A few prev threads suggest that car stuff is not as pure as mtb stuff and can not be used. Others say its fine. Is there a definitive answer on this?

Car stuff is about 1/3 of the price and more widely available than ipa.

most have detergants and rust inhibbitors which the car brakes can burn off …. not all of them do though

read the label .

Good answer

I use the Wurth car disc brake cleaner on my bike and had no problems.

As I understood it, many of the car brake cleaners have components that are burnt off by the heat generated by braking. MTB brakes don't get hot enough generally for long enough to burn off these chemicals so they coat the rotor and pads and reduce braking efficiency.

Can't remember where I heard that, but it's one of those statements that seems to make sense whilst not necessarily being true so I'd love to know if it is?

electrical conact cleaner is good as it doesnt leave nasty coatings.

IPA is pretty cheap Ebay link

£5.30 for a litre will last you for a lifetime and then you will have no worries about contaminants etc.

mattbee has it – I'd heard the chemicals described as 'oil'.

Would certainly make it shiny, which is the desired effect for a car disk.

Meths and cotton wool – cheap and effective.

You can buy IPA from chemists (I used to work in one) but you may have to ask nicely and look presentable my chemist refused me.

my chemist refused me.

Your chemist is an idiot. There's no way you can misuse IPA that you can't also misuse other chemicals which are rather easier to get hold of. Does your chemist actually have any training in chemistry or did they think "alcohol – wanting to drink it"? Unless of course it was just too much trouble for them, and what you were wearing had nothing to do with it.

knottie8 – Member

electrical conact cleaner is good as it doesnt leave nasty coatings.

again be careful – some sold as switch cleaner contains oil as I found to my cost.

we used to buy it by the litre from the chemist.

"bottle of Isopropanol alcohol please"

"what are you using it for"

"cleaning bicycle disk brakes at the bike shop i work at down the road"

"ok no bother what size , 250ml/500ml/1litre"

Hot soapy water

Available from most leading kitchens, free… 🙄

I've used Halfords car brake cleaner and Comma (?) and had no problem. I've tried spraying some on glass and letting it evapourate and there's no residue. I suspect this is an urban myth, and tbh I'd be more worried about oil residue on my car brakes than on my bike brakes. It's also sold as clutch cleaner. Oiled clutch, anyone?

Just bought some wynns disc and clutch cleaner. Contains NAPHTHA. Off to google to find out what it is.

hydrocarbon product … so oil 😉

"and tbh I'd be more worried about oil residue on my car brakes than on my bike brakes. It's also sold as clutch cleaner. Oiled clutch, anyone? "

of course you know better than the folk that make it im sure. You realise the temperatures car brakes get up to – that burns off the residues of the oil quick sharp ….

Or buy a pack of the alcohol wipes – £2.78 for a box of 100:

http://cgi.ebay.co.uk/100-x-IPA-Wipes-70-Isoropyl-Alcohol-Swabs-NHS-Quality-/140430053327?cmd=ViewItem&pt=UK_Health_Beauty_First_Aid_ET&hash=item20b2488fcf

(assuming you don't have medical professionals for friends who keep you in a decent supply…)

Else I've got a can of the cheap Halfords brake cleaner which I use for general de-gunking and that seems fine too with no residue left.

Your chemist is an idiot. There's no way you can misuse IPA that you can't also misuse other chemicals which are rather easier to get hold of. Does your chemist actually have any training in chemistry or did they think "alcohol – wanting to drink it"?

A pharmacist I spoke to a few years ago told me that kids sometimes try to buy it to dilute, as do some alcoholics. It's very, very easy to misuse: you just drink it. I've always had to explain to pharmacists why I want to order it and have always seen it as them being responsible, not stupid. The idiot chemist is the one who sells something to somebody who they suspect is going to misuse it.

hydrocarbon product … so oil

Methane – hydrocarbon product – so oil? 🙄

You realise the temperatures car brakes get up to

Try oiling your car brakes, see what temperature they get up to. No don't – it may be me that you crash into.

