Dry Sump

[Treachery]

Okay, with the exception of Jezer, who I hope will chime in here, none of us have the bike yet. Was looking through a blurb I got from the dealer and noticed that the 390 engine is a dry sump design. I suspect that it's different from old Triumphs and all Harleys that have a separate oil tank/reservoir. I had an Aprilia Mille that I believe was dry sump, and what that really meant (to me) was that all the oil was in circulation when the engine was running, with a 100% scavenging pump, as opposed to falling to the sump to be picked up from a (sloshing) reservoir. I suspect that the 390 works like that. Can anyone with other KTM experience (and/or Dr. Jezer) enlighten me? BTW, on the Aprilia, there was an oil sight tube that was used to check oil level. How does it work on this one?

Many thanks!

 

[guzz46]

Dry sump? the KTM website says its a wet sump.

 

[Treachery]

Well, I sees the contradiction: That's 'zackly what the KTM USA website says. OTOH, the KTM dealer release bulletin in my fat little hands says "dry sump lubricaton with crankcase evacuation." It's one or the other...

 

[guzz46]

That's not the only contradiction, on the RC launch video they said the RC weighs 166kg wet, the owners manual I downloaded said the RC weighs 152.5kg without fuel, and the KTm website said the RC weighs 147kg dry, so what's the real weight I wonder?

 

[Treachery]

Yeah, that's a pretty wide range. 166 kg is 366 pounds, higher than any published weight I've seen.

 

[Texas250]

I thought dry was without any fluids, ie. oil, brake, gas. Wet was with fluids and gas, and curb was the actual weight. You know the only way to know for sure is for someone to put it on a scale. Car and Driver curb weights rarely match what the manufacturer says a car is supposed to weigh.

 

[Treachery]

You're right, discussion of bike or car weight is a mess. My understanding is that "dry" is as you say, nada. Most publications define "wet" as "ready to ride," not uncommonly with a half tank of fuel. The "without fuel" seems to be an in-between measure.

 

[ToraTora]

All three numbers are probably correct. Dry would be with no fluids. Without gas would be with oils, and coolant, and wet would be with all fluids including fuel.

 

[guzz46]

I don't think so, the numbers don't add up, engine oil capacity is 1.6 litres, coolant is 1.1 litres, fork oil is just under 500ml, and brake fluid would be almost insignificant, so roughly 1.6kg + 1.1 kg + lets round up the fork oil to 1kg (in case 500ml is for one leg) = 3.7kg, 3.7 + 147kg = 150.7kg, (I don't think I've forgotten any other fluids) and if we add 10 litres of fuel (which apparently weighs 7.3kg) = 158kg fully wet.

And if you google "RC 390 wet weight" you get 154.2kg.

 

[Treachery]

You did the same math that I did. Absent some serious Austrian fibbage on the dry weight, no way it's 160+ wet.

 

[Gryphon12]

Dry weight used to be quoted without a battery as well. I don't know what KTM is doing these days, but the battery weight might be excluded in dry weight figures.

 

[guzz46]

That could be it, I don't know what battery they're using but I'm guessing it could weigh about 6kg or so, that would bring to around about the 166kg mark, give or take.

A quick google gave me this from Wikipedia:

"The dry weight of a motorcycle excludes some or all of the following: gasoline (or other fuel), engine oil, coolant, brake fluid, or battery.There is no standardized way to test the dry weight of a motorcycle. Inconsistencies will almost always be found between a motorcycle manufacturer's published dry weight and motorcycle press and media outlet's published dry weight. This is due to different testing techniques, differences in what is being excluded, and a lack of defining how testing was conducted by the organization doing the testing."

If only there was a standard.

 

[Treachery]

Huh, I hadn't thought of the battery, but that would make up the difference.

 

[guzz46]

Well it turns out that the RC's battery is an Exide ETZ-9-BS, which apparently weighs 2.3kg without acid, and about 3kg with acid, so the numbers still don't add up to 166kg wet, that number must be a mistake, the official dry weight is 147kg, and the manual says 152.5kg without fuel, so I'm guessing that the 147kg dry weight is without fuel, fluids, and battery, and 152.5kg without fuel is obviously without fuel but includes fluids and battery, because 147kg + 3kg for the battery, leaves about 2.5kg for fluids, then add 10 liters of fuel which weighs about about 7.3kg equals a wet weight of 160kg.
Minus about 2.2kg if you remove the rear pegs and use the R&G tail tidy, If you really wanted to you could save about another 2kg by using a Lithium battery.

 

[VAG944]

.........and getting rid of the ABS system would save (I think I heard 2kg) a bit more precious weight!!

 

[Treachery]

I'd rather save the 2kg on the battery and keep the ABS. The first generation BMW ABS was 30 pounds.

 

[guzz46]

I wondered about the ABS, but I imagine it would be very tricky to remove and could possible void your warranty?

 

[Treachery]

Warranty for sure. As to the plumbing, I'd guess you'd have to bypass the pump(s). Probably more trouble than the weight savings would justify.

 

[kalleh]

Warranty for sure. As to the plumbing, I'd guess you'd have to bypass the pump(s). Probably more trouble than the weight savings would justify.

Hope ABS can at least be permanently set to off though - on my Daytona it's always a bummer to exit the hot pits just to realize that I forgot to turn the ABS to track mode (it's a pretty big difference in feel in the last 20%).

 

[guzz46]

Currently you can't, it always defaults to being on, apparently KTM do a dongle that permantly disables ABS, I don't know if it works on the RC though, I asked my dealer about it and he advised me to wait as KTM may release a new ECU/software upgrade in the future that will keep ABS off permanently, they did that on some other bike apparently.