The BSA A7-A10 Forum
Technical (Descriptive Topic Titles - Stay on Topic) => Frame => Topic started by: PatM20 on 04.03. 2018 06:59
-
Hi,
Can anyone recommend a replacement speedo that is geared for a 61 swinging arm. Not too worried about total accuracy, but something that tells me I am around 30 mph would be a start.
I don't have the funds to justify anything other than an Indian copy at the moment.
Regards
Pat
-
Sorry, forgot to add "and Ammeter".
-
If you are not worried about originality what about something like this
https://www.ebay.com.au/itm/200KM-H-Car-Motor-Auto-Stainless-GPS-Speedometer-Waterproof-Digital-Gauges-AU/122862059881?hash=item1c9b264169:g:f-4AAOSw5eFZbs9S
100% accurate but you need to be running a 12volt system. No drive required.
-
Hi Brian
Thanks for this. Never thought of a GPS speedo.
I was going to set up the bike 6v positive earth, though the E3L probably pushes out in excess of 12v even on a 6V winding.
I haven't bought a regulator yet so not wedded to positive or negative earth. Was going to fit a DVR2 which will work 6 or 12v, but is polarity sensitive.
Can I put in a 6v to 12v power inverter?
Regards
Pat
-
I've used a cheap (£4 I think ) 6 to 12v inverter from China to run an LED headlight, so I would have thought it would easily run a GPS speedo.
-
Thanks BSAReg.
I put 6V LEDs on my M20. Lots of light, but no focus. Going above 10 mph was really dangerous. I was really disappointed.
The headlight was OK if there were street lights, but useless in total darkness.
How have you got on with yours?
Regards
Pat
-
Forgot to add, does the step up inverter need negative earth?
-
If you just want to know your speed fit a push bike computer. I use a Cateye Velo 9. It has to be a wired one as wireless ones wont work, to much interference.
It can be setup to be very accurate, I set mine up on a section of road that had a measured Km.
The default setting is very close to being right and would be near a enough.
Peter
-
The ‘best of both worlds’ option would be a bicycle gps speedo which runs on it’s own internal battery. Better still, if you have a smartphone, would be a mounting bracket and speedo app. for it.
-
Forgot to add, does the step up inverter need negative earth?
It’s almost certain to have two 6 V input wires and two 12 V output wires, so no.
-
I am a bit confused now.
For example, if my dynamo, battery and voltage regulator is set up for positive earth and I fitted a 6v to 12v step up inverter would I be able to use a 12v negative earth LED headlight bulb or (not that I am going to) fit a 12v negative earth radio?
My concern being that if a GPS speedo needs to be negatively earthed, then I might break it. I can always polarise the dynamo to negative earth to make things easy and fit a negative earth regulator.
To be honest, I was hoping that someone would come back and say a cheap £20.00 replica with a 2:1 ratio will be about OK. I just don't know the correct ratio for an A10.
-
no i was given some leds and my bike is 12v positive earth the leds were negative and dont work on a positive system, and i couldnt be arsed to change everything just to fit them, so i opted for a 12v 50watt hallagin as daylight riding light that works without having the back light on, leds are either positive or negative earth
-
Cheap led headlight are a waste of money except as a daylight warning to other road users. There are much better ones (that will throw a beam) available, but at the moment they are very expensive. Give it time before buying one, the technology is getting cheaper.
-
Surely, (stop calling me Shirley), as long as the device, (GPS or LED) is insulated from the machine you can feed it with + and ground it with -. No?
-
i dont think you can confuse a battery with oposite flows of current by doing that, and i want one if you can, its a new one on me
-
My concern being that if a GPS speedo needs to be negatively earthed, then I might break it. I can always polarise the dynamo to negative earth to make things easy and fit a negative earth regulator.
A GPS speedo has + and - leads. On a positive earth bike, the speedo - lead is connected to a switched live feed from battery -.
The speedo + lead (probably red) is connected to battery +. That can be achieved by connecting it to the engine, frame, handlebar or the headlight common return terminal, so long as whichever you use has good continuity to battery-.
-
You could, but it seems a faff when you should just convert the bike to the relevant (pos or neg) earth. The twenty quid jobs do work (for a time anyway!) and fit in the headlamp shell of the later bikes so look the part.
I'd do anything rather than have a modern looking device (like a push-bike speedo) on the bike. Just looks out-of-place.
