Indicated speed vs actual

[pmdave]

Forgive me if this subject has already been discussed.

Ever since purchasing my 2003 R1150GS Sport, I noticed that it seemed to motor along effortlessly, and it seemed that I wasn't actually moving as fast as the speedometer indicated. Even 70 or 80 mph (indicated) didn't seem that fast.

For the first time in December I installed the GPS on the GS, and got a very surprising comparison between indicated and actual speeds. At a road speed of 55 mph (according to the GPS) the speedo was indicating about 68.

Well, I knew that speedometers tend to be very optimistic, but a discrepancy of 13 mph seemed to me to be a warrantee issue, so I called the BMW shop today. The shop answer: "They all do that. It's normal."

Well, I don't know of any other brands that have a 19% error. I'm not surprised, but I'm again disappointed in BMW. Even if I think I'm "speeding" with the needle on 80mph, I'm really only doing 65. I'd really prefer to have the speedometer indicate actual speed, within say 5%.

Whatever BMW's reasoning, riding around in traffic at 19% under the posted limit seems to me to be a hazardous idea. I think this falls under the category of "safety defect", and I think BMW should be required to fix the problem.

I think I'll forward this to Bob Young, NHTSA office of Defect Investigations, ryoung@nhtsa.dot.gov

In the meanwhile, is there an easy way to recalibrate an oilhead speedo so it is closer to actual speed?

pmdave :dunno

[cat0020]

It should be no surprize that speedometer reads higher than actual speed, but 19% does seem little odd.. do you have your tires inflated at decent pressure??

[chasman]

GPS readings on my '02 K12RS...

40 mph on speedo = 38.5 GPS
80 mph on speedo = 77 GPS
100 mph speedo = 96.5 GPS

100 mph on GPS = 100+ on the speedo = 8>)


Riding Like the Wind (by GPS or speedo)...

CHASMAN
Black '02 K12RS

[SheRidesABeemer]

Wow that's a significant difference. I learned with my GPS that I'm running about 4mph off. I'm better off "pretending" the speedo is correct. But now I'm in the habbit of using just the GPS display.

[Grey Matter]

According to my Garmin GPS my speedometer is 5 mph off. If the bike speedometer reads 70 I am actually doing 65. A 19% discrepancy is not acceptable let BMW try again for a better answer.

[BradfordBenn]

My speedometer is about 10% off. I just do the math in my head.

[manicmechanic]

Has somebody replaced your front rim and tire with something a bit smaller?

[Shiner]

On a 2000 LT, at 80MPH the GPS indicated actually going 74. On a 02 RT, the GPS indicated the same descrepancy which was acceptable but certainly not your 19%. Shiner

[Braddog]

Tooling down the local streets when I came upon one of those stationary radar thingies that the local police put up to give people an idea of their speed. I always felt that I was going a bit faster than the speedo said (the opposite of Dave's problem). Indicated 29 MPH, radar showed 37.

I would think that BMW would want to do better than a 19% error. Even 10% is pushing it a bit, IMHO.

[dlearl476]

Dave, I think you're right to forward it to the authorities. It's true modern mc's are puposely optomistic to allow for any reasonable WRONG tire to still read UNDER the real speed, but I think 10% is the maximum allowable error. I would bet yours not funtioning properly. I'd call PaloAltoSpeedo and have a chat. They'll hip you to the good stuff.

[jgr451]

Chees ,Shiner,your speedo error is 13% AND you are OK with that?

Now I'm scared,since I don't have a GPS to check mine.

[Emoto]

According to my GPS the error on the R1200GS is rather small. Around 2-4%, if I recall correctly.

I would hound the dealer over a 19% error.

[Jim Shaw]

What's really irritating about these errors is that they are all unnecessary. My 01 1150GS is off by about 7%, yet the odometer is within 1%. It is trivial to provide speedos with less than 2% error - 1% is accomplished all the time.

I am convinced it's a sinister government plot or something. I've heard the same complaints from riders of every brand of moto. Yet in checking my last five or six cars, they are within 1% every time.

