68 replies to this topic

[Atesz792]

Thanks for suggestions, unfortunately I will need something plug & play. Routine maintenance is okay, but manufacturing custom made parts is not included in my skill set.

Re: bore size of MC. Well I never understood all the hype around the blue spots. My front brake is a load of crap, frankly. When I bought the bike 2 years ago, it was so bad it got disassembled, cleaned, and upgraded to EBC HH pads. Since then it's been... adequate. Nothing more.
Before, it was outright dangerous (though some PO installed GG pads so let's say that's understandable). But still, my GS500F with single front disc, 2 piston caliper, steel braided brake line and same EBC HH pads is worlds better. The feel, the stopping power, you name it. I just can't wrap my head around it. Especially seeing all the hype... major disappointment, every. single. time.
Sorry don't want to piss on anyone's parade. It's just been nagging me for 2 years, and there, I just said it. All I can think of is the braided lines, but they weren't as big an upgrade on the GS when I had them installed, IIRC.

@Edit: would it be possible to buy the stuff mentioned in the link, then fit the clutch perch & lever, and brake lever only, leaving the stock MC in place?

Edited by Atesz792, 14 March 2021 - 08:29 am.

[fixitsan]

Thanks for suggestions, unfortunately I will need something plug & play. Routine maintenance is okay, but manufacturing custom made parts is not included in my skill set.

Re: bore size of MC. Well I never understood all the hype around the blue spots. My front brake is a load of crap, frankly. When I bought the bike 2 years ago, it was so bad it got disassembled, cleaned, and upgraded to EBC HH pads. Since then it's been... adequate. Nothing more.
Before, it was outright dangerous (though some PO installed GG pads so let's say that's understandable). But still, my GS500F with single front disc, 2 piston caliper, steel braided brake line and same EBC HH pads is worlds better. The feel, the stopping power, you name it. I just can't wrap my head around it. Especially seeing all the hype... major disappointment, every. single. time.
Sorry don't want to piss on anyone's parade. It's just been nagging me for 2 years, and there, I just said it. All I can think of is the braided lines, but they weren't as big an upgrade on the GS when I had them installed, IIRC.

@Edit: would it be possible to buy the stuff mentioned in the link, then fit the clutch perch & lever, and brake lever only, leaving the stock MC in place?

 

You've got to get it off your chest....

 

The only time I've heard of problems with blue spots was due to air in the system, and that mirrors my own experience. (Apart from the usual corrossion behind the seals forcing the calipers to be held too firmly and not retract after use, common to almost all calipers)

 

If the brake fluid hasn't been changed it's worth doing it. Some say every year, I would say more like 3 - 5. Varies a bit with usage.

 

I replaced the caliper seals in my blue spots in December, the system felt spongy after a full bleed and I put it down to still having the original brake lines. I bought a braided set, fitted those and there was next to no difference. So I bought another 500ml of brake fluid and just kept on pumping and pumping while topping up the master cylinder....I kept tapping the pipes and leaning the bike one way and then the other so that the relevant caliper bleed nipple was always the highest point, and eventually it came good.

 

I got a slight improvement too taking some advice from this group to tie back the brake lever. and leave it overnight.

Edited by fixitsan, 14 March 2021 - 08:52 am.

[Atesz792]

Thanks but it doesn't feel like there's air inside, lever is not spongy, doesn't hit the bar cold or hot.
You just have to hold on for dear life if you intend to stop. Whereas my fossil of a design Suzuki stops nice on the light touch of just 2 fingers.
Calipers were nice and clean after the pad change. Fluid also got changed then (mid' 2019).
Maybe I should mention that I almost exclusively use the front brake for stopping, slowing down I just use engine braking, it's nice and flat where I live (not enough bends, boo-hoo).

[Sphere]

Thanks but it doesn't feel like there's air inside, lever is not spongy, doesn't hit the bar cold or hot.
You just have to hold on for dear life if you intend to stop. Whereas my fossil of a design Suzuki stops nice on the light touch of just 2 fingers.
Calipers were nice and clean after the pad change. Fluid also got changed then (mid' 2019).
Maybe I should mention that I almost exclusively use the front brake for stopping, slowing down I just use engine braking, it's nice and flat where I live (not enough bends, boo-hoo).

