wheel that stiff on a uni may be uncomfortable, although the steel frame would still absorb much of the road vibration. Also, at first I was thinking this would be a full carbon wheel build, not using regular spokes. Keeping the regular spokes would also offset this, but I don’t see why I’d bother with a $700 rim then.
Carbon is probably the least comfortable ride available, but also the most efficient. It’s just worth noting, that’s all.