Parking it up for the winter. - Page 7

FrankenDesmo · 01-06-2020, 10:12 AM

Thank you for the insight gentlemen. I'll give ol' spank n tug a few goes

...and then I'll follow the advice here about heat cycling the discs a few times over the next few weeks and see how it goes.

Mr Gazza · 01-06-2020, 01:08 PM

I found myself thinking about this on this mornings little errand running ride.

It's quite easy to hold the speed when approaching a big wide junction and then give a nice long firm brake application with plenty of time to ease the brake off before coasting to the line. I think constant firm pressure for as long as possible is the key?

I have also got into the habit, after a wash, (of the bike!) of getting it up on the stands, (sometimes I wash it on the stands.) and finishing with a wodge of rag soaked in clutch and brake cleaner run all the way round each face of each disc.
This removes any wax residue in the wax 'n' wash stuff I use, but more importantly should also remove any residual moisture, as the C&B cleaner is hygroscopic and will eat the water.
It also leaves the discs nice and clean for the next application, so the pads are biting clean metal and not dust, wax or resin deposits. I'm convinced it's keeping my discs in very good order.

FrankenDesmo · 16-08-2020, 02:18 PM

Finally coming back to the 'warped' discs issue... I've had the bike nearly a year now and have ridden it less than 500mi - seems I like spending more time with it in pieces than actually riding!

Booked in for an MOT on Tuesday, so of course I've left it until today to investigate the surface conditioning. Some quick reading via google backs up your theory Gazza - warped discs are far more likely to be variations in the friction surface left by the pads in the bedding-in process.

I had previously tried the spank n tug, but really I wasn't doing as described, so I'm going to put it on the hoist today and see if there is any visual evidence of places where surface friction has come off, then I'll take it out to a quiet road for a more methodical approach to the spank n tug.

They're old breaking wave discs so I'm not too bothered if I have to replace them as I'd rather have the oem brembo's on there anyway, but they can stay if they're not warped.

Must be my time for brakes - the freelander I brought a year ago (and sold yesterday) needed a full brake system overhaul when I got it (every component bar one caliper and the master cylinder needed replacing), and I noticed yesterday that my recently-acquired RX-8 has a slightly binding caliper on the drivers front.

FrankenDesmo · 16-08-2020, 02:21 PM

In addition to the brakes, I'm expecting that the headlight will get failed for the chip in the lense, so it'll be time to mount Gazza's ring (pun intended).

FrankenDesmo · 16-08-2020, 09:50 PM

Right, well, no amount of spanking and tugging helped, so I took the bike out and gave the brakes a number of long, firm pulls on the brakes - never coming to a stop, gently releasing. Eventually the brakes got hotter and I noticed the shudder severity rising with the heat.

So I'm fairly certain they're toast. Visually they look pretty well worn anyway (I'll have to remember to get the vernier out and measure thickness - I'm wondering if they're close to the service limit anyway). I've ordered a pair of EBC discs & the HH pads from Sportsbikeshop.

FrankenDesmo · 29-08-2020, 07:20 PM

New discs fitted, calipers stripped and kitted at the same time, with new pistons. Good to finally have properly functioning brakes. The old discs were definitely quite worn out, with quite a bit of variation in thickness around the discs - measured with a vernier though, not a dti, so not a good indicator, and I realise even pad deposits could be the culprit too. Couldn't find any info on service limit, but if it is the same as the EBC discs (4.5mm), then the old discs were very close to the limit anyway.

While I was working on the brakes, I also took the opportunity to drop the jet needle one clip to lean the mixture a bit - I had been playing with the pilot circuit but wasn't able to affect the hesitation on transition to the needle. Dropping the jet has definitely made a marked improvement - still a slight hesitation at times, but it is only for a moment before the bike pulls strong again.

That along with the brakes has made the bike much more a joy to ride - and I still need to replace those old tyres.

slob · 29-08-2020, 07:29 PM

If you have (had) Brembo discs, the service limit is stamped somewhere on the spiders.

FrankenDesmo · 29-08-2020, 07:58 PM

These were ABE discs, and don't have any service limit markings - or at least, not any more. According to the Haynes manual the stock discs have a limit of something like 3.8mm, so I guess the brembo ones are a bit thinner (than the EBC ones, at least) - maybe to save a wee bit of weight? Or maybe just changes to disc design over the years?

Darren69 · 29-08-2020, 08:32 PM

Brembo have quoted many min thickness over the years varying between 3.8 and 4.5mm to name but 2 but the original disc thickness specifications did change accordingly over the years. It should be stamped somewhere on the disc itself though.

FrankenDesmo · 29-08-2020, 08:44 PM

4.5mm is sounding like the more common number. No idea what the story is with those ABE discs, but I was measuring 4.6-4.9 across different points on the disc (granted, only with a small degree of accuracy), and given the EBCs are ~5mm with a 4.5mm limit, I'm going to extrapolate from that and suggest the ABE discs followed the same logic.

