| Member |
 Discussion Topic  |
|
|
Texasphotographer
 Advanced Member
746 Posts
[Mentor]
Copperas Cove, Texas
USA
Suzuki
2008 C50T
|
 Posted - 06/22/2008 : 6:00 PM
|
Yesterday, I rode with my son for about 150 miles. He said he was going the speed limit which is 70 MPH. To even try to keep him in site I was driving (according to my speedometer) at almost 80.
Last night, I was going with a bunch of friends about 65 miles away and they were riding at 60 - 65. My speedometer read 70 - 75. It this a common occurence?
Hopefully the dealership will fix this while I wait, but the bike has other problems as the key got stuck in the ignition. I think it may be in the shop for a couple of days. Drat it.
|
|
rioguy
Ex-Member
|
Posted - 06/22/2008 : 6:29 PM
|
| Speedometers reading way low is common to Japanese bikes. The Burgman reads about 10% low although the odometer is accurate according to distances measured on googlemaps. Same with my Majesty. |
 |
|
|
jnmobley
Senior Member
261 Posts
Carson, Virginia
USA
Triumph
2007 Speedmaster
|
Posted - 06/22/2008 : 7:26 PM
|
| My Triumph reads about 10% slow as checked by GPS. |
|
|
|
Deseret Rider
Advanced Member
721 Posts
[Mentor]
Helper, Utah
USA
BMW
R1100RT
|
Posted - 06/22/2008 : 10:06 PM
|
My speedometer is optimistic----reading 70 when I am actually traveling 64 according to the GPS----and the odometer is also less than accurate but reads only about 1% more than the gps miles. Both units are fed from the same cable which is gear driven from the front wheel. The interface with the speedometer however is a rotating magnet while the odometer is geared----thus they won't necessarily be showing the same percentage of error. If this general configuration is true for your bike then I think the dealership might exchange the speedometer unit and find one with a tighter tolerance on the magnet (or a slightly stiffer spring---which is a counter force to the magnet). If however, your shop guys have ever been educated in Germany---they will just tell you "They all do that" so it's "normal" and if it's normal it must not be a problem.  Good luck---let us know what happens! |
|
|
|
amhopf
Standard Member
216 Posts
Littleton, Colorado
USA
Honda
02 VFR800 ABS
|
Posted - 06/23/2008 : 8:16 AM
|
After changing the front sprocket, my spedo/odo are about 17% Optimistic. 
I need to buy a Speedo Healer
I have heard that most Honda's are normally about 5-10% optimistic |
|
|
|
babayaga
Junior Member
99 Posts
Omaha, NE
USA
Kawasaki
KLR650
|
Posted - 06/23/2008 : 8:30 AM
|
| My Kawi is indeed 10% optimistic. |
|
|
|
D R
Advanced Member
611 Posts
[Mentor]
Northern, Virginia
USA
BMW
R1200RT
|
Posted - 06/23/2008 : 9:04 AM
|
Many years ago, I was operating a GOV (government vehicle) on the Interstate in the vicinity of San Antonio. I was driving the posted speed limit (55 mph) -- or at least according to my speedometer. After a short while I became aware that I was consistently overtaking and passing traffic in the right lane.
Anyone with experience driving in and around San Antonio knows the traffic in the right lane rarely drives that slow. I reduced speed to match the flow of traffic and the speedometer now read around 45 mph.
When I turned the vehicle back in, I told the dispatcher they needed to check the speedometer. Sure enough it was off - when reading 55 mph you were actually going 75 mph.
I was lucky to suspect the problem before a police officer stopped me to let my know about it. |
|
|
|
Deseret Rider
Advanced Member
721 Posts
[Mentor]
Helper, Utah
USA
BMW
R1100RT
|
Posted - 06/23/2008 : 9:20 AM
|
Good post on the speedhealer! But alas for me my bike must not be 'modern' in the sense that it does not have an electronic speedometer.  Seems like a very reasonable, if a little pricey, solution for those with 'modern' bikes though. |
|
|
|
scottrnelson
Advanced Member
4748 Posts
[Mentor]
Pleasanton, CA
USA
Ducati
ST2, 888, + XR650L
|
Posted - 06/23/2008 : 9:38 AM
|
The speedometer on my 888 is off by a full 20%. If it says 100 mph, I'm "only" doing 80. 
