Racer Tech Thread
#4276
commu*ist spy
Joined: Aug 2012
Posts: 4,462
Likes: 5
From: oregon
Road Bike Crank Test - Fairwheel Bikes Blog
does a nice job summarizing everything.
I also did a crude analysis on the table, which suggests that BB30 leads to less average deflection on the non drive side, due to the thicker spindle, which makes sense. It also suggests a less stiff drive side, which is harder to explain, maybe because bb30 crank makers are making compromises in the chainrings to help justify their weight savings to get better stiffness/weight.. I only put stiffness/weight in there for ****s and giggles, because I think it's a stupid metric for weight weenie pro wannabes.
Capture.jpg
my personal conclusion is that this it's all smoke and mirrors. I have not noticed any difference at all in my experience with 30mm vs 24mm spindles. my bb30 caadx is actually 1-2 mph slower than my bsa caad9, which suggests that there are much easier ways to get faster on the bike than to pay out the ass on fancy ceramic bearings and stiff, lightweight cranksets.
does a nice job summarizing everything.
I also did a crude analysis on the table, which suggests that BB30 leads to less average deflection on the non drive side, due to the thicker spindle, which makes sense. It also suggests a less stiff drive side, which is harder to explain, maybe because bb30 crank makers are making compromises in the chainrings to help justify their weight savings to get better stiffness/weight.. I only put stiffness/weight in there for ****s and giggles, because I think it's a stupid metric for weight weenie pro wannabes.
Capture.jpg
my personal conclusion is that this it's all smoke and mirrors. I have not noticed any difference at all in my experience with 30mm vs 24mm spindles. my bb30 caadx is actually 1-2 mph slower than my bsa caad9, which suggests that there are much easier ways to get faster on the bike than to pay out the ass on fancy ceramic bearings and stiff, lightweight cranksets.
#4277
Senior Member


Joined: Feb 2007
Posts: 15,410
Likes: 189
From: Tariffville, CT
Bikes: Tsunami road bikes, Dolan DF4 track
When BB30 came out it was pretty light, and the SI cranks were the schnizzle. They're probably still one of the lighter cranks overall, although I'm not keen on their SISL set up. I don't know of anyone who pays retail on them, I wonder if they've come under the "Cannondale R2000" pricing policy. In that situation I think about 80% of those bikes were employee purchases so Cannondale priced them to be sold at employee prices, which meant that MSRP was higher than buying a frameset, Dura Ace group, and the rest of the build kit, I think MSRP was about $1k over retail, for a $5k bike, give or take. I know I haven't bought any of my SI cranks at anywhere near retail. I imagine most come on bikes and are sold as take offs.
It seems that non-BB30 cranks have caught up with both rigidity and, to a certain extent, weight. Shimano is super impressive.
It seems that non-BB30 cranks have caught up with both rigidity and, to a certain extent, weight. Shimano is super impressive.
__________________
"...during the Lance years, being fit became the No. 1 thing. Totally the only thing. It’s a big part of what we do, but fitness is not the only thing. There’s skills, there’s tactics … there’s all kinds of stuff..." Tim Johnson
"...during the Lance years, being fit became the No. 1 thing. Totally the only thing. It’s a big part of what we do, but fitness is not the only thing. There’s skills, there’s tactics … there’s all kinds of stuff..." Tim Johnson
#4278
Senior Member

Joined: Jan 2014
Posts: 10,588
Likes: 427
From: Southern California, USA
Bikes: 1979 Raleigh Team 753
Are we posting past each other? I am not/was not talking 30mm vs 24 mm, rather distance between bearings - or lever arm. A wider hub flange, wider rims, wider bearings, wider bars are all real physical things and have different performance characteristics. They may come at a cost of weight, aero - or be free, but far from marketing a smoke and mirrors.
#4279
Hmm after a bit more googling, I am considering etap. Not dealing with freaken wires and figuring out if battery can be shoved in to the seatpost appeals to me. Couple articles shifting on the back is slower then di2?
#4280
Senior Member

Joined: Oct 2013
Posts: 1,766
Likes: 89
From: East Bay Area ,CA
Bikes: not enough
yes slower.. but only a little. Also note there are 2 batteries but only 1 charger , they should loss power differently enough but something to keep in mind. The ppl I know that have etap buy another charger.
#4281
I think the shifting is negligible, no ones losing races because their eShifter is too slow.
#4282
I've done a couple test rides on older Shimano Di2 and eTap. I could not tell a difference. I know eTap is slower, but I think we are talking fractions of seconds difference.
As for the separate batteries, the FD battery should die a lot slower than the RD battery. Sram's argument is that if the RD battery dies, just put the FD on the chainring you want, then swap the FD and RD batteries so the RD will still be good to go.
As for the separate batteries, the FD battery should die a lot slower than the RD battery. Sram's argument is that if the RD battery dies, just put the FD on the chainring you want, then swap the FD and RD batteries so the RD will still be good to go.
#4283
¯\_(ツ)_/¯
Joined: Jun 2008
Posts: 10,978
Likes: 4
From: Redwood City, CA
Bikes: aggressive agreement is what I ride.
how long do the batteries hold a charge? looks like an extra is $35 or so, which is not bad if you want to put a charged battery in a race bag "just in case"
#4284
OMC


