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parallel twin and V twin

41K views 68 replies 37 participants last post by  Trumpettwins 
#1 ·
what are the advantages and disadvantages of a parallel twin versas a V twin or in this modern age isn"t there a big difference. I am trying to figure out which bike I would like to purchase. Back in late 60"s I owned a triumph 500 and 650, but have been away from bikes for quite a while.
 
#2 ·
pretty big difference. the v-twin has always developed power and torque down low in the rpm range. the parallel develops power with a few more rpms involved, and likes to spin higher. the new bonnies will run to 8,000 rpm if you like.
the v-twin has 1 cylinder behind the other, leading to a temp difference, the back one getting hotter, which has never really been addressed, in the air cooled version.
V-twins are typically, except for buell or ducatic, in a heavy cruiser type bike.
Parallels are in bonnies, thruxs, which handle a bit, and even the triumph cruiser line will out handle a harley, if you like that style. So we are a bit biased here, but we'll let you off the hook since you used to ride a trumpet.
G
 
#8 ·
pretty big difference. the v-twin has always developed power and torque down low in the rpm range. the parallel develops power with a few more rpms involved, and likes to spin higher. the new bonnies will run to 8,000 rpm if you like.
IMO, the actual cylinder configuration has little to do with HP/torque characteristics of the engine. I'd say the relation between bore and stoke has much bigger impact.

My Suzuki SV650 redlines at 11000 btw...
 
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#4 ·
I admit to loving the look of the triumph cruiser line, but not caring for the cruiser position, which, when I ride one, jolts my lower back on bumps, and because of the feet forward controls, cant get up on the pegs to avoid that.
when I see a bump coming on my bonneville, I get up on the pegs and dirt bike over it.
G
 
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#5 ·
help please !!

Hi , my mane is Les . I have had my thruxton for a year and love it . I just installed a new "off road" set of triumph pipes , and my bike start to seriousally "bag out" ay 4500 rpm .. Do I need to install larger jets ?
can you help find a digram for stock thruxton carbs , Have disasembeled mine . I live in a remote town in north west cacada , and have no access to machinics or manuals... thanks ,, les
 
#6 ·
twins

Geoff hasit down pretty well. Its looks , performance & handling. All better on the paralel twin. Better balance! Also FWD controls SUCK!! Ifyoudont hAVE the worldsbest shock under your but, your in trouble!! I have a bad back & I can as said "hike up" when a pothole or whATEVER comming . Not many parralel twins left now. In the old days Honda had the mkt there. Now its parralae tripples, 4's . HD look a likes V-twins
 
#7 · (Edited)
There are still a few parallel twins being made today. The list of gems includes the Triumph twins of course, the Suzuki GS500S and E, the Kwackers Versys, Ninja 250, 500, 650R and EN500 Vulcan, the BMW F800 series, the Honda CMX250 rebel and CB250 Nighthawk, the Chinese Qlink Legend 250, the Xtreme Sports Montana 250, and I'm sure I'm missing a few. The only advantages of the parallel twin is over the singles; they can be made with more cc's and made to run a little smoother due to the power pulses being smaller, other thant that not much advantages over the other configs.
 
#13 · (Edited)
Ducati twins have a few advantages such as the 90 degree L twin has good balance, plus the desmo's allow for pretty quick opening and closing of the valves.

If a harley twin revs any higher than a tractor it will shake itself to bits, it is more like two singles bolted together in an engineerd botch job rather than a real v-twin where the pistons actually work together to produce power rather than trying to sound like an iron potato!

We have forgotten to mention the boxer twins as well!

My description of the harley engine may sound a little harsh, but there is no other way I can describe it!

Talking of vibrating back and forth, I have seen alot of ladies riding the sportsters.
 
#53 ·
iron potato!

If a harley twin revs any higher than a tractor it will shake itself to bits, it is more like two singles bolted together in an engineerd botch job rather than a real v-twin where the pistons actually work together to produce power rather than trying to sound like an iron potato!

