Exhaust valve.

It seems that many new bikes are fitted with a flapper valve in the exhaust these days, Ducati being one. If you look back through the posts you will find that I took the exhaust valve motor out of my 848 and fitted a little box to fool the ECU into thinking that it was still fitted. Well I have another little box the same.

This picture shows the oil filter from a previous post but the exhaust valve gubbins is in the same area. The valve itself is under the triangular cover to the rear of the green circle, it is held on with three bolts. Just under the front of the green circle, the cable that runs to the motor, which is in the lower front of the fairing. is just showing, 

First thing that I did was to take a short video of the motor with the bike running to see when it was closing the valve.

This actually proves nothing apart from the fact that it is working. In my  view anything that is making a restriction in an exhaust system for no known reason is a waste of time, and does nothing for efficiency.

The motor and cable has been totally removed along with the brackets. This saves a bit of weight, not that I’ll ever notice while riding, and gets rid of that ugly cable hanging down. The valve itself is still in the exhaust but is wirelocked in the open position.

Time will tell if the modification has any effect on the way the bike runs, or on economy. It is very easy to reinstall everything if needed.

All that I need now is a spare exhaust box to see how easy it will be to cut open, remove the catalytic converter, and weld closed again. That is one modification that I know from experience makes the machine more economical and boosts mid range torque.


An 848 update

Folks will remember that I fitted the Lithium battery, not to save weight, but to see if they were all that they are cracked up to be. I still can’t feel the 3 kgs weight loss when riding the bike, but the battery is performing well. It cranks the engine quicker than the old battery did and has not needed any charging while the bike is idle in the garage.

The Worx exhaust is also working fine, it is a very pretty exhaust with little cut outs in the ends of the db killers. You will need to go back to that post to see the pictures. The exhaust is LOUD, but is a very pleasant sound. I fitted discs (old pennies beaten down to 30mm diameter) into the db killers to see if anything changed, it made no difference at all. With the Worx fitted the bike pulls a little stronger from lower revs, perhaps that is due to the lack of catalytic converters. The Worx is also quite a bit lighter than the original silencers.

There is also a post earlier about the exhaust valve motor eliminator. That is still fitted with no problems and I could not even say if that makes much difference any more, I have forgotten how it felt with the valve motor.

The headlight is fine as it is with the bi-xenon projector and HID in the right side and a H11 LED in a fixed Ducati projector (dip only) in the left. In normal daytime riding it looks like both lights are on and they look the same, but in the dark the LED adds nothing to the illumination of the road ahead. The next generation headlight with two HID bi-xenon’s is being built at the moment, but this one is going to be fitted with a relay and switch so that the headlights do not need to be on during the day and a pair of angel eyes will be fitted for daytime riding.

The Metzeler M7RR tyres are great and give confidence over every road surface, but the bike is such a peach to ride that I never expect it to frighten me. A great combination of tyre and bike then!

The back of the bike has the TST tail light and the LED indicators with LED brake light fitted to them. Everything is working fine with it as it is. I have not had time to fit the flash rate controller that I bought from ebay to see if it slows the indicator flash, but will do that over the next few weeks.

I have yet another video camera to add to the Gopros that I own, this one is called a Polaroid Cube Plus, and unlike the Gopros has built in image stabilisation produces better videos. The mounting options are also better. The cube also does time lapse so I made a little video of the bike on a windy day to test that function. Here it is:

Starter motor blues

The Ducati ST2 has been a strange starter since the day that I bought it. When the starter button was pressed there was a 1 to 2 second delay before anything happened at the starter motor. I had changed the battery on the bike from the almost new lead acid to a gel for other reasons and that had made no difference. I fitted a voltmeter to the bike to make sure that it was charging at all times and it was. The thing was that I did not trust it!

My wifes BMW F800ST was also playing up in that it was very sluggish to start despite a newish battery, and that would sometimes not start at all. Because of this she had started using the ST2 and found that she preferred it to the BMW. So the F800ST will be put up for sale.

