[tremorous]

Added a 240 metzler tire and lowered my bike last week but noticed lower mpg. Do I need to use a auto tuner to get my gas milage back? Has anyone had this problem?

 

[middleagecrisis]

No. Your mpg is decreased because the bigger tire alters the number of revolutions hence the change in gas mpg. The 240 actually gives you a more accurate mpg and mph.

 

[dejablu110]

Midlife is correct, if you have 2 strykers riding side by side all day...one with a 210 and one with a 240 you could see. I've had this experience with raiders, me and my other half, when I had the 210 and him the 240.

 

[toby]

Does any one know where the signal to the digital odometer/trip meters reading is generated from?
If the readings are generated by revaluations of the rear tire. Then the readings would be effected by a change in diameter of the tire.
A smaller diameter tire would take more revaluations than a larger tire to go the same distance. There for giving a larger reading on both odometer and speedometer than the larger tire would travailing the same distance.
For example. If your odometer reads 100 miles with the small tire and it reads 100 mile with a larger tire, you have actuary traveled more miles with the larger one. Maybe 5% more or 5 miles more thus burning five more miles worth of gas. So in reality you have traveled that extra 5 miles so mpg remain the same.
The amount of energy or gas the engine has used to go the same amount of miles has not changed. It's the reading on the odometer that has changed do to the change in diameter of the tire.
Also you are actually travailing at 60 mph when the spedo reads 65 mph with the smaller tire. And traveling at 65 when the spedo reads 65 with the larger tire thus burning a bit more gas traveling at 65 than 60.
Also larger tires and heavier tire take more energy to push. Which equates to more gas but would be offset by slightly less gas needed at freeway speeds because of lower rpm do to larger tire diameter. But I don't think these would be a factor in bike tires.

 

[dejablu110]

Huh??!!

 

[safetydanny]

Sooooooooo does anyone know the answer to Toby's post?! Great stuff Toby!

 

[Kuro1stGen]

Ok I may be wrong (that almost never happens, I swear) but, I thought the reading for the odometer came from tranny. I would say correct me if I'm wrong but that is a given on forums....

 

[11Stryker]

I believe you are correct Kuro!

 

[toby]

Correct me if I'm wrong, but even if it comes from the trans, if the larger diameter of tire increases the actual physical miles traveled and nothing has changed from the reading from the trans to the odometer then you have actually traveled more miles thus burning more gas with the same amount of miles showing on the odometer as with the smaller tire. Does that make sense? That's what I was trying to say/ask in that plethora, that Hodge-podg of menagerie of non sense in my earlier post





'

 

[straightjacket]

Hey Toby, the speedos off anyway so your just fixing their screw-up by puttin on a bigger tire to correct!

 

[toby]

Hey Toby, the speedos off anyway so your just fixing their screw-up by puttin on a bigger tire to correct!

Ya I suppose so but I think it's not so much a screw up as it is intentional knowing you are gonna want to get and have to spend money to put a nice tire on there to fit that nice big fender.lol.

 

[immortal13]

Hey Toby, the speedos off anyway so your just fixing their screw-up by puttin on a bigger tire to correct!

Ya I suppose so but I think it's not so much a screw up as it is intentional knowing you are gonna want to get and have to spend money to put a nice tire on there to fit that nice big fender.lol.

I highly doubt that.


You would think that with today's technology they could've put an accurate spedometer on the bike. Just my .02

 

[sfcmcgan]

Correct me if I'm wrong, but even if it comes from the trans, if the larger diameter of tire increases the actual physical miles traveled and nothing has changed from the reading from the trans to the odometer then you have actually traveled more miles thus burning more gas with the same amount of miles showing on the odometer as with the smaller tire. Does that make sense? That's what I was trying to say/ask in that plethora, that Hodge-podg of menagerie of non sense in my earlier post





'

The Speed sensor takes readings from the crank shaft.... the ECU take RPM, gear position and crankshaft speed... does all the math... then sends the signal to the speedometer. the factory sets the perameters to be 5 mph below actual MPH... don't know why.

