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Top Speed R1150RT


roger 04 rt

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I'm trying to refine my estimate of aerodynamic drag for the R1150RT. I have a pretty good model which calculates Cd at 0.66, not great, not terrible. The R1150RT has a frontal area of about 8 square feet.

 

My question is, what is the top speed you've seen and what gear were you in?

 

Happy Holidays,

RB

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R1100RT with side cases and tucked behind a Cee Bailey windscreen: 125mph indicated in 4th gear. Since the speedometer is about 4% optimistic (compared with a GPS) that translates to 120mph. Probably another 5mph available with a longer road and/or a tail wind.

 

With another 50cc, the R1150 should be good for a few more mph.

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Thanks, Tucked in behind the windshield takes about a 0.75 square-feet off my 8 sq-ft estimate. Thanks for the number. I don't have the road to get to top speed here in Eastern MA.

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130mph on the speedometer, 6th gear, with top and side cases fully loaded. I believe my actual speed was at least 5mph lower. 6th never seemed of much use, but over 90mph it felt right.

 

Made short work of Nevada's loneliest highway . What else is there to do?

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I've done the same as the lovely PB :wave:

 

Seen 130 indicated with top box only on the bike on I-10 a few times ;).

Got up there by redlining in 5th and flicking up into 6th.

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Thanks for the further inputs. They are helpful to my refining Cd which is about 0.66.

 

It takes 8400 RPM in 5th gear with a stock tire to hit a true 130 mph. In 6th it takes about 6500 RPM. My speedo reads about 5% high. You're likely at a true 124 or 125.

 

The problem I've had is that 5th gear only gets to 111 mph at 7250 rpm where the peak horsepower spec is and in 6th gear the engine is only making 84 HP based on 6250 RPM, where the torque is about 71 lb-ft. So there is a horespower reserve that can't be accessed in 6th but can be accessed in 5th for accelerating or going uphill (at 110 mph ;) ;) ).

 

With the data so far the 0.66 Cd is looking pretty good.

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Roger - Are you relying on some other method of speed measurement? The ODO is off on all bikes, right?

 

I think what created the needed thrust was the Harley's on the horizon. Subscribing to the previous adventures I'd deemed that pass to provide the needed oomph to get it done.

 

Hi Phil :wave: And on these beasts it felt like 85 didn't it :thumbsup:

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Roger - Are you relying on some other method of speed measurement? The ODO is off on all bikes, right?

 

I think what created the needed thrust was the Harley's on the horizon. Subscribing to the previous adventures I'd deemed that pass to provide the needed oomph to get it done.

 

Hi Phil :wave: And on these beasts it felt like 85 didn't it :thumbsup:

 

Kathy, Yes, I measure speed by logging the motor RPM and knowing the gear ratios and rear tire diameter at speed, confirmed with GPS.

 

I'm always surprised when I look down and see 110 on the speedometer. It doesn't seem that fast. Btw, it only takes about 44 HP to go 100. But it takes roughly 94 HP to go 130.

 

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Fastest I've hit was just over 100 on the GPS. As far as what gear I was in, I was wearing a smashing jacket with blue accents, grey trousers, and a white silk scarf. Hey everybody, come see how good I look!

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I was just looking through the R1100 specs. It is only 4 less HP at 7250 than an R1150, at 90 HP. And a couple less ft-lbs of torque at 5500 rpm, at 70 lb-ft.

 

However its gearing and rear wheel diameter give it almost perfect access to its top horsepower at its top speed.

 

Compared to the r1150rt whose 5th gear is too low, 111 mph at 7250, and whose 6th gear is too high, 124 mph is only 6200 rpm, the r1100rt has a 2% bigger rear tire and an 18% higher 5th gear resulting in a theoretical 133 mph at 7250 rpm. To me it seems a perfect match of gearing and HP, at least in its top gear.

 

Maybe one of the reasons for its enduring popularity.

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Roger,

On LeRoy, my R1100R (and my regular hooning companion :grin:) I've seen an indicated 135 and regularly see 130 :clap:

 

I have ride buddies with FZ1's and Bandit 1250's and LeRoy constantly amazes them with his performance. Especially in the twisties and driving out of corners as, IMHO, the gearing is perfect on the R1100R. However, when touring and loaded, the RT really can't be beat when cruising along at 80mph (indicated!) in 6th and the motor humming along turning just 4k.

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I once saw 130 on the GPS on my R1150RT - on a slight downhill on the Isle of Man (no speed limits there :clap:)

 

I was tucked in and had full luggage on board.

 

Andy

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Roger,

On LeRoy, my R1100R (and my regular hooning companion :grin:) I've seen an indicated 135 and regularly see 130 :clap:

 

I've always liked the R1100R. Does the wind beat the crap out of you on that thing?

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I got it up to 120 mph as indicated on speedometer, which I think reads +3 mph, and still had throttle left. That was with wife on board with luggage flat two lane.

Could have gone faster but if the OSP gets you over 100 mph you get your license suspended from 30 to 90 days and an $1103 fine. Used to be in Washington State above 85 and you see the man after a night in the old slammer.

 

Definitely agree the 1100 gearing is much better and more realistic than the 1150.

 

 

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I have seen right about 140 "indicated" on my R1100RT but that is off from actual. My speedo runs about 7-8% off so maybe my tires are slightly different OD than others. That put actual speed at 130 ish...I do not have GPS. Never saw the need.

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Not badly without a screen Jim :) !

