emilio700

iTrader: (3)

FD and RD have not found a home yet. Bar end shifters and TT brake levers going on Johns (engineer here) TT build. Shoot me an email.

I am actually working on 949 Racing kit these last few weeks. Look up Cycling Gear | Crafted in California ? Eliel Cycling
More info as we get further in.

hustler

iTrader: (6)

Ewww.

55/11, no ragrets.

I might do a 949 kit if it's prices for people people who cannot afford DA.

emilio700

iTrader: (3)

D/A cranks I ordered are 55/42.

Kit will not be entry level. Think Rapha fit, Castelli function, Pearl Izumi durability. It's basically kit for guys who ride a lot and are not on a team, like me. I want highly functional stuff, latest aero and materials. I'd rather pay extra now than be lamenting a flappy, hot, uncomfortable jersey that falls apart before the end of the season but saved me $50.

DNMakinson

iTrader: (3)

Emilio, would like to see picture of how you plan to do the rear wheel. When I did similar, I used a 32 hole rim, and taped over every 4th hole. ND side was 1X, D was 3X, but could have been 2X if deep rim. That way the offset drilling on the rim holes matched correctly, even though I had only 24 total spokes.

emilio700

iTrader: (3)

There are a few tutorials on doing split count lacing floating around the internet. Doing that on a hub with symmetrical spoke holes makes a weaker, heavier wheel so I chose not to go that route. Bikehubstore sells 16:8 hubs so a regular 24 hole rim can be built into something with the best possible strength to weight ratio.

Savington

iTrader: (31)

The Industry Nine Ultralites on my new CX rig are laced 24/2:1. NDS tension is slightly higher than DS tension which is super cool. I don't know why every bike wheel isn't built that way.

TurboTim

iTrader: (9)

Email sent, I will pass. Thanks though!

DNMakinson

iTrader: (3)

I don't think the 16-8 existed when I made mine. Still, I doubt it is any weaker or heavier than a wheel built with a 24 hole rim. Particularly this would be true on a deep section rim. Same number of spokes, just in sets of 3 like a Campy G3 arrangement.

Again, it would be best to use a rim that does not have offset drilled holes, if going with 24 holes.

hustler

iTrader: (6)

Please, refer to this gearing by it's proper name, "Belgian compact".

emilio700

iTrader: (3)

Think about it. If you have varying gaps between the spokes and two different length spokes on one side, it is an inherently weaker structure than a wheel with evenly spaced spokes of equal length and tension. Not terrible if it's implemented well, but never as optimized as a symmetrical side of a wheel.

I gave John my old Power Tap Pro+ hub (ca 2008?) to John when I replaced it with a Zipp 404 FC on PT G3. It was on 32h Mavic Open Pro. We wanted to convert it to something a bit more aero. I considered a 16/8 lacing but decided against it because of the asymmetric tension issue. Not only big gaps at spoke bed, but uneven tension because of the different spoke lengths on same side. Examined carefully, you have a sine wave of tension around the rim. Again, one can make it work but I'd rather build something with evenly balanced tension. So I laced the PT hub into a 55mmx 25mm wide U shaped tubeless compatible clincher with CX-rays. 2x D and 0X ND. Front wheel was same rim/spokes a BHS 20h wide flange laced 0X heads out.

Aero drag straight on with the 32h is virtually the same as a 24h. Wattage to spin at 40kph is also about the same. Where the higher spoke count shows a little extra drag is between 10-20° but even then, losses are modest. John's 6-4", 172lbs and a pretty strong rider so stiffness and fatigue life were top of my list. That and we were stuck with a 32h hub.

It's interesting that the BHS hubs are 16h D, 8 h ND. My Zipp 404 FC (non PT) is 10h D 0x and 10H 2x ND. That's done to bring D & ND side tension virtually equal. One of the reason's modern Zipp's are so laterally stiff and long lasting despite the low spoke count.

I would have laced my rear TT wheel like the Zip but the hub is 16h D, 8h ND.

Some interesting info on spoke count aero/stiffness here: http://www.aeroweenie.com/assets/bac...spokecount.pdf

Back in the day I ran a 56/42 on my TT bike and 54x11 for some road races. I don't make those kind of watts anymore and 11s allows a 23 or 25 cog without losing the 16 and /or 18 as it once did.

