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TECHNICAL MOTOBRICK WRENCHING In Remembrance of Inge K. => The Motobrick Workshop => Topic started by: daveson on November 03, 2020, 07:55:33 PM
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What are the extra lines on the speedo at 50, 150 and 220 km/h?
You might have it at 40, 80 and 135 mph, but that's 64, 129 and 217 km/h. At least the last number is about the same.
Previously I noticed 150 and 220 are about max revs in third and fifth, maybe to do with racing?
I'm wondering if the extra lines might vary a bit in different countries?
Another layer of confusion. In fifth gear on my K100, the speedo and tacho needles are always parallel. On my K75S they're not, it revs a bit more, understandable. But the extra lines are in the same place, the speedo looks identical.
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If I was to speculate.... I'd guess they may be calibration marks from the factory?? But that's only a guess.
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Hi Scott, thanks.
Do you have marks at 40, 80 and 135mph, with a k1100?
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Interesting article on calibrating K speedos, https://bmwmotorcycletech.info/Kpod-8.htm.
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While we're theorizing - 50 kph is max speed in built up areas, 150 kph is max with fairing & bags, 220 is simply max speed before things fall apart.
Actually I recall reading something along those lines somewhere. But mine will push 210ish even with fairing on! (and that's at redline)
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Hi Scott, thanks.
Do you have marks at 40, 80 and 135mph, with a k1100?
Why yes I do have them on the K
My R1100 does not have them, maybe because it's mechanically driven?
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Brilliant, never thought about that. Just looked in the riders manual, it says maximum speed with tragkorbs is 130 km/h, that's 81 mph, but that's for a metric bike with lines at 150, so a bit of a loose end.
Is 40 mph a common speed limit in the US? (or UK?)
Spose the R1100 is a bit of a loose end then.
Another loose end, recently saw an instrument cluster for a car (BMW 318) that had these marks at 65 and 130 km/h.
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Just noticed that your unit is in Km. Interestingly, the marks on mine are in different locations and at different speeds, even after converting km to miles or visa versa. except for the marks at 220kph. Hmmmm........
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Yep, so the speed limit might be different in a different country (40mph) but you wouldn't think the maximum speed with tragkorbs would be. Not easy to get this all to fit.
Fifth gear will redline at about 220km I spose on an RT, higher on an RS I think, but the extra lines are in the same place?
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Siding with Scott_ that they are calibration marks. Totally guessing here but the manufacturer is testing the electromechanics of the cluster in final assembly to ensure the needle deflects the correct amount for a given input frequency. They generate different frequencies which they know will cause the servo motor to rotate a particular amount. If the resulting needle deflection doesn't land between the tick marks, the unit is rejected. Marks have nothing to do with what the motorcycle is or is not capable of achieving or what is norm for a country's traffic laws..
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The big question here is why didn't MotoMeter put a small MPH scale on the Km/H unit like they did with the MPH unit with a small Km/h scale? Metric people don't care about archaic equivalents? :laughing1:
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I think I remember with the Aussie conversion to metric that speedos and road signs were in metric and Imperial, but it died out after some years, and looked too busy too I recon.
Good one RBM, all the ducks line up with that explanation, even why the R1100 doesn't have them.
The penny didn't drop for me with the first reply by Scott, but I see it now.
Thanks everyone.