Track Day Gearing

[ChasCrewChief]

I own a 2008 XB9sx. I attend track days at Robling Raod GA,. Gearing is fine for this small track, I top out by the end of the single long straight. This year I have the pleasure of a track day at Barber! Wondering if I should change the primary gearing to XB12 for more top end since this is a BIG track. Anyone attend a track day at Barber and can advise. Thanks.

 

[go cytocis]

Sorry I can't offer you any thoughts on your local track specifically, but the old track I used to ride on here had a front straight of ~2km (1.2mi) & although I never had an XB on it, I did get out on a V-twin powered Honda Hawk I used to own.

The issue I found with torque-focused V-twins on long straights is that taller gearing doesn't always result in a higher top speed because there simply isn't enough top end horsepower to push the bike any faster, especially on a naked bike like your SX. In fact, you may actually find that your top speed, in top gear, drops once you raise your final gearing.

Assuming your local track also has some twisty bits, you may find that you're still better off sticking with the lower stock gearing and just letting the I-4s sail past you on the straights, then reel them back in the corners.

It's worth experimenting with & I look forward to hearing your results!

 

[100thwindow]

I think cytosis may be right. I would imagine you would lose some power and tq. I have a xb12 and swapped to the 9 gearing and I love it. I did lose some top end but I noticed a big power increase throughout the entire power band. Especially down low. It wasn't difficult to swap out and I still have my xb12 gearing I could send you if you want to try it out

 

[Theycallmecrash]

How about convert to chain drive? That way its easy to swap between final drives, you can experiment with different ratios, no fuss with fluids, gaskets and only have the 2 options.

I have a 21 tooth front sprocket, and change the rear between 42, 46 & 54 depending on what i wanna do. Simple as removing the rear tire plus 10 minutes to swap sprockets and chains.

 

[go cytocis]

How about convert to chain drive?

Yup, great idea. I like belt-drives on the street, but quick & easy final drive changes are not their strong point, especially if you're doing track days on multiple courses.

A chain drive will allow for some track-side tweaking to more easily find the optimum final drive for any given track (which is the ratio that allows you to hit redline in top gear as you reach the end of the fastest straight on that track). Good luck!

 

[ChasCrewChief]

Thanks for the input, I think I will leave the gearing alone and just ride to have fun! If the old girl makes through a day at Barber I'll treat her to a change (and oil/filter too)

 

[go cytocis]

I think I will leave the gearing alone and just ride to have fun!

Sounds like a good approach! At least this way you'll have a baseline to know how much of a gearing change, and in which direction, will best suit the track.

You're a lot closer to sea level in GA than I am up here in the Rockies, so your experience may differ, but I can't hit redline in top gear on my 12; there simply isn't enough top end juice to overcome the drag. I'm suspecting you may have the same issue on your 9, and therefore no benefit from taller gearing...