Gizmo brake pad wear -- WAS: Re: motor torque question

[David Nelson-5]

Hi Dave & all,

> If you have gone through 3 sets of pads in 4000 miles you have serious
> problems.

Actually I've gone through 2 sets in 4000 miles, I'm just on my third
set. Too fast, that is for sure.

> Going through pads that fast means you are either constantly chewing away at
> them
> or really frying them in stops. Unless you drive around with the brakes on
> you
> should get 20,000 plus miles (and usually way more) on a single set of pads.
> People who drive around town dragging the brakes might see about 10,000
> miles
> on one set.

Is this for a regular car? Probably not since I usually get over
100,000 on a set on my vehicles, but then I drive quite a bit when I'm
not driving my Gizmo.

> If the pads are too small or the callipers are not retracting away from the
> rotor
> or the brakes generally are undersized for the weight then you should smell
> burning
> pads (a lot). As I'm sure someone has mentioned before if your range is crap
> then
> you should be looking at the callipers not releasing. And it could be the
> wrong
> brake material but then this would show up as a problems for any of the
> cars.

I don't smell any burning or the classic hot brakes smell. The brakes
are Brembo brake pad set 107.6949.10 and  caliper # 20.6950.10. I
ordered the pads from www.fastech-racing.com back in August of 2006 to
keep on hand but I don't see them on their site any more. Maybe the
107.6949.11 will work. They list the caliper here:
http://www.fastech-racing.com/product.php?productid=703&cat=0&page=1

> If that isn't the case then you should see if you feel any pulsing or
> vibration
> when braking. If not then jack the car up and spin the wheel by hand and
> feel
> for smooth function. If you can apply the brakes slightly and turn the wheel
> and feel if it catches and then turns smooth. If it is doing any of this
> then
> you probably have a bad rotor or the callipers are not mounted right.

Things are relatively smooth but there is a bit of flex in things. I
always hear a slight bit of rubbing on of the rotors on the pads. I
believe this isn't too abnormal but it might be more than it should
be. There were only 37 or so of these Gizmos built and I have #31. The
rotors are a custom job. The manual says it is a 10" rotor turned down
to 8.25". I have been unable to locate any. These are not a cast
material like rotors for a car so I don't know if they warp the same
or not.

> If you
> are going through pads this fast I'd say this is a good bet what your
> problem
> is. It doesn't take much to warp a rotor and they will even warp if they are
> not stored or shipped properly. And it doesn't take much warp to kill pads.
> You should be able to get your rotor turned for under $10. A few shops will
> turn or face all rotors before installation, including brand new ones.

These rotors are not typical. If I had these turned they would be too
thin so I would be better off just replacing them if I could find a
vendor who had them. The disk is from Tolomatic Part #09021210 but I
have been unable to find anything on the web about them.

> A set of standard pads is about $25 but you should be able to get better
> materials that will handle the heat if everything else works out. Any brake
> rebuilder can put new material on existing pads. There are several pad
> materials
> out there that will happily glow red hot and still work fine.

I'll have to keep looking around for something. If I could find a
brake rebuilder I could have thicker pads put on too. There is nearly
1/4" space available on each side of the disk when the calipers are
fully retracted and new pads are installed. Is there any way to
measure if the calipers are retracting the correct amount?

Thanks for the input.

--
David D. Nelson

http://evalbum.com/1328


_______________________________________________
For general EVDL support, see http://evdl.org/help/
For subscription options, see http://lists.sjsu.edu/mailman/listinfo/ev

[Dave King]

Yup even 2 sets in 4000 isn't quite right.

On older organic pads They would figure 20,000 ish city miles. Newer
materials
lasts and works a whole lot better. You can also kill lining materials by
not
seating them in right away. Or just by braking hard at lights.

If you can't smell brakes, then see if you can feel heat on the wheels. Go
for a drive and when you stop and get out put your hand on the wheel near
the hub. Should be barely warm if that.

Facing the rotor shouldn't remove much material. You might only take 10 thou
or so off. You are just knocking off the high spot. All it takes is dropping
the rotor onto the shelf or leaning it on something on the shelf and the
damn things
get bent. Won't be much or even visible but enough to do what you have
described.
You wouldn't think 50 pounds of steel (big rotor) could be that "delicate"
but
they are.

When they turn them which is the same thing but taking off more material.
The
minimum thickness is what you are not supposed to go below. after that point
if
the shop lets you take them home and you use them they can warp easier as
there
is less material to absorb and reject heat.