A 19% error is a product defect. I hope WA has a lemon law. Jam a few $16K bikes up BMW's factory exit and they might catch on. :nod

[Scootertrash]

I keep it simple and fly 10 miles above the speed limit....

[Mudbug]

BMW can install accurate speedometers on their bikes. They choose not to. And any reasons they give for not doing it are lame excuses.

Police vehicles, including motorcycles, have accurate speedometers. Most police use radar to gauge another vehicle's speed. They can gauge another vehicle's speed by following at a constant distance over a period of time.

H-D has calibrated speedometers on their police bikes and they use that speedometer on their civilian bikes. BMW is competing with H-D for a share in the Police mototcycle market. I'm sure that those bikes do not have speedo's that are off by 19%. I bet they are accurate.

The speedo on my 04 K-GT is optomistic by aprox 2.5 MPH. The speedo on my 91 K-RS is optomistic by 10%. I go 90 it shows approx 80. Some BMW's are more accurate than others.

So, it can be done.

[Jim Shaw]

I keep it simple and fly 10 miles above the speed limit....

Which by my calculations, on PMDave's bike will have you riding 4 mph UNDER the 70 mph speed limit.

That said, I sort of do the same thing - but with an error of +7% I ride about 15mph indicated over the limit. I've had one speeding ticket on a moto in 9 years - 81 mph in a Texas 70 mph zone. Some deputy was making money for the local JP.

Never paid it. Got a letter from the OH DOT with a copy of a Texas letter. OH said they didn't know what to do with it, so they sent it to me.

I knew what to do with it. :deal

[bikerfish1100]

10% high is what i have most frequently heard as the "typical" BMW speedo error. 19% is thoroughly wrong. yes, the mechanic was right when he said "they all do that". however, i've never heard of one that does it to such a momentous degree. i'd push it back on them.
jgr- check your calculator. on shiner's speedo, reading 80 when doing 74 is 6 mph error, which translates to a 8.1% error (6/80). of course, we might do the calculation as 6/74, but that would bring it down to a 7.5% error. don't mind me- just picking some nits.

[bmwmick]

[/QUOTE]

Dave,
Take a look at this thread on Advrider
http://www.advrider.com/forums/showthread.php?s=&threadid=701

[Cliffy777]

my jap bikes in the past were always off by 5-7%, so i guess i figure that is "normal" for bikes. when i was young and reckless i didn't pay much attention, now that i am old and have no desire to collect performance awards i figure if it reads 80 and i am only doing 74.4 mph then that is a good thing.
19% is worth squawking over with the dealership IMHO.

on a related note, J Shaw wrote about his TX ticket: "Never paid it. Got a letter from the OH DOT with a copy of a Texas letter. OH said they didn't know what to do with it, so they sent it to me. I knew what to do with it. "

so was it a trumped up ticket? is that your point and the reason you didn't pay it? or does your position as former moa prez and current ambassador come with non-ticket paying priviliges?

[85343]

I have a 1995 R1100RSL. As a LEO I have access to radar units. I mounted a spare radar on my bike with mass quantinties of duct tape. I checked the radar vs speedo at 10 mph increments. My speedo was 8% optimistic.

[Jim Shaw]

so was it a trumped up ticket? is that your point and the reason you didn't pay it? or does your position as former moa prez and current ambassador come with non-ticket paying priviliges?

No, the volunteer MOA work just gets us snotty **** from some.

I said I didn't pay it because I didn't pay it: truth withstanding. Guess I could have left that part out, and stayed your personal hero. I was lucky, was my point, that TX and OH didn't have reciprocity back then.

Now, what was your point?

Oh, and by the way, my calculation above is correct. I specified PMDave's bike, which he has pretty competently shown to be 19% off.

Jim
Damaging the environment by squandering capital letters.

[donkey doctor]

Hello; I was bothered by an inaccurate speedo too, that coupled with a mile speedo in a kilometer world, situation. I mounted a bicycke speedo on it to test the accuracy. I found that the error wasn't linear, and that it was closer at low speeds and got less and less accurate as the speed rolled up. I only intended to use the bicycle speedo as a check but now I use it all the time.

