Are harleys really that slow?

Every bike has is purpose, some you ride for thrills, some look good.

 

When I had my Sporster the other bikers called it 1/2 a harley and we called Jap bikes boat anchors and I had a boat anchor before I had my first harley. What matters the most your face in the wind or what your riding to get your face in the wind?

 

Well... my nose in the wind first... but I want what I am riding to last a long time too. I hear sporties dogged a lot. 1/2 a Harley, "Skirtsters", etc. But they have made some beast sporties. But what I am riding makes a huge difference. I would never buy a dual-sport unless I lived in the desert and used it mostly as a dirt bike. Would never buy a dual-sport, priod, over a street bike. So it does matter to an extent. But you're right... any bike is better than no bike. And the reason a biker rides should matter more than what he rides.

 

ive helped build some fast sporties run neck in neck with a v65 honda and a 1000j kawasaki . wich is pretty fast for a briggs and stratton

 

I'd like to have 6 months, about 3 or 4 Grand in Travelers Checks and a Honda GoldWing, ... so fully loaded that I wouldn't have any space left to bring-along any bad vibes or hang-up's.

I'd leave my house and ride to California.
Have a Doctor write me a prescription for 8 oz's of Hawaiian Sensimilla for chronically aching flat feet.
Get a Zig-zag Man tattoo.
Quit shaving.
Follow the Sun.
Scratch-off another line on my Bucket List.

See ya later.

 

You always make the most sense, rick!

Consider a 45 degree v-twin with forked connecting rods, so that they are pushing on the crankshaft only 45 degrees of rotation apart, so basically at the same time, but just far enough apart to be out of sync. I don't care about anything else; that is just a horrible, horrible engine design IMHO.

But only Harley makes those, and (as far as I know) all Harley's have those, it's what makes a Harley a Harley. Ergo, Harley has a bad engine design.

Any engine that has that much vibration but hits peak torque at ~2500 rpm and peak HP at ~3000 rpm, and redlines at ~5-6000 rpm just is a bad design. It's more important to look at the torque/hp graph. It looks like your 401(k) in the last half of 2008. Goes straight down. Seriously...look it up.

And that is the answer to the main premise to this post. The Harley engine is inherently flawed regarding performance, and is, in fact, slow. Look up performance parts for Harleys. For a lot of money and effort you can get your 1500+cc Harley to put out 128 hp. Or you can get a stock Triumph with well less than half the displacement that puts out about the same.

Go the the AMA drag racing site. Harley's need their own category, because the fastest ones can't beat the other bikes in the quarter mile, by 2 whole seconds. I couldn't believe it when I saw it. Harley requires it's own All Harley class just to keep up. It's like needing to separate men and women in Football. Harley ain't the mens class, either. Just in case you're wondering, it doesn't appear that there are any Harleys in the sub-5 second top fuel class.

I know lots of guys that are Harley fanatics. They won't even consider anything else, and I think that is similar to a lot of Harley riders. I have no doubt that if they took the name plate off the bikes, Harley wouldn't sell nearly as many units, and many of those Harley fanatics wouldn't find themselves riding a Harley.

Unless you are focused on how it sounds (IMO obnoxious). Or looks (IMO gaudy). Or you just don't care to take it past 3k rpm (IMO boring).

But others have different opinions and values. If I cared about those things, and I was the "buy American at all costs" type, and I worked to put out an image, then I might be interested in Harleys.

But I'm not.

 

i was visiting a friend recently who is a die-hard harley fanatic. i woke up early the next morning and was sipping coffee and perusing his service manual - and i will say it looks like it would be easier to do a complete engine overhaul on a harley - simply because the transmission is separate.

that said - i was dissapointed in the inner workings of the engine. I'd always assumed that the pushrods were driven off of cam lobes on the crank shaft. i.e. the crank shaft did double duty as a camshaft - this would make good sense to me as then there would be no cam chain to stretch.

unfortunately for my opinion of harley, i learned there not only is the crankshaft just a crankshaft and that there are 2 cams (i don't see why they couldn't use one). but one cam is driven via chain off the crank, and the other cam is driven by another chain connected to the first cam.

i can't think of a worse possible situation to be in - it seems to me that (at least part of) the reason these bikes can't rev very high is that the valve spring not only has to close the valve, but also has to push on the rocker arm and push rod. so the valves close more slowly = lower red line.

and, not only are you still dealing with the inherent problems of cam chains stretching, but you've got 2 different chains that can stretch differently. granted, they're shorter chains than what is in our overhead cam bikes, so the effects of stretch on timing should be, i think, less significant, but still - why have push rods if you're still going to have cams and chains anyway??

course, the biggest strike (for me) against harley is simply that for the price of a "cheap" introductory harley, i could buy 3 or 4 KLR650s or a dozen used XJ750's.

