Open mold wide profile carbon wheels
Moderator: robbosmans
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How do you get the nipple in place when the holes are not drilled through the rim bed? Drop a nipple through the valve hole then rattle until it pops out through a nipple hole?
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CallumRD1 wrote:With this in mind I ordered the rims without a brake track, without a bead hook, with 24 holes front and back, and with no holes (other than the valve hole) in the rim bed to allow for easier tubeless setup.
These rims are advertised as 460g +/- 15g. My two rims weigh in at 474g and 476g. This is a little disappointing as if you poke around the web site they say that a rim without the brake track and bead hook will likely be about 10g lighter than the quoted specifications. But I give them credit for consistency at least.
I have a 25mm and a 28mm Schwalbe Pro One that will be the primary tires for this wheelset. At some point I'm going to get a pair of good tubeless cross tires (exact model to be determined at a later date) for use on gravel and in the snow come winter.
Those look like super sweet rims, I had been eyeballing them recently on the LB website myself. Regarding the weight, perhaps the lack of brake track and bead hook was offset by the material that would have otherwise been removed when drilling the rim bed.
I am sure you noticed this on their site, but the hookless models have a lower max pressure rating than the hooked ones, 80psi if I recall. Most people buying them probably intend to run them with 28mm or greater tires, so under 80psi is realistic, but I just wanted to mention it to you given that you referenced 25mm as well. In reality, the scale of safe pressures should vary with tire width, because of the greater surface area and casing tension of a larger tire generating more hoop stress at any given pressure than a smaller tire, but it is a bit of a wild west situation out there right now with increasing rim widths, road tubeless, and hookless rims. Reynolds did a narrow hookless rim close to 10yrs ago, and intended it to be used at 100+psi, so it isn't clear cut, and I am just saying be sure you go into into it cautiously and with both eyes open.
Regarding cross tires and use in snow, maybe you are already planning this, but you may want to use brass nips rather than aluminum. There is ton of info on mtbr.com about people using LB rims tubeless with aluminum nipples and suffering corrosion and failure of the flanges on alu nips. It is unclear if it was due to a reaction between carbon and aluminum, something having to do with ammonia containing tubeless sealant, or the water exposure that commonly goes with MTB rides, but you definitely don't want to be having nip failures on a rim with an undrilled bed. It goes against the weight weenie credo, and I struggle with it myself, but it could save a whole lot of hassle.
I added some photos of the rims to my above post.
You make some good points. I hadn't thought about the lack of holes causing the slightly higher than expected weight. That's probably a significant contribution.
I'm currently running the Schwalbe Pro One tires on a set of 19mm internal rims and they measure up at 27.5mm for the 25c (front) and 29.5mm for the 28c (rear) tire. I'm running them at 60 psi front and back and they seem to do quite well. I don't expect to ever need to exceed 80 psi. I had given a lot of thought to the question of hookless or not but eventually decided on hookless mostly due to the wider internal width and impact resistance which will be great when on cross tires.
As to the brass nipples, I'm torn. I like the idea of more corrosion resistance and durability but I'm not thrilled with either the added weight (really not an issue but it bugs me) and expense.
Edit: fixed some grammar
You make some good points. I hadn't thought about the lack of holes causing the slightly higher than expected weight. That's probably a significant contribution.
I'm currently running the Schwalbe Pro One tires on a set of 19mm internal rims and they measure up at 27.5mm for the 25c (front) and 29.5mm for the 28c (rear) tire. I'm running them at 60 psi front and back and they seem to do quite well. I don't expect to ever need to exceed 80 psi. I had given a lot of thought to the question of hookless or not but eventually decided on hookless mostly due to the wider internal width and impact resistance which will be great when on cross tires.
As to the brass nipples, I'm torn. I like the idea of more corrosion resistance and durability but I'm not thrilled with either the added weight (really not an issue but it bugs me) and expense.
Edit: fixed some grammar
I saw this wheels sold by my local online shop which looks like they source from FarSport but this isnt in Farsport website. Looks interesting. Price at RM4,000 / USD1,200.
Perhaps Victor @vmajor or Jason @madcow can chime in. Are those filament wound rims?
