ST1100 'Wooden' brakes

If the ABS module failed, I think with more pad area, the ABS bike should stop better than the non-ABS bike.

Hey Phil, disconnect your ABS module and do a comparison test between your ABS and non-ABS bikes, if you have nothing else better to do some day.

Jim Van said:

If the ABS module failed, I think with more pad area, the ABS bike should stop better than the non-ABS bike.

Hey Phil, disconnect your ABS module and do a comparison test between your ABS and non-ABS bikes, if you have nothing else better to do some day.

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I don't need to since I very seldom 'trigger' the ABS (maybe twice in 150,000+ miles) and have plenty of miles in 'comparative' stopping between the different machines already. If you are taking about 'panic' stopping, then I'll let somebody else take that challenge since it can get pretty ugly if you use too much rear brake without an ABS. ;-)

OK, So do a non-panic comparison test, say from 60 mph. Seriously, I wonder what difference you would see. Just stop with both bikes at what you consider just short of a panic stop. There may be a significant difference even in what you would consider a non-panic condition. Results might be interesting.

Jim - I 'have' seen significant less effort to bring the ABSII bikes to a complete halt versus the standard. On the standard, you wonder sometimes if the binders are going to bring it to a halt in time (the 'wooden' brake effect) - and I have stainless steel brake lines on it so there's no 'play' in the lines. I wisely use the rear brake as much as possible without locking it. With the ABSII models, I just two finger the front lever and speeds scrubs off nicely. I've not put a 'tape measure' to it, but I have been in enough traffic on the slab with both models and enough near panic stops in said traffic (Nashville drivers think they are NASCAR level quality - they like to 'draft' on the car in front of them) to notice a big difference. ;-)

So this thread is becoming fairly interesting evolving from poor braking to comparisons of non-ABS to ABS. I mentioned earlier in this thread about doing a caliper upgrade from a 2 piston caliper to a 6 piston caliper. I still think this would be a great upgrade but I wanted to follow up on the 2 piston to 4 piston upgrade that I am in the middle of on my CB750.

So don't disregard this until you have complete reading it because I think it is 100% applicable to the poor braking that originally started this thread. As part of my upgrade I was originally going with 4 piston calipers and bigger rotors, but elected to use my existing rotors to begin with. This is still in the prototype stage so disregard the ugly mounting bracket.

After mounting the new calipers I wanted to test drive and to make sure I had maximum pad to rotor surface coverage. This would verify that my calipers were mounted properly. So once I had a high confidence level the brakes were function as I anticipated I want to go for a ride and test what I just discussed. On each rotor face inside and out I drew lines out with a marker from where the mounting bolts for the rotors are to the outside edge along the braking surface. The thought here was to see if the pads gave me full coverage on the rotors and that the mounting brackets were correctly position. Keep in mind that the rotors are from a 1983 bike, they are not warped and the thickness is well within spec and the overall braking surface is in good condition and there are brand new brake pads in the calipers.

So I went out for a breakfast ride to test many aspects of the new calipers, do they stop, can I now use two fingers, do the rotors get hot, etc. almost a 100 miles later I get home very pleased with the braking but still not thrilled as I was expecting more. But I did achieve two finger braking at 80 mph which before required one full hand and then some, rotors were warm but not hot, and everything else was good. Then I started to look at my rotors and what I discovered was surprising.

My rotors although not warped they are not flat across their surface. Meaning from inside to outside on each face I have high/low spots. See Picture. So if you look at the marker line that I put on the rotor faces you will see that parts of the lines are still there and some parts are gone. So this has done two things for me one it tells me looking at the lines that I more or less have full coverage of the pads against the braking surface. But more importantly it tells me that I do not have full contact of brake pad to rotor surface leading me to believe that this is also part of the poor braking issue. Remember I used new pads.



So is it reasonable to assume that on used rotors there is a good possibility that poor braking can be attributed to insufficient contact of pad to rotor leading to poor braking or wooden brakes. This is a simple test anyone can do but New pads are required as the are flat and not worn. I guess one could do it with used pads but I am unsure if it would tell much. The assumption here is that overtime the pads will conform to the surface of the rotors.

I think one thing that may be 'missed' in the conversation is that the better braking performance is not an issue of ABS vs Non-ABS but the nature of more pistons in the caliper and more braking surface as you've pointed out - whether there is an ABS system involved or not. The ABSII ST1100 system has more pistons and more contact surface that the standard - forgetting the ABS part - and hence it has better braking for the same reasons that you have better braking now after your revisions. ;-)

Grabcon said:

So if you look at the marker line that I put on the rotor faces you will see that parts of the lines are still there and some parts are gone. So this has done two things for me one it tells me looking at the lines that I more or less have full coverage of the pads against the braking surface. But more importantly it tells me that I do not have full contact of brake pad to rotor surface leading me to believe that this is also part of the poor braking issue. Remember I used new pads.



So is it reasonable to assume that on used rotors there is a good possibility that poor braking can be attributed to insufficient contact of pad to rotor leading to poor braking or wooden brakes. This is a simple test anyone can do but New pads are required as the are flat and not worn. I guess one could do it with used pads but I am unsure if it would tell much. The assumption here is that overtime the pads will conform to the surface of the rotors.

