/ !!<>Sram Hydraulic Road Brake Recall -Stop Use Immediately<>!!

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Timmd on 16 Dec 2013

http://singletrackworld.com/2013/12/sram-road-hydraulic-brake-recall-stop-use-immediately/

See here folks, they don't seem to work below a certain temperature.
balmybaldwin - on 16 Dec 2013
In reply to Timmd:

Odd that only road brakes are effected given that you would have thought they would copy the tech from the Elixir MTB range
Timmd on 16 Dec 2013
In reply to balmybaldwin:
Who knows, maybe it's to do with the size and shape of the seals needed to fit hydraulics into road shifter and brake units?

It could be anything that we wouldn't have thought of, I haven't a clue...
Post edited at 13:44
gethin_allen on 16 Dec 2013
In reply to Timmd:

All I can think of would be the seals being too rigid/brittle and failing at low temp. If a calliper seal leaked and contaminated the pads this would result in in pretty much no brakes.
Enty - on 16 Dec 2013
In reply to Timmd:

Thank got the uglyness put me off buying that groupset ;-)

E
Timmd on 16 Dec 2013
In reply to Enty:
> Thank got the uglyness put me off buying that groupset ;-)

> E

You'd think they'd make them a bit more rounded, and silver maybe?

They look quite utilitarian in shape to me.

(..for the UKC computer, this is some text, just less of it before having to write this...)
Post edited at 21:50
Timmd on 16 Dec 2013
In reply to Timmd:
What's going on UKC, keep seeing different messages of mine?

Ah, no I don't.
Post edited at 22:17
balmybaldwin - on 16 Dec 2013
In reply to Enty:

At last being a bike tart pays off!
TimB - on 18 Dec 2013
In reply to balmybaldwin:
> Odd that only road brakes are effected given that you would have thought they would copy the tech from the Elixir MTB range

One of the press releases from SRAM said that it was the master cylinder seals that can fail in sub-zero conditions - so the ones in the shifter not the (Elixir-style) caliper.


Post edited at 08:51
johnj on 18 Dec 2013 - 86.112.78.158 whois?
In reply to Timmd:

You don't need to stop using them, just for the time been don't ride em in sub zero temperatures, and get the replacement seals of sram and refit simple, innit?


Timmd on 18 Dec 2013
In reply to johnj:
Tell the Sram press team...
Post edited at 11:08
johnj on 18 Dec 2013 - 92.40.249.138.threembb.co.uk
In reply to Timmd:

Tell them what?
Timmd on 18 Dec 2013
In reply to johnj:

That they don't need to tell people to stop using them.

Thought that's what you had in mind. (:-))
johnj on 18 Dec 2013 - 86.112.78.158 whois?
In reply to Timmd:

Well obviously Sram would have to do a full recall, however as the seals are at fault all they'd do is take returns and fit new seals and reissue.

fitting seals in bike brake systems is really easy just like a technical version of changing an inner tube, so I just proposed an alternative solution, however I understand why people would want the factory re-issue job :)
johnj on 18 Dec 2013 - 86.112.78.158 whois?
In reply to Timmd:

Saying that though it is possible that it is also a tolerance issue on the slots that the seal fit into, so it may be a full retooling setup, which is a completely different scenario.
Timmd on 23 Dec 2013
In reply to Timmd:

Bump!
Timmd on 20 Jan 2014
In reply to Timmd:

b
Timmd on 11 Feb 2014
In reply to Timmd:

b u m p
3leggeddog on 11 Feb 2014
In reply to Timmd:

Please, Please. Please call the upgraded groupset something space shuttle related, keep old Feynman happy in his grave
Luke90 on 11 Feb 2014
In reply to balmybaldwin:
> Odd that only road brakes are effected given that you would have thought they would copy the tech from the Elixir MTB range

Not so odd, the Elixirs are crap too!
balmybaldwin - on 11 Feb 2014
In reply to Luke90:

Youre not wrong, but they are reliable. What I dont understand is why virtually every mtb comes with them....the shimano slx and up are so much better, as are formula etc
Timmd on 14 Feb 2014
In reply to balmybaldwin:
Rockshox and Sram and Avid are all part of the same conglomerate, I guess if Rockshox gets put on a bike it gives an opening for Avid brakes to be as well, or Sram gears, and visa-versa...
Post edited at 14:03
balmybaldwin - on 14 Feb 2014
In reply to Timmd:

that's no excuse for putting crap kit on expensive bikes... and probably why I've go Fox, shimano and Formula (and a big bill to pay off)
Timmd on 14 Feb 2014
In reply to balmybaldwin:
> that's no excuse for putting crap kit on expensive bikes... and probably why I've go Fox, shimano and Formula (and a big bill to pay off)

Don't look at me, I don't spec things. (;-))

No it isn't an excuse..
Post edited at 14:05
Timmd on 14 Mar 2014
In reply to Timmd:

b
Kimono - on 14 Mar 2014
In reply to Timmd:

who on earth would go biking in sub-zero temps anyway??
Certainly not me…opposite problem where i am…was climbing in 40C last weekend :)
Timmd on 14 Mar 2014
In reply to Kimono:
I've had ice forming in my water bottle while on my road bike in the past, probably due to wind chill.

