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Speedo error


interceptor69

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Does anyone know how much speedo error exists in the 5th gen VFR?  I've always been told it's fairly inaccurate w/ significnt error.

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Depends on your sprockets/rear tyre size as well.

Best is to ride at certain indicated speeds for some time and check what your GPS says. GPS needs a certain time to accurately calculate so keep her steady say 10 seconds or so

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By calculation, with stock gearing 100 km/hr (62 mph) should be 4280rpm. 

 

Get a GPS speedo app on your smartphone and check for yourself. 

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Well, depending on the accuracy of speed signs near me, mine is overstating by about 3mph when doing 30mph.

As for revs to speed? 6th gear, 70mph is approximately 5000-5250rpm (i've never spent more than a moment looking at the dash when doing...any speeds).

---

Wheels/chain/sprockets are stock sizes.

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Almost all bike speedos over read by 5-10% usually nearer 10, but your front sprocket size will have an impact on the speed displayed. Stock front is 17 teeth, many people fit 16tooth front sprocket, that will move your speedo towards 15% over reading.

 

use the gearingcommander site to play with the variables including speedo accuracy. Use GPS to get a base line, the error is normally constant, so if GPS says 50mph & the speedo shows 55mph, then the error is 10% !

 

have fun, YMMV

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I have stock gearing. Thanks for the responses. Just want my argument ready when the cop pulls me over.......

Sent from my GT-N5110 using Tapatalk

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When a California Highway Patrolman stopped me on my VFR and asked if I knew how fast I was going, I responded "87 indicated, officer, but this speedometer reads 23% high - it's really wacked. I hope my math was at least close."

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Never argue with a cop. If he asked you if you know how fast you were going, you just say Yes, and don't volunteer anything else. If he asked you how fast, just say Don't you know?. Don't volunteer anything

and don't get cop an attitude.

 

My '99 speedometer with stock gearing was about 6-7% off, but the odometer was right on. Now that I'm running a 45 tooth rear and stock countershaft, I'm about 12% off, and about 6% with the odometer.

I use a bicycle computer for my speedometer/odometer. A good $20 solution instead of the big bucks for a Speed-O-Healer.  The 45 tooth rear sprocket is highly recommended. Much easier pulling away from

a stop, especially uphill, and no decrease in fuel mileage. My last tankful which was about 90% freeway at 70-80 mph was about 41 mpg.

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good advice-I've never gotten 41 mpg, even before the PC II, the K&N air filter, and the pipe.  And I have the original gearing.  Wonder why I get such bad gas mileage....thoughts?

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The gas mileage drops precipitously if you're accelerating briskly, read fast, and/or a lot of stop and go with quick acceleration from the stop. My freeway was steady speed of about 70 miles at a time, so not a lot

of hard acceleration. Running right at 65-70 mph, I can get about 45 mpg.

 

If you spend a lot of time over 9,000-10,000 rpm your mileage will suffer. But you'll have a lot of fun. :beer:

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I fitted a speedo healer to my 97 VFR800 and adjusted it against a DGPS. My speedo was about 10kmhr out.

Fitting a speedo healer does make your odometer read less kilometres than you actually traveled though.

Good for resale but gets your brains thinking when it comes to servicing times.

It takes about 30min to fit and Is easy to adjust. If you don't have access to a DGPS a high quality standard gps is highly accurate and will give the same results for calibration.

My bike club did a run with the local cops.

The boys in blue did some speedo checks for us with there laser speed guns.

My VFR had the most accurate speedometer on the day

https://www.healtech-electronics.com/products/sh/

Highly recommend them.

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With stock gearing, 5th and 6th gens. are 8% high reading.  That used to be commonly known but not so apparently now.  

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Yes Bent, I thought I remembered that from back when I bought it but couldn't remember (along with most other things I learned back 19 years ago...).  

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I saw 155 mph the other day at around 10,000 rpm and still accellerating-pretty sure my bike won't go quite that fast.

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On 8/19/2017 at 11:45 PM, VFGRERR said:

I fitted a speedo healer to my 97 VFR800 and adjusted it against a DGPS. My speedo was about 10kmhr out.

Fitting a speedo healer does make your odometer read less kilometres than you actually traveled though.

Good for resale but gets your brains thinking when it comes to servicing times.

It takes about 30min to fit and Is easy to adjust. If you don't have access to a DGPS a high quality standard gps is highly accurate and will give the same results for calibration.

My bike club did a run with the local cops.

The boys in blue did some speedo checks for us with there laser speed guns.

My VFR had the most accurate speedometer on the day

https://www.healtech-electronics.com/products/sh/

Highly recommend them.

 

same here. I found speedo reading about 7% high. i think it works for mph too :P 

install was clean and quick. 

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On 8/30/2017 at 1:25 PM, interceptor69 said:

I saw 155 mph the other day at around 10,000 rpm and still accellerating-pretty sure my bike won't go quite that fast.

Based on the stock gearing and tyre size, 10,000 rpm in top would be 233 km/hr or 145mph, which would confirm a speedo error of 5-10%.

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