Yet another disc brake woes tread (this time about standards...)

Discuss light weight issues concerning road bikes & parts.
CallumRD1
Posts: 129
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by CallumRD1

bilwit wrote:
Fri May 11, 2018 12:40 am
even then the thread pitch standard isn't always the same regardless.. :x
That matters little; thru axles are nominally frame specific and come with the frame. So if you have a 12x142mm thru axle rear wheel it will fit on all corresponding disc frames.

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silvalis
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by silvalis

I don't see any of these being an issue, making mountains out of molehills. Especially half of your listed woes are for mtb, not road.
Chasse patate

by Weenie


joejack951
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by joejack951

bilwit wrote:
Fri May 11, 2018 12:40 am
CallumRD1 wrote:
Fri May 11, 2018 12:21 am
The road standard is 12x142mm at the rear, not 135mm.
even then the thread pitch standard isn't always the same regardless.. :x
I was thinking actual dropout spacing when I posted. With the 3.5mm pockets each side, you have a 142mm OLD hub but for chainline and general hub design purposes, it's a 135mm rear.

Thread pitch change would only mean a new thru axle. No big deal.

bilwit
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by bilwit

CallumRD1 wrote:
Fri May 11, 2018 12:56 am
bilwit wrote:
Fri May 11, 2018 12:40 am
even then the thread pitch standard isn't always the same regardless.. :x
That matters little; thru axles are nominally frame specific and come with the frame. So if you have a 12x142mm thru axle rear wheel it will fit on all corresponding disc frames.
...and that goes back to "none of this is a problem if you buy a bike fully built and are completely content with that." However, as this site is weight weenies, finding a suitable alternative is an issue. In my experience, none of the thru-axles offered by Extralite or Carbon-Ti or KCNC had compatible thru-axles with the correct thread pitch but I did find "Robert Axle Project" up to the task after some digging

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LeDuke
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by LeDuke

Is it so hard to measure thread pitch, thread length and TA length and compare that to the big standards out there?

I mean, people obviously buy Ti replacement bolts for everything on their bikes, and I’d hope they are measuring bolts before buying and installing, so how is it so difficult to measure a 12mm TA and compare it to the listed specs?






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mrlobber
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by mrlobber

LeDuke wrote:
Fri May 11, 2018 6:14 am
Is it so hard to measure thread pitch, thread length and TA length and compare that to the big standards out there?
It isn't, provided someone manufactures something like that.

A good example is Cervelo R5 - using RAT axles on paper (130g for a pair), but slightly different than those RATs which their sister company Focus is using. As a result, you're (currently) stuck with their heavy, unaero original axles. I almost bought replacement RATs from Robert Axle Project when they luckily told me they're not compatible.

None of this matters, of course, for the general public.
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TobinHatesYou
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by TobinHatesYou

bilwit wrote:
Fri May 11, 2018 2:52 am

...and that goes back to "none of this is a problem if you buy a bike fully built and are completely content with that." However, as this site is weight weenies, finding a suitable alternative is an issue. In my experience, none of the thru-axles offered by Extralite or Carbon-Ti or KCNC had compatible thru-axles with the correct thread pitch but I did find "Robert Axle Project" up to the task after some digging

Both Robert Axle Project and Shift-Up make pretty much every type of TA. I have one of the least common types ... Trek ABP/Maxle which is 1.75mm front and rear. Had no issue getting a Shift-Up set.

aaronpass
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Joined: Sun Aug 12, 2012 2:32 am

by aaronpass

People need to stop complaining. There is a fix for everything or don't buy a disc brake bike. Have two wheelsets, one with center lock and one with 6 bolt? Use a shim. Problem solved.

You don't see people on automotive forums saying "why can't I use my Honda wheels on my Range Rover???"
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mattr
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by mattr

Yes you do.

All. The. Bloody. Time.

spdntrxi
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by spdntrxi

I would love to use my Kinesis K5 on my Subaru...but when I bought them, I was driving an RX7.. Hell even my Forgelines wont fit my Subi... so gotta agree with Matt on this one.

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Lewn777
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by Lewn777

2old4this wrote:
Thu May 10, 2018 4:26 pm
I am building my first bike with disc brakes and know why disc breaks are not taking over as quickly as some people think disc brakes should.

No matter what you think about rim brakes, one thing we all agree, for the most part, you take one brand's brakes and put on a bike. It'll work. Yes, there are exceptions (tire clearance is one) but still...

On the disc brakes, there is no such thing.

- Brands are not compatible with each other
You can't simply take one of these and use on another one: Shimano, Magura, Tektro, Hope, Avid, Formula, Hayes, Fox, DTSWISS, Rockshox, Bengal, Quad, Echo,Giant...
- Even within the same brand's offerings, all calipers/hoses are not interchangeable.
- You'll need an adaptor to use the same caliper on two different bikes.
- Rotor sizes will force you to use different adaptors on the same bike
- Seriously what's up with all these rotor sizes (140, 160, 170, 180, 185, 203) ?
- Is your fork Flat mount or Post mount?
- Mechanical or hydraulic (or their electronic versions)
- If hydraulic, what type of fluid does you system use?
- Obviously bleeding kits are not compatible with each other.

I am sure I am missing some other "standards" but I think disc brakes are going to take a hit on the used bike/part market. After that, whenever a standard emerges, disc brakes may takeover ...
I have disk brakes on four mountain bikes and a CX bike. Two running Shimano hydraulic (oil), one SRAM (brake fluid) and one mech (BB7 road). Personally I hate the idea of disks on climbing road bikes. Why add 4-600g to your bike? Still if you live in a wet area it can make sense, but it seems they're gonna force this thing through even for people that don't want or need them.

IMHO Shimano brakes are unmatched in reliability, ease of maintenance and availability. So just stick with them to avoid compatibility issues.

What sucks is we're in for a huge game of standards musical chairs where manufacturers are going to be second guessing everything. Things will change to 12x1, 13x1, 14x1 and axle widths will adapt to match. Fine for the new rider but a disaster for the home building enthusiast that wants an interesting bike. Sure, the bikes will get better, but the marginal gains won't be worth all the annoyance, frustration and landfill.

I strongly recommend that everyone fight to make manufacturers keep a rim brake option for climbing bikes. I don't have any desire to hate on or ban disk brakes just leave me with the rim brake option on one kind of road bike indefinitely. Disk brakes for road bikes are the exact same thing as the 26 to 27.5 move for mountain bikes. Minimal gain, lots of pain. Lots more money for big companies, headaches for home builders and LBS's.

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Leviathan
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by Leviathan

Miller wrote:
Thu May 10, 2018 8:04 pm
As a side note it seems to me that the proportion of people assembling their own bikes is rather low these days. Even on this forum people are often discussing buying complete bikes. But where's the fun in that...
Notwithstanding my old git rant about how much better things were in the old days, the combination of "stock" complete bike options being much better (how many 6.5kg Cannondale Supersixes from their Florida LBS do we really need to see to substantiate that) with the HUGE price of third party specialist parts - (Lightweight RD? Ceramic Speed ANYTHING?) multiply the effect of having so many "standards" for everything these days, that its not surprising bike tech has regressed to the mean. Hence its cheaper and better just to buy off the shelf or to go straight to some grey import manufacturer who may or may not also make Pinarellos in their own factory in China (not to mock Chinese production per se, dont get me wrong).

Its a pity. I still loved the guy on the forum 5 years ago who wanted to drill his carbon frame all over to lighten it - remember him??

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