Wow, Nice...congrats on the purchase. Even I was considering the Duke when I went to pick my Ninja 3 months ago.

and now with you being a new Duke owner, I'm getting tempted...but I'll still be waiting for a few years before I switch from the Ninja

Thanx man. I am a relieved man now. Though I was till riding around before your clarification. The urge to ride is unstoppable really

That's not a fair comparision. You cannot compare the performance of a two stroke bike to a four stroke one.

In our bike, once the radiator liquid goes above a particular temperature (90 deg C, i think) the fans turn on (this happens more often in city traffic). The hot air blown by the radiator fans is what causes us discomfort.
Air flow at highway speeds is certainly better and helps cool the radiator liquid. Hence, the fans rarely come on at highway speeds.

Hope that clears your doubts.

PS: We are bordering on OT. Happy to discuss further over PMs/VMs.

These are considered Off Topic ? Hmmm... since some of the Duke owners, people like me, are relatively new to this kind of High powered bike and are novices when it comes to technology, every bit of information shared is useful for us

Apart from this thread, I follow probably the Accessories thread, not regularly though. So information / knowledge shared will always be useful

To answer your question here, this is not a restriction that a 25+bhp machine cannot be air cooled. You see the REs are over 350 and 500cc, I'm pretty sure they would be over 25bhp. But you see these engines are not as stressed as the duke, R15 etc.

So when engineers develop engines, they need to ensure that stressed engines, like the ones I mentioned above do not get heated up and cause threat to reliability of the engine. Thus then the stress on the engine goes above a certain level the development team needs to setup ways of reducing the stress. And cooler engines work better than hot ones.

But this is not valid for all engines you see. There is no one parameter you can pick and say whether the engine is stressed or not. the R15 being a 150cc and 17bhp needs to be liquid cooled to maintain reliability. while the Apache RTR 180cc producing similar power is not as stressed as the R15, so it does not require to be liquid cooled. Not at the moment at least.

There are a lot of big displacement bikes that are air cooled. For e.g. all the Harley Davidsons are air cooled. The thing with those bikes is that they are designed to be ridden at highway speeds, thus, air cooling will be sufficient. But, with a small engine developing a lot of power, the heat output from the engine will be high. In addition to that, city driving conditions do not offer long distance speed runs, so, to keep engine temperatures in check, liquid cooling is the only solution.

Now, coming to the Duke. The coolant starts circulating in the circuit when the temperature reaches 88 deg. C, at this point the coolant is passing through the radiator and is being cooled by the flow of air over the radiator fins, caused only due to the motion of the bike. At 93 deg. C, the radiator fan switches on to aid the cooling of the coolant. It switches off when the temperature again reaches 88 deg. C. That is why you might have noticed that hot air is felt on the legs from time to time and not constantly.
From my experience as an automobile engineer, I can say that, this is perfectly normal behaviour for the bike. Such high amount of heat output is a characteristic of high performance motorcycles because use an over square square engine.

A liquid cooled engine also benefits from a uniform power output and moreover a even temperature operation. A air cooled engine is bound to have certain parts that run hotter than the others. Moreover for constant high rpm operation, an air cooled engine will be stressed more than a liquid cooled engine, affecting its durability directly.

The duke's 200 cc engine can run at 10,000 rpm in 6th. I would not risk doing that in a RE in 5th gear at say constant 6000 rpm or higher. And the engines have vastly different designs, bore/stroke, displacements as well.

Thanks to an a***ole who decided to stop right in the middle of a junction, I skidded and fell on my 10 day old Duke

Looks like the left mud guard is slightly bent and the left mirror is shattered. Other than that looks ok to me. Planning to take it to the service center tomorrow. Any specific things I should get checked?!

Do share your highway experience here...

I am not sure whether it's possible for anyone to list all the posts discussed here about issues/observations on Duke. I would politely request you to take your time and go through the Thread to know anything and everything about the Bike. People who contributed in this thread added so much info, discussed so much aspects and replied to so much queries its the least any Duke owner should do.
BTW why 'possibly by the end of this month'?? I was under the impression that if payment is cleared there is no or very few days of waiting time for Duke.

