Disc Brake questions

andyanansu said:

Hi,
I'm still using V Brakes, but I'm planning to upgrade to disc
What is the main difference between the front & rear brakes?
I've brought a front Deore from ebay, can it be use on the rear as well?
Why there are so many different diameters for the rotor? how do I know which one I need?
Many Thanks
Andy

The calipers are not really different it's the bracket for fitting them that tends to differ to accomodate differrent sized rotor's. People generally tend to run bigger rotors up front as this is the primary brake, and simply the bigger the rota, the bigger the braking surface and the more powerful the brake! (and also heavier the brake) - the more piston's you have also increase power (the deore's have 2 pistons, and are a basic good value for money system, that perform great {usually} for general trail riding, and don't take much fuss to look after)

The obvious differences are length of cable and the brake levers on most systems are front and rear specific, ie which side of the bars they go on (i think u can flip the avid levers)

Upgrade you won't regret it, i'm a bit of a luddite but disc's for mtb's was a great move forward, I live in the peaks in Derbyshire, and for UK conditions they are great for year round riding!

stevemtbsteve said:

The calipers are not really different it's the bracket for fitting them that tends to differ to accomodate differrent sized rotor's. People generally tend to run bigger rotors up front as this is the primary brake, and simply the bigger the rota, the bigger the braking surface and the more powerful the brake! (and also heavier the brake) - the more piston's you have also increase power (the deore's have 2 pistons, and are a basic good value for money system, that perform great {usually} for general trail riding, and don't take much fuss to look after)

The obvious differences are length of cable and the brake levers on most systems are front and rear specific, ie which side of the bars they go on (i think u can flip the avid levers)

Upgrade you won't regret it, i'm a bit of a luddite but disc's for mtb's was a great move forward, I live in the peaks in Derbyshire, and for UK conditions they are great for year round riding!

Many Thanks for your reply 🙂

I've seen some posts on this forum, they are talking about constantly adjusting them after every ride!!! :eek:

I want to know more about what tend to go wrong or what will wear out etc that need so much adjusting? 😕

Also what sort of mantanence does it required? can you give me a brief explaination? 😕

Thanks again 😉

Andy 😎

andyanansu said:

Many Thanks for your reply 🙂
I've seen some posts on this forum, they are talking about constantly adjusting them after every ride!!! :eek:
I want to know more about what tend to go wrong or what will wear out etc that need so much adjusting? 😕
Also what sort of mantanence does it required? can you give me a brief explaination? 😕
Thanks again 😉
Andy 😎

Hi Andy,

This is just my opinion, but I have read many posts about disc brake probs, and in the 3 or 4 years I have had them I have never had any issues. I run two bikes, my mtb with Hopes on, and my cyclo-cross/ commutor with deore disc's.

Since fitting both set's I have never had any prob's, both are 2 piston closed systems, and providing u fit them ok initially (which really seems to be a matter of the right number of spacers), they are fit and forget, I spray them with a car disc brake cleaner (which my LBS recommended), and try not to get oil/ lube on them and the only work I do to them is change the pads when they wear out, and my deore pads last longer than the pricer hopes. I have bleed them when I have swapped cables/ put them on new bikes and this is also pretty straight forward.

I could be just lucky, but I have none of this adjusting after every ride, my hopes need the odd lever tweak when the pads are wearing out, but my deore's nowt! and I ride the deore's 5 days a week (18 mile round trip to work) as a commutor, and offroad at nights/ weekends. My main riding bud has deore's only his orange ev04, and hasn't attempted any maintenance since 04 as he is usless, and they work mint! Maybe we are just lucky

My only main tip is when u fit new pads put some coper grease on the back of the pad, where the piston presses and this seems to stop them squeaking! use no other type of grease! as I say this is just my opinion, but I hate fettling with my bike, and disc's have been spot on for me! I'm sure others may have had different experiences, but i can only say as I see!

Cheers

stevemtbsteve said:

People generally tend to run bigger rotors up front as this is the primary brake, and simply the bigger the rota, the bigger the braking surface and the more powerful the brake!

I have disc brakes with a 160 in the rear and a 185 in the front and when I am riding the trails I NEVER use the front brake unless I'm about to hit a tree. I don't know about you but I learned about fifteen years ago not to use the front brake on the trail or any surface that may have loose gravel, dirt or rocks, unless you have to and are going absolutly straight. I think of the front brake as mainly a secondary brake not primary.This is the same concept that is applied to motorcycles, the primary brake is the rear brake.

anteyeradio said:

I have disc brakes with a 160 in the rear and a 185 in the front and when I am riding the trails I NEVER use the front brake unless I'm about to hit a tree. I don't know about you but I learned about fifteen years ago not to use the front brake on the trail or any surface that may have loose gravel, dirt or rocks, unless you have to and are going absolutly straight. I think of the front brake as mainly a secondary brake not primary.This is the same concept that is applied to motorcycles, the primary brake is the rear brake.

I'm sorry to disagree about the motorcycle theory but you are incorrect. roughly 70% of braking on vehicles be it cars or motorcycles are preformed by the front brakes. Motorcycles use the front brake more than the rear. Most performance bikes have only one rear rotor about 250mm but have two front rotors commonly 320mm each. I do agree with you about non-ideal traction and wanting to favor the rear brake more though.

Tim

anteyeradio said:

I have disc brakes with a 160 in the rear and a 185 in the front and when I am riding the trails I NEVER use the front brake unless I'm about to hit a tree. I don't know about you but I learned about fifteen years ago not to use the front brake on the trail or any surface that may have loose gravel, dirt or rocks, unless you have to and are going absolutly straight. I think of the front brake as mainly a secondary brake not primary.This is the same concept that is applied to motorcycles, the primary brake is the rear brake.

Since I mainly ride on lose gravel, dirt, rocks and mud, I learnt to feather my brakes in order to avoid locking them on and washing out - it's quite a useful skill. Also trying to learn to pick a line going into a corner and shaving your speed of before you commit, allows you to hold line and speed through a corner - breaking in a corner is just a bit of poor form really - experience generally leads you to know how fast you can take ur corners - flowing through the bend and then puting the power down on exit tends to put the biggest smile on my face!

Obviously there are times to lay off your front and 'on the fly' adjustment when in the midst of the gnarly stuff is best done on the rear - the bike industry appears to have chosen the front brake as the 'primary' brake for power (it puts the bigger rota's up front)- wether you chose this as ur 'primary' brake is down to you and ur riding style!

To me it makes sense to learn to use this power - then you spend less time slowing on entry to a bend, and this should generally help you hold your speed longer and make you faster overall - to never use ur front brake seems a bit odd unless you have the touch of an elephant! Just learn a bit of feel, and work with ur bike, keep the speed! keep the smiles!

anteyeradio said:

I have disc brakes with a 160 in the rear and a 185 in the front and when I am riding the trails I NEVER use the front brake unless I'm about to hit a tree. I don't know about you but I learned about fifteen years ago not to use the front brake on the trail or any surface that may have loose gravel, dirt or rocks, unless you have to and are going absolutly straight. I think of the front brake as mainly a secondary brake not primary.This is the same concept that is applied to motorcycles, the primary brake is the rear brake.

I use my front brake all the time, and my rear brake occasionally, if it's really loose, in which case I prefer not to brake at all. I'm sure that your comment about motorcycles does not apply to road ones.

I didn't mean to start a fight or anything I was just making a stament about how I use my brakes. I am transfering over from the world of bmx were I did not have a front brake so I am not used to using it.You guys are probably right and I am probably wrong, in which case I generally am wrong. After all your comments I have been trying to get used to using the front brake more.