Inline 4s

Ive just come back to V-twins from IL4's for the time being. I can honestly say I like both, if I had to choose one to have forever it would more than likely be the 4 that would take my fancy. I find that despite the torque gains of a V-twin it doesnt make up for the drop in power for similarly sized engines. I doubt my RSV would noticably out perform a modern 1000cc IL4 at any point in the rev range.

Thing is its not ultimately about the power really. Otherwise I'd still be bombing about in 6th gear on the Hayabusa and having enough power to do whatever I want. Its about how you enjoy it. My RSV doesnt encourage me to go bat**** mental into 3 figure speeds and when i want it to be it can be quite a refined lazy ride for commuting. Commuting on something like a 600cc IL4 whilst trying to overtake etc is something I have left behind me as I no longer want to play hide and seek through the gear box for quick useable on-tap power. I love the way my V-twin rumbles its way through the rev range, making a racket but not so shrill my ears are bleeding when I get to work. I also loved the way my 'busa would roll on at 100mph in 6th and pull harder than anything I had ever ridden.

The two are very different for me and I love both in almost equal measure. I dont think its possible to say which one is best, as 'best' is incredibly subjective to the rider. For some best appears to mean 'fastest', for others its grin factor. As long as you enjoy it then its like arguing over what kind of steak is the best.

Ive tried a few triples in my time and these are supposed to be a combo of the two major genres but I didnt really enjoy it. What does have my mouth watering is the prospect of a 180bhp RSV4, and I wonder if this could be the missing link. Will have to wait a few years until I can buy one though

Mate's dad has an RSV4 factory with the akropovic exhaust and one tooth less on front sprocket. Needless to say it goes like **** off a shovel.

Originally Posted by muffles

I hope you're all looking at the torque on that graph I posted, not the HP... remember, torque is the thing that's going to give you that shove. And it does tail away after about 8k.

Torque gets you moving when you open the throttle, and give you the forward shove, but whether or not power builds and gives you blistering acceleration and speed as you get revs towards the red line, or whether it "tails off" is all about how many horses the bike produces. You can't look at either in isolation, the nature of the engine's power delivery is a combination of the two.

[sauluk]

I like il4's, I like twins (L & v), I like triples, I like bikes

I only really got to like my D650 (IL4) when at Scoobs's prompting I discovered the midrange. I used to try it out on the road to Montgomery and wow it was just fantastic.

Depends what you're after in a bike I spose.

Originally Posted by muffles

torque is the thing that's going to give you that shove. And it does tail away after about 8k.

BTW, whether something "tail's away" on a dyno graph all depends on the vertical axis scale on the graph.

The SV produces 28 ftlb from 2500 revs, peaks at 47, and "tails off" to about 35.

Most of the IL4's produce 15ftlb at 3000 revs. Peak at about the same, and "tail off" at about 35 as well, albeit both at much higher revs

By comparison if you put the two on the same vertical axis scale, the SV would have a relatively flat torque curve, which is what makes it pull like a bigger bike lower down the rev range

[yorkie_chris]

Originally Posted by lukemillar

??
Why would you burble along at 3k?

I have said this before about all engine configurations, be it twins, triples or 4's- Don't get hung up on the tach numbers! You use an engine wherever it is happiest i.e not labouring or over-revving. The only people who get hung up are the V-twin owners who say:

"Well, I travel in 4th gear at 4k rpm and it is 40mph, but when I do the same on an IL4, it is gutless"

Nah... you cruise along at what feels like a comfortable rpm.

Get on either bike and shift to what feels reasonable to bimble at: say 40mph and the SV will pull better from there.

[Sid Squid]

I don't prefer either, but technically speaking fours are better then twins. Technically twins don't make better power at the low end, they just run out of the necessary piston/valve area and thus their volumetric efficiency falls significantly when the revs rise, add to this that for a given capacity a twin's relatively heavy reciprocating parts reach their practical limits at a lower rotational speed and the piston speed limit, (which I understand is about 90m/s for a road engine about now), of the relatively longer stroke limits the max safe revs - racing twins spin much faster as their much reduced engine life is not important.
The suggestion that you need to rev the round things off a four to make it go is just plain wrong, they often make good power at the bottom and keep going when twins run out of puff. And even if they didn't it's just numbers on a dial, who cares where the needle is pointing? Pit your SV650 against a Panther and it would seem revvy, would this be a reasonable criticism of your SV?

Originally Posted by yorkie_chris

Modern inline fours just don't have it.

You need to ride more Kawasakis - they definately have it, lots of it, that's not in question, what 'it' is is the question - and I'm not even going to try and explain what 'it' is - but lots of bikes have it, all different kinds and with all different sorts of engines. However a good example of what 'it' might be is best experienced from the seat of a Laverda triple, which is a big, heavy, hairy chested motorcycle that could best be described as visceral.

Someone was telling me just that the other day...

I think it's all swings and roundabouts. Until recently I had a twin, a triple and a four all of which I love/d in their own special way.

Cylinder snobbery is pants.

What about this? 48 cylinders anybody?