While I had the BMW up on the ramp I removed the starter motor from the front of the engine, just two bolts and a power lead. On stripping it I found that the surface of the commutator (the copper bit where the brushes touch) was a bit black rather than copper coloured. A quick rub over with some very fine wet and dry, then a wipe with acetone to clean it had it looking like copper again. After refitting it (5 minute job) the bike sprang into life with a weak battery. It would probably now start on a watch battery!

That got me thinking about the ST2. The only problem is that the lower fairings have to come off, the left hand engine casing has to be removed and the flywheel has to come off just to remove the starter! Someone at Ducati needs a new job. I found that instead of all that work, I could get to the back of the starter from the right side of the bike and with the use of some bent 8mm spanners, I could remove the rear plate with the brushes on it. The commutator stays hanging on the bike, but there is enough room to clean it up in the same away as I had the BMW. It took quite a while to refit everything as it was not designed to come apart like that.

The ST2 was on the ramp, but I pressed the button anyway, I would not normally start a bike that is over a meter of the ground on a ramp, but it was just pure music. A mere touch of the button had the motor burbling away through the sweet sounding GPR exhausts. 30 seconds later my wife was at the garage door with a cup of tea for me and a huge smile at the sound of what has become her bike.

The sound of a Ducati

I am the owner of some Gopro video cameras which work great on my last bike, a BMW K100RS, a very heavy solid bike. I have made many videos of the local area and put some very nice French folk music on them as the sound track. The first attempts at mounting one of the Gopros on the front of the ST did not give very good results due to vibration and flimsy mountings. Last week I drilled a hole through the rear passenger hand hold which is made from aluminium and used a bolt into a Gopro tripod mount. Today I had the chance to test it with a visiting biker from the UK. I happened to pick up the Gopro that had the skeleton case on it so that the internal microphone caught all the Ducati noises from the GPR exhausts. Here is the video – enjoy.


The GPR sound

As it was a nice day today, and I have just about finished all the work on the 125 monkey bike, I thought that I should get the Ducati out for a few photos, Here is one that I put onto Facebook:

sidesmallThis shows the GPR exhausts finally fitted with the panniers. There is no interference now that the right side link pipe is bent slightly and enough hangers are used to keep the cans low.

DCIM999GOPROA wide angle picture taken with the Gopro camera.

There are a few things in this video that may interest other ST riders. The voltmeter is an LCD display wired to be on with the ignition. The daytime running light at the front is also always on with the ignition. The side/parking light is an LED but looks better than the camera shows. The front indicators have had the orange screens removed and have 21 watt orange bulbs instead of 10 watt white ones. The rear indicators are LED and the rack is cut down to look smarter – that might be silver instead of gold by next week. The swinging arms is painted high gloss metallic silver to match the bike. The Optimate battery charger lead is permanently wired to the battery. I also have a lead ending in a USB socket that can be attached to this for charging GPS, tablets, Gopro cameras, or the Sena SMH10 bike to bike intercoms that we use.

The sound of the GPR is not as good on a youtube video as it is in real life, and for the price that this is in Europe, (see earlier thread for ebay seller) it is great. You may notice the small dent in the left link pipe where I had to bend it to get it to fit, but that does not worry me. I have not fitted the GPR stickers as I do not like colours all over my bike.



GPR exhausts – 2

Now that I have had time to ride around and play with the exhausts I have found just one flaw with the design. As most ST owners know, the swinging arm is wider on the left side of the bike than it is on the right side, this is to accommodate the chain and sprocket.

GPR have done a fantastic job on the fabrication and welding of the parts, but do not seem to have realised that the two link pipes need to be different profiles. The right side is fine, but the left needs to be put under stress to get it to fit and still clear the swinging arm. The measurements that I have made were done without the pannier racks fitted and they would make the situation worse as they lower the end cans and will cause the cans to foul the swinging arm.



