Open mold wide profile carbon wheels

Everything about building wheels, glueing tubs, etc.
Harpoon
Posts: 13
Joined: Sun Jun 17, 2018 6:15 pm
Location: UK

by Harpoon

DutchMountains wrote:
Tue Jul 31, 2018 1:34 pm
from cyclingtips.com:
"[Hunt Wheels] were walking around the show with a prototype disc-specific aero rim in hand. With a former aerodynamics engineer from Campagnolo now on staff, this 48mm-deep rim was optimised for use with a 28c tyre. The 22.5mm internal width is a far cry from the 35.5mm external width. But instead of adding redundant material mass at the edge of the rim to make up that bead thickness difference, Hunt has a new patent-pending technology that uses a resin filler that’s a quarter the density of carbon fibre or similar structural material. The design is said to save 50g per wheel while providing the ideal aerodynamic properties. Such a design is only made possible by the use of disc brakes and is just the sort of innovation needed for discs to be widely adopted in races. The new wheel is expected to be out by the end of the year."

There is no further info on the Hunt website (yet). Also, AFAIK Hunt has up until now only used/rebranded existing rims (like the Kinlin XR31) so it would be interesting to see if there will be a manufacturer in the far east offering a rim with the same specs.
Just came across a bit about this prototype wheel in a GCN video. Hopefully the link below goes to the right section but it's about 6:00 in.

https://youtu.be/eH5oUxGbHY0?t=367

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Beaver
Posts: 501
Joined: Wed Aug 18, 2004 6:06 pm
Location: Lower Saxony - Germany

by Beaver

LightBicycle CNC brake track, someone on tour forum already got a picture:

For $30 one can order a pattern as seen on Campy AC3 and Zipp Showstopper...

Image

by Weenie


morganb
Posts: 601
Joined: Wed Mar 15, 2017 5:30 pm

by morganb

Beaver wrote:
Fri Aug 17, 2018 11:05 am
LightBicycle CNC brake track, someone on tour forum already got a picture:

For $30 one can order a pattern as seen on Campy AC3 and Zipp Showstopper...

Image
This is exactly what I have been waiting for, might make the jump for these when availab.e

morganb
Posts: 601
Joined: Wed Mar 15, 2017 5:30 pm

by morganb

https://www.hambini.com/blog/post/bicyc ... s-fastest/
For anyone that hasn't seen it, suprising how well Yoeleo does compared to the major brands. I wish there were a few more on there (Roval, the new LB rims) but no test can have everything and this is more exhaustive than most.

William42
Posts: 5
Joined: Fri Aug 17, 2018 2:05 pm

by William42

Thinking about ordering some light bicycle RR46C02 rims with the new braking track. I've read this thread, but I still don't know very much about aerodynamics, and I'd just like to check in and confirm I'm making logical decisions with this purchase.

First off, what are the advantages of the braking track? Better water venting? heat dissipation? stronger braking? Whats the gain? I don't ride much in the rain, and when I do its for commuting short distances without a lot of load in a flat area on bike paths, so strong brakes are less of a priority (I'm already running KCNC brakes, although I have a set of 7800's sitting around if they suck too much with carbon rims). I've only ever had aluminum rims, and the only carbon rims I've ever used in the rain were on new ENVE's, so they had a pretty good braking track. The brakes felt plenty strong, but I just don't have a lot to compare it to. I'm also generally fairly skilled at high speed descents and don't drag my brakes. The air resistance slows me down more than I'd prefer, and the brakes are just there for a surprise or emergency. I'm not in a hilly area right now so its a bit of a moot point, but I expect to be next year and I'd like some feedback on whether or not I need the newer braking track or whether I'll be just fine without (79kg rider). I'd prefer without, because shorter wait times and I want to be sure they come before the stupid tarrifs come into effect, and not to mention saving 60 bucks sounds like a good idea.

Braking track aside, I'm figuring 28mm outer width, 21mm inner will work just fine with my preferred 25c tires? I figure the tires will probably balloon to around 28-29mm, which wouldn't be ideal for the 105% rule but should be pretty close I'd think, and I don't think my brakes could manage a 30mm wide rim.

