GSX1400 Owners .org

General => Bike Chat => Topic started by: Dell Boy on Tuesday, 19 June 2018, 11:05 PM

Title: Speedo accuracy
Post by: Dell Boy on Tuesday, 19 June 2018, 11:05 PM
Hi Guys, recently discovered my speedo is reading upto 9 mph slower when travelling at 70 mph, is there a fix for this without braking the bank. Have looked at fitting a GPS speedo but have sat nav and camera already on handle bars so I am running out of space. Any ideas please.
Title: Re: Speedo accuracy
Post by: Hooli on Wednesday, 20 June 2018, 12:09 AM
That's unusual, they normally over read by 8% ish on average. It's not got a speedo healer fitted has it?
Title: Re: Speedo accuracy
Post by: Mister Fishfinger on Wednesday, 20 June 2018, 12:23 AM
Has it got a larger gearbox sprocket perhaps? Or a smaller rear sprocket?
Title: Re: Speedo accuracy
Post by: Hooli on Wednesday, 20 June 2018, 12:25 AM
Good call fishyfinger man.

Sprockets are 18-43 from memory.
Title: Re: Speedo accuracy
Post by: gsxbarmy on Wednesday, 20 June 2018, 02:49 AM
To get it bang on Andy, only way is to fit a SpeedoHealer

https://www.healtech-electronics.com/products/sh/
Title: Re: Speedo accuracy
Post by: KiwiCol on Wednesday, 20 June 2018, 03:03 AM
Quote from: Hooli on Wednesday, 20 June  2018, 12:25 AM
Good call fishyfinger man.

Sprockets are 18-43 from memory.
18  - 41 I think you'll recall Hooli

The Sat Nav would display the correct speed for you though wouldn't it?  Is this where you're getting the '9mph slower' reading from on the speedo display?   If so, then I'd be checking the above, sprocket tooth count & follow the speedo pickup wire to the plug, check to see it hasn't got something else plugged into it (speedo corrector of one sort or another) as well.  There are a couple of different brands of these & each has different ways to program it to function correctly. 
Have a check & let us know the outcome & we'll see where to go from there.
Title: Re: Speedo accuracy
Post by: Dell Boy on Wednesday, 20 June 2018, 04:45 AM
Checked both sprockets and drive chain, as that was my first thought but all correct. Checked the pickup and rota on the gearbox all seem OK. Also checked the wiring again no visible fault showing up.
Title: Re: Speedo accuracy
Post by: KiwiCol on Wednesday, 20 June 2018, 05:19 AM
Good job, well, a speedo corrector will fix it, Dave has posted a link in a previous post. I use a different brand than Healtech, can recall it at the mo, USA thing. works great & is easy to adjust / program.

Found the one I use, 12 O'Clock labs

http://shop.12oclocklabs.com/index.php?route=product/product&product_id=59
Title: Re: Speedo accuracy
Post by: seth on Wednesday, 20 June 2018, 05:30 AM
Ours reads about the same I know it so a just my speed to compensate.
70mph I do 80mph on.my Speedo
60 I do 68
50 I do 56
40 I do 44
30 I do 30
Works ok
Title: Re: Speedo accuracy
Post by: Hooli on Wednesday, 20 June 2018, 07:45 AM
Quote from: KiwiCol on Wednesday, 20 June  2018, 03:03 AM
Quote from: Hooli on Wednesday, 20 June  2018, 12:25 AM
Good call fishyfinger man.

Sprockets are 18-43 from memory.
18  - 41 I think you'll recall Hooli


You may be right, it's a couple of years since I changed them.
Title: Re: Speedo accuracy
Post by: gsxbarmy on Wednesday, 20 June 2018, 07:50 AM
When I had the Healtech fitted to my 14, I needed to set the adjustment to 87.5% - this being the accuracy of the OEM speedo - to get the correct reading as my speed - compared to my Sat Nav - was very similar to Seth's (above).

Suzuki speedo's are known to be "about 10%" out. Just the way it is.
Title: Re: Speedo accuracy
Post by: northern on Wednesday, 20 June 2018, 04:39 PM
Quote from: seth on Wednesday, 20 June  2018, 05:30 AM
Ours reads about the same I know it so a just my speed to compensate.
70mph I do 80mph on.my Speedo
60 I do 68
50 I do 56
40 I do 44
30 I do 30
Works ok

14's speedo is not linear - it's quite accurate up to 50km/h and then difference get bigger and bigger. @Thommohawk post table in the past (possible at old forum). In this situation, SpeedoHealer cant make it right for all speeds...

