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-   -   Racer Tech Thread (https://www.bikeforums.net/33-road-bike-racing/956936-racer-tech-thread.html)

spdntrxi 04-30-18 07:14 PM

the old saying.. don't race what you cant replace.. applies here too. I just use ultegra to keep cost lower (and not the current model)

Ygduf 04-30-18 09:31 PM

I have etap on a used frame. go cheap on frames and spend more on things that you touch a thousand times/ride

tetonrider 05-01-18 02:17 AM


Originally Posted by revchuck (Post 20314210)
I've been riding and enjoying the Turbo Cottons, but have stuck with butyl tubes because the latex tubes I have and the ones I can find have 40-50mm valve stems and my wheels are 44mm deep. The shortest extensions I can find are 30mm, which would leave a bunch of valve stem waving in the wind and looking...wrong. I'm looking for a source of latex tubes with 32mm or 60mm valve stems. Anyone?

no one will notice the length of your valve stems when you are riding faster due to that extra ~5w. ;-)

tetonrider 05-01-18 02:19 AM


Originally Posted by spectastic (Post 20315379)
what bugs me is that some of these graphs aren't consistent at opposite yaw angles. the graph should be symmetric with respect to the y-axis, should it not? the only thing that's not symmetrical on a bike is the drivetrain and the disc rotors.

no, it should not. the drivetrain has a material impact on aerodynamics.

that said, look at the units on the y-axis. these are not enormous differences.

more telling would be rider + bike; you'll see less effect (asymmetry) when presented that way.

tetonrider 05-01-18 02:21 AM


Originally Posted by spectastic (Post 20315758)
a lot (if not most) of them just post the positive yaw angles, and assume that it's the same for the other side, but it does appear there's a trend. the extra drag must come from the drive train then.

whole bike (right side sees more drag)
Blather 'bout Bikes: Win Tunnel Playtime - Part 2

only wheels (both sides same drag)
Blather 'bout Bikes: Win Tunnel Playtime - Part 1

wheels are basically symmetrical, esp rim brake wheels as tom prefers. :)

bikes are not symmetrical. if you remove a FD you can see the effect on drag.

tetonrider 05-01-18 02:27 AM


Originally Posted by spectastic (Post 20315777)
question for the fancy di2 etap people. do you worry about having to eventually replace perishable parts? for example, during crashes, the levers are often the first to hit the ground. same with the rear derailleur. also, overtime, the rear derailleur bushing will start to wear out, and the derailleur starts to wiggle at the hanger junction, leading to potential mis-shifts or sluggish shifting. are these things people have seen to be a problem? I've had this problem with my cable setup, and that's why I'm not considering upgrading to electronic anytime soon.

judging by regular participants around here, i've probably used electronic groups the most/longest. i've crashed out of races hard enough to break my femur. been hit by a car hard enough to crack my frame (shimano c24 wheels survived without going out of round/true ... and i knocked the bumper off the car! :D).

i wouldn't worry about wearing out the RD. the stuff that wears (pulleys) is pretty easily replaced, and if you care for your stuff (keep the drivetrain clean) parts last a long, long time.

never heard of anyone worrying about the RD bushing wearing out and leading to play at the hanger interface.

guess you need to consider what you can afford (or not) to replace. in racing, you do risk ruining parts. i've had levers get cosmetically scraped up, but they were always usable. you can replace hoods. it's rare to lose a complete group in a crash, so often you would be replacing a single part (RD or lever).

i think this should be pretty low on the list to NOT go electronic unless the delta on the single mechanical part vs the lowest level of electronic part is going to break you. e.g., even if you had an otherwise DA Di2 setup, if you absolutely had to you could replace it with a used Ultegra RD if you crushed the DA RD in a crash. probably would not be a big price difference between that and a mechanical replacement.

hard to say without knowing what you value and your financial situation.

