[samigo]

My NS has developed a disc problem just within 3 months of purchase. This is a serious quality issue with the product. Bought it from Krishna Bajaj @ Wanorie - Pune. I could feel the acceleration drag and the bike felt like 100 cc right from day 1. I had brought it to the notice of SA during 1st service. I could hear the disc squeal merely by pushing the bike to-and-fro. The SA told me that it would go away after the run-in period and now this mess.

Luckily, the disc jammed just half a KM from my house and I was riding at low speed. It could have been dangerous had I been at higher speed. There was a burning smell and smoke from the rear disc and the bike refused to move forward. Somehow I managed to pull it over to my house with the engine power :(. Today morning when I checked the bike it could move freely but I'm not taking chances. Have registered a complaint and Bajaj will be sending a pickup to service station tomorrow.

My question here is: What all should I take note of with the repair. Should I ask for complete disc unit replacement considering the risk with braking?

My problem is exactly the same as in this video.

https://www.youtube.com/watch?v=SVmSzoL_ht4

Thanks!

[a4anurag]

Originally Posted by samigo

My NS has developed a disc problem just within 3 months of purchase. This is a serious quality issue with the product. Bought it from Krishna Bajaj @ Wanorie - Pune. I could feel the acceleration drag and the bike felt like 100 cc right from day 1. I had brought it to the notice of SA during 1st service. I could hear the disc squeal merely by pushing the bike to-and-fro.

Get the piston checked as they might not be returning to position zero once brakes are released (pressure is released).

Ask for replacement of the brakes and do get the disc plates changed too.

Anurag.

[anjan_c2007]

Originally Posted by samigo

My NS has developed a disc problem just within 3 months of purchase. This is a serious quality issue with the product. Bought it from Krishna Bajaj @ Wanorie - Pune. I could feel the acceleration drag and the bike felt like 100 cc right from day 1. I had brought it to the notice of SA during 1st service. I could hear the disc squeal merely by pushing the bike to-and-fro. The SA told me that it would go away after the run-in period and now this mess.

Luckily, the disc jammed just half a KM from my house and I was riding at low speed. It could have been dangerous had I been at higher speed. There was a burning smell and smoke from the rear disc and the bike refused to move forward. Somehow I managed to pull it over to my house with the engine power :(. Today morning when I checked the bike it could move freely but I'm not taking chances. Have registered a complaint and Bajaj will be sending a pickup to service station tomorrow.

My question here is: What all should I take note of with the repair. Should I ask for complete disc unit replacement considering the risk with braking?

Thanks!

Sorry to read about the quality gremlin in your bike. Could have really been dangerous.

Apart from asking for a total replacement of the disc braking system at fault, you need to check up the engine and transmission. Especially the engine might have got overheated several times, due to the friction and the engine oil must have surely lost its rated viscosity and might have turned black. The engine compression needs to be checked as it is likely that due to the stress factor, the engine must have been prevented from its free and smooth revving and the revs must have been forcefully restrained. Please also get the transmission checked - the gears, clutch and the gear oil (may have metal tailings of gears mixed up but chances are less) for wear.

Its just like a car being driven with the handbrakes activated as some do so by mistake.

[sagarpadaki]

Looks like the caliper is jammed. Ask BASS to open the caliper and clean it and grease it. If it does not solve the issue then you will have to ask them to replace the caliper assembly.

Do not ride your bike in this condition . It will put undue stress on the transmission and engine

[Sankar]

1. Put the vehicle in main stand, put the gear in neutral.
   
2. Unbolt the caliper, like how its done to change brake pads.
   
3. Now try rotating the wheels. If its rotating smoothly then issue is with rear brake rotor/caliper.
   
4. Now with the caliper off when you rotate the wheel if its rotating freely just eyeball the brake rotor and check if its waving in and out? If yes then the problem is due to a warped rotor.
   
5. If wheel is rotating freely with caliper removed and there is no waviness of the rotor then issue might is with the caliper. The caliper piston may not be freely moving and thus not releasing pressure on the rotor.
   
6. If the rotor is steady and wheel is still tight with caliper off then check for excessive chain tension. If found too tight then loosen the chain according to the manual.
   