01-06-2020, 01:08 PM	#92
Mr Gazza Lord of the Rings Join Date: May 2013 Location: Norwich Bike: M900sie Posts: 5,983	I found myself thinking about this on this mornings little errand running ride. It's quite easy to hold the speed when approaching a big wide junction and then give a nice long firm brake application with plenty of time to ease the brake off before coasting to the line. I think constant firm pressure for as long as possible is the key? I have also got into the habit, after a wash, (of the bike!) of getting it up on the stands, (sometimes I wash it on the stands.) and finishing with a wodge of rag soaked in clutch and brake cleaner run all the way round each face of each disc. This removes any wax residue in the wax 'n' wash stuff I use, but more importantly should also remove any residual moisture, as the C&B cleaner is hygroscopic and will eat the water. It also leaves the discs nice and clean for the next application, so the pads are biting clean metal and not dust, wax or resin deposits. I'm convinced it's keeping my discs in very good order. __________________

29-08-2020, 08:32 PM	#99
Darren69 Transmaniacon MOC Join Date: Sep 2013 Location: Sutton In Ashfield Bike: Multiple Monsters Posts: 6,095	Brembo have quoted many min thickness over the years varying between 3.8 and 4.5mm to name but 2 but the original disc thickness specifications did change accordingly over the years. It should be stamped somewhere on the disc itself though. __________________ Roast Beef Monster! Termignoni and Bucci - Italian for pipe and slippers! S4 Fogarty, S4R 07T, 748, Series 1 Mirage

01-06-2020, 10:12 AM	#91
FrankenDesmo Member Join Date: Sep 2019 Location: Glasgow Bike: M900 Posts: 108	Thank you for the insight gentlemen. I'll give ol' spank n tug a few goes ...and then I'll follow the advice here about heat cycling the discs a few times over the next few weeks and see how it goes.

16-08-2020, 02:18 PM	#93
FrankenDesmo Member Join Date: Sep 2019 Location: Glasgow Bike: M900 Posts: 108	Finally coming back to the 'warped' discs issue... I've had the bike nearly a year now and have ridden it less than 500mi - seems I like spending more time with it in pieces than actually riding! Booked in for an MOT on Tuesday, so of course I've left it until today to investigate the surface conditioning. Some quick reading via google backs up your theory Gazza - warped discs are far more likely to be variations in the friction surface left by the pads in the bedding-in process. I had previously tried the spank n tug, but really I wasn't doing as described, so I'm going to put it on the hoist today and see if there is any visual evidence of places where surface friction has come off, then I'll take it out to a quiet road for a more methodical approach to the spank n tug. They're old breaking wave discs so I'm not too bothered if I have to replace them as I'd rather have the oem brembo's on there anyway, but they can stay if they're not warped. Must be my time for brakes - the freelander I brought a year ago (and sold yesterday) needed a full brake system overhaul when I got it (every component bar one caliper and the master cylinder needed replacing), and I noticed yesterday that my recently-acquired RX-8 has a slightly binding caliper on the drivers front.

16-08-2020, 02:21 PM	#94
FrankenDesmo Member Join Date: Sep 2019 Location: Glasgow Bike: M900 Posts: 108	In addition to the brakes, I'm expecting that the headlight will get failed for the chip in the lense, so it'll be time to mount Gazza's ring (pun intended).

16-08-2020, 09:50 PM	#95
FrankenDesmo Member Join Date: Sep 2019 Location: Glasgow Bike: M900 Posts: 108	Right, well, no amount of spanking and tugging helped, so I took the bike out and gave the brakes a number of long, firm pulls on the brakes - never coming to a stop, gently releasing. Eventually the brakes got hotter and I noticed the shudder severity rising with the heat. So I'm fairly certain they're toast. Visually they look pretty well worn anyway (I'll have to remember to get the vernier out and measure thickness - I'm wondering if they're close to the service limit anyway). I've ordered a pair of EBC discs & the HH pads from Sportsbikeshop.

29-08-2020, 07:20 PM	#96
FrankenDesmo Member Join Date: Sep 2019 Location: Glasgow Bike: M900 Posts: 108	New discs fitted, calipers stripped and kitted at the same time, with new pistons. Good to finally have properly functioning brakes. The old discs were definitely quite worn out, with quite a bit of variation in thickness around the discs - measured with a vernier though, not a dti, so not a good indicator, and I realise even pad deposits could be the culprit too. Couldn't find any info on service limit, but if it is the same as the EBC discs (4.5mm), then the old discs were very close to the limit anyway. While I was working on the brakes, I also took the opportunity to drop the jet needle one clip to lean the mixture a bit - I had been playing with the pilot circuit but wasn't able to affect the hesitation on transition to the needle. Dropping the jet has definitely made a marked improvement - still a slight hesitation at times, but it is only for a moment before the bike pulls strong again. That along with the brakes has made the bike much more a joy to ride - and I still need to replace those old tyres.

29-08-2020, 07:29 PM	#97
slob . Join Date: Jul 2003 Location: East London Bike: Multiple Monsters Posts: 9,736	If you have (had) Brembo discs, the service limit is stamped somewhere on the spiders.

29-08-2020, 07:58 PM	#98
FrankenDesmo Member Join Date: Sep 2019 Location: Glasgow Bike: M900 Posts: 108	These were ABE discs, and don't have any service limit markings - or at least, not any more. According to the Haynes manual the stock discs have a limit of something like 3.8mm, so I guess the brembo ones are a bit thinner (than the EBC ones, at least) - maybe to save a wee bit of weight? Or maybe just changes to disc design over the years?

29-08-2020, 08:44 PM	#100
FrankenDesmo Member Join Date: Sep 2019 Location: Glasgow Bike: M900 Posts: 108	4.5mm is sounding like the more common number. No idea what the story is with those ABE discs, but I was measuring 4.6-4.9 across different points on the disc (granted, only with a small degree of accuracy), and given the EBCs are ~5mm with a 4.5mm limit, I'm going to extrapolate from that and suggest the ABE discs followed the same logic.