tetonrider 05-01-18 02:28 AM


Originally Posted by Ygduf (Post 20316017)
I have etap on a used frame. go cheap on frames and spend more on things that you touch a thousand times/ride

nah, better to use cheap tires, a discount saddle, and cheap bars/tape/levers while splurging on a 12r carbon frame instead of 10r. ;-)

srsly, i think riding good tires/tubes makes a big difference to ride quality.... unless one is commuting through a ton of crap and really wants to avoid a flat at all costs.

topflightpro 05-01-18 06:52 AM


Originally Posted by tetonrider (Post 20316201)
srsly, i think riding good tires/tubes makes a big difference to ride quality.... unless one is commuting through a ton of crap and really wants to avoid a flat at all costs.

When I lived out in West Texas, I used to run Maxxis Refuse tires. They were cheap, held up well to the crap on the road, and lasted a long time. I kept using them when I moved back to the East Coast.

Then one day, I put GP4000s on my bike.

It was insane how different the ride quality was. I've never even looked at those cheap Maxxis tires again.

Flatballer 05-01-18 07:56 AM


Originally Posted by topflightpro (Post 20316368)
When I lived out in West Texas, I used to run Maxxis Refuse tires. They were cheap, held up well to the crap on the road, and lasted a long time. I kept using them when I moved back to the East Coast.

Then one day, I put GP4000s on my bike.

It was insane how different the ride quality was. I've never even looked at those cheap Maxxis tires again.

When I switched from Gatorskins to GP4000s it felt like the bike was pedaling itself for a while. Tires make a huge difference.

ancker 05-01-18 10:30 AM


Originally Posted by tetonrider (Post 20315688)
until eTap offer wireless braking, you still have to do maintenance with internal wiring.

Shimano's Di2 is pretty much maintenance-free (for shifting), so the installation is a one-time thing. Adds like an extra 30', maybe. Personally I feel that ergonomics (preference) and usability (battery issues) should be the reasons a person decides to put eTap or Di2 on a frame, but that's me.

Brake maintenance is pretty much nil. I think about/replace my brake cables like once a year.

Shifter cable maintenance is different, tweak endlessly until things shift right, then ride, then tweak some more, rinse/repeat. Then do it 2-3 times a year depending on mileage.

IMO, Di2 is more of a pain due to finding a location for the junction box, battery, and getting the cables to where they need to go. Is it impossible? Of course not, I just prefer not to deal with it.
eTap has it's quirks, I'm not pretending it's perfect. I just prefer it due to lack of those things above.
I don't think I have a preference on ergonomics. I started on Shimano and switched to SRAM, found them to be just fine for my smaller hands.

tetonrider 05-01-18 10:44 AM


Originally Posted by ancker (Post 20316816)
Brake maintenance is pretty much nil. I think about/replace my brake cables like once a year.

my point was that brake cables are being routed internally, so even if one has eTap there is still some internal work to be done. also, brake cable maintenance is a separate thing.


Originally Posted by ancker (Post 20316816)
Shifter cable maintenance is different, tweak endlessly until things shift right, then ride, then tweak some more, rinse/repeat. Then do it 2-3 times a year depending on mileage.

tweak endlessly?

my experience in setting up many mechanical DA drivetrains these days is that a clean install is really fast to get dialed.

are you replacing housing or just internal cables? just the internals should be pretty easy, no?

that said, if you are tweaking endlessly you sound like a fantastic candidate for electronic. there's almost no adjustment required, and the little that is required can be done easily on the fly (at least with di2).


Originally Posted by ancker
IMO, Di2 is more of a pain due to finding a location for the junction box, battery, and getting the cables to where they need to go. Is it impossible? Of course not, I just prefer not to deal with it.

fair enough, but what i don't understand is that those are truly one-time things, and maybe they take an extra 30 minutes over a mechanical installation (or maybe no time at all). and for most people, a shop sets up the bike. putting a battery in the seat post and a junction box in the downtube isn't too much trouble, esp with most bikes with large tubes.

i actively ride bikes from MY 2011, and the wiring has stayed in place.

do you really think about those things after initial setup? does +30 minutes at setup matter after 1, 3, 7 years?



