What is that fuzzy thing for?

Okay, you know that mini sweat band that gp bikes have on their master cylinders?...why?
I have never seen a leaking one...is it to contain the fluid in the event of a crash? If so, I could think of much more important things to contain in a crash like motor oils, my fudge etc. Is this just a "gay thing"? Is the mere sight of a naked master cylinder just too much for these pros to bare, or what?

 

One for leakage and two I believe as an insulator.

 

And three for good looks. If you notice they always match the color of the bike. It's much prettier than plain old fluid.

 

Ahha! I knew it was a gay thing...that's it! I'm wearing makeup when I race and I'm getting my tires buffed for that healthy glow!

 

Tip of the Day: Talcum powder in your leathers (for that "not so fresh" feeling).

 

Don’t tell me those things are now gay!!!
I just bought some.

But since I did not buy the color matched bands my heterosexuality should be secure.

The reason I got them was that I had a small crash in Atlanta that scratched the lid of the brake reservoir, but didn’t damage it in any other way. I wound up with a few white blotches on my tachometer that I am guessing are from brake fluid.
So go ahead and laugh, but if it keeps me from having to buy new gauges, then its worth it.
Ed

 

Yeah Ed. Brake fluid, sure! It couldn't be anything else but that!

 

As well as the fine reasons offered above, such "sweat bands" will keep ultraviolet wavelength electromagnetic radiation (UV light...) from penetrating (clear) plastic brake fluid resivours.

Conventional brake fluids are comprised of polyoxyalkylene glycols which, in the presence of UV light (and oxygen and water), will slowly break down to form lower molecular weight fluids (e.g. alcohols and carboxylic acids).

If allowed to proceed, the result may be residues, reduction of the boiling point of the brake fluid, as well as the potential for chemical etching of the interior metal surfaces of the brake system by the resultant acids.

Really.

 

Dammit Bell, you would know better than anyone.Thats why you have the lifetime supply of Goo Gone!!!!!!!!


Freddie

 

#545, WOW, thats the best explantion I've heard for the "sweat bands". It can't possibly be a gay thing. It's definately a neucleofusiphysistical thing ( I think )

 

Nice explanation, but plastic completely absorbs UV light anyway. Some high wavelength UV (borderline visible, like 400 nm) might make it through, but even if it did, it likely wouldn't be energetic enough to cause photolysis. My 2 pennies.....

Josh

 

Thanks Josh – my use of the term “plastic” was sloppy You are right – plastics containing unsaturation, and especially aromatic-type unsaturation (e.g. polystyrene) are transparent only above around 340nm (with the UV range being 200-400 nm). However, saturated plastics (e.g. polypropylene) are UV transparent down to near the “vacuum UV” range (150 nm). I’m guessing that our clear “plastic” brake fluid reservoirs are likely a (cheap) saturated thermoplastic (e.g. PET, polypropylene) and thus UV transparent, as the unsaturated plastics don’t hold up well to brake fluids (polyalkylene glycol ethers, not glycols like I earlier hacked...).

But I'll give you that UV is likely an insignificant contributor to decomposition of our conventional ether-based brake fluids and hardly justification for our color-coordinated reservoir booties. Hey, I was just trying to give my race buds a semitechnobabble reason (in addition to the reasons they already stated above) to justify purchase of such booties (i.e. justify to their significant others - which purchase of such bike booties may otherwise drive over the edge and find you immediately served with divorce papers...)

My guess is that the real reason of brake fluid failure is due to absorbed water as well as decomposition of the brake fluid (in the presence of dissolved oxygen and water) under the high temperatures the fluid encounters in the calipers.

So ... WHAT is that fuzzy thing for again?

 

You guys are scarin me. I'm gonna rush out tomorrow and buy "booties" for the reservoirs on all my bikes. My wife says " if I'm attracting all that UV stuff to me that can't be good for me. So everyone out there that needs "booties", ( maybe you better not call 'em that to your wife) tell her it's to protect you (and her if she rides with you) and the color matched "booties" provide ultimate protection. If she won't let you buy the good ones, wrapping an old sock around the reservoirs will provide the minimum of protection. If I can't be fast at least I can be stylish.

 

If yer wear em on yer 'nads' it would be a gay thing...

 

The nerds have spoken on this subject. Nuff said!

 

...yeah, but if you dont wear them, then your nads will get sunburnt.

 

Hey 545, what do you do for a living? Sounds like you're up on your polymer chemistry/plastics. I'm an analytical chemist (I test DRUGS for a living...) so I don't know a whole helluva lot about this plastic stuff, just enough to get me in trouble. I wonder how we could find out what our reservoirs are made of... Anyway, I'd concur with your reasoning about brake fluid failure. At mid ohio a coupla weeks ago I was talking to one of the guys on the team hammer crew. He happened to be changing fluid in hopkins' f.extreme bike. When it came out, it was a grayish black color (serious degradation??). He told me they change it every day! Any of you guys this hard on fluid? My guess on the fuzzy thing: Someone who likes to stir the pot put one on his bike first. Then the guys from the other teams saw this and thought "hmmmm.... what does he know that I don't?? Better get one for our bike!!"

 

I meet some "Analytical Chemists" in college

Sounds like that might be a problem if one didn't replace the fluid regularly - like once every 20 years or so. Changing the fluid once every 3 or 4 races should quell any fears of solar radiation degradation or damage by stray cosmic rays.

 

IR (infra-red) spectrum and carbon-13 NMR (nuclear magnetic resonance - similar to the "MRI" used to image humans...) would suffice. But I'd have to snick a wee test sample off of someone's reservoir. Alternately, we could just ask a manufacturer...

Sadly, gainful employment accompanied by random drug testing ended my DRUG testing days. I scrape up a meagre existence racing as a novice with WERA to support my hobbies (such as physical organofluorine chemistry

#545 (Keith Palmer)

 

As far as Hopkins brake fluid turning black it was probably one the the upper end fluids with a very high boiling point. I have looked at some of this and found the following out. The higher the boiling point the more hydrophillic it is which means that it absorbs water very easily. The Ferodo guys have some high temp stuff they said only lasts about 4-5 hrs before it has reached water saturation and boiling point has dropped about 150-200 degrees. Expensive stuff too once you open the bottle you use it or throw it away and at 75 bucks a bottle you have to be a big team like Team Valvoline-Emgo Suzuki.