However, I have a Cee Bailey's windshield that I use which works very well, except when I'm not snapping windshield support arms. Monday, for the third bloody time....so I am taking it into a local welding shop to see if we can build a more well thought out support. The so called designers made the lower support arms out of tubular steel then flattened the tube and bent it right where the support bolt hole is!

 

BMW wants $68 for this one arm and I've already shelled out for 3 and I'm done with it now. Sorry...rant over :) !

 

 

 

 

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philby...Interesting. I think essentially we have the same bike. Mine is 05 1150rt with 35k. I have the cee bailey 3+ on since new. I have never broken an arm. I ride with mine pretty far down. Just enough to take the wind over my head. In summer I ride with it all the way down to get wind. Only time I ride with it full up is rain or extreme cold...If you find a better answer, I would be interested just in case some day I do break one...although probably headed for a new bike about March or so.

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I thought the elves shut down the top speed at about 124 mph....Something in the dark recesses says "Ttttthats all folks"...Goes for the 12RT too....GPS clocked right in that area on the 05........

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Not badly without a screen Jim :) !

However, I have a Cee Bailey's windshield that I use which works very well, except when I'm not snapping windshield support arms. Monday, for the third bloody time....so I am taking it into a local welding shop to see if we can build a more well thought out support. The so called designers made the lower support arms out of tubular steel then flattened the tube and bent it right where the support bolt hole is!

 

BMW wants $68 for this one arm and I've already shelled out for 3 and I'm done with it now. Sorry...rant over :) !

 

 

 

 

Thanks for the info.

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David,

I was referring to my R1100R concerning the support arms :cry:.

Have no concern my friend, my RT has been faultless since I bought it in 2003.... :thumbsup:

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I thought the elves shut down the top speed at about 124 mph....Something in the dark recesses says "Ttttthats all folks"...Goes for the 12RT too....GPS clocked right in that area on the 05........

 

That was my recollection also.

I don't know, on the GT the boxers just become little dots in the rear view mirror.

:lurk:

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Wait no longer Tim LOL!

quote

I don't know, on the GT the boxers just become little dots in the rear view mirror.

unquote

 

Depends on who is riding the boxer ;)

 

 

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photo-L.jpg

 

This was fast enough for me. Came across an HD rolling roadblock east of Fallon, NV on US 50 while on my way to Colorado. There were about 30 of them traveling at approx 55 mph. I followed for a little while and gave a high beam flash to the last rider in the chain. He acknowledged me with a single raised finger.

 

I didn't look at the speedo when I went past and didn't even realize the actual speed until I got back into my normal riding rhythm.

 

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Every time I think I need another gear on my R1100RT I look down to find myself traveling way too fast. This was recorded a few weeks ago and is only 30 mph over the posted speed limit.

 

DSCN2383_zpsf1c82867.jpg

 

The bike was willing to keep going, but I quit. My top speed with a pillion is 93 mph riding the Three Twisted Sisters. It was my wife's first long distance ride on a motorbike and she loved it. I'm a lucky guy.

 

m

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Yea, gotta luv it! I'm going to be passing your way for a Saddle Sore this spring. Where else can your get a 1000 miles out and back and 9/10ths of it with a legal speed of 80? Of course once you get west of Ozona anything less is kinda cruel.

 

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Thank you all for the help. Using the top speed and top horsepower metric, I arrived at a coefficient of drag for the R1150RT (and I guess R1100RT too) of 0.66.

 

Yesterday before it started pouring, I went out and made 9 roll down decelerations (accelerate to 60, pull in the clutch and time every 5mph deceleration, then get out the slide rule). By that method I arrived at a Cd of 0.7.

 

So if you go to: RB Racing Calculator, and use:

 

0.7 for Cd,

8 sq-ft for the frontal area,

and (in my case) 815 lbs. for motorcyle, rider and side cases (top case won't change things too much I don't think),

 

you can get a pretty good estimate of the horsepower required for speeds between 20 and 130 MPH.

 

Because of gearing, assuming the Cd and Frontal Area are about the same, it seems like the R1100RT would eek out a 1-2 MPH higher top speed than the R1150RT.

 

It just stopped raining so I'm putting away the calculator and computer and going for a ride.

 

Happy Holidays,

Roger 04 RT

 

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I have spent at least half a tank of gas on several occasions with the throttle pinned on HW50. The first time was with a tall screen and warm weather. It only managed 6400 rpm and maybe 128 mph, but that finished the break in, and oil consumption went to almost zero.....this at 18k miles.

 

I have been back several times since, with a GPS. Fully loaded, at 7000' elevation, and less than 50 degrees farenheit, it shows a hair over 6500 rpm and 130 miles per hour on the GPS.

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I have spent at least half a tank of gas on several occasions with the throttle pinned on HW50. The first time was with a tall screen and warm weather. It only managed 6400 rpm and maybe 128 mph, but that finished the break in, and oil consumption went to almost zero.....this at 18k miles.

 

I have been back several times since, with a GPS. Fully loaded, at 7000' elevation, and less than 50 degrees farenheit, it shows a hair over 6500 rpm and 130 miles per hour on the GPS.

Wonderful, I can only imagine. NE Ohio.

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skinny_tom (aka boney)

50CC-45-L.jpg

 

Contrary to everyone else here, it is my GPS that is optimistic...

 

I've seen my speedo as high as 135, but the GPS only said 125. 6th gear, wide open on a slight down grade in the desert. It felt like it still had some pull left in it, but absolutely stopped accelerating at 125.

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