7. With caliper removed, with chain tension under spec and if the wheel is still tight then check wheel bearings and then the gearbox (but chances are low on a new bike for these to go bad).

PS: In the video it looks like the bike's got a warped rotor.

[4k_jz]

Originally Posted by Sankar

[list=1]
[*]Now with the caliper off when you rotate the wheel if its rotating freely just eyeball the brake rotor and check if its waving in and out? If yes then the problem is due to a warped rotor.


.

There might be a chance that the wheel/rotor is misaligned right from the day it came from the factory. It might have happened while loading/unloading the bike from the trailer. A wobbling rotor can be one the problem.
I had faced an issue of balancing on my week old Activa. It used to bend on the right side. On getting checked, the fork was bent( in a new vehicle!).
The 2-wheeler manufacturers in India have taken things for granted.

[samigo]

Originally Posted by Sankar

1. Put the vehicle in main stand, put the gear in neutral.
   
2. Unbolt the caliper, like how its done to change brake pads.
   
3. Now try rotating the wheels. If its rotating smoothly then issue is with rear brake rotor/caliper.
   
4. Now with the caliper off when you rotate the wheel if its rotating freely just eyeball the brake rotor and check if its waving in and out? If yes then the problem is due to a warped rotor.
   
5. If wheel is rotating freely with caliper removed and there is no waviness of the rotor then issue might is with the caliper. The caliper piston may not be freely moving and thus not releasing pressure on the rotor.
   
6. If the rotor is steady and wheel is still tight with caliper off then check for excessive chain tension. If found too tight then loosen the chain according to the manual.
   
7. With caliper removed, with chain tension under spec and if the wheel is still tight then check wheel bearings and then the gearbox (but chances are low on a new bike for these to go bad).

PS: In the video it looks like the bike's got a warped rotor.

Hi,

This is a new bike and under warranty so I'm bit hesitant on unscrewing the disc parts. Also, the NS 200 does not come with a factory fitted center stand. Have to get that fitted too as an accessory. Will go over to the service station with the bike and consider these inspection points with the mechanic there.

thanks

[a4anurag]

Originally Posted by samigo

This is a new bike and under warranty so I'm bit hesitant on unscrewing the disc parts. Also, the NS 200 does not come with a factory fitted center stand. Have to get that fitted too as an accessory. Will go over to the service station with the bike and consider these inspection points with the mechanic there.

thanks

Fair enough and I can understand. Do take it to ASC and do as suggested by Sankar. Pity on the QA from Bajaj for not checking before releasing it for the market.

Centre stand as an accessory?! WTH! Man, these guys are acting like Toyota. No features but priced high, don't know for what!

Update the thread as soon as you get an answer from Bajaj.

Anurag.

[ArizonaJim]

At this point, you are wise not to attempt to take anything apart.
Let the service mechanic do all of the work to avoid any warranty questions.

All of the posts above make good points. It could be due to a quality problem with any or all of the parts mentioned and if so, your warranty should cover all of the parts and labor needed to correct it.

One thing that was not mentioned which can cause the same issues is the brake fluid in the master cylinder was overfilled.

If the fluid level is filled completely to the top so that the rubber diaphragm is pushed against the lid the fluid will be under a slight pressure.
This can force the pistons in the caliper to exert a slight pressure on the brake pads causing them to rub lightly on the disk.
When the brakes are cold, this rubbing may not cause any noticeable drag so the motorcycle can be moved without a problem.

Riding the motorcycle and using the brakes will heat them up. This not only expands the disk and the pads but it will cause the brake fluid to expand.

With the master cylinder totally filled there is no place for the expanded fluid to go so it ends up applying more force to the brake pads and disk.
Of course, this results in the pads, disk and fluid getting hotter and expanding more so in a vicious cycle, the problem gets worse until the brakes totally lock up.

I've seen this happen with several brand new motorcycles in the past so it is not something new or found on only one brand.

The good thing about this is removing some of the excess brake fluid from the master cylinder will totally fix the problem in a matter of minutes.
Usually, none of the parts are damaged so there is no need to wait for the factory to send parts that the service center may not have on hand.

