St1300 design specifics

[CheeseWheel]

So I’ve been super curious about Hondas choice of design on the St1300. I adore the V4 and the power delivery (other than that hiccup at low speed, which I would love to solve) but I’ve always wondered why they chose to do a 360 degree separation crank angle. They essentially strapped two 90 degree V-twins together, which is why it needs the balance shafts. The VFR doesn’t have the same balance shafts or crank angle. Anybody know why Honda chose this crank layout? I don’t dislike it, just curious.

 

[Obo]

Perhaps because they didn't have to reinvent the wheel much from the st1100?

 

[Al st1100]

VFR and ST1300 are both 90 degree v4

 

[dduelin]

VFR and ST1300 are both 90 degree v4

Yes correct (VFR 750/800 anyway) but what he’s saying the VFR has a 180 degree crank and the STs have a 360 degree crank. I do not know why Honda chose one or the other but the ST1100 did not evolve from the VF series V4s, Honda’s first production V4s which all had 360 cranks. The VFR750F came out of the box with a 180 crank and the ST1100 with a 360 crank.

 

[CheeseWheel]

Yes correct (VFR 750/800 anyway) but what he’s saying the VFR has a 180 degree crank and the STs have a 360 degree crank. I do not know why Honda chose one or the other but the ST1100 did not evolve from the VF series V4s, Honda’s first production V4s which all had 360 cranks. The VFR750F came out of the box with a 180 crank and the ST1100 with a 360 crank.

Yeah I didn’t realize the 1100 was basically just a smaller 1300, I thought Honda redesigned it completely. Mainly thought that since Honda made the concept to have a V6, (woulda been sick!) so I assumed they were designing a new engine all together. But I’m so curious what made them choose that path.

 

[Firstpeke]

Could have been even more interesting if they had stuck two CX500 or 650 engines into a V4.... the 500 was an 83 degree v twin and I have no memory of the crank part of that design, I just know it worked!
Maybe two NT650 or 700 engines for an across the frame V4?
Not sure that Honda ever take an easy route in design.....

 

[motornut]

The VFR engine is mounted with the crankshaft horizontal to the frame so any rotational torque is not noticeable to the rider. With the crank in line with the frame when the throttle is goosed the torque causes the bike to want to tip to the side.
If you test drive the BMW it will rock to the side when the throttle is blipped, on the ST that is corrected with the balance shafts as well as smoothing the internal vibration.
My theory anyway.

 

[dduelin]

Yeah I didn’t realize the 1100 was basically just a smaller 1300, I thought Honda redesigned it completely. Mainly thought that since Honda made the concept to have a V6, (woulda been sick!) so I assumed they were designing a new engine all together. But I’m so curious what made them choose that path.

It might be more accurate that the STs are cousins more than siblings. True they share basic V4 architecture but the 1300 was much more than a do over of the 1100. The new dual counter balance shafts, the move to a cam chain rather than a belt and fuel injection to meet Euro 3 emissions required a clean sheet of paper. Moving the engine forward and down meant an entirely new frame was required. Better brakes, sharper handling, modern cartridge forks, cast aluminum swing arm. Of course it wasn’t all beer and skittles with the new bike. The 1300 has been dogged by questions of stability since the public release and the UK Coroner’s Report after a fatal authority bike accident knocked the bloom off the rose. Then there is linked brakes…..

 

[dduelin]

The VFR engine is mounted with the crankshaft horizontal to the frame so any rotational torque is not noticeable to the rider. With the crank in line with the frame when the throttle is goosed the torque causes the bike to want to tip to the side.
If you test drive the BMW it will rock to the side when the throttle is blipped, on the ST that is corrected with the balance shafts as well as smoothing the internal vibration.
My theory anyway.

Yes, I agree. A 90 degree V4 has perfect primary balance but still has some secondary imbalance hence the counter balancers. The alternator gear set reverses the rotation of the alternator so it along with the counter balance shafts also contributes to canceling the torque effect of the longitudinally mounted engine.

 

[TerryS]

The 360 degree V4 also simplifies the ignition coil arrangement compared to a 180 degree, and I assume it might make for a more stable cam drive system as the cam lobes on each cam on a bank are 180 degrees apart. As an owner of many V4s I do prefer the more characterful sound of the 180 crank compared to the drone of the 360 degree.

I was reasonably sure that a 90 degree V has perfect primary balance, so I was never quite sure why a balance shaft was needed on the 1300. My VTR1000F Superhawk was pleasantly vibration-free albeit with chunky power pulses. And my ST1100 was not a vibey bike either.

 

[RichKat]

The ST engine "looks like" a car engine more than any other motorcycle engine ever
The cylinders cast as part of the block is very unusual in the motorcycle world
You can see that Honda put a lot of money into the development of it, really a shame they haven't continued producing it

 

[motornut]

My engine certainly does not look as nice as that one. Can I trade mine for that one

 

[OldMcClelland]

question:
Stability was mentioned as a problem for the ST 1300. How so? I know that being in a truck’s air wash is horrible. Is there more?

 

[2WheeledPrivilege]

"Driving 4 answers", a youtube channel, may be able to answer the question. He has a lot of videos on engine designs, explaining the benefits and drawbacks of different designs. Pretty sure the 360° crank makes for a steady delivery of torque.

