ST2 Speeds at Revs in Top Gear

[OogieBoogie]

Hi all,

I've just aquired an ST2 (My first big Ducati - had a 450 Desmo in the early 80s) and while it goes and handles well something aint quite right.

I don't know if it's the speedo, counter or just me!

The problem is it seems to be pulling 9000rpm at just over 120, this seems too low geared for a bike that's supposed to be capable of around 135.

According to the specs makes peak power at about 8600revs, and the manual says don't rev it over 9000 but claims a top speed of 225kph?

Gearing is standard and there's no sign of clutch slip - in fact it had a new one fitted only 3000miles ago.

Can anyone tell me what revs their SP2 does on standard gearing in top at set speeds say 70 and a ton?

Stu.

[stevel]

OB/ There was a post on here a couple of weeks or so back, it had a link to a website that allowed you to input bike, model etc etc and it allowed you to play with various sprocket sizes etc and see the result - very handy, but can't recall the thread. The answer to most of your q's will lie in the search function, so I'd recommend using that and some judicious search word selection to find the link. Welcome by the way, hope you get what you need :wink:

[MarkST]

Stu, I know that this may be a stupid suggestion but they do have six gears and not five ??!!

[jlo]

Stu,

I'm currently running with a smaller front sprocket (it's a common change), and it revs pretty high now. I wouldn't be surprised if that's the reason. 120 max seems about right with the current ratio.

It feels a bit frantic.... more relaxed with the standard gearing but not so hot around town.

Count the teeth on your sprockets 15T front and 42T rear is standard.

I've currently a 14T front, (curtesy of Jan )

Jerry

[mike shannon]

hello
stuhow do you find the st2 with the 14t on the front both in town and open road
mike shannon st2

[mike shannon]

sorry ment for jerry my last e/mail
mike shannon

[OogieBoogie]

Originally Posted by Euromark

Stu, I know that this may be a stupid suggestion but they do have six gears and not five ??!!

SIX! Really dude? fancy Isn't modern technology a wonderful thing :wink:

Seriously though, the sprockets are the standard 15/42T setup and yes I am getting all six cogs.

I guess the question is, is the speedo under reading or the rev counter over reading?

[jlo]

Mike,

I'm only one day into it. Took it down the motorway and through London today.

The ST's has changed from a fast (well as fast as I've experienced so far) AND relaxed tourer into an easier machine in traffic to a mental accelerator, and very buzzy tourer. Spins up so fast in first

Ducati900ss (Jan) advised that it was too much of a change, and advocates 2 teeth up on the rear.

For info, the ratios are are follows:

Standard = 2.8
15T front (std) and 44 rear (2 up) = 2.93
14t front and 42T (std) rear = 3.0

The chain does seem to wrap a lot more tightly around the sprocket, (as Jan said!) and I've noticed an odd transmission whine. Found someone else report this too.

Very worthwhile test, and I'll keep it on a while to get it a chance, but may well be changing the rear to + 2 teeth. This seems a good compromise (Jan woz right!)

[OogieBoogie]

Originally Posted by stevel

OB/ There was a post on here a couple of weeks or so back, it had a link to a website that allowed you to input bike, model etc etc and it allowed you to play with various sprocket sizes etc and see the result - very handy, but can't recall the thread. The answer to most of your q's will lie in the search function, so I'd recommend using that and some judicious search word selection to find the link. Welcome by the way, hope you get what you need :wink:

Thanks for the info stevel. I found the gearing calculator. I now think it must be the rev counter over reading. 9000 in sith on std gearing would be around 152mph if it were possible on an ST2!

[jlo]

The ST2 has a rev limiter set to 9,500 (I think). So you should be able to tell :wink:

[OogieBoogie]

Originally Posted by jlo

The ST2 has a rev limiter set to 9,500 (I think). So you should be able to tell :wink:

Thanks jlo, that should give me a rough guide if the rev counter is over-reading.

[OogieBoogie]

Originally Posted by jlo

The ST2 has a rev limiter set to 9,500 (I think). So you should be able to tell :wink:

Cheers for the tip Jerry, I found that mine hits the limiter at an indicated 10000rpm so perhaps it is over reading, but I need to know for sure what revs it actually cuts in at.

The strange thing is that the error is not enough to account for the low speeds at revs through the gears.

My speedo is reading 70mph at 5000rpm, actual speed at 5000rpm on standard gearing should be 85mph 15/42t or 79mph with 14/42t front sprocket.

Of course I could have miss-counted the number of teeth on the front, I'm sure the back is standard (I've counted it 3 times now!).

So now it looks like my speedo under reads and my rev counter over reads (possibly).

The only other possibility is that the primary gears have been changed, but I can't believe anyone would do that!

Confused!

Stu.

[jlo]

Stu,

It is 9,500 for the ST2 and 10,000 limiter for the ST4.

The limiter is a function of the ECU so if it's got a none standard chip, that could be causing the confusion, althouh I don't know if the tacho output is controlled from the ECU.

J

[OogieBoogie]

Thanks for your help chaps,

Guess I'll just have to live with not accurately knowing my speed and hope not to pick up any speeding tickets.

I checked the front sprocket again and it's definitely a 15t.

Stu.

[OogieBoogie]

Thanks for your help chaps,

Guess I'll just have to live with not accurately knowing my speed and hope not to pick up any speeding tickets.

I checked the front sprocket again and it's definitely a 15t.

Stu.