Originally Posted by ancker
eTap has it's quirks, I'm not pretending it's perfect. I just prefer it due to lack of those things above.
I don't think I have a preference on ergonomics. I started on Shimano and switched to SRAM, found them to be just fine for my smaller hands.

most people i talk to have a preference about ergonomics. some love it, some hate it. seems like comparatively less are neutral.

i happen not to like it (using 2 hands to accomplish one thing is annoying to me), but part of that is i started with shimano. had i started with sram i might feel the other way. all top groups shift great.

people are psyched on no di2 central battery, though they less often talk about battery failure/replacement/communication issues with eTap. there are pros/cons to both.

my whole point is to say that i think things other than a few extra minutes during the initial installation should drive a decision. i do think electronic groups offer something that will be appreciated by nearly all riders; i've been a proponent for a long, long time.

if you don't have a preference based on ergonomics (and the parts you actually interact with), i can understand not caring as much which way you go. i just don't think someone who likes shimano ergonomics should rule out di2 and learn eTap because they have to bury a junction box out of sight.

i respect your opinion. i genuinely am interested in understanding why the initial installation comes up quite often in these discussions i have (online and offline, everyone seems to mention it first).

tetonrider 05-01-18 12:38 PM


Originally Posted by topflightpro (Post 20316368)
Then one day, I put GP4000s on my bike.

It was insane how different the ride quality was. I've never even looked at those cheap Maxxis tires again.


Originally Posted by Flatballer (Post 20316470)
When I switched from Gatorskins to GP4000s it felt like the bike was pedaling itself for a while. Tires make a huge difference.

had a long convo with a buddy the other day. i like the GP4000s a bunch and think they strike a good balance between being fast and survive some reasonable wear. that said, i think the turbo cottons and vittoria open corsas (all clinchers) have even more noticeable improvement in ride quality. neither of those tires lasts as long.

basically anything that will cause a puncture in one will cause a puncture in another, but the victoria's have worn down notably after ~1,000 miles (as a rear tire) and most certainly by 1,5000 that flats are nearly guaranteed. the GP4000s are a bit longer wearing and a bit more harsh.

the GP4000s may be faster overall (tend to mate better with a wheel for improved aerodynamics) even if the victorias and specialized tires are more supple. the latter 2 just aren't great aerodynamically.

ancker 05-01-18 12:55 PM


Originally Posted by tetonrider (Post 20316849)
my whole point is to say that i think things other than a few extra minutes during the initial installation should drive a decision. i do think electronic groups offer something that will be appreciated by nearly all riders; i've been a proponent for a long, long time.

if you don't have a preference based on ergonomics (and the parts you actually interact with), i can understand not caring as much which way you go. i just don't think someone who likes shimano ergonomics should rule out di2 and learn eTap because they have to bury a junction box out of sight.

i respect your opinion. i genuinely am interested in understanding why the initial installation comes up quite often in these discussions i have (online and offline, everyone seems to mention it first).

None of my issues are show stoppers for lots of people. I get that.
My tweaking is based on 105-5700 series, then switching to Force/Red, then to eTap. "Endless" is a little exaggeration. :)
Even when I was happy with mechanical, it seemed like it wouldn't last very long and I'd be fiddling with barrel adjusters to get everything nice, sharp, and noise free.
Then I'd repeat the process every 6-8 months when I swapped inner cables. So you're right, I'm the perfect candidate for electronic shifting.

I probably stressed myself out too much over Di2 installation on various frames. I've never done it myself and when eTap was initially announced, I wrote off Di2 because "why would I futz with wires when I don't have to?"
Also, I buy new frames every 2-3 years. If I had frame for much longer, obviously initial setup is much less of a concern. If I had to figure out eTube length, whether it was possible to seatpost mount, under bottle cage, etc the battery, and where to hide/install the junction box each time I bought a new frame, I'd probably be artificially limiting myself due to what others have done.
With eTap the question is null. Every frame is universally compatible without consideration. I have an Allez Sprint with eTap. The Di2 folks were/are constantly debating the best place to drill a hole to connect the front derailleur to the battery. Drill a hole? Seriously?