My old 535i has an electronic speedo, it was driven by an ABS sensor which would count rotations. Don't the modern generation bikes have electronic speedos? If there's an error in an electric speedo, then it is in the programming, and should be correctable. Or do they use a spinning cable and a balbnce spring?

My Old r100/7 has a gearbox on teh output gear that drives a cable that spins a magnet against a balance spring to indicate speed. I like my cheap GPS only cost $20, I suppose those expensive ones work too.

[Greg]

Go the the AdvRider link listed above. I did that mod and my ~10% error came down to less than 3%. Stock ratio is 2.85:1 and the Roadster Drive that is mentioned in the link above is 3:1. Mucho better on both the Speed and the Odo.

[dano]

Jap bikes are as bad as their European counter-parts, when it comes to inaccurate speedos.

More or less....an industry standard issue, and not a good one.

I've heard tons of reasons why this is so, and I still haven't heard one reason yet that made sense. :dunno

[Mr. Frank]

BMW speedos tend to be off from 5-10%, but I think you have a warranty issue. My understanding is that in excess of 10% is beyond tolerance. I'd ask the dealer to replace it.

[Cliffy777]

[QUOTE=Jim Shaw]I said I didn't pay it because I didn't pay it: truth withstanding. Guess I could have left that part out, and stayed your personal hero. I was lucky, was my point, that TX and OH didn't have reciprocity back then. Now, what was your point?"

didn't mean to poke such a sore point. i was surprised that someone of your stature in the bmw motorcycling community would ignore a legit ticket. i certainly don't like performance awards, but i figure any one that i get is more than balanced out by the times i should have gotten one and didn't. (well, except for the time i got popped for having 4 people in the front seat of my really big dodge pick-up and one of the 4 was a lil kid. this was before all the child seat laws and what not. i squaked at the officer writing the thing, but still paid the ticket.)
"personal hero" you weren't. what gave you that idea? my personal hero is, and shall remain, jimmy greenspoon - the great keyboard player from 3 dog night.

[Jim Shaw]

[QUOTE=Jim Shaw]didn't mean to poke such a sore point.

Being quick and clever to insult seems a pretty trivial skill. ;)

[Shiner]

I noted that when I checked a 00 LT and a 02 rt on a GPS they both were showing an indicated speed of 74mph and the bikes were doing an indicated 80mph on the speedo. jgr451 asked me if I would be OK with a 13% descrepancy and I wouldn't but that is not 13% off. 10% off of 80mph would be a difference off 8mph which would give you 72mph and I'm not that far off. Multiply 80 mph x .075 and you will come up with 6.0 The speedo on the LT and the RT were both off by 7.5% not 13%. Yes, 7.5% would be acceptable but not by much. Teachers like to get things right. Todd

[pmdave]

I decided to try a little diplomacy. Not being quite up to Jim Shaw aggressiveness, I called the salesman who sold me the bike. He's moved to a different shop, but since I didn't give him any flak on the lowish trade-in back at shop #1, perhaps he felt he owed me something.

Anyway, he discussed the situation with his shop guy, and they decided it qualified as a warrantee repair. "19% is excessive, even for a BMW." They have ordered a new speedometer, and after installation I'll be prepared to take a short run with the GPS on to see if it's closer to reality.

I wouldn't be surprised if someone at the factory got the speedos mixed up, and a batch of wrong ones got installed in certain models.

From various tests, I know that motorcycles tend to have speedometers that read a little faster than bike speed. Typically, speedos read 5 to 7% fast on new bikes. One reason may be so the manufacturer never has to assume any responsibility for speeding tickets. No one can say "hey it was the speedometer, man." (yeh, that's why I was doing 80 in a 55!)

A related reason is to provide acceptably accurate reading as the tires wear. One of the reasons stated to me by the "they all do that" guy at shop #1, is "it's in case you install different tires." uhhh, OK, but it sounds like an excuse rather than a reason. Seems to me that the speedo should read within 5% or so with the tires that come on the bike as sold. Are there any Adventure guys out there with bigger tires? What's your speedo experience?