Try www.tolomatic.com and look under drive train stuff. They should have a
dealer locater
as well.

All you want is the pads not to drag, anything more than that can cause
brakes to
be slow to work ie dangerous.

It is possible that the rotors are just too small for the weight. If you
can't upgrade
to a larger size then you can drill the rotors. Or you can try ducting fresh
cool air
onto them.

Dave
-----Original Message-----

Hi Dave & all,

> If you have gone through 3 sets of pads in 4000 miles you have serious
> problems.

Actually I've gone through 2 sets in 4000 miles, I'm just on my third
set. Too fast, that is for sure.

> Going through pads that fast means you are either constantly chewing away
at
> them
> or really frying them in stops. Unless you drive around with the brakes on
> you
> should get 20,000 plus miles (and usually way more) on a single set of
pads.
> People who drive around town dragging the brakes might see about 10,000
> miles
> on one set.

Is this for a regular car? Probably not since I usually get over
100,000 on a set on my vehicles, but then I drive quite a bit when I'm
not driving my Gizmo.

> If the pads are too small or the callipers are not retracting away from
the
> rotor
> or the brakes generally are undersized for the weight then you should
smell
> burning
> pads (a lot). As I'm sure someone has mentioned before if your range is
crap
> then
> you should be looking at the callipers not releasing. And it could be the
> wrong
> brake material but then this would show up as a problems for any of the
> cars.

I don't smell any burning or the classic hot brakes smell. The brakes
are Brembo brake pad set 107.6949.10 and  caliper # 20.6950.10. I
ordered the pads from www.fastech-racing.com back in August of 2006 to
keep on hand but I don't see them on their site any more. Maybe the
107.6949.11 will work. They list the caliper here:
http://www.fastech-racing.com/product.php?productid=703&cat=0&page=1

> If that isn't the case then you should see if you feel any pulsing or
> vibration
> when braking. If not then jack the car up and spin the wheel by hand and
> feel
> for smooth function. If you can apply the brakes slightly and turn the
wheel
> and feel if it catches and then turns smooth. If it is doing any of this
> then
> you probably have a bad rotor or the callipers are not mounted right.

Things are relatively smooth but there is a bit of flex in things. I
always hear a slight bit of rubbing on of the rotors on the pads. I
believe this isn't too abnormal but it might be more than it should
be. There were only 37 or so of these Gizmos built and I have #31. The
rotors are a custom job. The manual says it is a 10" rotor turned down
to 8.25". I have been unable to locate any. These are not a cast
material like rotors for a car so I don't know if they warp the same
or not.

> If you
> are going through pads this fast I'd say this is a good bet what your
> problem
> is. It doesn't take much to warp a rotor and they will even warp if they
are
> not stored or shipped properly. And it doesn't take much warp to kill
pads.
> You should be able to get your rotor turned for under $10. A few shops
will
> turn or face all rotors before installation, including brand new ones.

These rotors are not typical. If I had these turned they would be too
thin so I would be better off just replacing them if I could find a
vendor who had them. The disk is from Tolomatic Part #09021210 but I
have been unable to find anything on the web about them.

> A set of standard pads is about $25 but you should be able to get better
> materials that will handle the heat if everything else works out. Any
brake
> rebuilder can put new material on existing pads. There are several pad
> materials
> out there that will happily glow red hot and still work fine.

I'll have to keep looking around for something. If I could find a
brake rebuilder I could have thicker pads put on too. There is nearly
1/4" space available on each side of the disk when the calipers are
fully retracted and new pads are installed. Is there any way to
measure if the calipers are retracting the correct amount?

Thanks for the input.

--
David D. Nelson

http://evalbum.com/1328


_______________________________________________
For general EVDL support, see http://evdl.org/help/
For subscription options, see http://lists.sjsu.edu/mailman/listinfo/ev


_______________________________________________
For general EVDL support, see http://evdl.org/help/
For subscription options, see http://lists.sjsu.edu/mailman/listinfo/ev

[David Nelson-5]

Thank you, Dave,

The disks I have look like these:
http://www.tolomatic.com/products/sub_page_detail.cfm?tree_id=186&page_id=161&sub_page_no=59

http://tinyurl.com/66p94o

They have a quite different feel to them compared to the rotors on my
car. Maybe it is because they are so thin.

