Airhead on the Interstate

[captainsteve]

87 r80 rt

Interesting discussion. Being a fairly new owner (about 7 months/3,0000+ miles) of my 87 R80 RT I appreciate the input of my fellow airheads. Just went from a 2 hour ride and got to thinking about this thread so I headed up I-10 to check my numbers. I see a steady 75 at 4,500 and 80 happens at just under 5,000 (4,900?). The bike is smooth and steady at these speeds but since most of my riding is on 2 lane state highways I rarely run that fast.

 

[DonTom]

On my '71 R50/5, I run a halogen parking light bulb. I think it's bright enough to pass as a light in the daytime. It helps the marginal charging system. Anyway that's my story and I'm sticking to it.

It can easily be converted to 280 watts and then you can keep all your lights on all the time with better charging than you used to get with them off.

My bike fully charges below 2,000 RPMs with ALL the lights on. Only $200.00. See here.

Or you can go up to 450 watts if you want, which I thought was overkill for me.

BTW, I also got a new armature to completely rebuild my charging system.

Another thing to consider is buying a /6 front cover from E-Bay or wherever. It is vented, unlike the /5 cover, to help keep the charging system cooler. It fits the /5 perfectly.

See here for more info.

-Don- SSF, CA

 

[47512]

I have a R75/6 with 175,000 miles on it. The freeway never seemed to bother it.

 

[franko]

87 r 80 rt

Captain Steve: I have a 85 R80 RT. At 4,000 rpm, the bike is doing 57 mph, at 5000 rpm she is at about 70 mph.
Could you check to see what final drive you have on your bike? Maybe it's from a R100.
As the speeds are increasing in Wisconsin I'm looking to up the millage a bit and have room to keep up with traffic when it's moving at 80 mph.
A side thought for you, My speedo is very optomistic, by about 15 mph. The speed readers along the road were my first clue. I've just been using the garmin as my speedo, until I do the proper fix. Thanks Frank

 

[captainsteve]

87 R80 RT (Currently 72,000 miles)

Captain Steve: I have a 85 R80 RT. At 4,000 rpm, the bike is doing 57 mph, at 5000 rpm she is at about 70 mph.
Could you check to see what final drive you have on your bike? Maybe it's from a R100.
As the speeds are increasing in Wisconsin I'm looking to up the millage a bit and have room to keep up with traffic when it's moving at 80 mph.
A side thought for you, My speedo is very optomistic, by about 15 mph. The speed readers along the road were my first clue. I've just been using the garmin as my speedo, until I do the proper fix. Thanks Frank

Frank, my owners manual shows the final drive ratio as being 3.36:1. What is yours?

My speedo seems to be accurate as I ride with a number of others, many of whom have full time GPS displayed and my readings are always consistent with the rest of the pack.
The sweet spot for fast cruising seems to be at 75 - 4,500 and found the bike to be very smooth and steady at 5,500 which = 85 but I am not comfortable going that fast. Most of my riding is in the 55 - 70 range except for the infrequent visits to the interstates.

 

[franko]

Final drive R80/R100

Good Afternoon Captain Steve: On my Final drive housing, next to the oil fill hole for the swing arm, it is stamped 37/11. This would give the ratio stated in the owners manual.
I was curious as to weather a former owner had swapped out your final drive with one off a R100. The R80s were given a lower drive ratio than the R100s to help with acceleration. If yours has been swapped out, do you find the acceleration acceptable? Frank

 

[captainsteve]

Scoots like a scalded cat

Double post deleted

 

[captainsteve]

Scoots like a scalded cat

Good Afternoon Captain Steve: On my Final drive housing, next to the oil fill hole for the swing arm, it is stamped 37/11. This would give the ratio stated in the owners manual.
I was curious as to weather a former owner had swapped out your final drive with one off a R100. The R80s were given a lower drive ratio than the R100s to help with acceleration. If yours has been swapped out, do you find the acceleration acceptable? Frank

I just checked and yes mine is stamped 37/11. This would tend to confirm my suspicions that the bike is strictly stock.

As far as acceleration I have no complaints.... drop into third, jump on the throttle and hang on on right through 4th and 5th. It is no rocket ship off the line but by the time you hit third there is plenty of torque at work considering it is only rated for 51 HP. My speedometer could be off one, maybe two optimistic mph but certainly no more than that as I am consistently reporting the same speeds as my riding club buddies as we discuss the ride out over breakfast or lunch.

As noted earlier at 85 turning 5,500 it sure felt like there was plenty left and while I will never find out I have little doubt the theoretical top end of 105 is doable.

 

[globalrider]

What are your thoughts?

I ran a stock 45 HP 1980 R65 on the Autobahn for ten years in the upper end of the RPM range. I regularly cruised at 140 KPH (87 MPH).

Not an issue.