I honestly don't understand how people get caught up between shifting systems. I started on Shimano, switch to SRAM mechanical, then to eTap. Learning each took like 1 minute on each ride. I even switch back and forth as my trainer bike still has 105s. I can't think of a single instance where I did the wrong thing to shift.
How the hoods feel in your hands is more important. My small hands fit better on SRAM hoods, at least to me. As stated before, that R7000 group is interesting with its 'small hands' shifter option.
Also, I'm not married to SRAM. If Shimano released a wireless hydro system at an affordable price, I wouldn't hesitate to put it on my upcoming gravel build.

tetonrider 05-01-18 01:13 PM


Originally Posted by ancker (Post 20317093)
None of my issues are show stoppers for lots of people. I get that.
My tweaking is based on 105-5700 series, then switching to Force/Red, then to eTap. "Endless" is a little exaggeration. :)
Even when I was happy with mechanical, it seemed like it wouldn't last very long and I'd be fiddling with barrel adjusters to get everything nice, sharp, and noise free.
Then I'd repeat the process every 6-8 months when I swapped inner cables. So you're right, I'm the perfect candidate for electronic shifting.

modern shimano group sets are pretty darn maintenance free (in terms of adjustments), that your comment surprised me.


Originally Posted by ancker (Post 20317093)
I probably stressed myself out too much over Di2 installation on various frames. I've never done it myself and when eTap was initially announced, I wrote off Di2 because "why would I futz with wires when I don't have to?"

i get that. wireless sounds better.

did any of the eTap failures cause you to pause when making the decision?

just asking because neither system is perfect.


Originally Posted by ancker (Post 20317093)
Also, I buy new frames every 2-3 years. If I had frame for much longer, obviously initial setup is much less of a concern. If I had to figure out eTube length, whether it was possible to seatpost mount, under bottle cage, etc the battery, and where to hide/install the junction box each time I bought a new frame, I'd probably be artificially limiting myself due to what others have done.

well, even for a year you ride, what, 15, 20 hours a week? an extra 30' of installation is really minimal.

and wire length...it's really a non-issue. sure, someone tries to get the exact right length of wire, but the reality is that a 700mm section of e-tube wire weighs 7g, and an 800mm weighs.... right about 7g, too! assuming you're not a growing boy, we tend to rid the same size frames. i've moved wires over from one bike to the next.

not questioning your decision, just saying from my perspective that 'troublesome install' argument seems to get such a large amount of thought relative to the actual trouble.

batteries these days go into the seat post. pretty much been that way for 4, 5 years on all frames (i've had internal batteries for 8 or 9 years on some bikes). in some ways a mechanical installation is harder than a wired electronic installation (many times, actually) -- but i fully agree that wireless is always going to be faster than both.

personally i think this is more exciting with TT bikes than road bikes, but i think sram dropped the ball with their TT/tri add-ons (size/shape).

manufacturers have gotten more thoughtful about internal routing in many cases.


Originally Posted by ancker (Post 20317093)
With eTap the question is null. Every frame is universally compatible without consideration. I have an Allez Sprint with eTap. The Di2 folks were/are constantly debating the best place to drill a hole to connect the front derailleur to the battery. Drill a hole? Seriously?

not sure i understand. doesn't a mechanical FD need a wire? one could just route the e-tube wire where the shifter cable would go. sounds like you were getting distracted by people having some obsessive question about changing up the bike.

but, yeah, i've drilled holes in plenty of frames before (not just for electronic wiring). definitely not for everyone--and shouldn't be. that hasn't happened for a road frame since MY2011 for me, though i've done it for MTBs in the past (dropper posts, actually).



