[Gethu300]

After my first service, felt that rear braking isn't that great, any cleaning out of air is required or some other issues.
Service person informed that's the max possible and I haven't experience riding any other new ninja 300.
Bike is month old.
Any one please reply.

 

[jkv45]

You may need to make an adjustment to the brake lever if the travel is too much.

Rear brake usage should always be secondary. The front is the doing all the work when it really matters.

The rear brake needs to work properly, but shouldn't be relied on to slow the cycle. The faster you go, the less effective it is - which is the exact opposite of what you need.

 

[Gethu300]

Yes, that's what is happening. As new to Superbikes, needed to confirm it from experienced riders.
Thanks.

 

[IronWarrior]

The rear disk on the N300 is about 75% the size of the front brake.
When braking, the momentum of the bike tends to shift more weight onto the front wheel. This means the front tire will have more grip, and the rear tire less grip (since friction force is proportional to normal force). In general, this difference is larger on a "sport" bike than a cruiser due to geometry. Rear brakes are intentionally designed to be weaker than front brakes for this reason.
That doesn't mean that yours is definitely working fine, just that noticing a weaker rear brake doesn't always mean something is wrong either.

To put it in another perspective, let's assume the weight is pretty evenly distributed between front and rear wheels when stationary (CofG halfway between wheels).
Now consider the "stoppie" where you brake so aggressively, the back tire comes off the ground. It's pretty clear that no amount of rear brake pressure is going to have any effect on stopping.
Any brake application between these two cases is going to shift the weight (and therefore available friction force with the ground) to the front tire. The harder you brake, the less effective the rear brake becomes, and the more effective the front brake becomes. Also, this reduction in friction force means the rear wheel is more likely to lock up, since it has less grip on the ground.
Typical values for braking bias under "normal" conditions suggest between 70%-80% of your braking is from the front wheel.

 

[jkv45]

Yes, that's what is happening. As new to Superbikes, needed to confirm it from experienced riders.
Thanks.

The Ninja 300 could be considered a "Sportbike" - but not a "Superbike".

 

[Topaz]

deleted

 

[MAL]

I am probably doing this wrong...
...but on occasion I've caught myself not using the front brake at all or only at the very end; I'd slow down using the 'engine brake' from downshifting and my right hand is used for throttle control for the downshifts. The slowing is aided ever so SLIGHTLY with the rear brake. Then at the very end I use the front brake to come to complete stop; or sometimes not at all, if it's a slowing down for a turn.

The rear brakes might not be doing most of the braking on hard deceleration, but I use them just as often (if not more) than the front brakes, and they should work at 100% of their intended capacity, in my view.

It's this line by OP that has me slightly concerned: "After my first service, felt that rear braking isn't that great..."
Does that mean before the first service the brakes felt different?
I suggest OP gets a second opinion, maybe from someone familiar with the Ninja 300, just to make sure the rear brakes are okay.

 

[IronWarrior]

I am probably doing this wrong...
...but on occasion I've caught myself not using the front brake at all or only at the very end; I'd slow down using the 'engine brake' from downshifting and my right hand is used for throttle control for the downshifts. The slowing is aided ever so SLIGHTLY with the rear brake. Then at the very end I use the front brake to come to complete stop; or sometimes not at all, if it's a slowing down for a turn.

The rear brakes might not be doing most of the braking on hard deceleration, but I use them just as often (if not more) than the front brakes, and they should work at 100% of their intended capacity, in my view.

The way you're braking should be totally fine. Really, any way you want to brake that gets you stopped in a sufficient distance is "fine" whether it's best-practice or not. Obviously, if you had to stop more suddenly, relying on the rear only isn't going to cut it.
A common misconception with the 70%-80% coming from the front brake is that you only apply 20%-30% of the rear brake. This isn't what the bias means. What the 70%-80% means is that if you are using both brakes to their fullest capacity (100% of available braking for each wheel) under "normal" braking the front brake is doing most of the work. As a result, the rear brake can be designed to be "weaker" without affecting braking performance.

 

[jkv45]

The way you're braking should be totally fine. Really, any way you want to brake that gets you stopped in a sufficient distance is "fine" whether it's best-practice or not. Obviously, if you had to stop more suddenly, relying on the rear only isn't going to cut it.
A common misconception with the 70%-80% coming from the front brake is that you only apply 20%-30% of the rear brake. This isn't what the bias means. What the 70%-80% means is that if you are using both brakes to their fullest capacity (100% of available braking for each wheel) under "normal" braking the front brake is doing most of the work. As a result, the rear brake can be designed to be "weaker" without affecting braking performance.

At 100% of the braking available from your front brake, and the accompanying weight transfer, the rear wheel is going to be barely skimming the pavement - making the rear brake barely effective and almost certainly locked unless you are able to modulate it precisely.

Concentrate on learning how to really crank on the front brake. Keep it simple. Focus on one thing. It's all you need when the SHTF.

What seems to be working fine at low speeds doesn't work the same as speeds and forces increase.

 

[IronWarrior]

At 100% of the braking available from your front brake, and the accompanying weight transfer, the rear wheel is going to be barely skimming the pavement - making the rear brake barely effective and almost certainly locked unless you are able to modulate it precisely.

Concentrate on learning how to really crank on the front brake. Keep it simple. Focus on one thing. It's all you need when the SHTF.

What seems to be working fine at low speeds doesn't work the same as speeds and forces increase.

In most road riding cases, you'll lock the front wheel before you lift the rear, especially with the relatively low CofG of the Ninja 300. Tall bikes with a short wheelbase are going to have more of this problem.
But yes, the more you brake, the less effective the rear becomes. This is why you absolutely need to use the front brake if you need to stop abruptly. Gradual slowing, even to a full stop is fine with rear only, but may develop bad habits and not use the front brake well when you need it. As they say, practice makes permanent.

The fact the rear brake is less effective and more prone to locking when braking more aggressively is precisely why the rear brake is "weaker" by design.