If this overfilling issue is the problem, I am not suggesting that the mechanic should not totally examine the brake caliper, pads and disk for damage. Each of these parts need to be looked at to verify that no damage was done and if a part was damaged it must be replaced, as I said, at no cost to you.

Good luck to you and your motorcycle.

Jim

[man_of_steel]

Originally Posted by ArizonaJim

If the fluid level is filled completely to the top so that the rubber diaphragm is pushed against the lid the fluid will be under a slight pressure.
This can force the pistons in the caliper to exert a slight pressure on the brake pads causing them to rub lightly on the disk.
When the brakes are cold, this rubbing may not cause any noticeable drag so the motorcycle can be moved without a problem.

Riding the motorcycle and using the brakes will heat them up. This not only expands the disk and the pads but it will cause the brake fluid to expand.

With the master cylinder totally filled there is no place for the expanded fluid to go so it ends up applying more force to the brake pads and disk.
Of course, this results in the pads, disk and fluid getting hotter and expanding more so in a vicious cycle, the problem gets worse until the brakes totally lock up.

Rightly pointed out by AJ. Was about to suggest this. I have heard about this happening with the new Royal Enfield Thunderbirds too.

[saket77]

I really hope that the engine & transmission have not been damaged during this fiasco. I am more so concerned because they are still running-in.
I am not hopeful that Bajaj will replace the entire bike or engine+transmission, but do not settle for anything less than a replaced disc brake assembly; including the disc.

Do keep us posted.

[Maverick1977]

Firstly I would like to know if this is your first bike equipped with a rear disc brake. You will realize why I am asking this question in this post itself. I too have the same bike for almost 1.5 years now and have faced a similar problem in the first few days of ownership.
I found a very simple solution to the problem. Ensure that the right foot is nowhere close to the foot brake. The issue here is that we keep a very light foot on the brake but when the bike is going through small undulations on the road, the right foot invariably presses the brake to some extent. Imagine this happening continuously and the rear brake heats up and gets jammed.
When I got this feedback from my SA I initially doubted his observation. He then made me take a ride for about 5 km and would shout out each time the tail light would come on. It was then I realized that it was not the bike but the biker which was the culprit. This happens especially if the previous bike had drum brakes at rear. That's why I asked the question in the beginning of my post.
Tell your SA to slightly reduce the bite of the rear discs so that there is some play initially in the brakes.
Let me know if the solution works.

[bikertillidie]

Samigo, I am glad that you are safe.

Based on my past experience as a 200 NS owner, Krishna Bajaj is pretty responsive and I am sure they will resolve the issue to your satisfaction.

Calipers usually exhibit a tendency to drag especially if they are ridden during the monsoons or if the bike is left idle, and can easily be rectified with caliper grease, cleaning of the brake pads & minor adjustments ..

For some reason, rear discs seem to be impacted more than the front end and plagues many bikes I know of.
I suspect, the rubber boots are allowing ingress of water/dust & other contaminants.

There could be other reasons as well.

Do let us know once the problem is rectified and I do hope you enjoy your ride for a long time to come. The 200 NS is a beautiful machine and is quite trouble free.

[saket77]

Originally Posted by Maverick1977

Tell your SA to slightly reduce the bite of the rear discs so that there is some play initially in the brakes.
Let me know if the solution works.

I am not sure if that can be done with disc brakes. However, if you keep jabbing the brake pedal/ lever continuously while accelerating or going downhill, then they will overheat for sure. However, few inadvertent applications should not. I feel that the jammed brake pistons are the culprit here. Though hard to tell without physical examination.

[samigo]

Thanks folks for some really informative inputs. The bike is back from repair. Krishna Bajaj was very responsive and sent for a pickup Monday morning. Unfortunately, due to tight office schedule, I couldn't go over to the SC. They did not replace the Disc unit as usually expected when you are not physically present there. The problem was identified as stone particles stuck between callipers which, fundamentally and from design perspective, does not sound convincing. They also increased the play of the foot brake lever which may also be the cause of heating of the disc. Peviously it was bit tighter and close to my foot.

The bike does feel freed up now. I have to now start increasing the miles on the speedo ,in mix road conditions, till it's in warranty.

Thanks!