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Posted

maybe not immediately...you will notice I did say that if there is a drop or two that you missed, so I agree if you see a spill then you are ok, you can clean it up...if not and you hang your bike up for the weekend...ooo nelly.

 

See my correction below, its was dot5.1 is used for the elixir CR's. I do believe that it is in fact nasty stuff ito paintwork

 

http://www.gomog.com...brakefluid.html

 

It is nasty to certain types of paintwork (especially solvent based non catalysed paints), but modern automotive paints are much more resistant to brake fluid - It's not something to be overly concerned about - washing spills off with water will sort it out - and washing your bike after maintenance work is probably a good idea - gets rid of all the fingerprints...

 

The benefit of using brake fluid over mineral oil is that it has a much higher boiling point than mineral oil - and if you boil the brakes, you WILL have NO braking capability.... you don't see racecars using mineral oil in their braking systems for a reason....

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Posted (edited)

+1

 

The avids from sram is shite!!!

 

everyone always says that...I have had those avids with my xx for going on 3 years now and have not even done a bleed in that time..still solid braking and solid feel at the levers. my only complaint is noisy when wet...other than that - they do what they were designed to do...brake

 

edit...unlike the other comment - i use my brakes a lot.....go through about 2 - 3 sets of pads a year...alrgely because my weekly loop has a major downhill section

Edited by Stretch
Posted

everyone always says that...I have had those avids with my xx for going on 3 years now and have not even done a bleed in that time..still solid braking and solid feel at the levers. my only complaint is noisy when wet...other than that - they do what they were designed to do...brake

 

edit...unlike the other comment - i use my brakes a lot.....go through about 2 - 3 sets of pads a year...alrgely because my weekly loop has a major downhill section

Agreed the only issue is the squeel. All Avids do this and I have them on 3 bikes with different specs and ranges. they just do.

 

Recently changed one bike to entry level Shimano and i must say they are better than even my Avid ultimate s.

Posted (edited)

It is nasty to certain types of paintwork (especially solvent based non catalysed paints), but modern automotive paints are much more resistant to brake fluid - It's not something to be overly concerned about - washing spills off with water will sort it out - and washing your bike after maintenance work is probably a good idea - gets rid of all the fingerprints...

 

The benefit of using brake fluid over mineral oil is that it has a much higher boiling point than mineral oil - and if you boil the brakes, you WILL have NO braking capability.... you don't see racecars using mineral oil in their braking systems for a reason....

ah good info on the paint...but I am not sure I want to roll the dice on it.

 

I hear you wrt to boiling point, yes it does have a higher boiling point than mineral when its pristine...but here is the kicker...when its contaminated with water it will make the boiling much lower hence the spounge experience. I also agree that nascars need dot5.1 cause lets face it...their discs glow when they brake...do we really need the extra 15-20% more that it offers considering we dont weigh what a nascar does, nor do we travel the speed it does...

Edited by rouxtjie
Posted

Front der does not "give" or cause chain suck....chain suck is mainly caused by worn chainrings and funny enough a BAD rear Der....

 

that's not what the books / mechanics say...chainrings are brand new (4 months).

Guest Smimby
Posted

that's not what the books / mechanics say...chainrings are brand new (4 months).

 

Sram recalled some RD's a while ago for causing chainsuck, there is NO WAY a FD can cause chainsuck.

 

wrt to it over / under shifting, that is just limit settings....

Guest Karma
Posted

This is the comparison(or pretty much...not my own info...but from a website):

 

XTR - X0, XX

XT - X9

SLX - X7

DEORE\ALIVIO - X5

 

Any spec lower than that is irrelevant.

 

Mid spec goodies are more durable but heavier, with high end goodies being lighter(negligible) but not as durable. So X9\XT are on the same level and generally the way to go if your not trying win races. To win races all you need is a 29er :w00t: :ph34r: jokes

 

I run X7 shifters, X9 crank, X0 RD.