Last question, I am relatively new to carbon, and more specifically aero rims. Rim depth is proving to be a tricky thing to find advice on. I'm figuring some 46mm deep rims should hit a nice comfortable spot as far as giving me some significant aero benefits, without becoming a dick to handle in cross winds. I ride a pretty solid mix of commuting and road riding, when I'm out road riding I'm usually sitting closer to 20-22mph, when I'm commuting with the wife, closer to 13-14. Two wheelsets isn't in the cards for me at this point, and when I'm commuting with the wife I frequently ride with no hands while sitting upright. I'm thinking a 50mm or 55mm rim is just going to be getting to the "too much, gets blown around constantly" range.

Hexsense
Posts: 563
Joined: Wed Dec 30, 2015 12:41 am

by Hexsense

cant see in the picture clearly,
Other than coarse curvy line, is there any more fine grid pattern too?

EDIT: course -> coarse
Last edited by Hexsense on Fri Aug 17, 2018 9:17 pm, edited 1 time in total.

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Beaver
Posts: 501
Joined: Wed Aug 18, 2004 6:06 pm
Location: Lower Saxony - Germany

by Beaver

The idea behind a carved brake track is to interrupt the water film so that you don't need several rounds before the braking reaches its normal force.

Zipp ShowStopper and Campy AC3 feature the same:

Image

But it won't help as much as a fully textured brake track as seen on Enve rims:

Image

But maybe they could also add several small holes as on Bontrager rims:

Image

Question is, if the braking surface needs to be different, e.g. thicker, here.

If it's possible, the 105% rule is all right (only for the front wheel), but if rim and tire are nearly the same width you won't notice a difference on the road, that's just a theoretical playground - some low one digit watts of 450 watts at 45km/h. A 25mm tire works very well with the 28mm outer/21mm inner width.

Cross wind stability is a very subjective matter, but 46mm should be ok - if you are very sensible, you could also take the 36mm version.

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Calnago
Posts: 6620
Joined: Sun Nov 07, 2010 9:14 pm

by Calnago

My understanding of the little “curve” marks in the Campy AC3 brake track is that it is nothing more than an artifact left over from the manufacturing process of the surface. Does not affect braking one way or another. In fact, I can see the same remnant marks on the brake tracks of prior Bora rims, they’re just not as noticeable due to the less aggressive texturing. The water transfer thing is nothing more than a rumor, much like the rumor about Shimano’s direct mount hanger making rear wheel removal easier. No basis in fact, but if people want to make up favorable rumors about a company’s products, don’t expect the company to come running out and say they’re false.
Colnago C64 - The Naked Build; Colnago C60 - PR99; Trek Koppenberg - Where Emonda and Domane Meet;
Unlinked Builds (searchable): Colnago C59 - 5 Years Later; Trek Emonda SL Campagnolo SR; Special Colnago EPQ

William42
Posts: 5
Joined: Fri Aug 17, 2018 2:05 pm

by William42

Sounds like I can give the new braking track a miss.

Followup question: I can buy light bicycle rims for ~400 shipped. I have a set of powerway hubs I can lace them to, but it would require unlacing my current wheelset (basic 1260g climbing wheelset with kinlin rims). I have access to cx-rays and aerolights at cost and am quite comfortable building my own wheels, so out the door I'd be looking at about 420-430 bucks for my preferred rim and spoke combo.

On the other hand, there are some 45mm depth, 27mm wide, 16.9mm inner complete wheelsets from carbon cycles on ebay right now for 360. The narrower inner sounds kinda shitty, but it'll still be better than my 13.9mm inner kinlins. Is the wider inner rim and better overall rim (220c braking temp vs light 240c) worth only having one wheelset for?

romanmoser
Posts: 142
Joined: Sun May 06, 2018 8:30 pm

by romanmoser

na
once you go wide rims ... there is no coming back

Discodan
Posts: 48
Joined: Mon Oct 16, 2017 2:55 am

by Discodan

These RR46C02 based wheel sets look pretty good for what I’m after, I’d not planned on buying any more rim brake wheels but an unfortunate incident last week means I’ll be investing in one last set.

What’s the opinion on the Bitex hubs compared to the Novatech on the lightweight wheels? The Bitex is 30g lighter which is attractive but not if they are rubbish or too fragile. Does anyone have experience with either or both?