The only way I know of to correct it is to send it to a place like Palo Alto Speedometer and have them calibrate it. Their web site has exact instructions for measuring wheel rotations and speedometer cable rotations, requesting that you measure it all three different times and record what you get. They'll then make it exact. "One of these days" I might give in and have them calibrate my speedometer.
If yours is mechanical, like mine, there's nothing the dealer can do to adjust it. You have to take it apart and change weights and little magnets inside to adjust it properly. |
|
|
|
Mystic Red
Senior Member
292 Posts
Twin Lakes, Idaho
USA
BMW
K1100LT
|
Posted - 06/23/2008 : 9:44 AM
|
You think your speedo's are optimistic. Check out my GPS max speed!
 |
|
|
|
falcon1
Standard Member
247 Posts
Colorado Springs, CO
USA
Indian
Chief
|
Posted - 06/23/2008 : 10:47 AM
|
I'm at a loss with why this is an issue. The companies that supply speedometers for motorcycles all also have instructions available so that you can re-calibrate them yourselves.
I know for a fact this is true for both VDU and Autometer speedometers, and I know the instructions for both of those. In fact, for VDU speedo's, once you get the calibration code for that speedo on that bike, all similar speedos on that model bike with those tires use the same code. Just input the code and calibration is finished without moving the bike. Why spend cash on a speedo-healer when a couple e-mails or a phone call to the manufacturer can resolve the problem?
Changing tire size and/or pressure can cause incorrect readings, by the way. Make sure you have proper presuure in your tires when doing calibration runs. |
|
|
|
scottrnelson
Advanced Member
4748 Posts
[Mentor]
Pleasanton, CA
USA
Ducati
ST2, 888, + XR650L
|
Posted - 06/23/2008 : 11:10 AM
|
quote:
Originally posted by falcon1
I'm at a loss with why this is an issue. The companies that supply speedometers for motorcycles all also have instructions available so that you can re-calibrate them yourselves.
I know for a fact this is true for both VDU and Autometer speedometers, and I know the instructions for both of those. In fact, for VDU speedo's, once you get the calibration code for that speedo on that bike, all similar speedos on that model bike with those tires use the same code. Just input the code and calibration is finished without moving the bike. Why spend cash on a speedo-healer when a couple e-mails or a phone call to the manufacturer can resolve the problem?
I've owned twelve motorcycles that came with speedometers (and seven more without), and none of them, not a single one, had a way to enter a code to recalibrate the speedometer. Every single speedometer on those bikes was mechanical in nature.
What bikes are you talking about??? |
|
|
|
falcon1
Standard Member
247 Posts
Colorado Springs, CO
USA
Indian
Chief
|
Posted - 06/23/2008 : 11:17 AM
|
Indians, Harleys, and other bikes with electronic speedos. The button (or one of the buttons, if multiple are available) on the speedo (to reset trip miles, for instance) is used to enter the code on VDU speedos after you put it in calibration mode using the same button.
Mechanical direct-drive speedometers would not benefit from the speedo-healer anyway, if I'm reading the info on it correctly. For a lot of those, there is a calibration screw somewhere on the speedometer that can be used to set the reading higher or lower. But agin, not all mechanicals had that option. |
|
|
|
scottrnelson
Advanced Member
4748 Posts
[Mentor]
Pleasanton, CA
USA
Ducati
ST2, 888, + XR650L
|
Posted - 06/23/2008 : 1:24 PM
|
quote:
Originally posted by falcon1
Mechanical direct-drive speedometers would not benefit from the speedo-healer anyway, if I'm reading the info on it correctly. For a lot of those, there is a calibration screw somewhere on the speedometer that can be used to set the reading higher or lower. But again, not all mechanicals had that option.