 

I still rate SLX brakes higher than XX.

Posted

ah good info on the paint...but I am not sure I want to roll the dice on it.

 

I hear you wrt to boiling point, yes it does have a higher boiling point than mineral when its pristine...but here is the kicker...when its contaminated with water it will make the boiling much lower hence the spounge experience. I also agree that nascars need dot5.1 cause lets face it...their discs glow when they brake...do we really need the extra 15-20% more that it offers considering we dont weigh what a nascar does, nor do we travel the speed it does...

 

Race cars generally use dot 3 or dot 4 fluid - good old Castrol SRF.... :) In any case it takes about 2 or more years to get enough water into fluid through atmospheric contamination to even be a concern.

 

More important is water going in via a seal (and this happens to mineral oil based brakes too - with the same results)

 

Do you need high temp fluid - my opinion is yes, you do - work out the weight braked per volume (yes volume) of brake disk and you will see, it is easy to overheat a bike brake - they have very little heat sink capacity - as opposed to a 380mm 25lb piece of steel....

 

And the glowing on the surface of the disk is brake pad material deposited on the disk being heated, not the disk itself. I have an IR thermometer specifically for brake temps - trust me on this - mtb brakes get HOT, especially when they are dragged on long descents - given the right photographer you will also see glowing discs... have you never seen people with brake disks that are a kind of blueish hue? those have been well heated...

 

In any case, it's a moot point - rather concern yourself with the compressibility of the fluid at temperature than its effect on paint (which will be similar to that of anti-freeze - and you don't worry about that do you?)

Posted

a brake system is a closed loop system. contamination is going to be caused by one of two things , either a leaking seal ( which should be causing a loss of fluid ) , or being contaminated by the atmosphere via the continuous heating and cooling down of the brake fluid. :eek:

 

so if the seals are leaking replace them. ( possible brand fault ) :cursing:

 

it should not be necessary to be bleeding brakes every now and then, even if you riding everyday.

 

this being said, if bleeding is done properly the lever feel should remain fairly constant until the boiling point of the fluid is reached and exceeded causing a soft lever and thus a loss of stopping power. ( that's the users fault not the the make of brakes ) :thumbup:

 

NB:this is my 2c worth based on my experience with my bike and also in the motor / engineering industry. at the end of the day mine is and has been working just fine for the last 3years. :thumbup:

 

maybe others are not that lucky :blush:

Posted

Thanks for all the reply's, really helpfull

 

Picked the bike up on friday afternoon, did the tubeless conversion myself and rode Van Gaalens yest.

 

The SRAMS were power, they only thing that needed improving were my legs...

Posted

This is the comparison(or pretty much...not my own info...but from a website):

 

XTR - X0, XX

XT - X9

SLX - X7

DEORE\ALIVIO - X5

 

Any spec lower than that is irrelevant.

 

Mid spec goodies are more durable but heavier, with high end goodies being lighter(negligible) but not as durable. So X9\XT are on the same level and generally the way to go if your not trying win races. To win races all you need is a 29er :w00t: :ph34r: jokes

 

I run X7 shifters, X9 crank, X0 RD.

 

XX

X0 - XTR

X9 - XT

X7 - SLX

X5 - Deore

Posted

IMHO. SRAM rocks, but I would change the brakes. I rode XT in the past but had Elixir brakes. Had to keep setting the brakes, especially pads. New bike has XX but XTR brakes. At first I wasn't happy as I wanted all SRAM. But I must admit, the XTR brakes rock. Haven't touched them in 18 months myself. Never had to fiddle. So for me, SRAM but XT or XTR brakes. Value for money..... XT.

Posted

I am picking up my new bike tomorrow and it has SRAM x7 and x9

 

i have never ridden with SRAM

 

Should i upgrade the bike to xt, will i notice any difference?

 

Rave about it or slate it, some advise please

 

Why buy a bike and then want to worry about the parts?

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