 

[RichKat]

My engine certainly does not look as nice as that one. Can I trade mine for that one

I don't think anyone has one THAT pretty

 

[dduelin]

The ST engine "looks like" a car engine more than any other motorcycle engine ever
The cylinders cast as part of the block is very unusual in the motorcycle world
You can see that Honda put a lot of money into the development of it, really a shame they haven't continued producing it

It is believed that Sochiro Honda thought the V4 was the perfect motorcycle engine solution. It's compact fore and aft and allows mounting deep in the frame both transversely or longitudinally due to narrow width at the crank. It's naturally smooth in firing order. Honda spent millions of yen on refining the V4 but market forces favored the inline 4. The V4 was costly to build and early examples suffered from camshaft failures and persistent idling/fueling issues. Honda acted quickly to fix these but the motorcycle buying public weren't so quick to forget.

 

[RichKat]

It is believed that Sochiro Honda thought the V4 was the perfect motorcycle engine solution. It's compact fore and aft and allows mounting deep in the frame both transversely or longitudinally due to narrow width at the crank. It's naturally smooth in firing order. Honda spent millions of yen on refining the V4 but market forces favored the inline 4. The V4 was costly to build and early examples suffered from camshaft failures and persistent idling/fueling issues. Honda acted quickly to fix these but the motorcycle buying public weren't so quick to forget.

Yeah, it's a shame. My last Honda was a VF-1000R, one of the best engines ever, I think my ST is a close second

 

[dduelin]

question:
Stability was mentioned as a problem for the ST 1300. How so? I know that being in a truck’s air wash is horrible. Is there more?

Much more. The ST was shown to the public in mid 2002 at a press showing in France. Some motojournalist attendees there immediately noticed a high speed weave affecting some of the test bikes. Not a wobble, not a tank slapper, but a weave that manifests as a low frequency oscillation around the yaw axis. It's sort of a 'swimming motion' from the headstock back causing the tail of the bike to yaw back and forth. Honda stop-selled the bike in Europe for that summer and came up with a fix that involved loosening and a careful retorqueing of the engine hanger bolts. Some say the fix also involved a careful torqueing of swing arm pivot bearings. Some say the problem was never fixed because it regularly spooks riders that explore speeds in triple digits. In November 2005 a British law enforcement officer (RIP PC David Shreeve) was killed on a Merseyside police ST1300 that allegedly went into a weave at high speed. The Coroner's Report blamed the bike and most UK police departments immediately withdrew their ST1300s from service. The report was on the net for a while but hasn't been seen for many years. I remember reading Report excerpts on UK media sites at the time as I had bought my ST three months after the accident and my 2005 exhibited the weave on occasion. Many riders have experienced the weave, or the Pan Weave as it became, myself included. There are many references to the Pan Weave in this forum and elsewhere. One of the UK magazines Ride equipped a civilian model with data loggers and quantified the weave occurring at certain load configurations. A member of this forum posted the entire article but it was quickly taken down for copyright violations. Replacing the head stock bearings and careful suspension tuning pretty much fixed my 2005.

 

[TerryS]

The ST engine "looks like" a car engine more than any other motorcycle engine ever
The cylinders cast as part of the block is very unusual in the motorcycle world
You can see that Honda put a lot of money into the development of it, really a shame they haven't continued producing it

In the liquid cooled era, I believe most if not all Hondas have had integral cylinders and crankcases. Certianly all of the VF series, and the late 80's CBR600 and 1000 (below) used that layout. The ST13 engine differs from the other Honda V4s in that the clutch is located below the crank, rather than behind as on the transverse crank V4s, and the alternator hides in the V rather than on the end of the crank. Honda were certainly targeting a short engine front to back, and a low centre of gravity. I am continually impressed by the agility of the ST that this design confers. I just wish they had done a bit more to extract hot air away from the V and the rider's crotch...

 

[STRider]

Could have been even more interesting if they had stuck two CX500 or 650 engines into a V4.... the 500 was an 83 degree v twin and I have no memory of the crank part of that design, I just know it worked!
Maybe two NT650 or 700 engines for an across the frame V4?
Not sure that Honda ever take an easy route in design.....

Recall that the CX engines used pushrods to actuate its overhead valves (OHV) rather than the double overhead cams (DOHC) of the ST, VF and VFR V4s (did I miss any Hondas?). The NT and its derivatives were single overhead cam (SOHC) designs, as was the final VFR1200 engine which used Honda's Unicam design. It's generally accepted that pushrod motors deliver lower performance than overhead cams all things being equal due to the greater mass and inertia of the intake/exhaust hardware. Of course there are exceptions to this rule... Detroit still has a thing for extracting a lot of power from ancient pushrod engines, not to mention certain heavily breathed upon Milwaukee twins.

If I recall correctly, Honda's reason for using pushrods on the CX was to keep the engine compact and the crank to top of the valve cover short.

The CX was also the basis for one of the more unusual engine adaptations in racing. Wanting to enter AMA Dirt Track Racing, and finding a competitive advantage in delivering power offered by V-twins with transverse cranks and chain drives ala Harley, the guys at American Honda took a CX engine with its longitudinal crank and rotated it ninety degrees and equipped it with a chain drive!

The Honda That Took Over Dirt-Track Racing In The '80s

Indian isn’t the first company to take a stab at knocking Harley-Davidson from the top of the dirt-track hill. First, there was the Honda RS750 of the 1980s.

www.cycleworld.com

It was a mongrel, but it got the attention of Japan and a proper Harley competitor was designed and delivered to Honda several AMA Flat Track championships at the hands of Ricky Graham and Bubba Shoebert.