I've never seen such an adjustment screw on speedometers found on Yamaha, Suzuki, Kawasaki, or Ducati motorcycles.
I would love to see evidence of such an adjustment screw on any mechanical speedometer for any major brand of motorcycle. |
|
|
|
falcon1
Standard Member
247 Posts
Colorado Springs, CO
USA
Indian
Chief
|
Posted - 06/23/2008 : 1:40 PM
|
quote:
I've never seen such an adjustment screw on speedometers found on Yamaha, Suzuki, Kawasaki, or Ducati motorcycles.
I would love to see evidence of such an adjustment screw on any mechanical speedometer for any major brand of motorcycle.
BMW http://home.jtan.com/~joe/speedo.htm has an adjustable mechanical speedo, although not a set screw. I was speaking mainly about car speedos of the past, but since you asked, here's how to calibrate a mechanical KLR speedo as well: http://members.cox.net/watt-man/Spe...bration.html
You want to know about older jap bikes? Call old mechanics. I can't say for sure which (if any that weren't using recycled auto speedos) might have had a set screw, but since they had it for several car models and the same companies supplied bike speedos, the inference I feel is valid. |
|
|
|
scottrnelson
Advanced Member
4748 Posts
[Mentor]
Pleasanton, CA
USA
Ducati
ST2, 888, + XR650L
|
Posted - 06/23/2008 : 3:27 PM
|
Both of the references for motorcycle speedometers that you've posted involve taking the speedometer apart and making physical changes to parts inside. That's way different than turning a screw. And it's basically what I said had to be done to change the speedometer.
I feel that your "inference" based on what you've seen in a few cars is bogus.
Mechanical motorcycle speedometers require disassembly and modification of internal parts to change how they read. Wishing it were otherwise doesn't make it so. |
|
|
|
gwolfe1234
Starting Member
3 Posts
Houston, TX
USA
Yamaha
|
Posted - 11/04/2009 : 6:31 PM
|
Try SpeedoDRD, I know a few people who tried it and said it worked fine. You can get one at www.12oclocklabs.com.
quote:
Originally posted by Texasphotographer
Yesterday, I rode with my son for about 150 miles. He said he was going the speed limit which is 70 MPH. To even try to keep him in site I was driving (according to my speedometer) at almost 80.
Last night, I was going with a bunch of friends about 65 miles away and they were riding at 60 - 65. My speedometer read 70 - 75. It this a common occurence?
Hopefully the dealership will fix this while I wait, but the bike has other problems as the key got stuck in the ignition. I think it may be in the shop for a couple of days. Drat it.
|
|
|
|
Axiom2000
Moderator
527 Posts
[Mentor]
Georgetown, Delaware
USA
BMW
R1200RT/ R1200C
|
Posted - 11/04/2009 : 10:58 PM
|
Seems to me I remember some discussion on this before and there are actually some regulations regarding the percentage of error allowed manufactures must follow. Found this, but did not check it further for accuracy.
quote:
As of 1997, Federal standards in the United States allowed a maximum 5% error on speedometer readings (per "Auto Tutor", American Automobile Association of California magazine, Oct. 17, 1997). Aftermarket modifications, such as different tire and wheel sizes or different differential gearing, can cause speedometer inaccuracy.]Wikipedia
|
|
|
|
kml
Junior Member
75 Posts
englishtown, nova scotia
Canada
Suzuki
hayabusa
|
Posted - 11/04/2009 : 11:09 PM
|
http://good-times.webshots.com/slid...411332EervJX
Speedohealer install. Works great. No problems in 25000km. Corrected for 7% stock error. On site calculator works well. 100km/h on speedo is 99km/h on gps.
I've used it to correct for gearing and tire profile changes as well.
Top speed recall button too!
Handy gizmo.
cheers
ken
|
|
|
| |
Discussion Topic |
|
|
Most Recent Posts
|
Activity History
|
Safety Tips
Speedometer is way off