I’ve got an 8 year old ebike, was quite cheap and clearly built down to a price. Lots of no-brand components on it, but its been marvellous for me and I use it instead of a car to get around to work, shops etc., as well as for enjoyment.
One of my big gripes with it was the brakes. They’re mechanical, and although they were good to start with, they soon lost stopping ability. I adjusted them, worked ok for a bit then got poor again. Seemed to need adjusting every few weeks.
It wasn’t excessive brake lever travel, was just poor stopping ability.
I tried many different pads, some were better than others but all seemed to quickly be poor again.
I cleaned the discs, of course, with brake disc cleaner, in case there was oil on them.
When the brakes were good, they were pretty good for mechanical discs. But more often, they were poor.
One time, I was riding down a hill on the road towards a junction, and found I couldn’t stop in time and went partly into the road in front of traffic. Not good!
(btw, the bike is street legal, 250w motor limited to 15mph assist. It’s very hilly around where I live, so this flattens the hills somewhat, whilst still needing me to pedal so I get exercise without being totally exhausted).
Anyway, after having changed cables & pads, I thought I’d try some different discs.
I got some cheap genuine Shimano discs that were the same size and very similar design to what was already on there. The Shimano discs were slightly heavier.
The difference was astounding. Straight away, much better braking.
And, a year on from changing them, it still is. I now only have to adjust the brakes as the pads wear down, every few months.
So, the whole point of this post is.. does anyone know WHY?
Surely a disc is a disc, especially if they’re designed in a similar way (eg cooling).
Thoughts?
seanondemand on
My non-mechanic guess? The brakes weren’t bedded in properly on the old rotors. New rotors means a new opportunity to bed in the brakes, which you fortunately managed to get correct this time, even if it wasn’t done purposefully. If the brakes don’t get a good bedding in done, it doesn’t matter how high end they are, they’ll never be right.
Awesomebox5000 on
“Surely a disc is a disc…” Why would you think that? How did you come to that conclusion?
Materials, coatings, quality control, and more all play into the performance you can realize from any given component. Long story short, the genuine rotor feels heavier because it’s not made from the same material. Looks can be deceiving and shady manufacturers/merchants are counting on that.
NM1tchy on
I had some cheap shimano cable disc brake,. The calipers corroded really badly in a year, so I got the TRP spyre calipers. These use a double arm so both pads move rather than relying on 1 pad moving and the disc having to flex. Also I set the arm so that it is just more than 90 degrees as the pads hit the disc. This gives the best mechanical advantage.
billybrooker1 on
If its a flat bar bike you can upgrade to hydraulic shimano mt200 for about £40
Affectionate-Bug-861 on
The best and most important upgrade is the brakes; it was the first part on my entry-level mountain bike that I replaced, and I installed a pair of Shimano Deore brakes, and I’ve never had any brake problems since.
6 Comments
I’ve got an 8 year old ebike, was quite cheap and clearly built down to a price. Lots of no-brand components on it, but its been marvellous for me and I use it instead of a car to get around to work, shops etc., as well as for enjoyment.
One of my big gripes with it was the brakes. They’re mechanical, and although they were good to start with, they soon lost stopping ability. I adjusted them, worked ok for a bit then got poor again. Seemed to need adjusting every few weeks.
It wasn’t excessive brake lever travel, was just poor stopping ability.
I tried many different pads, some were better than others but all seemed to quickly be poor again.
I cleaned the discs, of course, with brake disc cleaner, in case there was oil on them.
When the brakes were good, they were pretty good for mechanical discs. But more often, they were poor.
One time, I was riding down a hill on the road towards a junction, and found I couldn’t stop in time and went partly into the road in front of traffic. Not good!
(btw, the bike is street legal, 250w motor limited to 15mph assist. It’s very hilly around where I live, so this flattens the hills somewhat, whilst still needing me to pedal so I get exercise without being totally exhausted).
Anyway, after having changed cables & pads, I thought I’d try some different discs.
I got some cheap genuine Shimano discs that were the same size and very similar design to what was already on there. The Shimano discs were slightly heavier.
The difference was astounding. Straight away, much better braking.
And, a year on from changing them, it still is. I now only have to adjust the brakes as the pads wear down, every few months.
So, the whole point of this post is.. does anyone know WHY?
Surely a disc is a disc, especially if they’re designed in a similar way (eg cooling).
Thoughts?
My non-mechanic guess? The brakes weren’t bedded in properly on the old rotors. New rotors means a new opportunity to bed in the brakes, which you fortunately managed to get correct this time, even if it wasn’t done purposefully. If the brakes don’t get a good bedding in done, it doesn’t matter how high end they are, they’ll never be right.
“Surely a disc is a disc…” Why would you think that? How did you come to that conclusion?
Materials, coatings, quality control, and more all play into the performance you can realize from any given component. Long story short, the genuine rotor feels heavier because it’s not made from the same material. Looks can be deceiving and shady manufacturers/merchants are counting on that.
I had some cheap shimano cable disc brake,. The calipers corroded really badly in a year, so I got the TRP spyre calipers. These use a double arm so both pads move rather than relying on 1 pad moving and the disc having to flex. Also I set the arm so that it is just more than 90 degrees as the pads hit the disc. This gives the best mechanical advantage.
If its a flat bar bike you can upgrade to hydraulic shimano mt200 for about £40
The best and most important upgrade is the brakes; it was the first part on my entry-level mountain bike that I replaced, and I installed a pair of Shimano Deore brakes, and I’ve never had any brake problems since.