750 V-Twin to 600 Inl.4... worth it?

[Cillit-BANG]

Here's the facts-

Age 25, male.
Started riding 125cc Oct 2004 on CBT
Passed DAS April 2005, progressed to Ducati 750ss (2002) £3k
Milage covered 9k, in ranging conditions.
K/D frequently this summer, but by no means a quick rider.
Bike crashes, 1, low slide on tight L-hander, no insurance claimed.
Ride purely for pleasure, mainly solo, 1-3hrs at a time.

I'm at that stage where I'm thinking about my next bike. Insurance was too high on a sports 600, hence the Ducati. But I'm considering 1 for next year. But my main concern is will the 600 be that much faster? ie. is it worth it.

The Ducati has 65bhp with 64nm torque. An average 600 would have 100-110bhp but with 40-50nm of torque. I'm aware that the inline 4 would need keeping higher in the revs to make it's power, but in the real world, would it feel much faster accelerating up to 70-80mph?

I really like my Ducati, and whenever I look around at the (Budget of £4k) sports bikes, they never seem to have the same feel. The Ducati feels a bit bulkier, but seems to have a certain something (despite being mainly viewed as a sports tourer). For this reason I'm not desperate to swap bikes, but I'd prefer something with a little more go, esp. in the 60-100mph department. There's always the 900ss, but I'd prefer to try something different whilst I'm at it.

So, what do you all think? Cheers, Anthony.



Now, before you all advise test-riding, I thought I'd run it past you first, as it won't be till next year anyway...

[Mr.Everready]

Keep what you've got if your happy with it.
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the undemocratically unelected mod of the Scottish section

[Cillit-BANG]

I do like it, I really do.

But I 'think' I'd like something with more accelleration, like I say, esp. around the 60-100mph mark, but will a 600 sports bike be that much better?

[G]

Haven't ridden a 750SS, but I do own a TRX850 (competitor to the 900ss if you don't know, generally considered to be a better performance than the ducati model of the time) I have also owned and ridden various sports 600s - have also ridden a Duke 748.

New sports 600s do seem to have a very 'polished' feel often, they do what you want them to do with relatively little complaint - you have to push them a lot more before they start to show up deficiences.
Personally I don't consider it a down side and personally would say the power delivery and handling offer a lot more 'charcter' than many twins.
Up to about 50 I would say my TRX should about keep up with a sports 600 just about. Above that the sports bike would be pulling away, definitely in the 60-100mph area.
Which gear you're in does matter more, partly because they're geared higher for a start. In other performance matters you should find a £4k sports 600 is way above your ducati.

Note that quoting a peak torque figure means little from my understanding - peak power figure is useful as is spread of torque.
A revvy 2 stroke can easily have a high peak torque figure but not a very good spread of torque.

One thing that often catches people out going between sportsy twins and fours is the maximum revs. Saying 'you have to rev it more' is often incorrect if you consider it as a total of the maximum revs available.
Yes my trx pulls from 4k rpm, but then it's only got a redline of 8k rpm, where by the sports 600 may only start to pull decently from 8k rpm which is where you're used to changing up, but if you consider it's got a redline of twice that it's quite reasonable. Once you get used to sitting in the correct part of the rev range it helps a lot more.


Incidentally, I've got a TRX850 not just on economics, but because I wanted a bike that wasn't quite so quick - sports 600s are bloody quick and I could easily see myself losing my licence on one.

[Cillit-BANG]

Wow, thanks for that G, very helpfull

My Ducati certainly feels fast, but at times, I just wonder if a 600 would excite me more.

Anyone else with experience from both types of bike?

[Valver]

I've never riden a 750ss but i have riden a 900ss and would say a modern sports 600 feels a fair bit quicker than the 900.

Good bikes though with plenty of character and old skool kool! Might be worth holding on to it for another year then getting something new. Good luck with it whatever you decide to do

[Kickstart]

Hi

Not ridden a 750SS, but have ridden a 900SS.

I would say that G is not correct on needing to use the same amount of the available rev range (remember his TRX has 5 valves per cylinder rather than the 2 of the 750SS, and is more biased towards revving). Very roughly I would say that on the 900 you can make acceptable progress using 50% of the rev range against 25% on a sports 600 (but that 25% will be far more effective).

The 900SS was certainly a bike where you could open the throttle at most revs and have it pull forwards with little effort. I would expect that a sports 600 would be quite easily faster than the 900 when trying (and more so against the 750), but when not trying as hard and just riding along rolling the throttle on and off being smooth then the 900 would be faster. The 2 valve per cylinder Ducatis are not really designed for top end power at all.

Depends on your riding style.

If you ride a sports 600 with the same riding style as you are used to with the twin, expect to spend half you rides waiting for the power.

All the best

Keith
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Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[G]

Fair point that the TRX is quite revvy.

However I've found even for less revvy twins you still need to use the top half of the revs with available power if you're properly 'going for it'. Even when not going for, they're usually a bit lumpy low down, meaning that you try and avoid the bottom of the rev range.

[Kickstart]

Hi

Yes, lumpy at low revs but that still gives you around 2/3 of the available rev range as decently useable. Going for it the sports 600 will be quicker, just that when not going for it and either normally or "spiritedly" the 900 (certainly) will be far easier to ride.

Depends on an individuals actual riding. And for me on the road it is not that otfen that I will be red lining a bike on full throttle through more than a couple of gears.

All the best

Keith
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Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[G]

I found a mildy tuned 750ss graph and an untuned GSXR 600 dyno graph - upuntil the gsxr hit the powerband (as the SS tailed off) the GSXR was between 1k - 2k rpm behind for the same power.

However as a percentage of the rev range, the GSXR always has more power.
Just found a 900ss graph - if you compare the power vs percentage of the revrange, again the GSXR has more power throughout the revrange.

Thus with the same gearing the GSXR should be 'easier' to ride at any point in the revs.

[Kickstart]

Hi

Sure it does, but with the gearing used the twin will be more useable, and will not need the gearing dropping to make it horribly buzy to get that performance.

My point is that if you want a bike to ride at a fair pace, rolling on and off the throttle then the lower geared, lazy powered twin will be easier. It is when you want to try harder than that the 4 will run away rapidly.

All down to the riders style and what roads they are using.

All the best

Keith
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Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[Kickstart]

Hi

By the way, found this page which allows you to select dyno curves to be overlayed.

https://www.deeknow.com/dyno/

Here you can see that between 4000rpm and 8000rpm (the GSXR grapg only goes that low) the 750SS produced between 17% and 40% more power. All nice and easy to get at on the road especially with the lower gearing on the Ducati.

All the best

Keith
____________________
Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[G]

Nice find , was getting annoyed with playing with graphs in photopaint and was wondering about making something like that myself.

I accept the gearing does make a difference, though if we're talking lazy no gear change style riding, not nearly as much so.
This leaves the sound/feel - something I'm starting to be covinced may actually be a lot to do with the experience, in a similar way to how smell effects taste.

In a gear with the same maximum top speed the GSXR is going to have more power at any speed. Some people may not like sitting at high RPMs for probably fairly illogical reasons.
Personally I have the same about sitting at 90% rpm what ever bike's it's on.

[Kickstart]

[Cillit-BANG]

Wow, thanks greatly.

So is the general consensus that unless I'm giving it some stick everywhere, the 750ss won't feel that much slower at 'normal' road speeds.

And for lazy overtakes on the Ducati <80mph, I would need to drop a cog on an inline 4 to have similar but maybe a more dramatic effect?

I usually like to keep mid-rev range for most riding on the Ducati, I rarely snick top (5th) until cruising above 80.

[Visitor Q]