Re: R1100SA 2-plug top speed disappointment

["Steve Makohin" <wateredg@xxxxxxxxxxxx>]

Hello Jack,

From: "Jack Bunce" <jackbunce@xxxxxxx>

> I am looking for some data on the top speed of the R1100SA; preferably
> either radar, lazor, or GPS derived. The BMW literature mentions either
> 139 mph or 140 mph and that was one of the main reasons I chose this
> model.
>
> Mine is a 2004 or 2003 1/2 R1100SA with 18,600 miles on it and is now
> wearing Metzeler Z6s.
>
> On my trip down to Branson, MO, with large system bags on, a small
> Helen2Wheels bag across the top, and a small Ventura pack on the rear
> rack, I could only get 116.8 mph while tucked. [This was a 6th gear
> roll on from 80 or 85.]
>
> Today, I tried it without all the junk hanging out and it was 118.2 mph
> tucked; very disappointing. I tried tit a couple of ways; through the
> gears shifting at 8000 rpm and the 5th and 6th gear roll ons. All were
> the same.]
>
> The bike seems to start to run out of steam around 107 mph and slowly
> reaches 118 mph. [Of course, the speedometer is wildly optimistic,
> indicating 125 mph or so.
>
> Does anyone have any data? Are there any obvious things I should check
> or have checked which would cause the apparent 21 mph loss of top
> speed?

You can bet your butt that BMW did not do top speed trials with System Cases
and a Ventura pack. Strip off the bike-fat, make sure your tires are not
under-inflated, ensure the bike is tuned to spec, and give it a try again.
Other things to consider are:

o The altitude and temperatures at which you are doing your runs.
o You speed measuring device (GPS)
o Check sources of resistance (brake rotors/pads, wheel bearings)
o Check your bike's compression

118 mph (slimmed down) is why of where you should be, assuming all is in
order. Tuning is a big consideration. Decades ago when I had a CB360, it
would do an indicated 93 mph (crouched) if it was tuned perfectly. As the
points wore and the timing ran out of adjustment, top speed would dip into
the mid to upper 80s. My current bike does an indicated 240 kph (149 mph).

- -Steve
 2000 R1100S/ABS, Mandarin
 Oakville, Ontario, Canada

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