 

[toby]

Hey Toby, the speedos off anyway so your just fixing their screw-up by puttin on a bigger tire to correct!

Ya I suppose so but I think it's not so much a screw up as it is intentional knowing you are gonna want to get and have to spend money to put a nice tire on there to fit that nice big fender.lol.

I highly doubt that.


You would think that with today's technology they could've put an accurate spedometer on the bike. Just my .02

Ok, all humor aside, I did read an an article on this subject, that stated that manufacturers of motorized vehicles including motorcycles, produce and sell vehicles with speedometers that vary in accuracy +/- 2% and often are set to read higher then the speed you are actually traveling. One article on the subject put forth that this was to prevent the manufacturer retaining any liability if there was an accident resulting from speeding etc.
this article in Car & Driver has a pretty good explanation =)

http://www.caranddriver.com/features/speedometer-scandal

 

[immortal13]

Ok, all humor aside, I did read an an article on this subject, that stated that manufacturers of motorized vehicles including motorcycles, produce and sell vehicles with speedometers that vary in accuracy +/- 2% and often are set to read higher then the speed you are actually traveling. One article on the subject put forth that this was to prevent the manufacturer retaining any liability if there was an accident resulting from speeding etc.
this article in Car & Driver has a pretty good explanation =)

http://www.caranddriver.com/features/speedometer-scandal
[/quote]

I stand corrected. Just seems that it should be dead on accurate.

 

[MY LIFE]

Ok. Let me get this straight. If the auto makers set the speedo off, then does that mean that the makers of GPS's set them off as well. My GPS reads the same as my speedo on my car? What do you think? I think it's all one big conspiracy, between a alien world and our Goverment. ;D

 

[immortal13]

Ok. Let me get this straight. If the auto makers set the speedo off, then does that mean that the makers of GPS's set them off as well. My GPS reads the same as my speedo on my car? What do you think? I think it's all one big conspiracy, between a alien world and our Goverment. ;D

GPS is accurate as it calculates from satellite signals...time traveled between point A and point B. That's how I realized how inaccurate my stryker speedo was.....several mph under.

I beat a speeding ticket in court(me vs. a city attorney), and we got into this debate. The judge seemed to think I was right lol. Thank God I saved that gas receipt. It ended up being all the evidence I needed to prove my case. The only speeding ticket I ever got in my life.

 

[WildFan]

Here's my experience with gps and speedos - I've driven in my truck and car with the gps, and they both seem to match the speed shown on the gps. I've also rode my previous bike ('05 ninja with a digital speedometer readout) and my Stryker with the gps. Here's what I noticed with both of the bikes - at slower speeds the speedo read a couple mph over the gps reading. As I went faster, the gap between the speedo reading and the gps reading got larger. For both bikes, when the gps read 75mph on the freeway, my speedos on the bikes read 83mph. Again, no answers, just my experience.

 

[immortal13]

Here's my experience with gps and speedos - I've driven in my truck and car with the gps, and they both seem to match the speed shown on the gps. I've also rode my previous bike ('05 ninja with a digital speedometer readout) and my Stryker with the gps. Here's what I noticed with both of the bikes - at slower speeds the speedo read a couple mph over the gps reading. As I went faster, the gap between the speedo reading and the gps reading got larger. For both bikes, when the gps read 75mph on the freeway, my speedos on the bikes read 83mph. Again, no answers, just my experience.

Well, not to sound like an ass but that's pretty obvious. The calculation is a ratio and therefore is more distorted at a higher speed (higher number).
Eventually I see GPS technology being used for speedos. That way, your speedo would always be accurate no matter what tire size, or other modification done to the vehicle.

 

[MY LIFE]

Immortal that is interesting and does make sense. Only problem is, What happens if a Sat goes down, bad zone or other problems? Then you have no way to figure out what speed your going. There would have to be some sort of back up plan. Also is not the odometer somehow connected to the same point that is used for speed?

Any one want to answer the question on, "If auto makers set the speedo off a bit, then why does my speedo match my GPS perfectly?