What you describe is not normal. Having just overhauled the brakes on my TDM with braided lines and HH pads, I can tell you the braking with this set up is very powerful. Only two fingers are needed on the lever from any speed. I am certain the front wheel could be locked (but I'm not the one to try).

 

Something is wrong with your brakes, which should be investigated and solved before you have an accident.

[Atesz792]

That's the thing, all repairs I described were done by a skilled and trusted mechanic, and I was watching the whole procedure. Apart from a whole lot of dust that was cleaned off, and the GG pads that were replaced, he didn't find issues with the brake.
He did find faulty front wheel bearings, and those were replaced, too.

[Sphere]

That's the thing, all repairs I described were done by a skilled and trusted mechanic, and I was watching the whole procedure. Apart from a whole lot of dust that was cleaned off, and the GG pads that were replaced, he didn't find issues with the brake.
He did find faulty front wheel bearings, and those were replaced, too.

 

I would be investigating further. What condition are the brake pistons in? Is there corrosion or dirt in the grooves for the seals? Is the master cylinder working as it should?

Weak front brakes aren't something the TDM suffers from, there must be something. Only you and your mechanic know what work was done, but a spray with brake cleaner and a scrub with a brush is unlikely to find the problem.

Edited by Sphere, 14 March 2021 - 11:04 am.

[fixitsan]

 

 

Weak front brakes aren't something the TDM suffers from, there must be something.

 

When I picked up my TDM it was from the home of a BMW salesman who couldn't shift the bike (which had been part ex'd) in their showroom due to it's age.

He was fully experienced on modern bikes. As I was just about to set off he told me to be careful "That front brake is very keen, go carefully at first" and he wasn't wrong !

[Snowbird]

I found the original front brake on my 4tx very wooden feeling and changed to blue spots with 14mm master cylinder and they have a much better feel, the old calipers would have probably felt better with just the smaller m/c, I went blue spot because my old fazer had them and it was the best front brake I'd ever had.

Sounds like you have an issue still.

[Atesz792]

Thanks for all the help guys.
Think I bought a lemon then... The issues just never seem to end. It's been 2 years since I bought this bike, and I went through it with my mechanic almost immediately, changed brake pads, front wheel bearings, all fluids including the often neglected fork oil etc. It was boiling the coolant before the fan kicked in, really frightening coming from an air cooled bike. Fluid change sorted that.

Since then I tried to love this bike, I really did.

Had a bunch of free time this weekend, read some of threads in the knowledgebase again.
Of course I have the often faulty original CCT.

The TPS recall hadn't been done on it by the PO's either, caused me headaches for weeks as a new 9er rider back then as it would die at idle and when shifting gears(!), spew black smoke like a diesel etc. It was fixed free of charge (13 years after the recall!), but still...

Little plastic side panels are buggered, clutch lever buggered, etc.

Shame as it's a comfy bike with a great engine, feels like my trusty little GS on steroids, but I'm thinking of letting go right now...

[dablik]

I can only add to the above re brakes on a 2002 900, the dogs bollocks and 2 fingers only, sure i've had my problems with them, especially bleeding in the past, cleaned a fair few times and replaced seals, by the way, i've found little corrosion behind the seals when i've done them, i think you have one of 2 issues, 1 air as mentioned, bluespots can be tricky even for a mechanic to bleed, easiest way is to reverse bleed, 100%,  i've done em every which way, and if struggling with that a banjo at the MC with a bleed nipple on it, the 2nd issue may be a leak, possibly from a banjo bolt but unusual, check the brake hoses, i've also had a hose bust on me and leak, minute but enough to give me a shit brake.

 

Also check everything from the wheel up to top yoke is straight and aligned as i've had this issue after a rebuild of calipers and it just needing slackening off and doing up incrementally from bottom to top, you should be stopping with those brake pads in-situ,  honestly these brakes are very good provided cleaned often... dont give up on them.

 

Their so good it's why many upgrade to bluespots and 14mm MC on the 850's although a good number are still happy with the 850 originals..

 

Edit.... where abouts are you located, maybe somebody could help you.

Edited by dablik, 14 March 2021 - 07:29 pm.

[fixitsan]

 

Edit.... where abouts are you located, maybe somebody could help you.

I was about to say the same...In his signature it mentions Hungary.... ?

[Sphere]

In his signature it mentions Hungary.... ?

 

I could do with a nice long ride.

