Speedo healer question

13/45 sprockets on a WR250X with R wheels...I checked my speedo against my GPS, a whopping 9-11mph off.
GPS 65mpg, speedo 74-76mph/
Ouch.

I think my speedo is near on 10 mph out a bit less at 30 mph...standard gearing and tyres.
I go indicated 43 mph through 30 mph static speed cameras daily.
So an indicated 90mph is more than likely 80 mph or less.

my speedo is way off wish there was a cheaper fix not looking to spend $115 just to see my correct speed ill just strap my iPhone with gps on the bars 13/48 speedo says 70 and i was going 56mph lol

wrxpro wrote:

my speedo is way off wish there was a cheaper fix not looking to spend $115 just to see my correct speed ill just strap my iPhone with gps on the bars 13/48 speedo says 70 and i was going 56mph lol

The 12 o'clock labs unit is cheaper than $115.

Also, how expensive is a speeding ticket, or replacing your iPhone if it gets damaged or broken?


Contact 12oclocker (a member here) and see if you can arrange a group buy.

And yes, with a 13/48 gearing ratio your speed is off by at least 20% from indicated. With Distanzias, mine was closer to 25% off.

I just installed mine this weekend and I now have my speedometer almost 100% accurate and my distance traveled is slightly low (Work is 13 miles from my home and the odometer indicated about 11.5 or so when I got here this morning).

This is cool with me though because I'm on an X with a dirt setup and I racked up a ton of 'extra' indicated miles without using a speedodrd.

I'd love to see a small GPS based LCD speedo display that I could plop over the existing speedo to get the correct speed. I have seen analogue ones but not LCD.

Finally ordered a SpeedoDRD from Motomummy.com for $70. Free delivery to US, $15 to Canada. I took a while to make sense of all the misinformation in the forums. Some of it is just plain wrong. My summary of the speed/odometer issue: From the factory, the speedo runs approx 7% hi but the odometer is correct ie if the speedo says you're going 107 mph, you're actually only doing 100. The odometer add 100 miles in an hour. With the speed calibrators, SpeedoDRD, Speed Healer or otherwise, you can adjust the signal going from your tranny to your bike's speed/odo to read higher or lower BUT the speedo will always be 7% higher than the odo.

A couple of examples of effects riding at a true 100 kph. I used kph cuz it's easier to see the math. I converted to mph further down[/u]

Last year, I changed the fronter from 13T to 12T. So 43/12 divided by 43/13 = 3.58/3.31 = 1.083 or an 8.3% increase. At a true 100kph, the speedo will read 100 +8 +7= 115 kph. The odo will add 100 + 8 = 108 km in one hour. Speedo off by +15%, odo by +7%. Soooo

If you calibrate your speedo to read 100 kph, your odo will only add 92 km after one hour.
If you calibrate your odo to 100 km, your speedo will still read 107 kph.

This year, I changed to a 47-12T set up. So 47/12 divided by 43/13 = 3.92/3.31 = 1.185 or an 18.5% increase. At a true 100 kph, the speedo will read 100 + 18.5 +7 = 125 kph. Your odo will now add 100+18.5 = 118.5 km in one hour. Speedo off by +25.5%, odo by +18.5%. Sooo

If you calibrate your speed to read 100 kph, you odo will only add 81.5 km after one hour.
If you calibrate your odo to 100 km, your speedo will still read 118.5 kph.

]u]
Now for the south side or the 49th with true speed of 60 mph.

Last year, I changed the fronter from 13T to 12T. So 43/12 divided by 43/13 = 3.58/3.31 = 1.083 or an 8.3% increase. At a true 60 mph, the speedo will read 60 + 4.8 + 4.2 = 69 mph. The odo will add 60+4.8 = 64.8 miles in one hour. Speedo off by +15%, odo by +7%. Soooo

If you calibrate your speedo to read 60 mph, your odo will only add 55 miles after one hour.
If you calibrate your odo to 60 miles, your speedo will still read 64 mph.


This year, I changed to a 47-12T set up. So 47/12 divided by 43/13 = 3.92/3.31 = 1.185 or an 18.5% increase. At a true 60 mph, the speedo will read 60+11 + 4.2 = 75mph. Your odo will now add 60 + 11= 71 miles in one hour. Speedo off by +25.5%, odo by +18.5%. Sooo

If you calibrate your speed to read 60 mph, you odo will only add 50.6 miles after one hour.
If you calibrate your odo to 60 miles, your speedo will still read 71 mph.



Just thought I's add my own spin on confusion. Haha

Marioscario wrote:

[...] I took a while to make sense of all the misinformation in the forums. Some of it is just plain wrong. My summary of the speed/odometer issue: From the factory, the speedo runs approx 7% hi but the odometer is correct ie if the speedo says you're going 107 mph, you're actually only doing 100. [...]

Might be true of yours, but mine is quite different. Over nearly 5,000 km, the average speed read 10% too high, and the odometer was 3.5% high. That's with stock gearing. Since I've changed to a 48-tooth rear, the speedo is 20% high, and the odo is 14% high. No "speedo healers" installed. Actual speed/distance measured by GPS. Speed also measured by radar

sturgeon. I have not yet installed my speedodrd. The +7% is what I've seen commonly posted on the forum. So I used the 7% in calculations to demonstrate the relationship between the speedo and the odo with calibrators and different gearing ratios. Your results show that you have 6.5% spread between the two. As well, a 48 -13T gearing calculates to about an 11% increase over stock....which is pretty much what you are seeing. Cheers

Just tryin' to say that my odo has never been correct, either with OEM gearing or modified. I kept some extensive records so I'd have an accurate understanding of fuel consumption and range under different conditions. I sometimes go places where fuel is hard to find, so I need to know how much extra to carry.

I assume you're running a GPS to get all your stats. I'm not usually too far from the truck but far enuf that there aint much left when we get back so I can appreciate where you're coming from. I hope to bang off a few longer trips this summer once I can find a couple of people to buy smaller dual sport bikes that will go in the same type of terrain I like to go. Most of the are XL or KLH 650 types.

PS- Did you collect your radar speed data or did the popo collect it for you?

Marioscario wrote:

I assume you're running a GPS to get all your stats. I'm not usually too far from the truck but far enuf that there aint much left when we get back so I can appreciate where you're coming from. I hope to bang off a few longer trips this summer once I can find a couple of people to buy smaller dual sport bikes that will go in the same type of terrain I like to go. Most of the are XL or KLH 650 types.

PS- Did you collect your radar speed data or did the popo collect it for you?

Yep, GPS goes pretty much everywhere with me. I get lost easily

Local gendarmes have clocked me twice at well over the limit, but always on deserted back roads. That plus my innocent old man act has kept me ticket-free so far on this bike. Got nailed a couple of years back on the R1150RT for 45 km/h over, which is pretty close to bike impoundment here.