Force AXS D2 vs UDi2 12sp

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TobinHatesYou
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Joined: Mon Jul 24, 2017 12:02 pm

by TobinHatesYou

Within seconds DOT fluid can turn a typical clearcoat slightly cloudy.

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robertbb
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by robertbb

TobinHatesYou wrote:
Wed May 24, 2023 11:31 pm
Within seconds DOT fluid can turn a typical clearcoat slightly cloudy.
Which tells you everything you need to know about it's composition and danger to the human body. Hard pass.

Nickldn
Posts: 1865
Joined: Mon Mar 25, 2019 12:35 am

by Nickldn

DOT brake fluid is nasty stuff, corrosive and absorbs water and so has to be changed frequently. Tolerable in automotive applications as it has a high boiling point, but this is much less important for bicycles as brakes don't get as hot.

Shimano and Campy wisely use mineral oil - not damaging to paint and doesn't absorb moisture. Don't know why SRAM persist with DOT brake fluid.
Giant Propel Advanced SL Red Etap 11s Easton EC90 wheels CeramicSpeed BB Zipp SL70 bars 6.5kg

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kervelo
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Location: Finland

by kervelo

Nickldn wrote:
Thu May 25, 2023 8:45 am
Shimano and Campy wisely use mineral oil - not damaging to paint and doesn't absorb moisture. Don't know why SRAM persist with DOT brake fluid.
Sram has made a move towards the mineral oil, but with only one product so far.
https://www.pinkbike.com/news/sram-quie ... rakes.html

I would rather have mineral oil brakes, but also don't see the current dot brakes a big issue.

TobinHatesYou
Posts: 12455
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by TobinHatesYou

I do favor a change from DOT to mineral oil, but DOT does have a few minor advantages.

- It’s standardized, so I can just go into any autoparts store and get some Motul, Prestone, Castrol, etc.
- If a mineral oil system does see water ingress, it can bubble, which is worse than it dissolving into DOT fluid.
- It does have a broader operating temperature range, maybe useful if you ride your bike in Yakutsk, Russia or something.

raggedtrousers
Posts: 416
Joined: Wed Dec 09, 2020 9:29 pm

by raggedtrousers

Thanks all for the replies.

If AXS had the hidden buttons, which having used I find really useful during intervals and when riding in winter gloves, then I think that would be my choice at this point. It's cleaner, the ratios would solve a problem, and I could get the rainbow cassette and chain :-) But as it doesn't have those buttons, and I can currently get UDi2 for £200 less... it's a tough one.

robeambro
Posts: 1828
Joined: Sat Jul 07, 2018 6:21 pm

by robeambro

I've used Di2 11s and now on AXS (a mix of Rival & Force).

My 11s Di2 "just worked". I never had to adjust settings or had a chain drop in many years. That said, the only one time I rented a 12s Ultegra Di2, I suffered two chain drops in one day. Definitely not enough to draw conclusions, but would be wary of thinking that 12s Shimano works flawlessly.

On AXS, I would echo what others have said. FD is finicky but can be adjusted well with patience (and tbh whenever I had an outboard chain drop, I have just shifted back to the small ring and the chain goes back on without me having to stop). I do have issues having quiet shifting everywhere on the cassette but that might also be partly due to UFO Drip not being the quietest lube.

The app and the shifting logic to me are a couple steps ahead of Shimano, and frankly I couldn't give a toss about a couple-millisecond faster shifting. A 46-33 / 10-36 is the perfect ratio for my N=1 bike (and if I could be bothered with trying non-SRAM cranks, I could get even more range), and likewise, I couldn't give a toss about a microwatt efficiency loss of the 10t cog (which I use only when descending and most often soft pedalling, and being aero is far more important. Yes, having those watts would be nice. But the cog is used little and in occasions where a handful of watts is not of much importance to me).

DaveS
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Location: Loveland Colorado

by DaveS

Major exaggeration about DOT fluid problems. I treat it no differently than I would an oil. I don't wear gloves using it and the fact that it wipes off with water means it's not the least bit difficult to deal with. With the bleeding edge kit, you shouldn't be getting the fluid on your paint. I had zero problems setting up my three bikes. If water gets into the system, it mixes with the fluid. That may lower the boiling point by a small amount. With oil, any water drops to or stays in the caliper where it will boil quickly or freeze. That's why it's not used in cars.

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wheelsONfire
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by wheelsONfire

Seamanatorr wrote:
Wed May 24, 2023 8:13 pm
I'm also weighing differences between the two. I lean to SRAM since its easier to run a 1x setup for road (very flat area), however I wonder how easy it is to switch cranksets to 2x and also add the front derailleur again if I'm expecting a hilly area.
It's no problem at all setting up the new FD. The FD cage edge, 1-2mm over big cainring tooth. Then you line up the white markings on the FD parallell to the big chainring. Some clearance 1-2mm using small chainring and largest cassette cog.
Big ring and 10 tooth at the cassette same clearance.
When done, mount the FD tab. Done :thumbup:
You also adjust the RD with an app you down load on your phone. You can even pick which cassette you have.
It's not difficult at all.
Bikes:

Ax Lightness Vial EVO Race (2019.01.03)
Open *UP* (2016.04.14)
Paduano Racing Fidia (kind of shelved)


Ex bike; Vial EVO D, Vial EVO Ultra, Scott Foil, Paduano ti bike.