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There is always a 'bedding in' period with new pads on old rotors, but your picture looks like those rotors aren't in the best of shape to begin with (all the radial scratches don't look normal to me). My experience with motorcycle rotors is they usually wear fairly flat as long as you don't let the pads wear down to the metal backing plate before changing them and score the rotors, which may have happened with the ones in the picture. The bedding in process is usually minimal.

editorial: I think this thread started when someone used 'GG' spec pads instead of 'HH' spec pads, and noticed less braking power, which is logical, and is the most likely explanation for the wooden brakes feel. All the other replies have been interesting to discuss, but basically if you use the wrong brake pads to begin with you're going to get sub-optimum braking performance.

Uncle Phil said:

more pistons and more contact surface that the standard - forgetting the ABS part - and hence it has better braking for the same reasons that you have better braking now after your revisions

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This I 100% agree with. But I guess my point is regardless of the type of braking system one has, at its best there are only 100 points of braking capabilities measured against itself and not other systems. So in my example with my brake upgrade I did not achieve 100 points of braking because I do not have 100% contact between pads and rotors assuming that everything else calipers, hoses, master cylinder, etc. is 100%. So in my case I may have only achieved 80 points of braking capabilities but maybe over time that will improve as the pads wear and conform to the rotors more contact will be achieved. Or the other option is new rotors or refinished rotors it that is possible.

dwalby said:

but your picture looks like those rotors aren't in the best of shape

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Sometimes pictures lie. If you were to take your finger nail and rub it across the face you really feel nothing. They are fairly smooth no gouges, ridges, etc.

If your rotors are not warped, then the pads should wear to 'match' the rotor surface and you should get a higher percentage of contact in theory. Of course, everything works in theory ...

Uncle Phil said:

Of course, everything works in theory

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That would be the hope. But they still are significantly better than before.

Grabcon said:

That would be the hope. But they still are significantly better than before.

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I'm pretty sure they will improve as they wear a bit. You've got an interesting project there. BTW, I know of one ST1100 personally that has a 17" front rim and totally different calipers. And I hope to put the ABSII calipers and the ABSII forks on my standard ST1100 one day (already have the parts) to get the better stopping power.

I mounted a ZX14 Radial master cylinder today to my 1998 non abs ST1100 very nice improvement in feel over the factory master cylinder
if I get energetic this evening I will mount the ZX14 radial clutch master as well

I have some stock ZRX 6 piston Tokio's that may go on next.

I went with the ZX14 stuff as it is what I used when upgrading my ZRX to full ZX14 USD Forks wheels and brakes last year

Check out the entire brake system again...master cylinders, calipers, shoes, hoses, bleeding.
My 1991 non-abs feels anything but 'wooden'. That has always been either binding caliper or a plugged vent port in a master cylinder on my previous bikes. Air in the system, damaged component in the master cylinder or worn out hoses will give you a spongy feel.

No issue with mine, as a matter of fact I was impressed with the stock brakes for a bike this size. I had the extra set of ZX14 Masters and some free time today and after the improvement in feel, not stopping power I like the improvement. Besides I have to feel that a 2013 master cylinder tech is far superior to 1998 tech

Oldbikefixr said:

Check out the entire brake system again...master cylinders, calipers, shoes, hoses, bleeding.

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+1...
Upon investigation all complaints about ST brakes come down to one or two items not fully serviced...

Styles said:

However correct Jim is, Phil, and however your STs stop, I trust you'll never be replaced.


Styles

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And I'm pretty sure even Lasarus died eventually ..............

Jim Van said:

And I'm pretty sure even Lasarus died eventually ..............

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What a nice Christmas gift, JV. Here to see who's knocking my "wooden" brakes, and what do I see today, your apt reminder that even Uncle Phil could make "longevity" disreputable by his untimely persistence in it. Cheers.

At the risk of resurrecting a long, dead thread....

I too find my ST1100 brakes a bit on the wooden side, they have got good Nissin HH pads in them but still need a big old squeeze to get much deceleration. Now some of this is the weight of the ST compared to my other two bikes (VFR800 and VTR1000) but I think quite a bit has to do with the hydraulic leverage effect between the master cylinder and pistons. My freshly bled and clean brake system has a very firm lever feel, but just seems to lack a decent amount of bite on the pads.

On my other bikes I have done some brake experimentation with different calipers and master cylinders. What is clear is that for any given caliper piston size, by using a smaller master cylinder you can increase the mechanical leverage of your hand, at the expense of increased lever travel. At one end of the continuum is a wooden feeling brake with limited power, at the other end is a softer, squishier feel but much more power.

The ST11 (non ABS etc) that I have has a 14mm master cylinder, but I just happen to have a leftover 12.7mm master from my VFR that will be a direct mechanical and visual swap. The 12.7mm master is also used on the LBS versions of the ST. I wondered if anyone has done something like this before and what the outcome was?

Terry - That would be an 'interesting' swap. I've never thought about swapping an ABS master for a standard master to see the different. Since I have 'extras', I'll have to put that in the list of things to do!