Crux 2021

Especially for light weight issues concerning cyclocross / touring bikes & parts.

Moderator: Moderator Team

Post Reply
cbro
Posts: 10
Joined: Fri Oct 15, 2021 4:45 pm

by cbro

I'll be building up a Crux with AXS 2x either at the end of this week or the beginning of next. I'm curious to see where the supposed incompatability is. I have a normal Force 48/35 crankset, and if that doesn't work I plan to swap the whole 48/35 spinder+chainring assembly over to a Force Wide crank assembly and see if I can get it working with a (non-wide) AXS front derailleur.

by Weenie


Visit starbike.com Online Retailer for HighEnd cycling components
Great Prices ✓    Broad Selection ✓    Worldwide Delivery ✓

www.starbike.com



LegPower
Posts: 162
Joined: Sun Jun 17, 2018 8:10 pm
Location: San Francisco
Contact:

by LegPower

FlatlandClimber wrote:
Mon Oct 18, 2021 3:56 pm
This is all personal, depending on where you ride and what you prefer, but:
I really would hate a 1x with a small chainring and 10-36 or 10-40 for road...
A 44t would probably be okay for road riding where I live, although I would like to sprint on in or ride intervals to power.
For going into the mountains... so basically very vacation I have done in the past 2 years:
44/36 gearing is 13.6kph at 80rpm. For an 80kg system (70kg rider, 8kg bike, 2kg stuff) that's roughly 340W at 10% grade.
Considering several climbs in the Alps have several kilometers at that grade, I wouldn't want that. Also, the "saved weight" goes out of the window with the:
A. Biomechanical inefficiency of pedaling at low cadence B. The inefficiency of the drivetrain with that chainline.
Also, large gear jumps on a road climb annoy me. I rode a good 20HC climbs this year, most of them with 48/35 10-36 and while the gearing was great, even those gear jumps were too much for me. I will switch to 11-34 for that reason for the next season.

For Gravel the 42 10-44 *CAN* definitely work, especially if you use it as a true "gravel" bike.
I use my Gravel bike more as a "go anywhere bike". Basically anything from road (not primarily obviously), beat up tarmac, light gravel, forest paths, double trail, single trail, mud, heavy gravel, gras etc. Nothing is off limits (unless I reach my physical or skill limitations).
42 10-44 would allow me to go fast enough for anything but sprinting or road descents, but 42/44 clearly wouldn't be nearly enough for me on muddy climbs (that force you to stay seated), steep pitches in the forests or even longer off road climbs on gravel marathons or bike packing.

So if it works for you: great.
I would really find this extremely compromised for both road and gravel.
I live in Europe and frequently visit San Francisco so climb a lot (as referenced above). This year I'm at 8000km and 111k meters climbed. I'm not sure what you mean by "small ring". 44/10 is plenty to sprint with especially if you can't do 340w up a climb. There are hardly any climbs that sustain 10% for more than a km at most. That being said, my FTP is 355 so I guess it's right in my "wheelhouse". I thought I needed 2x, but am completely converted now that I've gone 1x.

FlatlandClimber
Posts: 1764
Joined: Tue Mar 31, 2020 3:37 pm

by FlatlandClimber

"If you can't do 340W up a climb"
Firstly, sustained power and sprinting power have little to do with each other. I am not a great sprinter and spin out 46/10 far too easily for me to be considered comfortable in a sprint out of the saddle.
340W at my BW is 4.78W/kg.
In case your weight is say 180lbs, that means to maintain 80 cadence on 10% would take you 390W.
I know it's a power Someone with a 355W FTP should be able to do, but if it is the average of 1km, then at 13.6kph (that's 80rpm with 44/36) then that's 4.5 minutes of that.
During a long ride in the Alps, I'd just not want to be forced to pedal at or above threshold at a rather uncomfortable cadence for extended periods of time. The altitude and pre exertion of climbing a large mountain does its job, too.

This is my use case, as mentioned above, so obviously these things apply to me, not necessarily to anyone else.

In SF Bay Area, there might not be many climbs, that sustain 10%+ for a full kilometer or more, in the Alps there are... well hundreds, including Alpe d'Huez, Ventoux, Stelvio, Gavia, Col de la Madeleine, Croix de Fer, Galibier, Glandon, Col de la Loze, Basically anything in the Dolomites...