You get beautiful days in the Peak District when it's cold and clear.
Post edited at 12:17
FactorXXX - on 14 Mar 2014
In reply to Timmd:

I've had ice forming in my water bottle while on my road bike in the past, probably due to wind chill.

I don't think wind chill has any input into water freezing and it is solely down to the ambient temperature.
Chris Harris - on 14 Mar 2014
In reply to FactorXXX:

Any warm object will cool faster in a draught. See Newton's Law of Cooling.

That's why you blow on stuff to cool it - gets the heat away from the object quicker.
martinph78 on 14 Mar 2014
In reply to Chris Harris:

Windchill isn't applicable to inanimate objects, it's a perceived feeling of temperature on the surface of the skin.

A water bottle would cool faster, but the water in it would not freeze unless the ambient temperature was below freezing, no matter how hard you blew on it!
TomBaker - on 14 Mar 2014
In reply to Chris Harris:

It won't however cool it below the ambient temperature obviously.
gethin_allen on 14 Mar 2014
In reply to Martin1978:

> Windchill isn't applicable to inanimate objects, it's a perceived feeling of temperature on the surface of the skin.

> A water bottle would cool faster, but the water in it would not freeze unless the ambient temperature was below freezing, no matter how hard you blew on it!

If the bottle was open and the wind was causing molecules to evaporate would the energy taken to cause the surface molecules to evaporate result in a decrease in the temperature of the liquid? Just like when you sweat or if you put a damp cloth over a can?
Enty - on 14 Mar 2014
In reply to Timmd:

FFS Tim, look what you started ;-)

E
In reply to Enty:

But that's because more bollocks gets spoken about windchill on UKC than anything else. I think anyone who mentions windchill without understanding basic physics should face an immediate 5 match ban from UKC. ;-)
MG - on 14 Mar 2014
In reply to Martin1978:

> Windchill isn't applicable to inanimate objects, it's a perceived feeling of temperature on the surface of the skin.


No, it's real! As above, Newton's law of cooling

> A water bottle would cool faster,

That's windchill

but the water in it would not freeze unless the ambient temperature was below freezing, no matter how hard you blew on it!

Correct.

Timmd on 14 Mar 2014
In reply to Enty:

Cool, today I've learnt something about windchill, and also another way of starting a debate almost as fierce as Peak v Peaks.

(;-))
FactorXXX - on 14 Mar 2014
In reply to TobyA:

But that's because more bollocks gets spoken about windchill on UKC than anything else. I think anyone who mentions windchill without understanding basic physics should face an immediate 5 match ban from UKC. ;-)

Would it being on a treadmill (or bike equivalent) make any difference?
Also, would a Southern Hemisphere location such as the Falklands have any impact?
martinph78 on 14 Mar 2014
In reply to MG:

> No, it's real! As above, Newton's law of cooling

Newton's law of cooling makes no mention of windchill "the rate of change of the temperature of an object is proportional to the difference between its own temperature and the ambient temperature" This transfer of heat may be from convection, conduction or radiation.

> That's windchill

No, that's forced convection. Windchill is a perceived drop in temperature by the flow of air over the skin. Unless inanimate objects have skin and can perceive then windchill is not the correct term.

> but the water in it would not freeze unless the ambient temperature was below freezing, no matter how hard you blew on it!

> Correct.

I know, because THAT is Newton's Law of cooling :)
martinph78 on 14 Mar 2014
In reply to TobyA:

Maybe a definition of windchill should be agreed upon before deciding if it's balls, or whether it's and understanding of physics or physiology that is required ;)
Timmd on 14 Mar 2014
In reply to Timmd:

> Cool, today I've learnt something about windchill, and also another way of starting a debate almost as fierce as Peak v Peaks.

> (;-))

Not that I'd troll, but it's kind of entertaining, and interesting too.
FactorXXX - on 14 Mar 2014
In reply to Timmd:

Not that I'd troll, but it's kind of entertaining, and interesting too.

Chill and try not to wind people up in future...
Timmd on 14 Mar 2014
In reply to FactorXXX:

I am chilled.
Turdus torquatus on 14 Mar 2014
In reply to FactorXXX:

> Not that I'd troll, but it's kind of entertaining, and interesting too.

> Chill and try not to wind people up in future...

Otherwise all that natural warmth will just evaporate.
FactorXXX - on 14 Mar 2014
In reply to Timmd:

Try and read what I said again: -

Chill and try not to wind people up in future.

:)
Timmd on 14 Mar 2014
In reply to FactorXXX:

Oh yeah. (:-))
MG - on 14 Mar 2014
In reply to Martin1978:

> Newton's law of cooling makes no mention of windchill "the rate of change of the temperature of an object is proportional to the difference between its own temperature and the ambient temperature"


Windchill is an example of NLC, which is a description of forced convection. Windchill isn't a perception of more rapid cooling, it *is* more rapid cooling.




MG - on 14 Mar 2014
In reply to Martin1978:
Oh, and NLC is just convection, not radiation (which is non-linear). Strictly convection is a form of conduction (between a solid and fluid) but it is normally thought of as a separate heat transfer mechanism.
Post edited at 22:55
martinph78 on 14 Mar 2014
In reply to MG:

We shall have to agree to disagree on the definition of windchill :)

Either way, it will be a long time before I revert to hydraulic brakes, so no need to panic :p


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