I did send a copy of the original message to NHTSA. If more of us sent messages that related to defects we believe are "safety" issues, the manufacturers would at least have to respond to NHTSA, and that would trigger them to pay closer attention to customer complaints. There is no magic "minimum" number of complaints to trigger a recall. If NHTSA believes the problem is safety related and potentially involves a large number of motorcycles, they can require a manufacturer to come up with a fix.

In the best scenario, your dealer will go to bat for you, and convince the tightwad reps to take care of the problem. That's probably cheaper for the manufacturer in the long run. For instance, there have been a number of temporary "failures" of the power brakes on late model BMWs, as reported in MCN. The test rider was able to pump the lever and get the brakes working again. BMW was given an opportunity to respond, and they chose to explain it away rather than treat it as a potentially dangerous situation. If there is an ongoing problem with the power system (or calipers or whatever) I'd like to believe that BMW would jump on the bike and test it to see why it occurred, and if there is a potential problem, come up with a fix before the feds have to force them to.

BTW, for the guy with the airhead speedo that reads much slower than his actual speed, I'd suspect someone has swapped rear ends for one with a lower ratio than it came with. The reverse happens when you drop in a higher ratio final drive (say a 37/11 to replace a 32/10). On the airheads, the speedo is driven off the transmission output. For you airhead guys, on the oilheads, the speedo is driven off the front wheel, so there shouldn't be any excuses.But hey, I'm forgetting the engineers are German. If you look in your dictionary under "arrogance" there is a picture of a German engineer.

pmdave :type

[108281]

For anyone without a GPS, which includes me, you can still check your speedometer if there's a highway near you with mile markers. Just get up to the speed you want to check and check the second hand on your watch when you go by the first marker, then hold to that speed as close a possible and check you watch again when you pass the next marker and remember the elapsed seconds. At 60 mph it should take you 60 seconds. Suppose it takes you 64 seconds. Divide 3600 (the number of seconds in an hour) by 64. Your speed is 56.25 mph.

AR

[Jim Shaw]

I checked with my local auto engineer/DOT expert. He says motorcycles fall under the same DOT rules as cars. They must not read below actual vehicle speed with the delivered tires. They can read any amount above and meet DOT.

Police vehicles must be accurate to within +/- 1% of actual speed and must be scaled in 1 mph increments.

US DOT specs are only one item of interest on this issue, but here it is.

[pmdave]

Hi TECAWP,

Yeh, I realize the DOT regulations allow BMW to be really sloppy about speedo accuracy, but when I part with my hard-earned greenbacks, I expect quality equal to the inflation in the price. I wouldn't complain about a speedo on a Ural being off, but on a new BMW-anything I expect accuracy.

And, others, I have the stock speedo, front wheel, front tire, etc. etc. that came from the factory. Absolutely stock up front.

BTW, there's a detailed discussion over on www.advrider.com about this same issue. It's been discovered that speedo drives from other BMW models will slip into the same style of wheel, and slightly different drive ratios may correct speedo error. (depending on the speedometer and it's setup, of course) Cost: about $50.

Now, if there are BMW parts in the system that will provide greater accuracy, why doesn't BMW put them in? Or, if only some machines exhibit inaccuracy, why not allow dealers to swap the speedo drives to correct the problem?

I'll be checking the accuracy of my "new" speedometer with the GPS after they install it. If it's still off more than about 5%, I'll order up the #62-12-2-306-532 (2.875 ratio) drive for the front wheel and install it myself. There is also a lower ratio available. The dealer's shop didn't mention anything about this, of course. It's not a fix blessed by BMW.

pmdave :thumb

[Jim Shaw]

I assume you are considering that if you accomplish a 13% reduction in your speedo reading, it will also give you a 13% increase in your warranty distance? BMW just MIGHT be thinking about that!
-Jim

[pmdave]

Well, TECAWP,

The odometer isn't as important to me as it used to be. These days I end up with my machines parked in the garage while I go flitting off in silver tubes to other lands to ride OPB's (Other People's Bikes). So, my odos don't turn over fast enough to approach the limits.