For some reason they get grooves in them quite easily. I don't know if
this is due to pad material or disk material. I know Fred, also on
this list, has the Gizmo made just before mine and he has the same
problem with the disks but he hasn't had his Gizmo long enough to know
if it is a general Gizmo issue or not. The disks started out at 0.157"
thick and are now 0.125" thick. Turning them to get the grooves out
would likely make them down to 0.100". that seems a little thin to me.

Another possiblilty that Fred pointed out to me is that the wheel
bearings are sealed ball bearings not tapered roller bearings so there
is going to be a little slop. This might be part of the problem since
there is always brake drag noise. Of course, there isn't the distance
and sound deadining material between me and the wheels like there is
on a car.

Thank you agian for the input. As soon as I get the throttle controll
unit back I will check the temperature of the hubs/disks.

David

On Thu, Jul 24, 2008 at 12:25 AM, Dave King <kingdws@...> wrote:

> Yup even 2 sets in 4000 isn't quite right.
>
> On older organic pads They would figure 20,000 ish city miles. Newer
> materials
> lasts and works a whole lot better. You can also kill lining materials by
> not
> seating them in right away. Or just by braking hard at lights.
>
> If you can't smell brakes, then see if you can feel heat on the wheels. Go
> for a drive and when you stop and get out put your hand on the wheel near
> the hub. Should be barely warm if that.
>
> Facing the rotor shouldn't remove much material. You might only take 10 thou
> or so off. You are just knocking off the high spot. All it takes is dropping
> the rotor onto the shelf or leaning it on something on the shelf and the
> damn things
> get bent. Won't be much or even visible but enough to do what you have
> described.
> You wouldn't think 50 pounds of steel (big rotor) could be that "delicate"
> but
> they are.
>
> When they turn them which is the same thing but taking off more material.
> The
> minimum thickness is what you are not supposed to go below. after that point
> if
> the shop lets you take them home and you use them they can warp easier as
> there
> is less material to absorb and reject heat.
>
> Try www.tolomatic.com and look under drive train stuff. They should have a
> dealer locater
> as well.
>
> All you want is the pads not to drag, anything more than that can cause
> brakes to
> be slow to work ie dangerous.
>
> It is possible that the rotors are just too small for the weight. If you
> can't upgrade
> to a larger size then you can drill the rotors. Or you can try ducting fresh
> cool air
> onto them.
>
> Dave
> -----Original Message-----
>
> Hi Dave & all,
>
>> If you have gone through 3 sets of pads in 4000 miles you have serious
>> problems.
>
> Actually I've gone through 2 sets in 4000 miles, I'm just on my third
> set. Too fast, that is for sure.
>
>> Going through pads that fast means you are either constantly chewing away
> at
>> them
>> or really frying them in stops. Unless you drive around with the brakes on
>> you
>> should get 20,000 plus miles (and usually way more) on a single set of
> pads.
>> People who drive around town dragging the brakes might see about 10,000
>> miles
>> on one set.
>
> Is this for a regular car? Probably not since I usually get over
> 100,000 on a set on my vehicles, but then I drive quite a bit when I'm
> not driving my Gizmo.
>
>> If the pads are too small or the callipers are not retracting away from
> the
>> rotor
>> or the brakes generally are undersized for the weight then you should
> smell
>> burning
>> pads (a lot). As I'm sure someone has mentioned before if your range is
> crap
>> then
>> you should be looking at the callipers not releasing. And it could be the
>> wrong
>> brake material but then this would show up as a problems for any of the
>> cars.
>
> I don't smell any burning or the classic hot brakes smell. The brakes
> are Brembo brake pad set 107.6949.10 and  caliper # 20.6950.10. I
> ordered the pads from www.fastech-racing.com back in August of 2006 to
> keep on hand but I don't see them on their site any more. Maybe the
> 107.6949.11 will work. They list the caliper here:
> http://www.fastech-racing.com/product.php?productid=703&cat=0&page=1
>
>> If that isn't the case then you should see if you feel any pulsing or
>> vibration
>> when braking. If not then jack the car up and spin the wheel by hand and
>> feel
>> for smooth function. If you can apply the brakes slightly and turn the
> wheel
>> and feel if it catches and then turns smooth. If it is doing any of this
>> then
>> you probably have a bad rotor or the callipers are not mounted right.
>
> Things are relatively smooth but there is a bit of flex in things. I
> always hear a slight bit of rubbing on of the rotors on the pads. I
> believe this isn't too abnormal but it might be more than it should
> be. There were only 37 or so of these Gizmos built and I have #31. The
> rotors are a custom job. The manual says it is a 10" rotor turned down
> to 8.25". I have been unable to locate any. These are not a cast
> material like rotors for a car so I don't know if they warp the same
> or not.
>
>> If you
>> are going through pads this fast I'd say this is a good bet what your
>> problem
>> is. It doesn't take much to warp a rotor and they will even warp if they
> are
>> not stored or shipped properly. And it doesn't take much warp to kill
> pads.
>> You should be able to get your rotor turned for under $10. A few shops
> will
>> turn or face all rotors before installation, including brand new ones.
>
> These rotors are not typical. If I had these turned they would be too
> thin so I would be better off just replacing them if I could find a
> vendor who had them. The disk is from Tolomatic Part #09021210 but I
> have been unable to find anything on the web about them.
>
>> A set of standard pads is about $25 but you should be able to get better
>> materials that will handle the heat if everything else works out. Any
> brake
>> rebuilder can put new material on existing pads. There are several pad
>> materials
>> out there that will happily glow red hot and still work fine.
>
> I'll have to keep looking around for something. If I could find a
> brake rebuilder I could have thicker pads put on too. There is nearly
> 1/4" space available on each side of the disk when the calipers are
> fully retracted and new pads are installed. Is there any way to
> measure if the calipers are retracting the correct amount?
>
> Thanks for the input.
>
> --
> David D. Nelson
>
> http://evalbum.com/1328
>
>
> _______________________________________________
> For general EVDL support, see http://evdl.org/help/
> For subscription options, see http://lists.sjsu.edu/mailman/listinfo/ev
>
>
> _______________________________________________
> For general EVDL support, see http://evdl.org/help/
> For subscription options, see http://lists.sjsu.edu/mailman/listinfo/ev
>
>