TLN
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by TLN

wheelsONfire wrote:
Thu May 25, 2023 3:10 pm
You also adjust the RD with an app you down load on your phone. You can even pick which cassette you have.
You can also do that without app, using small buttons inside paddles.
His: Orbea Orca OMX
Hers: Cannondale Synapse HM Disc

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wheelsONfire
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by wheelsONfire

TLN wrote:
Thu May 25, 2023 5:23 pm
wheelsONfire wrote:
Thu May 25, 2023 3:10 pm
You also adjust the RD with an app you down load on your phone. You can even pick which cassette you have.
You can also do that without app, using small buttons inside paddles.
Ofcourse, just like Etap. I know that since i mount all my groupsets and bikes. But i feel that the app is what i prefer.
You can set the bike up and sit just infront of the RD and cassette.
Bikes:

Ax Lightness Vial EVO Race (2019.01.03)
Open *UP* (2016.04.14)
Paduano Racing Fidia (kind of shelved)


Ex bike; Vial EVO D, Vial EVO Ultra, Scott Foil, Paduano ti bike.

CasualRider
Posts: 118
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by CasualRider

Shifting of new Force rear derrailer is no different than old one or even Rival. You won't notice any difference, it is still ok. I have Sram Force 1x though on one bike and Dura Ace on the other. It's night and day difference. DA (same as ultegra) is superior in every way such as battery life, shift quality, shift speed, shifting under power. You name it. And I can tell you even people who work at Sram think the same way.
Tarmac SL8 Maganta Gold
Crux Green Pearl

Previous bikes:
Crux Forest Green
Tarmac SL7 Snake Eye
Venge Bora Team
Venge Purple
Trek Madone SLR 7

Seamanatorr
Posts: 28
Joined: Tue Apr 18, 2023 4:00 pm

by Seamanatorr

wheelsONfire wrote:
Seamanatorr wrote:
Wed May 24, 2023 8:13 pm
I'm also weighing differences between the two. I lean to SRAM since its easier to run a 1x setup for road (very flat area), however I wonder how easy it is to switch cranksets to 2x and also add the front derailleur again if I'm expecting a hilly area.
It's no problem at all setting up the new FD. The FD cage edge, 1-2mm over big cainring tooth. Then you line up the white markings on the FD parallell to the big chainring. Some clearance 1-2mm using small chainring and largest cassette cog.
Big ring and 10 tooth at the cassette same clearance.
When done, mount the FD tab. Done :thumbup:
You also adjust the RD with an app you down load on your phone. You can even pick which cassette you have.
It's not difficult at all.
Thanks for the info. It feels like SRAM is more customizable and easier to adjust and mess with. Their app looks more intuitive too.

I can ride 50miles from my house with less than 200ft elevation gain.


Sent from my iPhone using Tapatalk
S-Works SL7 RTP

TLN
Posts: 630
Joined: Wed Jul 12, 2017 4:50 pm

by TLN

Seamanatorr wrote: Thanks for the info. It feels like SRAM is more customizable and easier to adjust and mess with. Their app looks more intuitive too.

I can ride 50miles from my house with less than 200ft elevation gain.


Sent from my iPhone using Tapatalk
I was running 50x11-28 in Chicago and it was perfectly fine. Current 10-33 cassette will cover anything. No potential issues with FD in that case.
Can keep bigger cassette or smaller ring for any trip to mountains.
Last edited by TLN on Fri May 26, 2023 1:19 am, edited 1 time in total.
His: Orbea Orca OMX
Hers: Cannondale Synapse HM Disc

apr46
Posts: 252
Joined: Thu Aug 26, 2021 1:46 pm

by apr46

I suspect that if regulators decided to get into ebike or bike safety, we would see mineral oil brakes go away like they did for cars. DOT is both generally higher performance, safer in cases of neglect, and largely avoids potential internal corrosion issues.

I have a couple of AXS bikes and the big pluses for me are being able to rotate batteries, so I never worry about charging, I prefer the shift ergonomics and the damper on the RD makes for a really silent ride even when the roads arent the best. As above, I consider DOT to be an advantage despite environmental concerns around disposal, etc.

The disadvantages are front shifting and I think its harder to find a mechanic who actually does good work on Sram systems. Sram also recommends 405mm chainstays for 2x disc bikes. This means some bikes are barely out of spec with 404mm chainstays while others like the Basso Diamanté might have issues with its 400mm chainstays. No idea what Shimano's frame fit guidelines are.

by Weenie


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