hey weight weenies....have you regretted going disc OR aero?

Discuss light weight issues concerning road bikes & parts.
Hexsense
Posts: 904
Joined: Wed Dec 30, 2015 12:41 am

by Hexsense

dcorn wrote:
Tue Oct 23, 2018 11:03 pm
When I switched out my rotors, I didn't have to adjust a thing. No rotor rub with calipers in the same spot. Maybe you didn't fully seat the rotor on the hub?
Nope switched back and forth three times, on two wheels (front 160 and rear 140), use torque wrench at 40N.m as Shimano lock ring specified, it's consistently like this.
It's either the rotor are designed not sit at the same place, or coincident of one of rotor's centerlock interface have something weird with my hub (like tapered centerlock teeth at the end mating each other, maybe?)

I think it wouldn't be hard to give Sram rotor some shims to move it away from the rim and stay where Shimano sits.

EDIT: I don't think i'm alone, other member mention about Sram rotor sit most far to the frame (which mean closer to the wheel?) in another thread too
https://weightweenies.starbike.com/foru ... 0#p1314206

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stringbean
Posts: 34
Joined: Sun Jul 06, 2008 2:18 pm
Location: Darkest Africa

by stringbean

Also fell for the marketing BS and got myself a Spez Tarmac disc a few months ago.
It’s been a learning experience and very interesting comparing it to my other 2 rides ( Factor one and Colnago v2 R)
Here are a few of my thoughts:
Moving from a bike with qr to a bike with thru axle ( as most disc bikes are)is huge difference.Bike is a LOT more stiffer.Some good some bad.Good for acceleration bad for overall comfort.
Add to the mix your favorite cool looking deep section wheels and you add to the stiffness some more.
If you riding a package that is aero,disc deep sections ,thru axle wheels im sorry that must be the most uncomfortable ride EVER.I know the guys with venge will slate me but where I am there is a far mixture of A B and C roads and the moment you go off anything but smooth tarmac you feel the difference.
Disc wheels are heavy and have a bit of catching up to do to their rim brake counterparts.
Although my disc bike comes in at a not bad 7.3kg I can definitely feel the extra weight in the wheels compared to my rim brake bikes when climb and accelerating.
Will disc take over?No,I believe manufacturers will continue to produce both.
My advice to those going disc.
Don’t go aero and don’t be tempted to go cool looking deeeep sections.Imo coupled with thru axels it just makes a uncomfortable package.
My 2 C

by Weenie


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LeDuke
Posts: 1527
Joined: Sun Oct 07, 2012 2:39 am
Location: Front Range, CO

by LeDuke

stringbean wrote:Also fell for the marketing BS and got myself a Spez Tarmac disc a few months ago.
It’s been a learning experience and very interesting comparing it to my other 2 rides ( Factor one and Colnago v2 R)
Here are a few of my thoughts:
Moving from a bike with qr to a bike with thru axle ( as most disc bikes are)is huge difference.Bike is a LOT more stiffer.Some good some bad.Good for acceleration bad for overall comfort.
Add to the mix your favorite cool looking deep section wheels and you add to the stiffness some more.
If you riding a package that is aero,disc deep sections ,thru axle wheels im sorry that must be the most uncomfortable ride EVER.I know the guys with venge will slate me but where I am there is a far mixture of A B and C roads and the moment you go off anything but smooth tarmac you feel the difference.
Disc wheels are heavy and have a bit of catching up to do to their rim brake counterparts.
Although my disc bike comes in at a not bad 7.3kg I can definitely feel the extra weight in the wheels compared to my rim brake bikes when climb and accelerating.
Will disc take over?No,I believe manufacturers will continue to produce both.
My advice to those going disc.
Don’t go aero and don’t be tempted to go cool looking deeeep sections.Imo coupled with thru axels it just makes a uncomfortable package.
My 2 C
Here’s what I’ve experienced.

1) Disc RIMS are lighter for a given depth/width/profile.
2) Disc RIMS can be more aero.
3) Disc wheels are stiffer, as they almost always have more spokes than their rim brake counterparts.
4) Thru axles don’t make any difference in comfort.
5) Disc rims can be wider for a given weight. This CAN result in wider tires, and more comfort based on what tires, inflation system and pressure a rider will run.
6) Disc rims, particularly those without hooks, can use different construction methods and materials that build a more durable wheel.


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Hexsense
Posts: 904
Joined: Wed Dec 30, 2015 12:41 am

by Hexsense

1.)
If you inflate the same pressure, wider tire (resulted from wider rim), although roll faster, is ACTUALLY LESS COMFORTABLE.
source: https://silca.cc/blogs/journal/part-3-t ... nd-comfort

you are supposed to reduce your pressure a bit to get comfort back, and reduce further if you want to gain comfort. 45psi MTB tire is rock hard while is very squishy on road tire. wider rim width do the same effect, just much less magnitude.

2.)
Does frame compliance still matter?
https://cyclingtips.com/2018/04/jra-wit ... ll-matter/

dcorn
Posts: 314
Joined: Thu Oct 05, 2017 4:21 pm
Location: NoVA

by dcorn

Yeah thats another thing. All these disc and aero bikes can now take wider tires, so use wider tires! I have 32c tires (tubeless) on my Aeroad disc and the ride is amazing compared to my other bike with 25c. I run 80 psi on the 32s compared to 110psi on the 25s. I could probably go a bit lower, but I'm 205 lbs and don't want the tire to deflect too much in normal riding.

Mr.Gib
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by Mr.Gib

stringbean wrote:
Wed Oct 24, 2018 8:33 am
Moving from a bike with qr to a bike with thru axle ( as most disc bikes are)is huge difference.Bike is a LOT more stiffer.Some good some bad.Good for acceleration bad for overall comfort.
I don't think it is the through axles that change the feel of the bike. It is more likely that the fork must be designed and built to be very strong and stiff to deal properly with the braking forces of a disc system. This is nice for braking and some sprinting and cornering situations, but IMO it makes the bike feel like riding a brick in the hands. On uneven surfaces it really jolts the rider. Some older cross bikes with more flexible forks avoid this problem but then the braking is of course not as good.
wheelsONfire wrote: When we ride disc brakes the whole deal of braking is just like a leaving a fart. It happens and then it's over. Nothing planned and nothing to get nervous for.

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stringbean
Posts: 34
Joined: Sun Jul 06, 2008 2:18 pm
Location: Darkest Africa

by stringbean

Is there a possibility that the sudden urge to ride 28 and 30c road tires is because we’ve built up a complete system focusing on “flex free” thus making it uncomfortable.

Monkeyfudger
Posts: 305
Joined: Thu Apr 11, 2013 7:26 pm

by Monkeyfudger

32c tyres on an Aeroad seems kinda like running single ply tyres on a DH bike no?

spdntrxi
Posts: 3018
Joined: Sat Jul 20, 2013 6:11 pm

by spdntrxi

stringbean wrote:
Wed Oct 24, 2018 8:42 pm
Is there a possibility that the sudden urge to ride 28 and 30c road tires is because we’ve built up a complete system focusing on “flex free” thus making it uncomfortable.

could be... My Parlee XD is going to live on 28c for all rides with a majority of pavement.... but the plan for the aero bike is Turbo Cotton 26c and call it done.

dcorn
Posts: 314
Joined: Thu Oct 05, 2017 4:21 pm
Location: NoVA

by dcorn

Monkeyfudger wrote:
Wed Oct 24, 2018 8:52 pm
32c tyres on an Aeroad seems kinda like running single ply tyres on a DH bike no?
I don't follow. Science shows that wider, lower pressure, tubeless tires are faster than super high pressure skinny tires, with the side effect of being much more comfortable. Am I supposed to sacrifice all comfort because I like the look of an aerodynamic bike?

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kgt
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Location: Athens, Greece

by kgt

32s are crap in terms of aero. I gues that's what Monkeyfudger says.

timmerrr
Posts: 69
Joined: Wed Sep 26, 2018 10:09 pm

by timmerrr

dcorn wrote:
Thu Oct 25, 2018 4:01 am
Monkeyfudger wrote:
Wed Oct 24, 2018 8:52 pm
32c tyres on an Aeroad seems kinda like running single ply tyres on a DH bike no?
I don't follow. Science shows that wider, lower pressure, tubeless tires are faster than super high pressure skinny tires, with the side effect of being much more comfortable. Am I supposed to sacrifice all comfort because I like the look of an aerodynamic bike?
If the tire makes a lightbulb shape (the tire is wider than the edge of the rim) the air will detach from the wheel and the aero benefit of the wheels is greatly reduced. I don't know of any rim that is wide enough to support a 32c with out 'lightbulbing' so in terms of aero, you may as well be running aluminium box section wheels...

Hexsense
Posts: 904
Joined: Wed Dec 30, 2015 12:41 am

by Hexsense

Right,
With my previous 21mm internal width wheelset (28mm outside)
23c is 27.3mm wide
25c is 28.3mm wide

front wheel shouldn't be more than 25c clincher for best aero performance. Even 23c at 27.3mm is full two mm wider than what pro use (25c tubular at 25mm, they don't run oversize like modern clincher tires on wide rims).

Under around 30km/h your 32c, providing it is made thin and fast, will be faster due to better rolling resistance. But once aerodynamic take over at higher speed, you better use 25c front (and probably 28c rear). This is assumed your wheels are not 36mm wide externally or something crazy wide.

Bigger Gear
Posts: 474
Joined: Fri Mar 27, 2009 6:58 pm
Location: Wet coast, Canada

by Bigger Gear

Hexsense wrote:
Thu Oct 25, 2018 7:47 pm
Right,
With my previous 21mm internal width wheelset (28mm outside)
23c is 27.3mm wide
25c is 28.3mm wide

front wheel shouldn't be more than 25c clincher for best aero performance. Even 23c at 27.3mm is full two mm wider than what pro use (25c tubular at 25mm, they don't run oversize like modern clincher tires on wide rims).

Under around 30km/h your 32c, providing it is made thin and fast, will be faster due to better rolling resistance. But once aerodynamic take over at higher speed, you better use 25c front (and probably 28c rear). This is assumed your wheels are not 36mm wide externally or something crazy wide.
This is correct, and a lot of people get hung up solely on a wider tire providing lower rolling resistance, but they completely miss the boat on the aerodynamics. I believe Josh Poertner (of current Silca fame, but when he was at Zipp), found the relationship to be rim width=105% of tire width for maximal aero performance.

Hexsense
Posts: 904
Joined: Wed Dec 30, 2015 12:41 am

by Hexsense

But to be fair. At his weight, 28c and giving up some aero might be a better compromise.
Tell people that you care more about comfort than speed over 30km/h. While the wheel set-up is not aero optimized, at least the frame is aero. Keep doing what you like. :beerchug:

by Weenie


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