-
You could, but it seems a faff when you should just convert the bike to the relevant (pos or neg) earth. The twenty quid jobs do work (for a time anyway!) and fit in the headlamp shell of the later bikes so look the part.
I'd do anything rather than have a modern looking device (like a push-bike speedo) on the bike. Just looks out-of-place.
Connecting a GPS speedo to a + earth bike is exactly the same “faff” as connecting it to a - earth bike.
You connect + to + and - to -.
A polarity-sensitive LED headlight with dip, main and common return terminals is another matter.
And a cheap magnetic speedo of the right ratio, that fits your cable, is very probably good enough.
-
As I said, the polarity of the device can be independent of the bikes wiring. HOWEVER, if the device case is internally grounded you
will may have a problem as it will could short out negative to bike positive/earth. If the gizmo is insulated from it's internal connection then I think it should be possible to use a NEG earth device on a POS earth machine.
-
I’ve only used one GPS speedo. It has a plastic case and has leads for connecting to positive and negative of a power supply.
All the other ones on EBay look similar.
Using the speedo casing as a connection to negative would seem like a strange thing for a manufacturer to do.
-
I just went searching for information and found this, which may help to explain what I'm on about. Similar problem.
https://www.mgexp.com/phorum/read.php?1,860081
-
Using the speedo casing as a connection to negative would seem like a strange thing for a manufacturer to do.
Well, in their design for a modern vehicle negative is equal to earth/ground so why not use the case as part of the return feed? I'm just putting forward a possible scenario; I don't have experience of doing this.
-
I just went searching for information and found this, which may help to explain what I'm on about. Similar problem.
https://www.mgexp.com/phorum/read.php?1,860081
A fag lighter socket has to be wired for the same polarity as all the handy electronic devices you stick in it. He can have it that way in his Morris, so long as he doesn’t mount the socket directly contacting a steel panel. Hope someone told him that.
-
A fag lighter socket has to be wired for the same polarity as all the handy electronic devices you stick in it...
He's connecting it up so he can use modern, negative earth devices so he will feed it the opposite of normal; he will connect Neg to the metal outer of the socket and Pos to the centre connector, (After re-reading this I've swapped those around).
He can have it that way in his Morris, so long as he doesn’t mount the socket directly contacting a steel panel. Hope someone told him that.
They did.
As I said on page 1:
....as long as the device....is insulated from the machine you can feed it with + and ground it with -.
-
Well, in their design for a modern vehicle negative is equal to earth/ground so why not use the case as part of the return feed? I'm just putting forward a possible scenario; I don't have experience of doing this.
Earthing through the case makes sense for some things. Original old bike speedo illumination used the case as a return path, although loss of good continuity was quite likely.
The makers of these GPS speedos just connect all the wires from the printed circuit to a multi pin plug in the base. There’s a separate coaxial to the sensor, but it’s not electrically connected to any part of the bike.
-
i dont think you can confuse a battery with oposite flows of current by doing that, and i want one if you can, its a new one on me
If you consider removing the battery from the bike and using it to power an electrical device on the bench you would not be bothered about Negative or Positive earth would you; you'd put the Pos to Pos on the device and Neg to Neg? So, my thinking is as long as the device is insulated from the machine you can do the same thing on the bike.
-
greybeard if the battery on the bike is earthed - and you put an independent led which is+ earth acroos the battery it will not work because the battery is already polerised
-
greybeard if the battery on the bike is earthed - and you put an independent led which is+ earth acroos the battery it will not work because the battery is already polerised
Connect a 6 V LED between the battery terminals the right way round and it will light. One terminal being connected to the frame doesn’t change that.
-
Insulate the instrument (GPS) run its + wire to + on the battery and it's - wire to - on the battery, leave the bike wires as is. So long as the instrument is isolated it will work.
Cheers
-
My first experience with using a extarnal device was when I was 17, bought a ewe-beaut Pioneer stereo and jury-rigged it into my old lady's Austin 1800..no-go, so switched wires and was ok (didn't realise was +ve earth) but blew a channel ....(Space Oddity on one channel is not so good *conf*)
I agree with mainly the last two comments that so long as this kind of speedo is electrically isolated from the frame it'll work, and in the case of the LED light, depending on the if base is isolated like a P43t, the wires should be able to connect as as normal, as the dipping wires only run through the switch and don't earth, and horn doesn't (generally) matter- but well leave that out- and lighting, these should be debated in another arg-thread
-
mmmm my bad i should have stayed in the pub, apologies greybeard ime totaly minced up today
-
To go back to the original question, with regard to various Bicycle speedo options, Ive tried a few, the first two on my Gutzzi;
1> Cateye bicycle wired jobbie, which worked fine for a while but a wire broke internally, and after it not working for a while went 'missing' one night in town.