I get that not everyone rides these on the daily, but I ride climbs like this relatively frequently and - as aforementioned - wouldn't want my "climbing bike" to compromise me here.
Open WI.DE (2019) - 8.7kg
Specialized Shiv TT Disc (2020) - 7.9kg
Specialized SW Æthos (2021) 6.5kg
Trek Émonda SLR9 (2021) 7.3kg
Specialized SW Crux (2022) 7.9kg

*all weights are race ready bikes, large frame size.
Sold: SW Venge, S5 Disc, Roubaix Team

bikewithnoname
Posts: 1655
Joined: Tue Sep 22, 2009 1:29 pm
Location: Paris

by bikewithnoname

I wouldn't want my climbing bike to be a Crux

Tarmac will go up and down "better"
"We live in an age when unnecessary things are our only necessities." Oscar Wilde

whinefields
Posts: 37
Joined: Tue Apr 13, 2021 11:08 pm

by whinefields

toronto-rider wrote:
Mon Oct 18, 2021 3:38 pm
I plan to run this with GRX 2X and will be selling my 2016 Sworks SL5 road bike and Open Gravel Bike. I ride my road bike maybe 20 times outside on the road a year, and almost nothing from October to May. I am 90% gravel. Have already 700c and 650 B wheels for my Open.
I live in Toronto, so most of my gravel rides involve a fair amount of road. So prefer 2x.

Just before I take the leap, I presume using a Gravel NG Rotor ALDHU R 24mm w/ Cranks 2x Chainring Package would be ok. I plan to run 700 x 40 0r 42 and 650 x 42.
I guesses I will wait until I see what the people have said with 2x and tire clearance. Would be interesting to see what Ten Dam and Boswell use, as they are 2x and sponsored by Shimano and Specialized.
You should be fine. Like you, I decided to build my Crux with GRX 2x. I emailed with the folks at Power2Max and they assured me you can run their 2x set up on the Crux given the GRX spacing (even with the road q-factor). I hope they're right since I ordered the gravel Easton EC90sl crankset with 48/31 chainrings. I guess we'll know for sure in a bit, since the frame and powermeter are coming tomorrow.

FactoryMatt
Posts: 927
Joined: Tue Apr 14, 2015 4:35 am

by FactoryMatt

Moots just told me their Routt RSL is Gravel Wide only. apparently they don't rate ANY road 2x chainsets for use due to chainstay interference. sad boyz.

rothwem
Posts: 106
Joined: Wed Jul 09, 2014 4:45 pm
Location: Asheville, NC

by rothwem

LegPower wrote:
Mon Oct 18, 2021 4:24 pm
...especially if you can't do 340w up a climb...
Image

FactoryMatt
Posts: 927
Joined: Tue Apr 14, 2015 4:35 am

by FactoryMatt

And no mention of self selected cadence or weight... Power =/ torque

FlatlandClimber
Posts: 1764
Joined: Tue Mar 31, 2020 3:37 pm

by FlatlandClimber

FactoryMatt wrote:
Mon Oct 18, 2021 10:51 pm
And no mention of self selected cadence or weight... Power =/ torque
Who are you referring to?
Open WI.DE (2019) - 8.7kg
Specialized Shiv TT Disc (2020) - 7.9kg
Specialized SW Æthos (2021) 6.5kg
Trek Émonda SLR9 (2021) 7.3kg
Specialized SW Crux (2022) 7.9kg

*all weights are race ready bikes, large frame size.
Sold: SW Venge, S5 Disc, Roubaix Team

FactoryMatt
Posts: 927
Joined: Tue Apr 14, 2015 4:35 am

by FactoryMatt

^nvm, legpower, but i had the context wrong. nvm.

Basscadet
Posts: 36
Joined: Thu Aug 12, 2021 2:38 pm

by Basscadet

Specialized has a "Coming Soon" for the new 12 speed DA Di2 Aethos. Why not do the same for a GRX Di2 Crux, even though it might be delayed by supply chain issues? Or, alternatively, why not offer a SRAM 2x solution?

It's just very weird that Specialized is gestuing for anyone who wants a 2x setup to go custom. Realistically, what size of the market is comfortable building their own bike?

whinefields
Posts: 37
Joined: Tue Apr 13, 2021 11:08 pm

by whinefields

Finally arrived! Along with a bunch of other goodies. First thoughts? This thing is light. Crazy light.

Image

TwC
Posts: 9
Joined: Sat Jul 25, 2020 9:33 pm

by TwC

First thought, get a crank on it and tell us what fits!

sib
Posts: 299
Joined: Mon Jun 15, 2015 2:03 am

by sib

@whinefields
That looks lovely..!!

Size and weight?

by Weenie


Visit starbike.com Online Retailer for HighEnd cycling components
Great Prices ✓    Broad Selection ✓    Worldwide Delivery ✓

www.starbike.com



bilbobogeins
Posts: 12
Joined: Wed Dec 02, 2020 5:13 pm

by bilbobogeins

whinefields wrote:
Tue Oct 19, 2021 11:38 pm
Finally arrived! Along with a bunch of other goodies. First thoughts? This thing is light. Crazy light.

Image
Can you post pic of FD Hanger.

Post Reply