But odometer is linear and quite precise, so I ajust my (have -1 front sprocket and 55 height rear tire) SpeedoHealer to show correct distance, and do not care about speed to much :)
Title: Re: Speedo accuracy
Post by: seth on Wednesday, 20 June 2018, 05:27 PM
My speeds weren't set using a Speedo healer.
I just sat at the speeds I said and noted the actual speed using a GPS.
I first noticed my Speedo being so far out when in a 40mph average speed camera zone for road works I was sitting at 42ish and a bus was getting very upset as he wanted to go faster my real speed was nearer 34mph .
So I did the test using my GPS at all the common speed limits and now sit at the speeds I said .
As then I'm always within10% of the speed limit usually below especially in a 30 as there isn't really any need to go fast in town .
:cheers:
Title: Re: Speedo accuracy
Post by: northern on Wednesday, 20 June 2018, 05:39 PM
@seth , I just use your numbers, to confirm changes are not liner :cheers:
Title: Re: Speedo accuracy
Post by: seth on Wednesday, 20 June 2018, 05:46 PM
All good buddy
:onya:
Title: Re: Speedo accuracy
Post by: KiwiCol on Wednesday, 20 June 2018, 05:52 PM
For what it's worth, using my 12o'Clock labs speed corrector, my speedo & GPS are reading the same (+/- 1kph) right up to 120ish, & I'm not looking too much at the speedo if I'm still 'climbing' after that . . . 
Title: Re: Speedo accuracy
Post by: seth on Wednesday, 20 June 2018, 06:01 PM
Do you have a link for where to get one @KiwiCol
:onya:
Title: Re: Speedo accuracy
Post by: Dell Boy on Wednesday, 20 June 2018, 06:15 PM
Thanks guys, all this has been very helpful will be looking into a calibrator. Thanks again.
Title: Re: Speedo accuracy
Post by: KiwiCol on Wednesday, 20 June 2018, 06:22 PM
Quote from: seth on Wednesday, 20 June  2018, 06:01 PM
Do you have a link for where to get one @KiwiCol
:onya:
Yeah mate, posted it up earlier in this thread.
http://shop.12oclocklabs.com/index.php?route=product/product&product_id=59

I was looking at some of their other gear today, they've got some 'flash' indicators !! 
Title: Re: Speedo accuracy
Post by: seth on Wednesday, 20 June 2018, 06:38 PM
Sorry @KiwiCol I never noticed thanks .
I must pay more attention  :doh:
Title: Re: Speedo accuracy
Post by: KiwiCol on Wednesday, 20 June 2018, 06:56 PM
No prob mate, all good.
Title: Re: Speedo accuracy
Post by: grog on Wednesday, 20 June 2018, 07:01 PM
just a question, will fit one tooth bigger front sprocket next change. should make speed reading nearly correct? odometer will then need healer? will be slow, am i correct?
Title: Re: Speedo accuracy
Post by: KiwiCol on Wednesday, 20 June 2018, 07:19 PM
I dunno the answer to that Grog, only way would be to record / measure distance covered on a trip using GPS (on phone if you've not got one mounted) & comparing the Odo reading, obviously, the longer the distance the better the accuracy.
Title: Re: Speedo accuracy
Post by: Hooli on Wednesday, 20 June 2018, 07:40 PM
Speedo healers affect the odo too, as they modify the signal before it reaches the clocks. I seem to recall Tallman looking at adjusting the speedos directly & thought it was a near impossible task as it involved reprogramming a load of chips.
Title: Re: Speedo accuracy
Post by: shanered6 on Wednesday, 20 June 2018, 09:11 PM
Glad i read this as i didn't know about the speedo inaccuracy problem  ??? but it would explain why 80mph feels very fast  :whistling:
Title: Re: Speedo accuracy
Post by: Mick_J on Wednesday, 20 June 2018, 10:02 PM
Quote from: grog on Wednesday, 20 June  2018, 07:01 PM
just a question, will fit one tooth bigger front sprocket next change. should make speed reading nearly correct? odometer will then need healer? will be slow, am i correct?

In theory 1 extra tooth on the front sprocket will add 4 mph at 4000 rpm so up from 85 to 90 mph.
Title: Re: Speedo accuracy
Post by: Latty66 on Wednesday, 20 June 2018, 11:36 PM
Could you work the difference out off the rev counter i think from memory at 4250 rpm mine shows 100 mph ish i.v got 18/41 but the rear wheel is 240/40/18
It feels accurate i know cameras in road works trigger at 60/67 mph 50/57 mph and 40/46 mph and 30/34mph oh yeah by the way on all smart motorways ie hard shoulder running all gantry cameras are set at 85mph now 24/7 unless the over head speed is lower then the above apply
Title: Re: Speedo accuracy
Post by: Mick_J on Thursday, 21 June 2018, 01:38 AM
Are you sure you have an 18" wheel?
A 240/40/17 is just about the same diameter as a 190/50/17 so the difference in speed will be very small.
Title: Re: Speedo accuracy
Post by: Latty66 on Thursday, 21 June 2018, 04:03 AM
Aye 240/40/18 mate
Title: Re: Speedo accuracy
Post by: Hooli on Thursday, 21 June 2018, 07:24 PM
Do you know half your swingarm has fallen off?
Title: Re: Speedo accuracy
Post by: Latty66 on Thursday, 21 June 2018, 08:29 PM
Thought summit was missing   :doh: just been out on it and 4000rpm on mine is 85mph so is this running fast or slow or is it about right
Title: Re: Speedo accuracy
Post by: Hooli on Thursday, 21 June 2018, 09:24 PM
3,600rpm shows as 70mph on mine & I never* speed....
Title: Re: Speedo accuracy
Post by: Latty66 on Thursday, 21 June 2018, 09:27 PM
Aye thats about the same as mine
Title: Re: Speedo accuracy
Post by: Hooli on Thursday, 21 June 2018, 09:51 PM
9k at 100... Oh hang on, that's in 2nd  :devil:
Title: Re: Speedo accuracy
Post by: Mick_J on Friday, 22 June 2018, 01:34 AM
Quote from: Latty66 on Thursday, 21 June  2018, 08:29 PM
Thought summit was missing   :doh: just been out on it and 4000rpm on mine is 85mph so is this running fast or slow or is it about right

Assuming you are on standard sprockets you are reading a little low, should be 88mph with your tyre (in theory).
Title: Re: Speedo accuracy
Post by: Latty66 on Friday, 22 June 2018, 03:46 AM
Cheers mjgt
Thats close enough for me mate thanks everything around the legal limits should be near enough  :cheers: