Suzuki VS 1400 Final Drive Mod

Just wondered if anyone was considering doing the upgrade of the final drive to the VS1400.
I have been considering this for a while and I'm almost at the point of spending the cash. It's not a cheap mod but when everything is taken into consideration of the other power enhancement modifications we do, its not particularly expensive either.
From what I understand you get a lot less vibration, a 14% higher gear ratio, meaning that the gears will be held longer around town and in turn makes the bike much better for motorway or high speed riding.
What do you think?

It's like an overdrive. You don't get a lot less vibration. In fact at the same revs you get the same vibration, it's just that on the motorway you will have lower revs and hence less vibration at the same speed. Not worth doing if you don't drive over 60 or 65mph much but 70mph+ would make it worthwhile. Technically not a performance upgrade.

Well done, only two posts and already I am gettin lost

So there is less vibration and there isn't less vibration. Surely in real terms there is less vibration if lower revs are used to reach the same speeds that were got before at any given point?

As for being a prformance upgrade. If you are able to ride at any given speed at a lower rev than you did before then surely there is less stress on the engine and if you are able to ride at lower revs at any given speed because of this mod and at the same speed within the rev range you are also using less fuel because of that then surely it is a performance upgrade?

captain crash wrote:

Well done, only two posts and already I am gettin lost

So there is less vibration and there isn't less vibration. Surely in real terms there is less vibration if lower revs are used to reach the same speeds that were got before at any given point?

As for being a prformance upgrade. If you are able to ride at any given speed at a lower rev than you did before then surely there is less stress on the engine and if you are able to ride at lower revs at any given speed because of this mod and at the same speed within the rev range you are also using less fuel because of that then surely it is a performance upgrade?

The Bike has gears so you choose the revs where you want to change gear. You would only have lower revs at all speeds if you change gear at the same speed as before.

Lower revs do not result in less engine wear except where very high revs are involved. At any speed in the same conditions you will need the same power and since power=torque x revs you will need more torque at lower revs for the same speed. More torque means a larger throttle opening and more load on the engine components per rev. Also at lower revs you have the potential for lower oil pressure.

What does all this mean - well you change gears accordingly so except for the ability to get through a junction after a stop before shifting from 1st to 2nd and losing some buzziness above 65mph it really doesn'y make a whole load of difference to anything. (Top speed is reported to be a little lower too - I haven't been thee)

Interesting reading CB, I agree in principal, but must admit though, a lot of mods are done for personal choice and not physics.To answer your question Dave,if you do a lot of motorway riding it seems the way to go,I have not thought of the idea of doing it for I do not use the bike for speed or motorways,only very occasionaly,so pottering around town,with the chance to get on the Welsh roads at 60/70 is sufficient.Good luck if you go for the mod and like always photos and write up.

well done CB grate comon sence imformation about engines / geers and how the way you ride efects your bike if i have questions about such stuff in the fucher hope you have some imput aswell as everyone else on the site . dave you got the mod bug bbbaaaaaaD all i can say is if you want it go for it mate sounds like it will be good if you fancy exerciseing your rist and cranking the bike along at high speed .why is the top speed less though is it because the vs 1400 has a lower top end might have a look at that

fat intruder wrote:

.why is the top speed less though is it because the vs 1400 has a lower top end might have a look at that

You can't keep making the gearing taller and increasing the speed. The optimum will be max power at max speed. At that point more revs will give less power and thus speed. If you are over geared like with an overdrive you don't have enough revs to give you enough power to overcome the wind resistance to get you to maximum power and speed.

I don't think this is an issue of any concern - an overdrive is an overdrive. I just mention it so no-one thinks you can necessarily go faster with taller gearing.

I did the mod on my bike but all the speed limits for miles around me are 60mph and then if I go further east it is 65mph for a couple hundred miles.

you da man thats why i said hope you can give advice if i have questions in the fucher ( yes im shit at spelling )

I have changed the gearing on plenty of bikes over the years and not once had a negative effect, the reason for this is because I have never over geared them. A 14% change to the gearing would seem to me to be advantagous as I would have thought that this could not be deemed as over gearing. it is not an overdrive as the 14% is not there in only 5th gear, it is there from the off. also for the guys that have added power enhancements that increases the bhp & torque, this mod would surely have even more benifit as the bikes are already running at a higher output and the gearing of the standard final drive could even be deemed as under gearing from that percpective as the gearing was set for a lower powered bike!

I basically agree with Captain Crash except that you have to keep in mind that more torque does not always come at lower revs. To get the maximum bhp out of an engine you want high torque at high revs. High torque at low revs does nothing for max bhp. In tuning for more power - and hence more torque at high revs - you can end up with lower torque at lower revs and thus reduce the tractability - the ridability due to the spread of power throughout the rev band.

The standard gearing would be nice with a sidecar.