Originally Posted by ancker (Post 20317093)
I honestly don't understand how people get caught up between shifting systems. I started on Shimano, switch to SRAM mechanical, then to eTap. Learning each took like 1 minute on each ride. I even switch back and forth as my trainer bike still has 105s. I can't think of a single instance where I did the wrong thing to shift.
How the hoods feel in your hands is more important. My small hands fit better on SRAM hoods, at least to me. As stated before, that R7000 group is interesting with its 'small hands' shifter option.
Also, I'm not married to SRAM. If Shimano released a wireless hydro system at an affordable price, I wouldn't hesitate to put it on my upcoming gravel build.

muscle memory, i guess. i agree hood shape and lever feel are supremely important. i have sooooo many miles on shimano that when i get a sram bike to work on my impulse is to control the levers that way. sure, it takes me just a minute to re-learn that, but as someone with a background in usability and design i am attentive to the sum of all those "insignificant" things we have to learn throughout the course of our day. none of them is big, but collectively they add up.

a pet peeve is when people put a vertical handle on a door that is meant to be pushed. generally that is an indicator that a door should be pulled. i worked in a building in NYC years ago that did just this thing, and every single day i would see people walk up to it and do the wrong thing. it makes a person feel stupid and could be prevented.

(i know sram's choices vs shimano's choices are not bad like the choice in my door example, but they are something else for the user to learn. when i have to ride a sram bike, i'll inevitably make a mis-shift at some point during the ride. i suspect you might, too, if for example you got crashed out of a crit and got handed a neutral bike with another system. might cause you a few minor issues when you are breathing hard and maybe not thinking clearly.)

the other thing that is an issue for me with wireless (aside from multiple batteries and some documented issues with communication failures) -- we all have brake cables. they go through the frames. i'm still shoving cables through a frame. once i'm doing this, i have my tool kit out to pull wires through, so pulling another couple more wires is just minutes of additional work.

anyway, not trying to convince you. i appreciate you shedding some light on your thoughts.

this is a great book on design if anyone is so inclined: the design of everyday things.

ancker 05-01-18 03:37 PM


Originally Posted by tetonrider (Post 20317134)
did any of the eTap failures cause you to pause when making the decision?
just asking because neither system is perfect.

and wire length...it's really a non-issue. sure, someone tries to get the exact right length of wire, but the reality is that a 700mm section of e-tube wire weighs 7g, and an 800mm weighs.... right about 7g, too! assuming you're not a growing boy, we tend to rid the same size frames. i've moved wires over from one bike to the next.

not questioning your decision, just saying from my perspective that 'troublesome install' argument seems to get such a large amount of thought relative to the actual trouble.

personally i think this is more exciting with TT bikes than road bikes, but i think sram dropped the ball with their TT/tri add-ons (size/shape).

manufacturers have gotten more thoughtful about internal routing in many cases.

not sure i understand. doesn't a mechanical FD need a wire? one could just route the e-tube wire where the shifter cable would go. sounds like you were getting distracted by people having some obsessive question about changing up the bike.
but, yeah, i've drilled holes in plenty of frames before (not just for electronic wiring). definitely not for everyone--and shouldn't be. that hasn't happened for a road frame since MY2011 for me, though i've done it for MTBs in the past (dropper posts, actually).

(i know sram's choices vs shimano's choices are not bad like the choice in my door example, but they are something else for the user to learn. when i have to ride a sram bike, i'll inevitably make a mis-shift at some point during the ride. i suspect you might, too, if for example you got crashed out of a crit and got handed a neutral bike with another system. might cause you a few minor issues when you are breathing hard and maybe not thinking clearly.)

eTap failures were pretty hard to come by when I ordered/got mine. In fact, I'm aware of only a few issues. None I've seen myself on either eTap bike. 1) Battery tabs breaking. 2) FD limit screw hitting/scratching crank arms. 3) Poor FD shifting 4) RD losing signal.
I kinda get #3, but I'm not entirely convinced it isn't my weird combination of rings, P2M spider, and BB30->GXP adapters.