I will admit that I think the XR1200 looks to be fun as heck. although i can't for the life of me figure out why they put the voltage regulator right behind the front tire - seems like the worst possible place to put electronics.

edit: oh yeah - i forgot the main reason i posted in this thread: i wanted share my analogy. i tend to think of harleys as andre the giant, while [insert favorite better performing motorcycle here] is more like bruce lee. take that to mean what you will.

 

skeeter all harley evo motors 1200 and big bike use 1 camshaft gear driven the only motor that uses 2 is the harley twin cam

 

Hell ya! Well... unless you are a zx12... then you ARE Bruce Lee.
What i don't get is with dual overhead, 4 or 5 valve per cylinder technology, and the tech to water-cool the twins and the tech to really produce better output to displacement, why does Harley stick with push-rods?

 

i think that ALL v-twin motors lack power. not just harleys. harleys are 45, japs are 53 degrees i think it was.

i had an 86 v65 magna that couldn't keep up with harleys though. i don't know if the cam was worn out. due to the cam problems the magnas had. but i'm thinking in 86 the power was tweaked down. it's the only motor that didn't blow second gear. but the gear was also redesigned. i test rode an 84 and it beat the pants off that 86 i had.

i've been looking at a lot of the horses on the vtwin motors and they are all weak compared to what the 4 cylinder motors used to put out.

right now i have an 81 yama 650 maxim. it's a little on the weak side but it's been keeping up with the newer vtwin bikes.

 

I want to share a story that addresses another reason people own Harleys. Almost two years ago, when I first become interested in XJ bikes I started going by the area motorcycle shops to get information on bikes in general. There is a shop near me that sells and services Harleys and I got to know the owner and his employees, a great bunch of guys. One day I noticed a sudden influx of bikes for sale and I asked why, wasn’t there a recession going on? The owner said most of the bikes were there on commission via their owners. He then proceeded to explain that most of his customers had brought their Harleys as future investments relying upon the Harley Davidson “mystic” to push their value up; they never really intended to ride them. Even he called his customers “yuppies”. Most of the bikes sat for several months, their prices too high for any offers. What are the owner’s biggest sellers today? Scooters.

 

& now for my 1/2 cents worth...

My natural inclination is that Harley riders at least around here often are snobs which has nothing to do with the thread question. It does though cause me to see them with some skepticism. To wit: yesterday I was riding & extended my hand to wave hi to a pair of harley riders running together and both of them obviously & intentionally in perfect synchronization, turned their heads to the right to snub me as we passed each other. I've seen this same exact childish thing happen often enough and only from Harley riders, that I honestly find it hilarious.

OK so I have a basic disinterest in Harleys but then to be fair, what are the bike comparisons in terms of "slow". I found this marvelous website which has the stats of most major bikes ever made. Here's the link to the page on it for my xj650 Maxim (they don't have the YICS listed)
http://www.motorcyclespecs.co.za/model/ ... _maxim.htm You can find your bike du jour on this page.

However looking at the horsepower, my 650 has 71HP and most of the Harleys I looked are in the 50-60HP range and weigh far more than this XJ.

I'm really not into going so fast I loose my licence or pay big $ for fines & ^ my insurance rates... so top end really doesn't interest me any but I found it interesting that the 650 does the quarter in 12.6 seconds

As a side note, I found it interesting how similar in stats all the XJs seem to be including mileage & quarter times.

So as to the topic "Are harleys really that slow?", the statistics on that above link otter answer most of your questions on any of the bikes.

 

Buuuut

Torque wins races, horsepower sells stuff

XJs have 40-50ftlb of torque, Harleys have 80ftlb....


So no, Harleys aren't really that slow, if you mean slow in a straight line. Still a big air cooled Vtwin isn't good for much other than going straight, giving low end power and making noise.