Your chemist is an idiot

possibly, they also (different occasion) refused to sell me syringes to reverse bleed my brakes.

What? syringes and IPA can be misused? Well I never.

A bit of googling found this contents list for some car brake cleaner which is probably the nearest I've found to a definitive answer. It seems to consist of naptha (petroleum), acetone and 2-Methyl-1-propanol aka isobutyl alcohol. Nothing there that I'd worry about too much. Would probably make a good flame thrower though.

Well I've used car brake cleaner for several years. Less than a tenner for 5 litres. Never any problems.
Try Unipart/Partco for a deal – and while you are there grab 25 litres of 'TFR' (Traffic film remover) and never have a dirty bike again. This will be less than £40 and it will last you for ever.
Hth
Marko

IPA…
India Pale Ale?

Contains NAPHTHA

naphtha = unrefined petrol, prety much c5-c8 hydrocarbons, its abbit like when consmetics state "aqua" to avoid telling you that theyve sold you 99% water, naphtha is like saying well its 99% petrol you could pay £1.12.9/l , but we're still charging £5 a litre for it.

petrol = a mixture of the stuff that comes out of the refinery that barely meets the spec.

Why bother though, I've never cleaned mine, never needed to, just spray on value price floor cleaner/kitchen cleaner/bathroom cleaner, hose off, wipe arround joints and check for cracks, stanchion lube, chain lube, done.

Ok – so what is mtb disc brake cleaner made of?

India Pale Ale?

Isopropyl Alcohol. I used to get it from my mum (who was a pharmacist before she retired) for cleaning tape heads and such. Versatile stuff.

India Pale Ale has the opposite effect on heads, in my experience.

Why do people clean brake rotors? Doesn't the abrasion in use from mud/dust etc clean them sufficiently? I've never 'cleaned' mine.

Not a troll, an honest question.

got oil on the roters then on the pads – now the breaks are weak. looking for a cure.

why clean car brakes then? surely the heat would burn anything off?

why clean car brakes then? surely the heat would burn anything off?

Well, yeah?

Exactly, why clean car brakes?

I used the stuff to clean grot of brake pistons and uprights, but jut kept my fingers off the brakes themselves.

if its on the pads they will never be the same again … they will get reasonably close but youll put new pads in when they are worn and think "shit these are powerful"

I've never cleaned car brakes, why would you?

And what is contaminating your bicycle disc brakes so badly that you think they need an industrial process to clean them?

in my case it was customers oiling their brakes with 3 in 1 oil …..

some IPA and new pads good as new !

Ok – so what is mtb disc brake cleaner made of?

This?

I've never cleaned car brakes, why would you?

Car Brakes can create a lot of dust and I would presume some people might want to clean this off and would use 'Disc Brake Cleaner'. The dust can make them squeal too.

I've only ever used meths on my mountain bike disks and sometimes on the rims of my road bike.
The car disk brake cleaner is a bit of a red herring really as there are very few occasions when you would actually want to clean the disk (possible when you are fitting new ones would be the only occasion in normal use), other times it'll be used are for cleaning calipers when you are fitting new pads.

http://www.solxsolutions.com/files/msds_sol_x_brake_cleaner_bulk.pdf

I use something similar to that for degreasing lots of bike bits.

Does the job. Never used it for cleaning my brakes though, but it's great for degreasing a chaing quickly

Why do people clean brake rotors? Doesn't the abrasion in use from mud/dust etc clean them sufficiently? I've never 'cleaned' mine.

Maybe they spend too much time on the internet worrying about their brakes and not enough time riding. 🙄

Car Discs sometimes come wrapped in greased brown paper. As they are not made of stainless steel they might corrode in transit . New discs should be cleaned with brake cleaner for this reason.

Hospital alco-wipes often contain emmolients for the skin, not just neat alcohol, so are possibly more likely to cause problems than a can of car brake cleaner.

Wouldn't ask an NHS friend to try and get any either, as people have been sacked for less in the NHS nowadays.