Sent from my iPhone using Tapatalk
Perhaps Victor @vmajor or Jason @madcow can chime in. Are those filament wound rims?
Sent from my iPhone using Tapatalk
CallumRD1 wrote:I added some photos of the rims to my above post.
You make some good points. I hadn't thought about the lack of holes causing the slightly higher than expected weight. That's probably a significant contribution.
I'm currently running the Schwalbe Pro One tires on a set of 19mm internal rims and they measure up at 27.5mm for the 25c (front) and 29.5mm for the 28c (rear) tire. I'm running them at 60 psi front and back and they seem to do quite well. I don't expect to ever need to exceed 80 psi. I had given a lot of thought to the question of hookless or not but eventually decided on hookless mostly due to the wider internal width and impact resistance which will be great when on cross tires.
As to the brass nipples, I'm torn. I like the idea of more corrosion resistance and durability but I'm not thrilled with either the added weight (really not an issue but it bugs me) and expense.
Edit: fixed some grammar
I suspect rim drillings are the issue with the weight. I was closer to Light Bicycle's quoted weight, with the rear being closer (I suspect because it had more "holes").
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CallumRD1 wrote:I did end up ordering a pair of Light Bicycle 46mm deep, 28mm external width rims.
I like the 28mm width but it isn't a aero problem the V-shape ? Compared to the U-shape ?
Fundamentally in a low yaw angle head to slight crosswind, there's little aerodynamic difference between V shaped and U shaped rims. The biggest difference is how they handle in a crosswind. Modern U shaped rims are vastly better in a crosswind than an old deep section pointy V rim. These rims are very wide, not all that deep (relative to their width), and do not taper to a true point like early deep section carbon rims did. These are rather blunt, so they are more akin to modern U shaped rims than old pointy V shaped rims.
I haven't ridden (or built) mine yet, but reports are that they handle well in crosswinds. I'm sure that others here can chime in with first hand experiences.
I haven't ridden (or built) mine yet, but reports are that they handle well in crosswinds. I'm sure that others here can chime in with first hand experiences.
jeanjacques wrote:CallumRD1 wrote:I did end up ordering a pair of Light Bicycle 46mm deep, 28mm external width rims.
I like the 28mm width but it isn't a aero problem the V-shape ? Compared to the U-shape ?
viewtopic.php?f=3&t=145548&start=45#p1324930
CallumRD1 wrote:Fundamentally in a low yaw angle head to slight crosswind, there's little aerodynamic difference between V shaped and U shaped rims. The biggest difference is how they handle in a crosswind. Modern U shaped rims are vastly better in a crosswind than an old deep section pointy V rim. These rims are very wide, not all that deep (relative to their width), and do not taper to a true point like early deep section carbon rims did. These are rather blunt, so they are more akin to modern U shaped rims than old pointy V shaped rims.
I haven't ridden (or built) mine yet, but reports are that they handle well in crosswinds. I'm sure that others here can chime in with first hand experiences.
Any scientific proof for that thesis ?
I mean SCIENTIFIC; not claims, reviews, opinions, nor adverts. DATA. NUMBERS. From not financially spoiled source.
I'd like to see it . Really.
PS before posting reply to my post read it again : SCIENTIFIC; not claims, reviews, opinions, nor adverts. DATA. NUMBERS. From not financially spoiled source.
Go to Heaven for the climate, Hell for the company.
Mark Twain
I can be wrong, and have plenty of examples for that
Mark Twain
I can be wrong, and have plenty of examples for that
As I'm sure you know, there doesn't exist a perfect set of wind tunnel data produced by true scientists that is beyond criticism, but here is the next best thing: a set of computational fluid dynamics calculations for a number of wheels. Take the time to read the whole paper carefully and then get back to me.
http://www.altairhyperworks.com/html/en-us/rl/ACUSIM/papers/AIAA10_2010-1431_MNGodo.pdf
http://www.altairhyperworks.com/html/en-us/rl/ACUSIM/papers/AIAA10_2010-1431_MNGodo.pdf
And here's another peer reviewed CFD paper for you:
http://www.sciencedirect.com/science/article/pii/S1877705816306397
http://www.sciencedirect.com/science/article/pii/S1877705816306397
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