Joined: Oct 2010
Posts: 6,973
Likes: 142
From: South Louisiana
Bikes: Specialized Allez Sprint, Look 585, Specialized Crux E5 Sport, Trek Domane SL6
SRAM says 1,000 kilometers. Maybe it's the curmudgeon in me, but I think that if you can't keep your batteries charged, you're a poor candidate for electronic shifting.
__________________
Regards,
Chuck
Demain, on roule!
Regards,
Chuck
Demain, on roule!
#4286
¯\_(ツ)_/¯
Joined: Jun 2008
Posts: 10,978
Likes: 4
From: Redwood City, CA
Bikes: aggressive agreement is what I ride.
I need a vest.
I have a vest I like, voler team vest, but it has the state champion print on it and since I don't need to be inviting that attention all the time, I want a vest like the voler that has a few things, pockets, double zipper, mesh back. I can't handle the heat of a fully-closed vest with solid back and sides.
I have a vest I like, voler team vest, but it has the state champion print on it and since I don't need to be inviting that attention all the time, I want a vest like the voler that has a few things, pockets, double zipper, mesh back. I can't handle the heat of a fully-closed vest with solid back and sides.
#4289
My wife and I stopped in a bike shop in Paris, and while looking around, I noticed a seatpost with a rear taillight built in. Seemed like a pretty ingenious idea to me. I wonder why there aren't more options like that?
#4290
Senior Member
Joined: Aug 2012
Posts: 606
Likes: 0
From: Houston
Bikes: Trek Madone, Blue Triad SL, Dixie Flyer BTB
I need a vest.
I have a vest I like, voler team vest, but it has the state champion print on it and since I don't need to be inviting that attention all the time, I want a vest like the voler that has a few things, pockets, double zipper, mesh back. I can't handle the heat of a fully-closed vest with solid back and sides.
I have a vest I like, voler team vest, but it has the state champion print on it and since I don't need to be inviting that attention all the time, I want a vest like the voler that has a few things, pockets, double zipper, mesh back. I can't handle the heat of a fully-closed vest with solid back and sides.
#4291
I've done a couple test rides on older Shimano Di2 and eTap. I could not tell a difference. I know eTap is slower, but I think we are talking fractions of seconds difference.
As for the separate batteries, the FD battery should die a lot slower than the RD battery. Sram's argument is that if the RD battery dies, just put the FD on the chainring you want, then swap the FD and RD batteries so the RD will still be good to go.
As for the separate batteries, the FD battery should die a lot slower than the RD battery. Sram's argument is that if the RD battery dies, just put the FD on the chainring you want, then swap the FD and RD batteries so the RD will still be good to go.
That crossed my mind, then trying to fish it out from the seat tube.
#4292
Senior Member

Joined: Jan 2014
Posts: 10,588
Likes: 427
From: Southern California, USA
Bikes: 1979 Raleigh Team 753
Anyone used the KCNC CB3 brakes? They looks like a parachute, but are very light. The KCNC stuff we have is on-the-edge and if you like that kind of stuff - very cool looking.
But do they work very well?
Any guesses (as that is all I expect to get) on the AERO penalty?
But do they work very well?
Any guesses (as that is all I expect to get) on the AERO penalty?
Last edited by Doge; 11-28-16 at 04:27 PM.
#4294
Senior Member

Joined: Jan 2014
Posts: 10,588
Likes: 427
From: Southern California, USA
Bikes: 1979 Raleigh Team 753
Yea - this is a "Christmas present" for the hill bike, but the hill bike is also a local multi-purpose dry weather training and racing bike. The shape of those brakes are hurting me - for the reasons you imagine.
Right now I have the temporary brakes on. A 1984 Campy Delta brake - beautiful, aero and heavy and do not work so well. the front is the Tri-rig which gets an eh.. in performance and is very difficult to adjust between rims widths.
The DA 9000 just work so well, but are boring and also 100g heavier than these.
Most of this should be on weight weenies, other than I was wondering if anyone actually had used them racing.
I expect not.
Right now I have the temporary brakes on. A 1984 Campy Delta brake - beautiful, aero and heavy and do not work so well. the front is the Tri-rig which gets an eh.. in performance and is very difficult to adjust between rims widths.
The DA 9000 just work so well, but are boring and also 100g heavier than these.
Most of this should be on weight weenies, other than I was wondering if anyone actually had used them racing.
I expect not.
#4295
¯\_(ツ)_/¯
Joined: Jun 2008
Posts: 10,978
Likes: 4
From: Redwood City, CA
Bikes: aggressive agreement is what I ride.
for those of you who like them, Excel Sports - Online Bicycle Retailer has conti gp4ks for $33 apiece right now.
#4296
Thread Starter
Senior Member
Joined: Aug 2007
Posts: 4,449
Likes: 0
rear shifts are slower. period. it is noticeable to someone who knows both systems really well.
IMO, even though i noticed it, it didn't make any difference.
what i didn't like, however, is that i'm a guy who shifts the rear EVERY TIME i shift the front. it's ingrained -- shift from small to big ring and i drop down a cog or two in the back (or the reverse if shifting big to little....except maybe if i'm transitioning to a steep hill).
with eTap, since you need both paddles to effect a front shift you can't get both shifts done simultaneously. yeah, you can hit both paddles then leave one paddle pressed int, but it is another things that is slower. this is for sure noticeable and makes eTap less desirable *for me*.
the bottom line, i think, is about ergonomics: some people are used to shimano and will probably prefer it due to familiarity; others will have the same opinion for sram ergonomics.
#4298
Thanks for feedback.
How does it deal with grime and ****. I am also thinking upgrading my rain bike to 11 speed, and going with etap there also.
I know CA + rain = lulz, what? But still it does rain here in NorCal once in a while.
How does it deal with grime and ****. I am also thinking upgrading my rain bike to 11 speed, and going with etap there also.
I know CA + rain = lulz, what? But still it does rain here in NorCal once in a while.
#4300
Sorry one more question. On my rain bike I have clampon FD. Looks like FD for electronic stuff is brazeon. Will there be an issue to use it with an clampon to brazeon adapter?
Something like this Shimano Braze On Adaptor | Chain Reaction Cycles
Something like this Shimano Braze On Adaptor | Chain Reaction Cycles