 

It's not just the V-Twin design that causes a low max horsepower design in a Harley, it's that the two cylinders are in the same plane, and use the same crank pin. That forces the engine to be very uneven, especially at idle. Any engineer with half a brain could see that immediately without even running a dyno test. But Harley doesn't sell performance, folks.

Of course, that is also what causes the "potato potato" sound of the Harley engine. And truth be told, Harley engines do have MASSIVE torque output at only 2500 rpm. Imagine a 1500 cc single cylinder. It's not too far from that. I would imagine, though I don't know, that would make a Harley easy, if not fun, to ride.

If it wasn't vibrating like a fat guy was jumping up and down on your tank. My friends brand new Harley...I swear the fender moves 3 inches back and forth at idle. He doesn't see the problem, but I don't think he's ridden anything other than V-Twins. And I think I've heard that the vibration is even another selling point. I don't get it.

Other V-Twins use two crank pins to allow a better primary balance in the engine and also a broader torque curve. And unless I am mistaken, such a tight, 45 deg V is uncommon if not never found in metric cruisers. There's a reason for that.

Ducati doesn't have any valve springs, and their 90 degree V-Twin with a desmodronic valve system allows engine speeds in excess of 11,000 rpm. Speed times force equal power, and Ducatis make a bunch of power when those two big cylinders are firing 11000 times a minute. And they win races.

I took a Monster for a test drive awhile back. I couldn't stand the vibration, but it felt awesome going from 50 - 80 mph. I won't be buying one though.

I probably will never buy a V-Twin, but unfortunately that limits my bike selection to sport bikes (inline 4), Beemers (boxer twin), and Triumphs (inline 3). Don't like sport bikes , can't afford another BMW :lol: , saving up for the Triumph! (or dumping 8 g's into my XJ!, honestly haven't decided.)

That's my preference though. How I personally like engines to feel. Lots of people like the V-Twin for it's higher low rpm torque availability, and with the proper gearing they do make nice cruisers.

 

just go look at the quarter mile times.

They may have a ton of torque, but their fastest bike, a stock VRod doesn't post faster times than any competent competitor.

 

dawsoner...that is a very common, but misleading, perspective on the relationship between torque and horsepower.

There are more elaborate treatises on the internet, but my favorite HEREis down right now, but I can sum it up with this:

Unless you are looking at the dyno graph, the peak torque and HP numbers don't really mean that much, especially looking at two completely different engine designs.

Imagine two engines...engine 1 with 10 ft-lbs of force output except for at 2750-3000 rpm where it has 100 ft-lbs of force, and then redlines at 3250 rpm

engine 2 has 20 ft-lbs from 1000 to 10000 rpm.

Engine 1 will have a horsepower peak of 100*3000/5252 or 57 hp. And a torque peak of 100 ft-lbs.
Engine 2 will have a horsepower peak of 20*10000/5252, or 38 hp. And a peak torque of 20 ft-lbs.

Engine 2 looks like it has both a lower torque and a lower hp, but if you were to put them both on the quarter mile strip, engine 2, with TWICE the available torque, and therefore horsepower, at MOST rpm ranges, would smoke engine 1. Of course it would be a long, slow race!

Unless engine one had the GEARING to keep itself at 2750-3000 rpm at all times. Like a CVT or maybe just 20 gears.

Then you could maximize the output of that engine, and it would be faster.

In the real world, it's all about WHERE in the rpm range the peak torque is. A harley engine seriously peaks just above idle. And it falls dramatically after that.

It won't be winning any races, and you may notice harley only publishes their torque peak number. Their horsepower peak number has been calculated at about 55 hp, less than half of any other engine of a similar displacement.

So to prove that rule you stated is false...for Harley, torque sells, but doesn't win races!

 

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Hey! Don't forget the BMW K motors. Horizontal 4 cyl (originally 3 cyl). It's amazing how reasonably these bikes can be picked up in the used market. Smooth, comfortable, reasonable purchase price and long lived. Not unusual to get 200K + miles out of the engines. Parts prices? EXPENSIVE!!!

Loren

 

Are they 4 cyl? The ones I see appear to have two exhaust headers, but I haven't examined them that close.

 

here it is to prove it all, xj750 vs hardly 1200 watch in 720, much better
http://www.youtube.com/watch?v=xYAClrkJV6c


the 750 wins, but the guy driving it sucks at take off, if you watch his other vids... so i think it would have done even better

 

No, torque wins races, HP sells cars.

Enzo Ferrari said that.