2> Another wired Cateye that I spilled braked fluid onto and it dissolved *eek*
3> A different brand of wired type, which fell apart or failed for no reason after only a short time....at this time I decided a GPS one that I can use on both bikes would be better, so>
4> Garmin GPS 'Edge 200' which came with two handlebar mounts (one for each bike *wink2*) but seemed to split the LCD when I dropped it *pull hair out*...(unrelated, but Garmin backup was crap), so....replaced with>
5 > Bryton Rider 100?- basic and USB socket failed but replaced under warranty, had it about a year and a half...fits on the Garmin mounts, but not the other way...(Garmin>Bryton) It stops working sometimes but starts again...just a backup really- is handy 'cos I've set it to Km/h.
NB; Don't really need it now as both bike speedos now function (Original Vaguelia reads +10mph/Smiths Chrono reads -10% *conf2*).
Just briefly re; system polarity, I originally had +ve earth, but was too confusing-kept blowing other things up so changed to -ve earth, but I think you also need to rearrange the brush wires in the dynamo-- the gurus can clarify that in a different thread
If I recall GB some time ago talked about installing a small inverter to run a GPS speedo/whereamIagain ?
-
Swapping brush wires is for changing dynamo direction of rotation, not polarity.
-
If I recall GB some time ago talked about installing a small inverter to run a GPS speedo/whereamIagain ?
I don't think so. I did blather on about using a 6v to 12v voltage convertor device for lighting. I bought one but haven't done anything with it. I was persuaded that it wasn't a good idea. Also it's too big to hide on my machine.
Mostly irrelevant to this discussion: When I use my GPS I put a battery pack in my pocket and run a lead to the GPS. My current GPS has an earphone socket so I use earplugs to listen to the instructions. This means I don't need to have the GPS visible.
-
Hi at the start of this post you asked about the cheap Indian version and if it would work /was value for money , well I went down that route .For £25 I got a KM speedo which I sent back expecting never to hear again from the company . To my surprise they returned a MPH speedo within days , got a royal enfield speedo connecting ring/nut fitted to a BSA speedo cable by Vernhill engs for about £15 , fitted easy in about an hour and that included making a new plate to fit to the top yoke and works great ,very steady ,doesn't look out of place and even better is bloody accurate , that will be for 3 yrs this year so I would suggest you consider this option ,regards Bob
-
Topdad, did your bsa cable fit the indian speedo? All the indian speedos I've bought have been for 2.4 mm square drive cables. I have to strip the speedo and resize the drive square to receive the Smiths cable. I always buy clocks with 12mm fittings already instead of the RE type. These accept the standard connecting nut. Apart from all the faffing, I have found them to be a fair substitute for the originals.
-
Hi BSAreg , yes , I asked verhills to just change the speedo connect ring on a standard BSA speedo cable from the smaller bsa to the larger RE size ,no problem use it to fit the speedo to the fitting plate I knocked up ,easy peasy ,musky said he'd done similar as well, anything else ,aphoto etc just ask regards Bob
-
Hi Bob
Thanks for this.
Did you fit the speedo to the top of the forks (cafe racer style)?
If so what length cable did you go for?
Regards
Pat
-
yes ,I've a separate head light not a cowl so just fabricated a flat piece of plate metal and fitted it to the original holes on the top yoke ,I'll have to measure the length but I'm sure it's just a standard length from when the bike first came back on the road. In the first instance I used a later A65 speedo holder with a rubber cup holding a magnetic speedo more for show it fitted to the left hand fork stanction now its more center and higher but not tight .
-
Thanks Bob, just ordered one.
Bike is a bit away from needing one right now.
Regards
Pat
-
Topdad, any chance you tell me who the supplier was ? It would be much quicker for me to modifiy the nut, than keep doing complete stripdowns ( you have to completely dismantle the clock to open the square for the inner cable ). Thanks.