Zen Photon Pro - Disc Brake Pad Replacement

[CincyKid]

I'm approaching 600 miles in. Lots of climbing (22,000+)...and descending. It's close to requiring a pad replacement. Any suggestions as to the type of pad to replace with?

Good videos to view for the process.

Appreciate the help.

 

[Deacon Blues]

Just curious, how do you know you need to replace your brake pads?

 

[CincyKid]

Just curious, how do you know you need to replace your brake pads?

A couple of reasons:

1) Brake fade on long, steep descents to such a degree the brake lever comes all the way to the bar.

2) Less reactive and squishy feeling when using them

I have not taken them out to "officially" check.

 

[il Munduato]

A couple of reasons:

1) Brake fade on long, steep descents to such a degree the brake lever comes all the way to the bar.

2) Less reactive and squishy feeling when using them

I have not taken them out to "officially" check.

You may need to do a lever bleed to top off the fluid.

 

[Deacon Blues]

Your two reasons look to be a brake fluid problem, not brake pad wear issue.
I agree with il Munduato-you need to have your brakes bled.
Your pads may also be worn, but before you replace them take them out and measure them.
New brake pads are usually 3-5mm thick and should be replaced when their thickness reaches 1mm or less.

 

[CincyKid]

You boys are right. I took the brake pads off. Lots of wear remaining.

Now, what brake bleed kit to get?

 

[fooferdoggie]

if you are getting that much brake fade you need to look at how you are braking doing a lot of downhills. hard braking then letting uo for them to cool or changing from back to front to give cool time.

 

[CincyKid]

if you are getting that much brake fade you need to look at how you are braking doing a lot of downhills. hard braking then letting uo for them to cool or changing from back to front to give cool time.

100% Agree. I was with a group. My front break squeals so loudly. I was definitely leaning on the back too much. Ordinarily, I use both and do a more aggressive brake and release on the long super steep hills. This time I had to keep my speed in check so I didn't run over anyone.

 

[Deacon Blues]

You boys are right. I took the brake pads off. Lots of wear remaining.

Now, what brake bleed kit to get?

Depends on the brand of brakes. My wife's Zen bike has Tektro hydraulic brakes, which use mineral oil. A bleed kit for this brand of brakes can be found on Amazon, etc.
For me, bleeding bike hydraulic brakes has been hit and miss. Sometimes it's easy and other times it's been a real PITA.

 

[il Munduato]

Depends on the brand of brakes. My wife's Zen bike has Tektro hydraulic brakes, which use mineral oil. A bleed kit for this brand of brakes can be found on Amazon, etc.
For me, bleeding bike hydraulic brakes has been hit and miss. Sometimes it's easy and other times it's been a real PITA.

A few tips...
If possible raise the front of the bike higher than the rear for the rear brake.
You can also remove the caliper and let it dangle low
Rotate the levers so that the bleed screw is parallel to the ground.
Tap the brake lines to help release any bubbles while squeezing the levers
Don't be in a rush... But 30 minutes to an hour should be plenty of time.

 

[fooferdoggie]

100% Agree. I was with a group. My front break squeals so loudly. I was definitely leaning on the back too much. Ordinarily, I use both and do a more aggressive brake and release on the long super steep hills. This time I had to keep my speed in check so I didn't run over anyone.

on our tandem, I don't like going over 28 downhill anymore so it can be tough when the bike and us weigh 400 pounds. Luckily the bike came with a rim brake in the back too. though it had a crappy disc setup we changed out. Shimano 4 piston and ice tech rotors (they are good and bad)

 

[Blunoser]

much good advice here. For sure remove caliper and pads to do a bleed. You don't want brake oil anywhere near pads/ rotors. Just find a youtube video for Shimano bleed for reference. What you describe is for sure air/lack of fluid in lines, most likely from overheating on the big descent you talk about.
If you are going to repeat these conditions you might wish to use Metal pads, they will tolerate heat better(less fade) at the cost of a bit more noise. I think your pads are the same ones that Shimano uses on their 4 piston brakes(size wise) so should be easy to obtain.
ps. If your front brake squeals loudly the pads are likely contaminated, or glazed from overheating and might need to be replaced anyway. Disc brakes are very touchy about oil on pads/rotors. I learned the hard way you can't even touch them with oily fingers at all. Now that I know I've put over 4k on my brakes with no issues(not an ebike..yet).

 

[PCeBiker]

2) Less reactive and squishy feeling when using them

You boys are right. I took the brake pads off. Lots of wear remaining.

My Tektro front brake was all squishy feeling and the lever started hitting my fingers (two fingers on the grip, and two on the lever).
I had bled the brakes a couple of times and it didn't really help.

I removed the pads and there was lots of pad left, but when I measured them with a caliper, I found that the pads had worn tapered.
The leading edges were worn slightly more than the trailing edges, and the inner edges (closer to the axle) were also thinner.

So the caliper piston, pads and rotor weren't mating squarely.

I decided to flip them over and reinstall them instead of replacing them because there was lots of pad left.

It worked!!
My front brake was instantly more responsive and Solid feeling.

So I could adjust my lever closer to the grip without hitting my fingers.
I had adjusted them out to give me more finger clearance, but I always rest my two fingers on the lever and it was too far to reach comfortably.

