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Bradyclt
Posted on Saturday, September 25, 2004 - 06:34 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only)

Got the bike back Thursday and have put 150+ miles on it (mainly hwy, but enough city stop & go to make judgments) since going with the XB12 primary setup. This mod does change the character of the bike more than I'd anticipated, so here are the impressions and results:

I'll start with the bad... The change makes first gear so tall that I would not consider doing this at all if you ride two up more than a few times a year, or are a larger individual. I'd be very hesitant about doing it if stop and go traffic is a normal part of the routine... I'm having to feather the clutch a bit more to get it going smoothly, and now it shouldn't be fully engaged until you're doing approx 15 mph. Top speed has actually dropped... it tops out in fourth now, and shifting to fifth just keeps you where you're at: approx 128. It might have been able to spin up a few more mph, but it was very slow in doing so and I was running out of open road. I'd like to explore this more but it's not practical on public freeways. The bottom line is that if it can actually pull to 135, it will take forever to do it. Downshifting to fourth is sometimes necessary now passing uphill on the freeway (depending on steepness, etc.). Previously I just put it in fifth and forget it.

The indifferent: fuel economy is the same as it was prior... I'm getting 47 mpg on the Interstate keeping it between 70 and 80 (closer to 80). But it's probably a tick better since on this tank I had a couple of runs checking how the top end was affected. Commuting I get 47 mpg, and the riding done on this tank closely resembled daily use.

The good: Loafing along doing 80 @ 4000 RPM makes the engine *seem* to have more displacement... each power stroke has noticeably more juice behind it than when running 4400+ RPM... but definitely not lugging the motor either. The engine (or maybe the owner) seems happier and the exhaust note sounds more like, well, a Harley. That might be good or bad depending on your inclinations... Engine parts that transmit power or absorb those forces like the piston crowns, con rods, wrist pins, crank and main bearings are now taking a harder hit on each firing compared to before, but are doing that at 7 or so fewer times per second than before. As far as fatigue and wear are concerned I'm not sure that makes it a net positive or not (any metallurgists out there?). Moving parts not transmitting power (valvetrain, oil pump, etc.) are better off...

So there you have it... given my riding style and typical usage I'm keeping the 1.5 primary ratio. But in a perfect world it would've come with a 6 speed that retains the original 5 gears and a slight 6th gear overdrive for cruising...
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Bradyclt
Posted on Saturday, September 25, 2004 - 06:39 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only)

I don't know what's up with the funky smiley on the main board listing, and I didn't put it there intentionally....
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