TurboTim

iTrader: (9)

That's quite interesting and a bit perplexing at the same time.

Any idea when this was written?

emilio700

iTrader: (3)

First paragraph: "and the wind tunnel information relates to
a 50 hour session occurring in January 2004 at Texas A&M University LSWT, during which these issues and others
were specifically tested."

More aero geek: http://www.aeroweenie.com/data.html

TurboTim

iTrader: (9)

Yeah saw that but I hope bike aero knowledge has changed in the last 12 years.

emilio700

iTrader: (3)

Wind tunnel and spokes haven't changed too much. Data is still relevant IMO. Perhaps not absolute values but certainly relative values. Modern wide, blunt nosed aero rim profiles have improved performance at angle past 5° over old pointy "V" rims but again, I'm sure the relative values are meaningful. In any case, why would you be concerned if I may ask?

TurboTim

iTrader: (9)

Because I am becoming increasingly interested in bicycling.

Your second link is also pretty cool to page thru. But so far I see no dates on their data. It is just something that bothers me in general...like "transition vs shiv"...well which transition, which shiv? What about across brands, "shiv vs P4 vs trinity". i don't know much about those particular bikes, but Gen Y Shiv may be better, but Gen S Shiv may not. Just put a date on your data or papers.

Too bad there's only one link there with info about the Fuji Norcom Straight and it doesn't have data comparing it to it's rivals.

emilio700

iTrader: (3)

I wouldn't obsess over the frame too much. Rider position is biggest factor by far, rider clothing second. Everything else is lower down the $/wattage benefit ratio. The Norcom is among the best but I'm sure it falls behind the top frames by a handful of watts. Just keeping my head up and not looking down during a TT is worth something like 3x what the worst vs best frame gets you.

One might liken it to obsessing over a few ounces of wheel weight on your Miata and running wheels one inch too narrow to save those ounces. Focus on getting your fit on the TT bike dialed, get your body making full wattage when in the position, wear the slipperiest rider gear you can afford, decent wheels and learn how to suffer for 20 or 40k. The frame is much less important to final results than the aforementioned.

It's fun to geek out and aero and want the best, who doesn't. Just don't get into the mindset that it will be impossible for you to reach your goals if you pick the "wrong" frame. I have had my *** kicked by better prepared riders on two wheeled pieces of **** more times than I can recall.

DNMakinson

iTrader: (3)

Emilio,

Cross does not affect tension. Grab one of your Zipp rear wheels and pluck the spokes. You will hear that the ND has much less tension than D.

Still, I'm not sure you are picturing what I built. All D spokes are same length, and are laced like any 32 hole wheel would be laced, with same tensions. Perfectly symmetrical.
All ND spokes are the same length and are completly symmetrical, but only 8 spokes. Crossed because Campy does not allow radial spoking on these hubs.
Both sides are also radially symmetrical in such a manner that there is no torque induced into the hub. I did not lace the ND spokes but equalized the heads-in heads-out.
Here are pics:
Drive Side:


Non-Drive Side:


Complete Wheel:


Note, I'm not asking for agreement, just want us to both be on the same page.

DNMakinson

iTrader: (3)

100% correct. Position trumps all else. Take a road frame, add a set-forward post to allow you to rotate the body around the crankset to get the aero tuck without folding yourself up. Get some clamp-on areo bars. Now you are 90% there on improvement and 10% there on the cost of a full-on aero set-up. YMMV

Chooofoojoo

iTrader: (7)

You're absolutely right. I hate most of the garbage that comes out of most 'tests' from the industry. No one will cite their results, procedure, equipment, etc. Big S has their own wind-tunnel, says their bike saves X seconds of X miles... Without actual data... cool story bro.

emilio700

iTrader: (3)

Big S's "data" on the new Venge Vias was an utter joke. Most of the gain was from the rider changing to a jersey that wasn't flapping around then lowering the stem. Thanks guys, just saved me $12k!

I'm sure the bike is fast but the gains they purported were comical if you didn't read the fine print.