Shift light on a road bike.... Why?

[Prof Prolapse]

Yesterday I realised, after an embarrassing length of time, I have a standard GSXR fitment shift light... It's quite cool in that you can set the rpm, then three warnings at 1000,500, or 250 rpm increments as you approach it. You can set to an intense flashing when you reach this point which presumably is designed to keep epileptic riders off the road.

But, as much as I enjoy discovering a gadget, I don't understand if there's any point to this on the road, and why you would need to vary the RPM even on the track?

The peak torque/power/whatever, will surely vary per gear and this system only allows one limit from 7,000-~13,000rpm, regardless of gear. So it really won't help very much in terms of optimum changes.

So I thought, bks, I'll just set it for the limiter, but now realise on the road I will basically never see this outside possibly 2nd/3rd gear, an extremely small amount of the time, as this typically translates to "I don't have time to look at my fking dash" road speeds.

Something solely for the track then? I take it even there it just serves as a warning you're approaching the limiter?

If it's just for the track, why on Earth would you set it for 7,000rpm?

Am I missing something?

Cheers.

[Prof Prolapse]

Speed addicted said:

You could have it low for running in I suppose?

Good thinking.... Does seem a needlessly over-engineered solution though!

[Prof Prolapse]

MDUBZ said:

does power vary based what gear you are in? I'm a complete knuckle dragger when it comes to anything mechanical but i would have thought the gears just help transfer the power to the wheel(s) via the final drive chain.

Certainly in cars my power band always appears to be in the same rev range?

I thought it did, but happy to be proven wrong. It certainly would make the light more useful.

[Prof Prolapse]

trickywoo said:

Peak power is always at the same revs. I think you may be recalling where some manufacturers retard the timing in the lower gears to soften the power delivery. Which is easily removed. A variable shift light per gear would be mad.

I've only a basic grasp of this, but would have thought we're talking about maintaining peak torque and obviously it will vary depending on your gear (but usually be at redline).

I don't understand all of this, but I agree with what I do understand;
http://glennmessersmith.com/shiftpt.html

You get shift lights per gear, examples;
http://www.speedhut.com/about-shiftlights.html

[Prof Prolapse]

sc0tt said:

Shift lights are like wheelies.

No purpose other than they look ace.

Well you'll see fk all of either on my bike...