How-some-ever, it it happens that I get fewer odos stacked up on the GS during my warrantee period, I could at least chuckle at the deal. :thumb

pmdave

[glinm]

On my 05 LT I have a digital average mph. When the speedo reads 70 my gps reads 64. If I reset the average speed, the digital reads 64. I have done this at several different speeds and the gps and digital are always within 1 mph of each other. The accuracy is there, it is just not used.

[pmdave]

On my 05 LT I have a digital average mph. When the speedo reads 70 my gps reads 64. If I reset the average speed, the digital reads 64. I have done this at several different speeds and the gps and digital are always within 1 mph of each other. The accuracy is there, it is just not used.

Gee Glinm, I've looked and looked for the digital average mph reset switch on my 1150GS, and I can't seem to find it.

pmdave ;)

[glinm]

Gee Glinm, I've looked and looked for the digital average mph reset switch on my 1150GS, and I can't seem to find it.

pmdave ;)
Go to your friendly BMW dealer. He can fix you up with the switch. Just expect the bike to weigh a little more after he gets finished.

[kbasa]

The R12GS ones are pretty accurate.

http://kbasa.smugmug.com/photos/6151265-M.jpg

[username]

duuuuuuude! :)

[pmdave]

Ahh, handy those digital cameras. Looks to me like the speedo is reading 115 ~ 116 mph. That would be only 2% or so off--I'd be very happy with that!

My GS goes to the shop tomorrow for a new speedo under warrantee. If it's still reading fast, I'll try the 2.875 speedo drive, part no. 62-12-2-306-532.

pmdave :brow

[pmdave]

South Sound BMW (Tacoma, WA) replaced the speedometer for me with no hassles. Great shop, BTW, with a display of several restored vintage BMWs, lots of riding gear, and a good place to spend an afternoon. The Parts Manager, Darren Thackeray is an enthusiast, and has lots of goodies for all models, including airheads. Wayne (sales) happened to notice that the oil fill cap had just started leaking, and they took care of that too. tel 253 922-2004 or 800 303-1838 or www.southsoundbmw.com

Now, the speedo indicates 70 mph at a GPS speed of 64.4. If my math is correct, that's an 0.087 error, well within BMW limits.

I could live with a mere 5.6 mph "error" at 65 mph, but now that my curiosity has been stimulated, I want to see if I can tweak it even closer. So, I've ordered the (R1100R) spoked wheel 2.875 ratio speedo drive, which should bring the error down to about 2.8 mph--about the width of the speedometer needle.

The BMW part number is 62-12-2-306-532. Cost is about $45.

pmdave :clap

[Jim Shaw]

[QUOTE=pmdave]South Sound BMW (Tacoma, WA) replaced the speedometer ... Now, the speedo indicates 70 mph at a GPS speed of 64.4. If my math is correct, that's an 0.087 error, well within BMW limits.
pmdave :clap[/QUOTE

I had my oil changed on no notice at that dealer this summer. It was about the first day they were open. I was blowing down I-5, saw their sign, and about did a stoppie. The service manager suggested I enjoy the showroom (mostly empty then) and use their writing desk to make some cell phone calls. I got involved on the phone, and about 45 minutes later went back to check on the GS. It was gone!

The oil change was done and the service mgr had it in the wash bay, washing it for me. I told him that was a pretty nice thing to do. He says, "Wouldn't you do it for me if I came to your place? Besides, what else do I have to do right now." Never charged me for the wash at all. After AK and the salt spray on the AK Marine Highway, it was good to have it clean.

As I understand it, they are owned and managed by the Seattle BMW dealer people. I'd go back in a minute, if they weren't 2362.9 miles from my house, by the shortest route. Their price for the service was fair, too.

Their showroom is the nicest, biggest, and best I've ever seen in a BMW shop.

You are somewhat easily pleased with BMW if the best they could do under warranty was an 8.7% error. Granted, it was probably the best the Tacoma dealer could do.

It seems to me that a company with the reputation for quality of BMW could supply a speedo that tells the truth, stock, from the factory. :doh