My description of the harley engine may sound a little harsh, but there is no other way I can describe it!
ROFLMAO!!!:ride:rofl:rofl:rofl:faceplant:laughhard
 
#14 ·
One thing not mentioned yet, Harleys (and not many/any others that I can think of) have a single pin crankshaft design which means that both rods connect to the crank in the same position, so the firing degrees are fixed by the layout of the cylinders, HD uses a 45 degree Vtwin which = 315 degree firing pattern (compared to our 360/270) which means there is a long pause for the crankshaft to turn around then 2 quick ignitions, hence the potato-potato sound. A HD vtwin really acts more like a big single cylinder motor than a true twin since the pulses are so close together, and it's also why some of them barely idle (when the owner has the idle set really low).

They were Harley's simple solution to how to add another cylinder to their single cylinder bikes, oh some 90 years ago. It's a very simple motor, a poor design, and it has been around forever and probably will be for another 100+ years. It sounds cool as hell!
 
#17 ·
One thing not mentioned yet, Harleys (and not many/any others that I can think of) have a single pin crankshaft design
One comes to mind, and I don't think Honda builds it any longer (not sure). It was a cruiser called the ACE, or American Classic Edition. Honda used the HD approach of having both rods on the same crank plane (doubt they used the HD fork and blade solution ... probably two pins side by side).

This gave the ACE the potato-potato sound, and I think it was at that time HD was about to go to court to see if they could copyright/patent the sound of their v twin engines. (I don't think that's motorcycle myth)

Bob
 
#16 ·
The legendary Phil Irving, Vincents's Chief Engineer, had this to say about V-Twins:

Phil Irving in "Motorcycle Engineering" said:
It is very little wider overall and not quite so tall as a single of half the capacity, and though it is much larger at cylinder-head height the extra inches can be accommodated in corners which are not normally fully occupied in a conventional frame. ... one way and another, the V-twin will provide a greater number of working cubic centimetres in less block bulk and with less weight than any other arrangement.
Rich
 
#19 ·
2006 Bonneville: 395cc (right cylinder removed)-4mm intakes, -3mm exhaust, super-restrictive air filter, AI re-installed, Mikuni BSR26, 25 pilot, 55 main, needle glued down, 1985 Ford Tempo GL exhaust, single shoe drum brake conversion front and rear, wheels and Cheng Shin tires from a 1977 Peugeot 103 moped, front and rear suspension removed, handlebars from a Bolens 250H roto-tiller, mirrors from a 1993 Ford Aeromax LTL9000, seat from a 1974 Komatsu D155A
Pictures?

Rich
 
#32 ·
after buying a new sportster well with 171 miles on it I call it new anyways just some of my thoughts on it.
1.is it faster than a T 100 no
2.does it handle better than a T 100 no

this will answer the questions that most of y'all are into.

for me..

with the rubber mounted engine it is a smooth bike not the rattler of days of old.the trany is very smooth and the gearing is set up with the torque the engine puts out.at 70-75 mph the mirrors are clear.

the brakes also have come along way on the sportster.they do work very well as I found out a few weeks back when a idiot try to take me out.

if you are the type that likes to findle and change things around there is a ton of parts out there to do just about anything.it is endless.
the first thing I changed was the seat and the org. seat while looked kool would kill you a$$ in a 200 mile run.next thing I am going to change out is the pipes but after the warranty expires in july.
gas mileage on my last run I got 56-57 MPG.thats was running 70-75 mph on the back roads here in the hill country.not bad my t-100 never got close to getting that.
my insurance went up $7.00 a year with progressive.when I changed over the gave me free roadside asst. if I ever needed it.

so if you see a blackcherry sporty and he waves to you here in cen tex it is me.

y'all have fun.
pete



 
#35 ·
after buying a new sportster well with 171 miles on it I call it new anyways just some of my thoughts on it.
1.is it faster than a T 100 no
2.does it handle better than a T 100 no
Which Sportster is it, the XL883? The XL1200R would be the best performing model in the Sportster range. Motorcyclistonline has a "Sportster vs Thruxton" comparism road test, and the erstwhile was slightly faster while latter handled better.
 
#36 ·
it is a 06 883 L.picked it up for $5,500.00.I bought it as I could ride it for a couple of years and sell it atleast what I paid for it.I think I am just going to keep it.I really like this one.
once the warranty is up it just might get a 1250 kit.with the close ratio gears on the 883 it would rip.
pete
 
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