[fixitsan]

 

I could do with a nice long ride.

 

[dablik]

 

I could do with a nice long ride.

 

 

Check the MC piston an all for leaks.

[leehenty]

Fettle day in Hungary.... Now that's a long ride.

[Studley Ramrod]

HH pads might not be working as well a GG pads, esp. when it's cold and the pads don't get up to temps. Just wondering if your old GG pads were contaminated and the new HH pads aren't working at optimum temps 

 

Interesting info from Wemoto...

 

Brake Pad Frictional Formulation

Brakes work on the crude principle of friction between two surfaces. To give a uniform measure of the frictional characteristics of a Brake Pad the SAE J866A test procedure is used to give a two character code e.g EE FF GG HH.

HH or GG

• HH Pads These have the highest coefficient of Friction and are ideal for high-performance motorcycles and race track use. Some modern performance motorcycles specify HH as standard. HH Pads can sometimes prove grabby, scary in the wet and ineffective in every day use when they fail to reach a good operating temperature.
• GG Pads This grade of Pad is a great all rounder and will perform well in most conditions. GG are softer than HH pads and bed in quicker on worn discs.
• Mixing HH and GG Pads Many manufacturers specify HH for the front of performance Motorcycles with GG in the rear. This is because GG pads can give you more feel and control of the back brake. It is not considered safe to use HH in the rear with GG pads in the front.

Obviously Pads are only as good as the condition of the whole braking system. When first used, brake pads can sometimes give poor braking, as residual moisture from the manufacturing process works its way out and the pads bed in. It is best to bed in pads with gentle use and very heavy initial use can result in glazing, a condition where the resins in the pad crystalize with resulting poor performance and squeal.

[Rallyist]

The early 900, (prior 2004) had better brakes than later models as the original master cylinder had a 14mm bore whilst later models 2004 on, including ABS models, had a 19mm bore which would degrade both the feel and stopping power with equal finger pressure applied.

Thats what I found anyway and so did a mate who rode both back to back.

[dablik]

 

HH pads might not be working as well a GG pads, esp. when it's cold and the pads don't get up to temps. Just wondering if your old GG pads were contaminated and the new HH pads aren't working at optimum temps 

 

Interesting info from Wemoto...

 

Brake Pad Frictional Formulation

Brakes work on the crude principle of friction between two surfaces. To give a uniform measure of the frictional characteristics of a Brake Pad the SAE J866A test procedure is used to give a two character code e.g EE FF GG HH.

HH or GG

• HH Pads These have the highest coefficient of Friction and are ideal for high-performance motorcycles and race track use. Some modern performance motorcycles specify HH as standard. HH Pads can sometimes prove grabby, scary in the wet and ineffective in every day use when they fail to reach a good operating temperature.
• GG Pads This grade of Pad is a great all rounder and will perform well in most conditions. GG are softer than HH pads and bed in quicker on worn discs.
• Mixing HH and GG Pads Many manufacturers specify HH for the front of performance Motorcycles with GG in the rear. This is because GG pads can give you more feel and control of the back brake. It is not considered safe to use HH in the rear with GG pads in the front.

Obviously Pads are only as good as the condition of the whole braking system. When first used, brake pads can sometimes give poor braking, as residual moisture from the manufacturing process works its way out and the pads bed in. It is best to bed in pads with gentle use and very heavy initial use can result in glazing, a condition where the resins in the pad crystalize with resulting poor performance and squeal.

 

 

Summit in all that, the last lot of pads in my old 9r were Brembo Red and initially i really was'nt impressed, especially given the cost but after a few hundred miles much better, they were brilliant once up to temperature though.

[fixitsan]

The early 900, (prior 2004) had better brakes than later models as the original master cylinder had a 14mm bore whilst later models 2004 on, including ABS models, had a 19mm bore which would degrade both the feel and stopping power with equal finger pressure applied.

Thats what I found anyway and so did a mate who rode both back to back.

 

I wonder how a 19mm MC with non ABS brakes would feel, because it displaces more fluid for the same lever travel, but requires more force to do so

[Norwegian]

 

I wonder how a 19mm MC with non ABS brakes would feel, because it displaces more fluid for the same lever travel, but requires more force to do so

All other factors the same, it would require nearly twice the force at half the travel. Crossection 14 mm is 154 mm sq, against 283 for the 19 mm.