RPMs@60mph

[HawkeyeSpecial]

Was wondering what the normal rpm range was for a 1980 XS1100LG Midnight Special? I am running at about 4000-4500 and think this is way off. Anybody have any thoughts or suggestions on what may be wrong with the bike.
Note: Stage 1 installed on the carbs (K&N)

Thank You!

Go Hawks!

[foxjohnc]

Sounds about right.

[ratbyk]

RPM/Speed

You have given us your cruising RPM but not what speed you are showing. I know out on the highway normal cruise/running with the traffic flow my tach reads between 4000-5000. (100-120kph). Feels great and has instant throttle response. These are not Harley's. Let em rev. XS's smile at these speeds just like you should.
Ken/Sooke

[foxjohnc]

Look at his post carefully, he said @ 60mph.

[Winterhawk]

4500 RPM = 55 MPH
5500 RPM = 90 MPH

[Hepcat]

I run just under 4000 rpm for 60 mph.

[ratbyk]

Speed vrs RPM

This chart is for a 1978 XS 1100 E with a 17" Rear wheel. If yours is a special the gear ratios are the same but your speed will be marginally lower because of the 16" wheel. If you have the 17" wheel the chart should be right on.

Gear 1 2 3 4 5
MPH per
1000RPM 6.2 8.6 10.9 13.5 15.8

Eg. 4.000 by 15.8 = 63.2 MPH

5.000 by 15.8 = 79 MPH

Does this answer your question?
Ken/Sooke

[Ken Talbot]

Ah, so redline in 5th gear is really cooking along then, just about 215km/h!

[HawkeyeSpecial]

Thank You!

Thanks everyone for the help. I am new to the XS scene and appreciate the information.

Go Hawks!

[strom]

As I'm running in the 78E, my top RPMs are at 4000.... and it's bout 100 kmh/60 mph.... in 5th.

LP

[Winterhawk]

My mistake sorry

3500 RPM = 55 MPH

[2fast]

speedo error

I hate to rain on the parade, but if any of you run with a GPS, you have found out that the speedos tend to read at least 5mph more than you are really travelling. The other guys I ride with on different machines report nearly the same errors. I am convinced that the manufacturers have built in this error. Most likely to make us think we are cranking a little more than we really are. 5mph is hard to notice, 10 would be more obvious.

[TopCatGr58]

Well,

2fast, that was just a feature to help Specials not get as many speeding tickets, since they look faster than Standards!

I saw an FYI Radar Sign coming home yesterday, you know the kind, that points to the road and tells you your speed as you drive by. Will have to check it out at the posted limit of 45, and maybe a second run a little faster to see how my speedo checks out!

Of course, it might still not apply as much to the rest of us, since I'm running an XS650 120MPH Speedo that I put on to replace my 85mph one with the broken odometer! Hey, it's a Rat Bike!!
T.C.

[pgg]

Well I put on a small digital speedo - the local kart boys use them. Dialed in by wheel diameter and claimed as accurate plus minus 1mph. On my XS at least, the rev counter seems real accurate but the stock speedo's basically untrustworthy. Dunno where Ratbyk got that chart, but the figure of 15.8mph per 1000 revs works out bang on.

[UncleSpot]

small digital speedo

hey pgg - where did you get your small digital speedo? How did you mount it? do you have any fotos of yours? ...give us some more info - I'm ready to change my stock one out...