The pads were off square by about 0.3 mm.
So now I'll wear them out backwards, just like rotating the tires on your car.

 

[Blunoser]

My Tektro front brake was all squishy feeling and the lever started hitting my fingers (two fingers on the grip, and two on the lever).
I had bled the brakes a couple of times and it didn't really help.

I removed the pads and there was lots of pad left, but when I measured them with a caliper, I found that the pads had worn tapered.
The leading edges were worn slightly more than the trailing edges, and the inner edges (closer to the axle) were also thinner.

So the caliper piston, pads and rotor weren't mating squarely.

I decided to flip them over and reinstall them instead of replacing them because there was lots of pad left.

It worked!!
My front brake was instantly more responsive and Solid feeling.

So I could adjust my lever closer to the grip without hitting my fingers.
I had adjusted them out to give me more finger clearance, but I always rest my two fingers on the lever and it was too far to reach comfortably.

The pads were off square by about 0.3 mm.
So now I'll wear them out backwards, just like rotating the tires on your car.

Curious, which model of Tektro brakes do you have? I believe the Photon has E725(4 piston caliper) on the latest ones.

 

[PCeBiker]

Curious, which model of Tektro brakes do you have? I believe the Photon has E725(4 piston caliper) on the latest ones.

I can't find a model number printed on the caliper but the website says that they are Tektro Auriga HD-E500.
They are two piston calipers.

I've got this printing on the calipers, but I guess that they are serial numbers?

I would assume that a four piston caliper would do a better job at keeping the pads more square and aligned against the rotor.
With two pistons on each side and probably a larger wider pad, they are probably less inclined to wear unevenly.

 

[Blunoser]

I can't find a model number printed on the caliper but the website says that they are Tektro Auriga HD-E500.
They are two piston calipers.

I've got this printing on the calipers, but I guess that they are serial numbers?


View attachment 180867
View attachment 180868


I would assume that a four piston caliper would do a better job at keeping the pads more square and aligned against the rotor.
With two pistons on each side and probably a larger wider pad, they are probably less inclined to wear unevenly.

 

[Blunoser]

I was wondering if you had 2 or 4 piston brakes mostly. Your assumptions are correct that the pads are usually bigger(wider) and better managed with the extra pistons farther apart. Some of them even have two different sized pistons to compensate for the uneven forces applied to the pads(my SLX 4 pots are like this).

I notice that you have what looks like salt on the caliper in the second pic? If so, that could mean your caliper is partially seized. Living on the Atlantic coast of Canada I know all about parts locking up after a winter. What a pain, it makes for a lot of extra maintenance. Anyway, I like your plan to simply rotate them as needed. If this works out all good. I like the way you think.

 

[PCeBiker]

I notice that you have what looks like salt on the caliper in the second pic?

That's mostly dust from the gravel roads that I ride, but oddly enough I got salted good about a month ago.

I was out for a ride and thought that it had rained on the gravel road ahead me.
After a mile of dirty spray, I passed a farm tractor spraying the road with brine solution.
They use it in the summer to help keep the dust down.
My e-bike and I were covered in concentrated salty slop.

If so, that could mean your caliper is partially seized. Living on the Atlantic coast of Canada I know all about parts locking up after a winter. What a pain, it makes for a lot of extra maintenance.

I live in the Great North Eastern salt belt that runs through Ontario where they salt the roads in the winter.
This is the caliper from my now deceased car,..

I couldn't replace the brake piston or the caliper because my brake line would have broken off, then I'd have to replace the brake lines as well.

So I just cleaned it up and stuffed it back in the bore.
(I did replace the boot eventually though.)

Lots of SIL-GLYDE silicone brake grease and the caliper worked again for years without leaks or problems.

I cleaned and polished the rotors and pads too.

Anyway, I like your plan to simply rotate them as needed. If this works out all good. I like the way you think.

Thanks, I went out for another ride today and everything was fine.

Living on the Atlantic coast of Canada,..

You probably have a Zen bike?
It was @Ravi Kempaiah that recommended Suntour forks.
I bought them for my new e-bike.

 

[Blunoser]

Judging from your pics you know exactly what I'm talking about lol. You are correct about the Zen as I have a Photon on the way. I worked at the University where they were developed so got to see the early Samurai prototypes and wanted one ever since. It's going to be a long few weeks waiting for it. It will be my first ebike, and I hope it lasts me for years. I won't be riding it on salted roads(mostly rail trails) so I went with the Johnny Watts tires. I'm used to full knobby tires on my MTB so didn't want to go to much towards a pavement tire. Having met Ravi and team in person I have to say I'm pleased to be getting one of their bikes.

 

[PCeBiker]

I won't be riding it on salted roads(mostly rail trails) so I went with the Johnny Watts tires.

I've got the Super Moto-X tires to help increase my range.

I was on this trail a month ago further up, where there were rutts from the mud and quads.

I was in the right rut (about 1½" deep) and tried to go over to the left rut, and my tire wouldn't climb out of the rut.
I started falling left, my left foot hit the ground at 25 kph and I managed to get the wheel out of the rut.
I ended up hanging way over my handlebars and 3 feet off off the left side of the trail.

I almost lost the bike and went over the handlebars.

I think that I'm going to put my Schwalbe Hurricane tire on the front?
It's got some side knobs to help me climb out of ruts.