Burning rubber smell from new brake blocks

sketchley

Fitted some Swiss Stop greens about a week ago, all was fine until Thursday night home when I smelt a very slight burning rubber smell after really heavy braking a couple of times so I stopped and check every thing was aligned correctly and it was and nothing was hot and it wasn't. This morning noticed the same smell so checked, double checked and tipple checked that the block is square on the braking surface and not touching the tyre when the brake is applied. Nothing else appears to be rubbing. Can't be 100% sure it was coming from the bike though as I've stopped smoking (again) so my sense of smell has come back, I might just be smelling the traffic as it doesn't seem to happen all the time and I'm certainly noticing more diesel smells etc.... I've wondered if it combination of new blocks and crap on the rims....

Question: Is it normal for these brake blocks to smell a bit when they are new?

On a different note, they are very very good at stopping all 112kgs of me very quickly even in the wet so I can more than put up with a bit a whiff....

MonkeyMonster

Could it be you (or kit) is smelling such a way so it's only when you stop that odour has a chance to waft around your nose? Otherwise it's always behind you keeping drafters away?

SimonAH

Just theorising but I'd be surprised if you are generating sufficient heat to burn rubber! Some rubber compounds are very aromatic (think spacehopper!) and even a gentle warming can make them smell.

Have you sniffed 'em cold?

(mental image of people watching Sketchly bent over in his lycra sniffing at his caliper and thinking bad thoughts)

Gussio

My vote is that you are smelling of poorly maintained, insurance-free, unlicenced minicabs.

sketchley

SimonAH wrote:

Just theorising but I'd be surprised if you are generating sufficient heat to burn rubber! Some rubber compounds are very aromatic (think spacehopper!) and even a gentle warming can make them smell.

Have you sniffed 'em cold?

(mental image of people watching Sketchly bent over in his lycra sniffing at his caliper and thinking bad thoughts)

First it's Sketchley not Sketchly.... Some people :roll:

If you were in the works car park this morning you would have seen exactly that! And no they don't smell cold, neither are the rims particularly hot....

sketchley

Gussio wrote:

My vote is that you are smelling of poorly maintained, insurance-free, unlicenced minicabs.

I'm kind of thinking the same thing, maybe the odd scooter or too as well.... I'm certainly smelling the general polution more than I was say in December....

Omar Little

maybe the block is rubbing when you are on the bike? (presumably when you check you are off the bike so no weight on the tyres)

i would imagine you would be able to see marks on the tyre if this is happening though

sketchley

Omar Little wrote:

maybe the block is rubbing when you are on the bike? (presumably when you check you are off the bike so no weight on the tyres)

i would imagine you would be able to see marks on the tyre if this is happening though

That crossed my mind. However, load would cause tyre drop at the bottom not the top where the brakes are, plus I've check the tyres there are no marks. Next time I smell it I'm going to jump straight off the bike and sniff it....

mudcow007

you don't wear rubber underwear do you?

sketchley

Not on the bike :oops:

SimonAH

My MD was bitching that his wife bought him Superdry underwear for Christmas :-D He wasn't aware that it was a 'trendy' brand.

davis

SimonAH wrote:

My MD was bitching that his wife bought him Superdry underwear for Christmas :-D He wasn't aware that it was a 'trendy' brand.

Tell me you didn't reveal the truth... There's good mileage in that one

DrLex

SimonAH wrote:

My MD was bitching that his wife bought him Superdry underwear for Christmas :-D He wasn't aware that it was a 'trendy' brand.

LOL- it does sound like they're aimed at urinary incontinence sufferers- no doubt he's of the age group to be at risk of enlarged prostate and all the concomitant issues...

Gussio

mudcow007 wrote:

you don't wear rubber underwear do you?

The liberal application of sweat would reduce friction and reduce the likelihood of combustion.

il_principe

Sketchley wrote:

Fitted some Swiss Stop greens about a week ago, all was fine until Thursday night home when I smelt a very slight burning rubber smell after really heavy braking a couple of times so I stopped and check every thing was aligned correctly and it was and nothing was hot and it wasn't. This morning noticed the same smell so checked, double checked and tipple checked that the block is square on the braking surface and not touching the tyre when the brake is applied. Nothing else appears to be rubbing. Can't be 100% sure it was coming from the bike though as I've stopped smoking (again) so my sense of smell has come back, I might just be smelling the traffic as it doesn't seem to happen all the time and I'm certainly noticing more diesel smells etc.... I've wondered if it combination of new blocks and crap on the rims....

Question: Is it normal for these brake blocks to smell a bit when they are new?

On a different note, they are very very good at stopping all 112kgs of me very quickly even in the wet so I can more than put up with a bit a whiff....

I can't say I've ever noticed a smell from Swisstop Green and I've used them for Alpine descents when the rims do get fairly warm. Suspect you smelt something else.

rjsterry

Noticed when cycling back from a meeting with my boss: his brake pads were badly adjusted and just catching the edge of the tyre, heating it up and giving a very distinctive burnt rubber smell. Check your pad alignment.

sketchley

rjsterry wrote:

Noticed when cycling back from a meeting with my boss: his brake pads were badly adjusted and just catching the edge of the tyre, heating it up and giving a very distinctive burnt rubber smell. Check your pad alignment.