Sent from my iPad using Tapatalk

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LouisN
Posts: 2454
Joined: Mon Feb 19, 2007 3:44 am
Location: Canada

by LouisN

I built more than 25-30 wheelsets (all rim brake though :oops: ) the last 11 years with Novatec A291-F482 (some with newer SL) hubs. They build nice wheels for the budget. The rear is a good hub IMO, especially with the anti bite guard system on the freewheel. I had a few loose front wheels (little lateral play when wheel tightened). Also bearings are ok for fine conditions on road, but when used for cyclocross, they don't last (easy to change for better bearing though, like NTN). I built a few wheelsets with two Bitex hubs models. The UL190's (Ultralight ?) NDS tension was so low I constantly had a few spokes coming loose and had to readjust the wheel almost every 2 weeks (24h 2X pattern) ! As a disclaimer, the wheelset was used by a cat.1-2 racer (70kg). Had good success with the SL210.

Louis :)

hambini
Posts: 358
Joined: Tue Nov 15, 2016 8:13 am

by hambini

morganb wrote:
Fri Aug 17, 2018 1:06 pm
https://www.hambini.com/blog/post/bicyc ... s-fastest/
For anyone that hasn't seen it, suprising how well Yoeleo does compared to the major brands. I wish there were a few more on there (Roval, the new LB rims) but no test can have everything and this is more exhaustive than most.
The reality is there is the shape cannot effect the drag that much. It's more defined by the deepness of the wheel. However even that said the Yoeleo wheels would be my choice for value.

Hunt and Flo cycling wheels which were touted as designed by an algorithm were just that. Very good at one particular Reynolds number and poor at everything else. My colleague said he thought the FLo wheels in particular had been designed by consultants who sit behind computers all day and don't have any experience of the real world. He thought their performance was shameful.

Hambini

William42
Posts: 5
Joined: Fri Aug 17, 2018 2:05 pm

by William42

Light Bicycle just gave me an update on their new braking surface -

"For your information. The new barking surface is adding graphene on the advanced high TG resin. On one hand, the high TG resin enhances the brake tacking performance. On the other hand, graphene, the advance nano-technology material, boost the heating dissipation, greatly reduce the temperature when braking, and lower the braking track failure.


Best regards
Charlie Su"

I don't know much about graphene properties, and have no idea if incorporatingit into the resin will actually improve heat dissipation or if thats BS.

Edit: What are you all using for rim brakes on these ultra wide rims? I have a set of KCNC CR1's and some dura ace 7800's with SRAM red. The KCNC's only open to 27mm without sanding down the pads, and the dura ace 27.5-28mm. I could probably get the dura ace to open to 28.5 if I disassembled and did some grinding I guess.

by Weenie


Gary71
Posts: 44
Joined: Wed Aug 21, 2013 5:25 am
Location: Brisbane Australia

by Gary71

hambini wrote:
Sat Aug 18, 2018 2:36 pm
morganb wrote:
Fri Aug 17, 2018 1:06 pm
https://www.hambini.com/blog/post/bicyc ... s-fastest/
For anyone that hasn't seen it, suprising how well Yoeleo does compared to the major brands. I wish there were a few more on there (Roval, the new LB rims) but no test can have everything and this is more exhaustive than most.
The reality is there is the shape cannot effect the drag that much. It's more defined by the deepness of the wheel. However even that said the Yoeleo wheels would be my choice for value.

Hunt and Flo cycling wheels which were touted as designed by an algorithm were just that. Very good at one particular Reynolds number and poor at everything else. My colleague said he thought the FLo wheels in particular had been designed by consultants who sit behind computers all day and don't have any experience of the real world. He thought their performance was shameful.

Hambini
Hi Sachin
Thank you for sharing this information.
Can you comment on why you think the Bontrager 60's are 25Watts more efficient than the Flo Cycling 60's at 50km/hr?
Surely they would share a similar drag profile to the wind. Marketing Algorithm or not, how can one wheel be that much more efficient? A 60 is a 60 or is the Bontrager profile shape that much different?
I am interested to here your thoughts.
regards
Gary

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