--
David D. Nelson

http://evalbum.com/1328


_______________________________________________
For general EVDL support, see http://evdl.org/help/
For subscription options, see http://lists.sjsu.edu/mailman/listinfo/ev

[Dave King]

Yikes those are skinny!. They look like industrial/agricultural stuff. I
think the rotor
on my bike was about 250-280 thou. With a unvented disk it won't reject heat
very fast.
That and the thin size would make a good hard stop push those to the limit.
It sounds
like you have both rotor and pads going away on you. You shouldn't get
grooves in either
even under hard use. Well you won't until you are stopping using the rivets
;-]

If the bearings cause a wobble that would add some accelerated wear as well.

I have a feeling that if you run the rotor size and your vehicle weight
through a few
of the online calcs you will find they are rather undersized for the task.
If you can't change the rotors for a vented style you might want to get them
drilled
and get some directed vents onto them. You could also get some semi ceramic
pads
that would handle the heat but boy would I be concerned about warping those
rotors.

Dave

-----Original Message-----

The disks I have look like these:
http://www.tolomatic.com/products/sub_page_detail.cfm?tree_id=186&page_id=16
1&sub_page_no=59

http://tinyurl.com/66p94o

They have a quite different feel to them compared to the rotors on my
car. Maybe it is because they are so thin.

For some reason they get grooves in them quite easily. I don't know if
this is due to pad material or disk material. I know Fred, also on
this list, has the Gizmo made just before mine and he has the same
problem with the disks but he hasn't had his Gizmo long enough to know
if it is a general Gizmo issue or not. The disks started out at 0.157"
thick and are now 0.125" thick. Turning them to get the grooves out
would likely make them down to 0.100". that seems a little thin to me.

Another possiblilty that Fred pointed out to me is that the wheel
bearings are sealed ball bearings not tapered roller bearings so there
is going to be a little slop. This might be part of the problem since
there is always brake drag noise. Of course, there isn't the distance
and sound deadining material between me and the wheels like there is
on a car.

Thank you agian for the input. As soon as I get the throttle controll
unit back I will check the temperature of the hubs/disks.