See OP, I've done that three times already, the pads clearly hitting the rim perfectly square. Will check again though....

bails87

Pah, you only need to worry when you're halfway down a huge MTB descent and can see the brake pads smoking

notsoblue

Il Principe wrote:

I can't say I've ever noticed a smell from Swisstop Green and I've used them for Alpine descents when the rims do get fairly warm. Suspect you smelt something else.

I use them too, and have never noticed a smell. Not been down any Alpine descents, but after wussing out and braking most of the way down Winnats pass in the Peak District, my rims were hot to the touch but there was no smell of burning. I doubt you'd be putting your pads through anything like that on your commute...

Don't want to awaken any latent hypochondria but...

rjsterry

Sketchley wrote:

rjsterry wrote:

Noticed when cycling back from a meeting with my boss: his brake pads were badly adjusted and just catching the edge of the tyre, heating it up and giving a very distinctive burnt rubber smell. Check your pad alignment.

See OP, I've done that three times already, the pads clearly hitting the rim perfectly square. Will check again though....

Sorry, really not very awake today (see SCR thread for further evidence).

sketchley

notsoblue wrote:

Il Principe wrote:

I can't say I've ever noticed a smell from Swisstop Green and I've used them for Alpine descents when the rims do get fairly warm. Suspect you smelt something else.

I use them too, and have never noticed a smell. Not been down any Alpine descents, but after wussing out and braking most of the way down Winnats pass in the Peak District, my rims were hot to the touch but there was no smell of burning. I doubt you'd be putting your pads through anything like that on your commute...

Don't want to awaken any latent hypochondria but...

Thanks for that!

sketchley

"AIDS can initially present with smell loss," he says. "Or it could be anything from vitamin deficiency to Alzheimer's to hypothyroidism to head trauma to stroke to diabetes to medication to leprosy."

Greg T

Aren't the green ones for ceramic rims? Do you have a rim problem?

sketchley

Greg T wrote:

Aren't the green ones for ceramic rims? Do you have a rim problem?

No. http://www.swissstop.ch/Road.aspx & http://www.swissstop.ch/Compounds.aspx

veronese68

You need to go carbon.
When Ferrari bought out carbon discs as an option on the 360 one of the mechanics did a brake test from ridiculous speed to dead stop. Got out to feel the discs. Said he could feel the heat in the alloy wheel radiating off, but could hold the carbon/ceramic disc and it was barely warm.
This was, of course, done on a closed test track.

il_principe

Veronese68 wrote:

You need to go carbon.
When Ferrari bought out carbon discs as an option on the 360 one of the mechanics did a brake test from ridiculous speed to dead stop. Got out to feel the discs. Said he could feel the heat in the alloy wheel radiating off, but could hold the carbon/ceramic disc and it was barely warm.
This was, of course, done on a closed test track.

I've heard horror stories of Carbon rims delaminating during/after long descents. It's one of the big issues manuf's have had with Carbon Clinchers.

veronese68

Il Principe wrote:

Veronese68 wrote:

You need to go carbon.
When Ferrari bought out carbon discs as an option on the 360 one of the mechanics did a brake test from ridiculous speed to dead stop. Got out to feel the discs. Said he could feel the heat in the alloy wheel radiating off, but could hold the carbon/ceramic disc and it was barely warm.
This was, of course, done on a closed test track.

I've heard horror stories of Carbon rims delaminating during/after long descents. It's one of the big issues manuf's have had with Carbon Clinchers.

I'm sure the technology is there to make a reliable carbon rim. They make carbon discs for very fast vehicles and you can certainly get carbon rims for motorcycles. I think the problem may be in trying to combine the brake and the rim into the one item, added to keeping the weight down to a minimum. Whilst maintaining a reasonable cost. Also a motorbike whilst obviously a lot heavier also has suspension to absorb impact from road imperfections.
I don't really think it is anything like the answer for a cycle commuter. Decent disc brakes could make a carbon rim more viable, but the consequences of failure due to hitting a large pothole at speed are pretty poor.

medoramas

I've been using these pads on my MTB for the last few weeks. Never noticed any smell at all. There is just one thing that makes me wonder: do you also hear that "cheap brake pad scratching noise" when braking in wet? Every time when braking in the rain or when having fun on the muddy trails... I use Kool Stops on the rear and they are dead silent, even under horrible conditions. But Swiss Stops... Crrrrrshhhhhhhhhh... Sometimes it happens even in dry, when going fast downhill and applying the brake quite hard (I've got two junctions like that on my commute) - it's silent for two seconds, and then grinding all the way
I checked the pads - no aluminum bits in them.

Have you got similar experience?

bails87

"Decent disc brakes could make a carbon rim more viable, but the consequences of failure due to hitting a large pothole at speed are pretty poor"

The same goes for any wheel though!

veronese68

Very true Bails. I'm a little like EKE in that carbon scares me a bit. It is wonderful material, but can shatter when overstressed rather than bend.
My bias is predominantly based on jealousy as I could only afford cheap or second hand carbon. Given those circumstances I think it's best I avoid it.

sketchley

No smells on the way home. Must of been something else.