Here is the link pipe fitted to the bike and attached with the spring to the bikes headers, as can be seen, there is only 1 cm clearance without the end can fitted.

secondThis shows the view from the back. The end can will reduce this clearance to nothing!

thirdAs can be seen in this picture.

The solution is to have a different link pipe on the left hand side to the one on the right. Rather than trying to make complex bends in that pipe, the solution is to add 25 mm of length to the link where it attached to the header. That would bring the whole assembly outwards by 25mm as shown in the next picture.

fourth GPR are made in Italy and I thought that I should bring this problem to their attention, but they do not publish an email address so I will have to use their contact form on their website and give them a link (pun) to this post. In the mean time I will attempt to get a 25 mm piece of stainless steel and make an extension myself, I might be able to get a local welder to attach it but I am not sure yet.

I will keep the blog posted on any response from GPR, but at this time I would not recommend a GPR system for a Ducati ST.

Update on some things

Having ridden the bike for a few more miles now, I am even more pleased with the new exhausts. They look great, a nice shiny stainless steel instead of dull grey alloy. The sound is a smooth low pitched grumble that is not too intrusive for the rider and compliments the quiet Schubert C3 Pro helmet that I bought for my Christmas present a short while ago. I can also say that the bike seems to have a bit more grunt at lower speeds, it will now rumble along at around 3000 rpm when it needed another 500 rpm before the exhausts were fitted.

I filled up with fuel today and can report a fuel consumption of 46 miles per imperial gallon, (6.1 litres per 100kms) and that has involved loads of messing around like a lunatic. I was a bit disappointed to find that the fuel gauge is showing 2 bars and the light comes on with about 8 litres left in the tank, that is over a third of the 21 litre tank. I will have to see if I can find a way to adjust that so that the light comes on with around 3 to 4 litres left.

I was following an active discussion on lighting on the Ducati ST2 Facebook page over the last few days. The subject was headlights with one member trying to tell people that you could just fit an LED bulb to an existing headlight and have a good beam, I don’t believe it. The standard ST headlight has a projector unit inside it for the dip beam, this comes with a 55 watt halogen bulb fitted. Watts are a measure of power consumption and not light output. You can fit a HID xenon unit inside a projector, but should not use one in a normal reflector headlight due to the increased light output being harder to control and causing dazzle for oncoming drivers. HID xenon units consume 35 watts but give over twice the light output. The next generation of lighting is LED lighting, and you can buy LED bulbs to replace the halogens, but they will not give enough light to ride at night with. LEDs at the moment cannot be easily of cheaply retrofitted to existing bikes and need a reflector especially designed for the LED.  I have found that Hella make a 90mm LED unit in the style of a projector that is a dedicated LED unit. And this is it: https://www.rexbo.eu/hella/headlight-1al010820021?c=700243. You will see that with a price tag of €600 it is not simply a case of fitting any old LED bulb to any old headlight.

I am an aviator as well as a motorcyclist and so am very interested when I see people talking about reducing the weight of their bikes, but it is very easy, and expensive, to go too far. Saving weight will do nothing for the top speed but could improve acceleration, having said that I have never felt the need to accelerate as fast as the ST2 is capable of. The standard ST weighs in at around 215kgs. Compared to my BMW K100RS that is very light. I have a quantity of aircraft grade titanium bolts in my toolboxes that weigh about a third of what a steel bolt weighs and are super strong. If I were to change a whole handful on the bike I might be able to reduce the weight of the bike by half a kilo. If I then spend a sum of money that would be equal or more than the bikes value, I could make myself some nice carbon fibre fairing panels and save another kilo or so. In total I would have saved two kilos. That is 1% of the weight of the bike, or about 2 and a half litres of fuel, or the weight of the tolls that are under my seat, and would I feel the difference in the ride? Not a chance. If I rode with the tank nearly empty and without the tools under the seat I could save about 15 kilos, and if I ride naked 18 kilos, but I doubt if I would feel the difference then apart from freezing my nuts off! So the moral to this story is that if you thing the ST is too heavy and want a lighter bike then sell it and buy something else, you know it makes sense.