David

On Thu, Jul 24, 2008 at 12:25 AM, Dave King <kingdws@...> wrote:

> Yup even 2 sets in 4000 isn't quite right.
>
> On older organic pads They would figure 20,000 ish city miles. Newer
> materials
> lasts and works a whole lot better. You can also kill lining materials by
> not
> seating them in right away. Or just by braking hard at lights.
>
> If you can't smell brakes, then see if you can feel heat on the wheels. Go
> for a drive and when you stop and get out put your hand on the wheel near
> the hub. Should be barely warm if that.
>
> Facing the rotor shouldn't remove much material. You might only take 10

thou
> or so off. You are just knocking off the high spot. All it takes is
dropping

> the rotor onto the shelf or leaning it on something on the shelf and the
> damn things
> get bent. Won't be much or even visible but enough to do what you have
> described.
> You wouldn't think 50 pounds of steel (big rotor) could be that "delicate"
> but
> they are.
>
> When they turn them which is the same thing but taking off more material.
> The
> minimum thickness is what you are not supposed to go below. after that

point

> if
> the shop lets you take them home and you use them they can warp easier as
> there
> is less material to absorb and reject heat.
>
> Try www.tolomatic.com and look under drive train stuff. They should have a
> dealer locater
> as well.
>
> All you want is the pads not to drag, anything more than that can cause
> brakes to
> be slow to work ie dangerous.
>
> It is possible that the rotors are just too small for the weight. If you
> can't upgrade
> to a larger size then you can drill the rotors. Or you can try ducting

fresh

> cool air
> onto them.
>
> Dave
> -----Original Message-----
>
> Hi Dave & all,
>
>> If you have gone through 3 sets of pads in 4000 miles you have serious
>> problems.
>
> Actually I've gone through 2 sets in 4000 miles, I'm just on my third
> set. Too fast, that is for sure.
>
>> Going through pads that fast means you are either constantly chewing away
> at
>> them
>> or really frying them in stops. Unless you drive around with the brakes

on

>> you
>> should get 20,000 plus miles (and usually way more) on a single set of
> pads.
>> People who drive around town dragging the brakes might see about 10,000
>> miles
>> on one set.
>
> Is this for a regular car? Probably not since I usually get over
> 100,000 on a set on my vehicles, but then I drive quite a bit when I'm
> not driving my Gizmo.
>
>> If the pads are too small or the callipers are not retracting away from
> the
>> rotor
>> or the brakes generally are undersized for the weight then you should
> smell
>> burning
>> pads (a lot). As I'm sure someone has mentioned before if your range is
> crap
>> then
>> you should be looking at the callipers not releasing. And it could be the
>> wrong
>> brake material but then this would show up as a problems for any of the
>> cars.
>
> I don't smell any burning or the classic hot brakes smell. The brakes
> are Brembo brake pad set 107.6949.10 and  caliper # 20.6950.10. I
> ordered the pads from www.fastech-racing.com back in August of 2006 to
> keep on hand but I don't see them on their site any more. Maybe the
> 107.6949.11 will work. They list the caliper here:
> http://www.fastech-racing.com/product.php?productid=703&cat=0&page=1
>
>> If that isn't the case then you should see if you feel any pulsing or
>> vibration
>> when braking. If not then jack the car up and spin the wheel by hand and
>> feel
>> for smooth function. If you can apply the brakes slightly and turn the
> wheel
>> and feel if it catches and then turns smooth. If it is doing any of this
>> then
>> you probably have a bad rotor or the callipers are not mounted right.
>
> Things are relatively smooth but there is a bit of flex in things. I
> always hear a slight bit of rubbing on of the rotors on the pads. I
> believe this isn't too abnormal but it might be more than it should
> be. There were only 37 or so of these Gizmos built and I have #31. The
> rotors are a custom job. The manual says it is a 10" rotor turned down
> to 8.25". I have been unable to locate any. These are not a cast
> material like rotors for a car so I don't know if they warp the same
> or not.
>
>> If you
>> are going through pads this fast I'd say this is a good bet what your
>> problem
>> is. It doesn't take much to warp a rotor and they will even warp if they
> are
>> not stored or shipped properly. And it doesn't take much warp to kill
> pads.
>> You should be able to get your rotor turned for under $10. A few shops
> will
>> turn or face all rotors before installation, including brand new ones.
>
> These rotors are not typical. If I had these turned they would be too
> thin so I would be better off just replacing them if I could find a
> vendor who had them. The disk is from Tolomatic Part #09021210 but I
> have been unable to find anything on the web about them.
>
>> A set of standard pads is about $25 but you should be able to get better
>> materials that will handle the heat if everything else works out. Any
> brake
>> rebuilder can put new material on existing pads. There are several pad
>> materials
>> out there that will happily glow red hot and still work fine.
>
> I'll have to keep looking around for something. If I could find a
> brake rebuilder I could have thicker pads put on too. There is nearly
> 1/4" space available on each side of the disk when the calipers are
> fully retracted and new pads are installed. Is there any way to
> measure if the calipers are retracting the correct amount?
>
> Thanks for the input.
>
> --
> David D. Nelson
>
> http://evalbum.com/1328
>
>
> _______________________________________________
> For general EVDL support, see http://evdl.org/help/
> For subscription options, see http://lists.sjsu.edu/mailman/listinfo/ev
>
>
> _______________________________________________
> For general EVDL support, see http://evdl.org/help/
> For subscription options, see http://lists.sjsu.edu/mailman/listinfo/ev
>
>

