Rt 1200 Top speed

[Tucker2930]

I was wandering what folks are getting topped out. GPS speed if you have it verses speedo reading.

[ShovelStrokeEd]

Don't have one but, I can make a fair guess.

 

My 1100RS made, after a chip and a pipe, 81 RWHP on the dyno and had a HP limited top speed of around 132 mph, GPS, no rev limiter in the chip.

 

A good 1200 hex head motor usually will be in the region of 100 RWHP and, due to the gearing changes between the two bikes, top speed is probably also HP limited. Make a quick assumption that the aerodynamics of the two bikes are probably not far apart. (The 1100RS had less frontal area but was not as clean, aerodynamically).

 

cube root of (100/81)=1.073*132=141.605 mph.

 

Let's see how I did.

[NakedRider]

Don't have one but, I can make a fair guess.

 

My 1100RS made, after a chip and a pipe, 81 RWHP on the dyno and had a HP limited top speed of around 132 mph, GPS, no rev limiter in the chip.

 

A good 1200 hex head motor usually will be in the region of 100 RWHP and, due to the gearing changes between the two bikes, top speed is probably also HP limited. Make a quick assumption that the aerodynamics of the two bikes are probably not far apart. (The 1100RS had less frontal area but was not as clean, aerodynamically).

 

cube root of (100/81)=1.073*132=141.605 mph.

 

Let's see how I did.

 

Interesting way to look at it. I think that might be a little high, however.

 

I believe the ST does about 145 on the top and has much less frontal area as did the 1100RS. My bet is it's below 140 since it uses the same engine as the ST but has more weight and a larger frontal area trying to punch a hole in the wind.

[Pictou]

I recall reading a magazine review where they claimed a 137 mph top end for the RT.

[Highway41]

135.2 on GPS without bags and with Aeroflow w/s. Stock pipes and motor. Wasn't paying attention to the speedo.

Bill

[uk1200RT]

I had mine up around 150 indicated on the Autobahn. I was following a BMW 740 that was moving pretty well too...he just pulled away from me. They are limited at 155, so maybe it was close. BTW, it was smooth as silk.

[marcopolo]

I recall reading a magazine review where they claimed a 137 mph top end for the RT.

 

I believe that was Motorcycle Consumer News.

[ShovelStrokeEd]

Weight really doesn't impact top speed so long as their is enough to maintain traction. Plays hob with acceleration.

 

Frontal area and aerodynamic efficiency are the big things, along with HP of course. HP requirement to overcome aerodynamic drag varies as the cube of the change in speed. It can be interesting, to some, to do a reverse plot on that and see why, on certain bikes, 10 mph difference in cruising speed can make a significant difference in fuel consumption.

 

Getting a tow from a car can make a dramatic difference in the speed. It is amazing how far back, at high speeds, the wake of a vehicle can extend. My Blackbird's cooling system is really sensitive to air flow over the bike. It is adequate in clean air and maintains coolant temperatures at or near the thermostat temperature on all but the hottest days. If I get within 50 yards of a car in my lane while doing even 85 mph, temperature rises 10 degrees F. 20 yards (yeah, I know that's too close) at the same speed and it will go up about 20 degrees.

[Tapatio]

Most have topped out at 135. Here's a previous thread.

 

Previous Top Speed Post

[JJZorro]

This past spring on a long straight stretch in New Mexico, fully loaded side and top cases, sleeping bag, tent and chair in bags on back seat I saw my GPS read 112 mph. Took a long while to get there and I am sure the drag and weight of my gear was the limiting factor.

[RoSPA_man]

This past spring on a long straight stretch in New Mexico, fully loaded side and top cases, sleeping bag, tent and chair in bags on back seat I saw my GPS read 112 mph. Took a long while to get there and I am sure the drag and weight of my gear was the limiting factor.

 

Sounds like you need a TwinMax

[CoarsegoldKid]

Speedo reading on mine(stone stock screen down, no bags attached) indicated 134/5 bouncing on the limiter in 5th gear. A shift into 6th didn't seem to gather much more MPH and I was really trying to keep my eyes on the road way ahead. So I let up. A ground squirrel could ruin your day.