Speedo error......again

[Gordon C]

Well here we are about two years on since i read my first post on this here forum. Not wishing to rush things you understand i have finally taken delivery of my first Seven.

A 1700 Supersprint. Talk about smiles per miles. What a joy to drive. The sound, the smell and the ride. i absolutley Love it. So different from anything i have driven before.

 

Anyway a question for you good people.....Speedo error, i know i know that ole chestnut again but it seems that Caterhams are prone to over read and my car is no different. It's purely a guess at the moment but i'm guessing i might be over reading by as much as 15 or so mph. Seems to be worse the faster i go. For the time being i've wired in my Originb2 camera thingy however that seems to be struggling to lock on at the moment and show me my true speed. Will sort that sooner rather than latter though.

 

My question to you.....if i where to replace the gear box angle adaptor thingy am i likely to get a result i'm looking for or i'm i wasteing my time ?

I have installed in the car a speedo gauge that has Caterham written on it, is there a particular adaptor if thats the right word that i should be looking to instal to give me the best chance of success.

 

Be interested in you thoughts guys. Be gentle, 1st post

 

Gordon

 

 

 

Edited by - whoosh on 21 Apr 2008 23:21:26

[jamiegb]

Welcome Whoosh

 

I had a problem with my new build with speedo overreading. The new speedos are programmable according to wheel size and speedo drive output from gearbox (the different drive spindles are colour coded according to the number of teeth on the cog) and final drive ratio. The easiest way was to contact Caterham with the relevant details and they talked me through the set up proceedure for the speedo - since then it's been spot on.

 

Hope this helps

 

Jamie

[Johnty Lyons]

Hi Gordon and welcome Yep notorious for reading fast But hey better that way No chance of you getting Nicked for speeding when your close to limit and The car always seems faster than it is because your so close to ground So a fast reading speedo keeps the illusion

 

Caterhams come with 3 main different wheel sizes and a selection of differentials and gearboxes

Modern speedos can be changed by a selection of dip switches But in your case the setting was done by the drive inside the gear box not the adaptor outside so altering it is a fairly big job Most of us just get to know and deal with the error After all it's a specalised vehicle not a mass produced model 😬

 

jj

N.I. L7C AR 🙆🏻

Membership No.3927.

 

[I.Mupferit]

You can get the speedo head calibrated by 'Speedy Cables' in Swansea. They are part of Caerbont who manufactured the Caterham gauges. I had this done on my first 7 with mechanical speedo like yours and it is not expensive to do.

 

You disconnect the cable from the speedo head and put a bit of masking tape on the inner cable, sticking out like a flag, then put a chalk mark on one of the tyres at the bottom and push the car along for one revolution of the wheel. While you're doing that, get somebody else to count the number of revolutions the inner cable makes, to the nearest 1/4 turn, then send that info together with the speedo head to Speedy Cables and they will recalibrate it for you.

 

For greater accuracy, use more revolutions of the wheel IYSWIM.

 

 

 

Brent

(aka Arfur Nayo)

 

2.3 DURATEC SV You know when you've been AMMO'd 😬

R470.69 😬

 

 

 

 

 

Edited by - Brent Chiswick on 22 Apr 2008 07:59:34

[alextangent]

Welcome to the wunnerful world of xflows 😬 😬 😬

 

My speedo is accurate to about 30, then won't go past 60 regardless of speed. I've stopped using it; the revcounter is far more accurate. Mine does 2100RPM at 40 in top (it's a 4 speed), so 5500rpm is... errr... too fast...

 

Alex McDonald

PASSED THE MOT!!!

[Gordon C]

Thanks for your replys and thoughts guys. Really apprieciate that. I guess what with the spring and summer just around the corner i'm not going to do to much just now, however it's all food for thought for those colder months and will give me a little something to be getting on with to while away the time.

 

Thanks again chaps

 

Gordon.

[neil.cavanagh]

sort or relevant but I did a calibration run on my car last night comparing the speedo to the GPS.. obviously on a closed road... 100 'units' on the speedo was 82 'units' true... 😬 😬

[Gordon C]

100 units 😬 haven't heard it called that before. All being well i hope to check me units tonight. See if my b2 is working again. I'm expecting at least a 15 mph difference between the two. We'll see.

 

Gordon.

[Gordon C]

Well i've sorted out my b2 and all seems to be working as it should do again. Blat over to the Phoenix last night shows 15mph error at the top end. Oh well

 

Gordon.

[chrisb]

Hmmmm, well my speedo is accurate to 100 units per hour with new tyres on (Matches the GPS speed)

 

There again it should be, as it is a stack gadget, that I calibrated

 

Generally above 100 units, it is ok, but over 120 Units, things go a bit AWOL (I'm guessing counting prop bolts at that speed gets a bit blurry 😳)

 

 

 

 

[Graham King]

Whoosh, I don't know what wheel and tyre combo you are running but I have always suspected that Caterhams are correctly calibrated for 14" 185/60 setup, certainly my previous cat with that combo was pretty accurate, but my SL with 13" 185/60 is about 20% out (overreads). I fitted (very easy to do) a bike computer (Sigma BC1200), you programme these to the wheel circumference, and then they are extremely accurate (as measured agianst a GPS device).

 

I was actually more concerned about the mileage reading as a 20% overread, on a car where values are affected by relatively small increases in recorded mileage readings and are often on limited mileage policies, adds up to quite a lot over the life of the car. However whilst the speedo is about 20% out the odometer is only about 10% out, I still haven't quite worked that one out.

 

Graham.

 

R7 GPK

Superlight #85

[Gordon C]

Graham, on my car at the moment are a 13" wheel 185/70.

 

You mention the Sigma bike computer nice bit of kit so i've read. I've installed the Originb2 which detects speed cameras, displays GPS speed and trip.

As i said i have found an error in my actual indicated speed however it will be interesting to compare the Origin trip to the current caterham speedo/trip gauge.

 

Found this Graham, thought you might be interested...

 

Tyre calculator and another one here

 

......and a little something for those that have trouble sleeping here

 

 

 

Gordon.

 

 

 

Edited by - Whoosh on 25 Apr 2008 17:57:17

[Gordon C]

Not long retured from another afternoons blat 😬 Lovely lovely afternoon.

 

Anyway one reason i went out was to do a comparison between the trip on my b2 and the Caterham gauge trip.

 

findings....actual mileage 33 miles (thats the b2)

& the

Caterham gauge indicates 41.6

 

 

Brent think i'm going to have a play along the lines of what you sudjest. Over reading speed is one thing i can accept but over reading mileage.....well i think we can do better than that hope so anyway.

 

Gordon.