The wire length thing is probably a non-issue now. Back when I was really considering it, battery placement and junction box could drastically change how much wire you needed.

The 'thought' of the install being difficult was definitely larger than reality would have been. But it was enough that when eTap was announced, the perceived lack of difficulty made it an easy choice for me.

I agree. SRAM's Blipbox is horrendous. The actual shifter buttons are way more attractive than Shimano's though.

For the Allez Sprint, the FD housing exits the frame about 6 inches up the downtube from the BB. It then seats in an external stop located a couple inches up the seat tube from the BB. So you'd have the FD etube running for about 8 inches external to the frame with nothing holding it in place. You could use tape or something, but that's an ugly solution. So they were looking to keep it internal and drilling a hole closer to the FD to minimize exposed etube.

I respect your opinion on Di2 vs SRAM/eTap, but I personally, and others I've talked to, find it to be way more intuitive. Switching back to mechanical SRAM and even Shimano 105 has never caught me out. Switching to a neutral bike with mechanical SRAM/Shimano would probably phase me for all of 1/4 of a lap.

Ygduf 05-02-18 04:47 PM


Originally Posted by tetonrider (Post 20316199)
wheels are basically symmetrical, esp rim brake wheels as tom prefers. :)

bikes are not symmetrical. if you remove a FD you can see the effect on drag.

I'm days late, but brakes and brake cables are also not symmetrical. and skewers. sure we're forgetting other things.

tetonrider 05-02-18 09:52 PM


Originally Posted by Ygduf (Post 20319446)
I'm days late, but brakes and brake cables are also not symmetrical. and skewers. sure we're forgetting other things.

in a wind tunnel (which is where the data for those charts are coming from), the don’t use QR (asymmetrical) skewers.

hack 05-04-18 08:58 PM


Originally Posted by Philitup (Post 20323150)
Thanks for the response. I've actually looked at that exact fork multiple times. The shape of the fork crown is a completely different design from the 2011 model. It wouldn't fit. I was going to post a picture of the 2011 frame for reference, but BF won't let me yet because I'm a new user.

Probably better served in this thread. You need this fork?
https://cimg1.ibsrv.net/gimg/bikefor...81a38a7b18.jpg

hack 05-04-18 09:20 PM

If it's your dream bike, this may be worth a dice roll:

https://www.ebay.co.uk/itm/263647595...m=263647595699

Philitup 05-25-18 02:05 PM

I am so sorry... just now seeing your messages. Yes, I need that exact red/white/black fork from 2011. I've looked at the other shiv forks on ebay, including that one, and unfortunately they don't have the same crown shape as the one for my frame. In addition, I don't think the taper is the same to begin with. You don't have that 2011 fork, do you?

Ttoc6 05-27-18 05:20 PM

Anyone have alead for getting a rotor crank spider tool? I've got get my old power meters off and sent back to P2M but have had **** for luck trying to find a tool locally. I even called rotor (in SLC) and they don't have one to sell me.

topflightpro 05-28-18 12:38 PM

My wife's Garmin 510 died. She decided she wanted the new Wahoo Bolt. It comes with two mounts, but she has four bikes. (We had K-Edge mounts for two of her bikes and just Garmin mounts for the other two.)

It turns out that K-Edge now offers a replacement insert so you can convert their Garmin mount to Wahoo. The inserts are only $5 - much better deal than buying a couple new mounts.

revchuck 05-28-18 01:56 PM

:thumb:

Ttoc6 05-28-18 08:31 PM

Wahoo ELMNT was a huge upgrade from my edge 500. She'll love it.

Ttoc6 06-06-18 06:41 PM

Read over the LoToJa guide today and they make specific mention of no earbuds for music. But since this a cat 1/2/3 race, I was wondering if anyone knows whether a race radio would be permitted?

I could see this being useful in such a long road race for me to get in touch with my support vehicle to let them know I'm getting close to aid stations and if I need anything special in the musette.

Also, anyone have lead on where I can buy musettes? I only have like 1..


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