--
David D. Nelson

http://evalbum.com/1328


_______________________________________________
For general EVDL support, see http://evdl.org/help/
For subscription options, see http://lists.sjsu.edu/mailman/listinfo/ev


_______________________________________________
For general EVDL support, see http://evdl.org/help/
For subscription options, see http://lists.sjsu.edu/mailman/listinfo/ev

[markgrasser]

Solid rotors? Is this for the front wheel? Solid rotors hold their heat for
a long time and can affect braking after braking. In other words each time
you brake the rotor heats up and the next time you brake more heat. This
goes on until there is so much heat it creates gassing of the pads and
because of the gassing you have no braking. BUT I don't think that is your
immediate problem, unless you think you might be baking your brakes.

What caught my read is you say you have constant brake drag noise. This is
not right. A properly designed brake system knocks the pads away from the
rotors. This is done by the Rotors being out of true by +/-.003" or there
about, If you have pads dragging there is something not right. Either the
caliper is stuck (It must float in the holder.) OR big OR here. It has the
wrong master cylinder or it is connected improperly.

In a car with discs in the front and drums in the back or in a car with all
four drums (non I know of being made today) The cylinder supplying the drum
brakes has a residual pressure valve in it. It holds 5 to 10 psi in the line
to hold pressure on the drum system. Has something to do with positioning
the shoes, I never really understood it and most people don't even know it
exists. This 5 pounds in the line will make disk pads drag constantly (Don't
ask how I know, yes I've been there) Easy way to tell if they picked the
wrong master cylinder, well probably not all that easy, is to remove the
line from the master cylinder and look into the port. There should not be
anything in there except smooth empty passage to the piston. Usually for the
residual pressure there is a spring loaded check valve at the bottom that
creates this 5 to 10 pounds.

I suppose another way to tell if there is pressure on the pas would be to
pop the bleeder and see if it spurts then stops. Without pressure on the
pedal there should only be a slow flow when you open the bleeder.

Hope I've helped,

Mark Grasser
Eliot, ME

-----Original Message-----
From: ev-bounces@... [mailto:ev-bounces@...] On Behalf
Of David Nelson
Sent: Friday, July 25, 2008 1:57 AM
To: Electric Vehicle Discussion List
Subject: Re: [EVDL] Gizmo brake pad wear -- WAS: Re: motor torque question

Thank you, Dave,

The disks I have look like these:
http://www.tolomatic.com/products/sub_page_detail.cfm?tree_id=186&page_id=16
1&sub_page_no=59

http://tinyurl.com/66p94o

They have a quite different feel to them compared to the rotors on my
car. Maybe it is because they are so thin.

For some reason they get grooves in them quite easily. I don't know if
this is due to pad material or disk material. I know Fred, also on
this list, has the Gizmo made just before mine and he has the same
problem with the disks but he hasn't had his Gizmo long enough to know
if it is a general Gizmo issue or not. The disks started out at 0.157"
thick and are now 0.125" thick. Turning them to get the grooves out
would likely make them down to 0.100". that seems a little thin to me.

Another possiblilty that Fred pointed out to me is that the wheel
bearings are sealed ball bearings not tapered roller bearings so there
is going to be a little slop. This might be part of the problem since
there is always brake drag noise. Of course, there isn't the distance
and sound deadining material between me and the wheels like there is
on a car.

Thank you agian for the input. As soon as I get the throttle controll
unit back I will check the temperature of the hubs/disks.