It's not correct to calculate mileage by reserve to reserve method(you can see that even when you see the low fuel indicator first time, move/shake the bike a little and that indicator will go). Best thing to do is to follow Tankful to Tankful method. Fill the tank completely or upto a mark you can see and distinguish, then ride for some 200 - 300 Kms and then fill the tank again upto the same mark/or completely. Now check the amount of fuel and divide the distance travelled by this amount. Try this method and post your results.

It's a plessure that you joined this thread. Do post your experience(in detail obviously ) soon.

I was going to explain this query but you have already done it nicely.

BTW not all REs produce power over 25 bhp. The 350 cc REs produce around 19.8 bhp at 5250 rpm and 500 cc REs produce 27.2 bhp at 5250 rpm. So, much less power is produced at even lesser rpms. That's why whether they are ridden in city or highway they always feel less stressed and so no need of liquid cooling. That makes them a good choice from touring points of view.

Nicely explained. Indeed REs are never a high rpm machine. IMO they are built for 4000 - 6000 rpm band.


Sorry to hear that buddy. However, it's good that you are OK. It seems that you are referring to the left part of the leg guard not mud guard?? Right? If that is the only thing damaged, then it's not a big deal. Also do check for any oil/engine oil/coolant leakage, front fork and rim damage, clutch lever bent issues throughly. Also check for any visible scratches and radiator fin bent/damage. Hope you do not get any of them.


A little piece of advice(surely not a Gyaan) - Though it's a very good bike in terms of handling and braking, try to spend more time with the Bike to know it's characteristics better. Then you'll feel more comfortable with the Bike and do keep a safe distance always.

Oops. Yes I meant leg guard
Thanks for all that buddy. Hopefully there aren't any more problems other than the leg guard. Will go get it checked today. Thank you.

And you're right. I need to get a better handle on it surely.

@AnupamOnWheels

" It's not correct to calculate mileage by reserve to reserve method(you can see that even when you see the low fuel indicator first time, move/shake the bike a little and that indicator will go). Best thing to do is to follow Tankful to Tankful method. Fill the tank completely or upto a mark you can see and distinguish, then ride for some 200 - 300 Kms and then fill the tank again upto the same mark/or completely. Now check the amount of fuel and divide the distance travelled by this amount. Try this method and post your results. "


u mean i need to ride until the bike stops and then again fill it till the brim ?
but i was said not to run the bike when low fuel light sign pops up !

.

ok il update u guys with my highway experience ,
my plan got postponed to the weekend

il post after that

Problem on the Duke is that if you tank it up to the brim, then there are a lot of petrol fumes that emanate from the fuel filler. This causes a lot of wastage of petrol.

Better option would be to wait till you hit reserve , start your trip meter when you do. Tank up a fixed amount - say 5 litres, and then measure till you hit reserve again.

Not been able to put in more than 7-7.5 litres of fuel once the bike hits reserve, and still the fuel fumes are a bother for the first 20-30 kms.

Stalling issue

Hi,

Thanks man, I ordered it years ago from http://dogtagsonline.com/ Thought it looks better as a Duke keychain than it did on my neck. I think it was $6 for a set delivered from US.


I would like to let everyone know that the stalling issue with my Duke has been resolved. The problem was fuel related. Yesterday I emptied the tank to a low level and moved to a different fuel station. The bike does not stall like it did earlier. I also reved it hard as it has now completed 1100 Kms. Hope this will help someone else.

heating engine

i think the engine designer should have also design fins around the outer jacket of engine, which might help in reducing stress over engine and even if there is any miss hap and radiator get damage, the bike might manage to coverup distances at low speed.

please correct,....

^^ that would be against the concept of a liquid cooled engine then right? The additional weight of the cooling fins would be unnecessary.

yes in the event of a crash, the bike will be un usable if the radiator or the cooling system leaks. However the performance benefits are what the liquid cooling is for.