Royal Enfield Thunderbird 500

Did anyone else face rear brake failing on the move ?
I faced this issue twice recently.
When you're riding the bike and when you apply the rear brake, it goes all the way down as if nothing is attached to it and it doesn't stop the bike. It is as if the disk brake fluid pipe is removed from the brake lever.
Yesterday i was riding in a ghat enjoying the curves, when i approached one of the curve, which was a bit steep, i wanted to slow down and down shift, but brake stopped working suddenly i had to manage with front brake and engine braking luckily i got saved.
This is scarier than it looks like.
Same thing happened in another ride before yesterday as well.
The brake becomes normal after waiting for a few minutes and keep pumping the brake.
The mechanic said it's the problem with the pump attached to the brake.
I was riding in rain both the times.
Anyone faced the same issue or what could be the issue ?
Mine is a 2015 model Thunderbird 500

Re: Royal Enfield Thunderbird 500

Where all the experts at ?

Re: Royal Enfield Thunderbird 500

This issue happens when the Air is trapped in the hydraulic brake lines, To fix this issue bleed the brake fluid by a proper local mechanic.

Re: Royal Enfield Thunderbird 500

This happens due to the continuous usage of he rear brake on the downhill. Break oil gets hotter looses its properties.
After waiting for some time it comes back to normal temp, and it regains its properties.

Try DOT 4 or 5 break oil and use engine breaking.

Regards
Mandar

Re: Royal Enfield Thunderbird 500

I do engine braking, that's what saved me.
If you don't mind can you explain how it affects when it gets hot?
How can it become as if there is no oil inside the brake pipe when the oil gets hot?

Re: Royal Enfield Thunderbird 500

I mean use engine braking instead of rear brake on turns, use rear brake in case where it is really required
regarding, fading the rear brake just google it, there are many help available.

Check this out

Re: Royal Enfield Thunderbird 500

I DO use engine braking [emoji1] Alot.

Re: Royal Enfield Thunderbird 500


When you say Jerking, Did you mean like the engine jerks as if its about to Stall? Does this happen even in gear and in motion as well as in idling?
or did you mean like the engine knocks and gives jerks while Not in idle and while in gear and in motion? (if yes, then does it happen in any gear or only in top gears?)

How does the tacho respond at this time ?

Re: Royal Enfield Thunderbird 500

Yes engine jerks and stalls if clutch is not pulled and needs some throttle input. On highway I felt negligible lag (guess due to warmed up engine). During idling RPM drops especially when engine is cold. At present idling is set at 900rpm if its set to 1100-1200rpm too much of vibrations. I presume this issue is related to faulty auto decompression lever spring I'll get it checked during next service. Tik Tik noise is too much when engine is cold.

Auto decompression spring

Re: Royal Enfield Thunderbird 500

You really should not worry too much about the tappet noise. It will come back no matter what you do to fix it.

If it was automatically decompressing the engine will die and you will have to restart. Do check it nevertheless. The auto decomp does not activate above 600 rpm btw in normal operation.

By the looks of your description the jerks sounds like a broken/worn ot drive chain. If it is too loose or too tight you are up for a kick. Check if the slack is perfect as recommended. Check for worn out links or hooked sprocket.

Clutch slip can also give jerks. Don't think you have checked your clutch plates. Sometime clutch slippage also occurs due to the engine oil being not of recommended grade.

Can be a fuel pump issue where the EFI and fuel pump is not in sync. It can also be the throttle position sensor sending wrong signals to ECU. You can simply flash the ECU/EFI and check for starters. Its free!

Also you said it's more when fuel is low. I.e. I would expect close to reserve, in that case water can cause this problem. However since you said you cleaned everything I guess we can rule this one out.

Lastly check for plugs in the engine breather tube. Should not be connected to the issue but check it.

Mind you don't go for the most expensive repairs as the mechanic may suggest. Start with the simplest solutions and work your way up. Do keep us updated.

Re: Royal Enfield Thunderbird 500


Thanks for the inputs, clutch plates and sprockets were checked during service they were in good shape. Chain and clutch cable were replaced as they had become hard. ECU mapping was done at RE service center. I'm not sure regarding ot drive chain and TPS I'll confirm with my mechanic friend regarding these.

Re: Royal Enfield Thunderbird 500

Anyone using the michelin sirac 110/90 18 tyre on their bikes. I due for a tyre change and am concerned how the downsizing will affect the ride and handling

Re: Royal Enfield Thunderbird 500

Recently my friend changed his Standard 500 rear tyre with RALCO SPEED BLASTER 120/80 he gave a positive feedback after couple of long rides.

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I serviced my bike couple of days back and after a short ride of 20 kms I feel the jerking issue is resolved, I'll post my feedback as I much more miles.
I was informed to below parts were replaced to fix the issue,
Auto decompression lever and the spring (we dont get new spring as RE doesnt provide part number for the same) my mechanic replaced it with a spare lever and spring which was available with him.


Any suggestions for good chain brand for Thunderbird 500, stock chain lasted for ~2500Kms I had replaced it in my previous service need to repeat the same this time, but my mechanic informed O-ring beading is of better quality in replaced one to believe his words I need to much more miles and check. I dont want to burn a hole in my pocket every service replacing the chain.

Re: Royal Enfield Thunderbird 500

Does anyone know how much it costs for the LED tail lamp ?



Mine stopped working.

Re: Royal Enfield Thunderbird 500

It costs around Rs-2080 -/ .

If none of the led rings illuminating then first check for any wiring issue before investing for the new unit.