David

On Thu, Jul 24, 2008 at 12:25 AM, Dave King <kingdws@...> wrote:

> Yup even 2 sets in 4000 isn't quite right.
>
> On older organic pads They would figure 20,000 ish city miles. Newer
> materials
> lasts and works a whole lot better. You can also kill lining materials by
> not
> seating them in right away. Or just by braking hard at lights.
>
> If you can't smell brakes, then see if you can feel heat on the wheels. Go
> for a drive and when you stop and get out put your hand on the wheel near
> the hub. Should be barely warm if that.
>
> Facing the rotor shouldn't remove much material. You might only take 10

thou
> or so off. You are just knocking off the high spot. All it takes is
dropping

> the rotor onto the shelf or leaning it on something on the shelf and the
> damn things
> get bent. Won't be much or even visible but enough to do what you have
> described.
> You wouldn't think 50 pounds of steel (big rotor) could be that "delicate"
> but
> they are.
>
> When they turn them which is the same thing but taking off more material.
> The
> minimum thickness is what you are not supposed to go below. after that

point

> if
> the shop lets you take them home and you use them they can warp easier as
> there
> is less material to absorb and reject heat.
>
> Try www.tolomatic.com and look under drive train stuff. They should have a
> dealer locater
> as well.
>
> All you want is the pads not to drag, anything more than that can cause
> brakes to
> be slow to work ie dangerous.
>
> It is possible that the rotors are just too small for the weight. If you
> can't upgrade
> to a larger size then you can drill the rotors. Or you can try ducting

fresh

> cool air
> onto them.
>
> Dave
> -----Original Message-----
>
> Hi Dave & all,
>
>> If you have gone through 3 sets of pads in 4000 miles you have serious
>> problems.
>
> Actually I've gone through 2 sets in 4000 miles, I'm just on my third
> set. Too fast, that is for sure.
>
>> Going through pads that fast means you are either constantly chewing away
> at
>> them
>> or really frying them in stops. Unless you drive around with the brakes

on

>> you
>> should get 20,000 plus miles (and usually way more) on a single set of
> pads.
>> People who drive around town dragging the brakes might see about 10,000
>> miles
>> on one set.
>
> Is this for a regular car? Probably not since I usually get over
> 100,000 on a set on my vehicles, but then I drive quite a bit when I'm
> not driving my Gizmo.
>
>> If the pads are too small or the callipers are not retracting away from
> the
>> rotor
>> or the brakes generally are undersized for the weight then you should
> smell
>> burning
>> pads (a lot). As I'm sure someone has mentioned before if your range is
> crap
>> then
>> you should be looking at the callipers not releasing. And it could be the
>> wrong
>> brake material but then this would show up as a problems for any of the
>> cars.
>
> I don't smell any burning or the classic hot brakes smell. The brakes
> are Brembo brake pad set 107.6949.10 and  caliper # 20.6950.10. I
> ordered the pads from www.fastech-racing.com back in August of 2006 to
> keep on hand but I don't see them on their site any more. Maybe the
> 107.6949.11 will work. They list the caliper here:
> http://www.fastech-racing.com/product.php?productid=703&cat=0&page=1
>
>> If that isn't the case then you should see if you feel any pulsing or
>> vibration
>> when braking. If not then jack the car up and spin the wheel by hand and
>> feel
>> for smooth function. If you can apply the brakes slightly and turn the
> wheel
>> and feel if it catches and then turns smooth. If it is doing any of this
>> then
>> you probably have a bad rotor or the callipers are not mounted right.
>
> Things are relatively smooth but there is a bit of flex in things. I
> always hear a slight bit of rubbing on of the rotors on the pads. I
> believe this isn't too abnormal but it might be more than it should
> be. There were only 37 or so of these Gizmos built and I have #31. The
> rotors are a custom job. The manual says it is a 10" rotor turned down
> to 8.25". I have been unable to locate any. These are not a cast
> material like rotors for a car so I don't know if they warp the same
> or not.
>
>> If you
>> are going through pads this fast I'd say this is a good bet what your
>> problem
>> is. It doesn't take much to warp a rotor and they will even warp if they
> are
>> not stored or shipped properly. And it doesn't take much warp to kill
> pads.
>> You should be able to get your rotor turned for under $10. A few shops
> will
>> turn or face all rotors before installation, including brand new ones.
>
> These rotors are not typical. If I had these turned they would be too
> thin so I would be better off just replacing them if I could find a
> vendor who had them. The disk is from Tolomatic Part #09021210 but I
> have been unable to find anything on the web about them.
>
>> A set of standard pads is about $25 but you should be able to get better
>> materials that will handle the heat if everything else works out. Any
> brake
>> rebuilder can put new material on existing pads. There are several pad
>> materials
>> out there that will happily glow red hot and still work fine.
>
> I'll have to keep looking around for something. If I could find a
> brake rebuilder I could have thicker pads put on too. There is nearly
> 1/4" space available on each side of the disk when the calipers are
> fully retracted and new pads are installed. Is there any way to
> measure if the calipers are retracting the correct amount?
>
> Thanks for the input.
>
> --
> David D. Nelson
>
> http://evalbum.com/1328
>
>
> _______________________________________________
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> For subscription options, see http://lists.sjsu.edu/mailman/listinfo/ev
>
>
> _______________________________________________
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>
>

--
David D. Nelson

http://evalbum.com/1328


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[storm connors]

Good thought Mark!
If the master cylinder does have the check valve, you can punch a hole
in it to use it with disk brakes. Just removing it could affect the
tension on the return spring.

On Fri, Jul 25, 2008 at 8:20 AM, Mark Grasser <markgrasser@...> wrote:

>
> What caught my read is you say you have constant brake drag noise. This is
> not right. A properly designed brake system knocks the pads away from the
> rotors. This is done by the Rotors being out of true by +/-.003" or there
> about, If you have pads dragging there is something not right. Either the
> caliper is stuck (It must float in the holder.) OR big OR here. It has the
> wrong master cylinder or it is connected improperly.
>
> In a car with discs in the front and drums in the back or in a car with all
> four drums (non I know of being made today) The cylinder supplying the drum
> brakes has a residual pressure valve in it. It holds 5 to 10 psi in the line
> to hold pressure on the drum system. Has something to do with positioning
> the shoes, I never really understood it and most people don't even know it
> exists. This 5 pounds in the line will make disk pads drag constantly (Don't
> ask how I know, yes I've been there) Easy way to tell if they picked the
> wrong master cylinder, well probably not all that easy, is to remove the
> line from the master cylinder and look into the port. There should not be
> anything in there except smooth empty passage to the piston. Usually for the
> residual pressure there is a spring loaded check valve at the bottom that
> creates this 5 to 10 pounds.
>
> I suppose another way to tell if there is pressure on the pas would be to
> pop the bleeder and see if it spurts then stops. Without pressure on the
> pedal there should only be a slow flow when you open the bleeder.
>
> Hope I've helped,
>
> Mark Grasser
> Eliot, ME

--
http://www.austinev.org/evalbum/1059
http://stormselectric.blogspot.com/
Storm


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[David Nelson-5]

Hi Dave, Mark, Storm, et al,

Thank you for the insights. I took another look at the calipers,
disks, master cylinder. The disks are about the thickness of those on
a motorcycle, the clipers are motorcycle calipers and the brake
handle&cylinder are motorcycle type. I doubt it has a check valve.
When I bled the brakes after replacing the fluid I had to create a
reverse flow setup to get the bubbles out since the fluid has to go
straight down the handle to get to the brakes. You can see the brake
handle and reservoir in this picture on my evalbum listing:
http://evalbum.com/popupimg.php?6917

This handle controls only the brakes on the front wheel. The rear
wheel has a mechanical brake on a disk on the motor. I probably don't
have overheating issues since this vehicle only goes about 40mph
unless I'm going down hill. I believe it is only about 1000lbs.

The brakes don't look like they are getting baked. I had to replace
the front calipers on my S10 because they were getting hot enough to
make the pads delaminate from the metal backing.

Mike, you said
>What caught my read is you say you have constant brake drag noise. This is
>not right. A properly designed brake system knocks the pads away from the
>rotors. This is done by the Rotors being out of true by +/-.003" or there
>about, If you have pads dragging there is something not right. Either the
>caliper is stuck (It must float in the holder.) OR big OR here. It has the
>wrong master cylinder or it is connected improperly.

Do you think this might be because of using ball bearings rather than
tapered roller bearings in the wheels? These calipers have a separate
cylinder for each pad rather than one cylinder with a floating half. I
noticed that there is a dent in the flexible line going from the brake
handle to the "T" in the line. Maybe it would be worth replacing this
and see what happens. I haven't found any delay in the braking,
however.

It would be nice to get this figured out and resolved so I don't go
through pads so fast and it should have a positive impact on my
range/charge.

--
David D. Nelson

http://evalbum.com/1328


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