Uk law question- what gauges are needed in law

I've decided to move from rebuilds to customizing bikes. This is just a simple hobby to prevent me from going senile. Bought a Suzuki gn250 for my first bobber / off road type customization. I'm looking to declutter the instrument panels and lose unnecessary wires, my plan being to have a single, central speedo only.
What is the law (uk) about which gauges are required. If I ride with no gauges at all, so no speedo, no odometer, no warning lights, is that legal and would it pass an mot?

 

Basically no. You need a speedo and if you have indicators you might need a warning lamp BUT only if you can't see them when riding the bike.
If you don't fit indicators then fine. Any engine warnings are up to you eg oil or generator(ignition)
Not sure about the high beam?
A lot of single aftermarket(custom) speedos come with warning lights built in.
Apart from anything else lights/indicators help on the safety side.
This is just to show the idea but this one says MPH in the ad but shows a KPH speedo.
You can get them cheaper without the warning lights and you could get a set of LED's to put in a bracket to minimize the size?
https://www.ebay.co.uk/itm/Speedo-6...830603?hash=item1c95f33e0b:g:HpoAAOSwYBRbMiPa

 

PS you'll need to find out the speedo drive ratio on the gn250 before getting a speedo.
it'll be something like 2-1 or 2.25-1.
If you can't find the info on line you'll need to mark the tyre and make up some sort of pointer to attach to the cable or drop in the drive and count the revolutions v drive revolutions. (bent nail squared off??) lol

 

Thanks I wasn't aware of the ratio issue, I figured that only related to wheel changes. Ill get a speedo with odometer then probably prefab a small light box with neutral and indicator warning leds. I don't need a power light or head light warning as I'm sure its obvious when the bike is running and lights are on?!
I can then declutter a lot of the leads and rev cable and clean up the front end a lot. The fun begins when I start removing unnecessary wires as I'm bound to get it all wrong.
Incidentally, does a speedometer need to illuminate at night or is that optional?

 

I believe it needs to be illuminated but most will have an led anyway. At least the older bikes are simpler with no electronics apart from ignition. Most LED sets come with red and black wires so make sure you get them round the right way as they'll either blow or just won't work.
This is an early effort of mine

 

No working speedo required for mot, although it must be present, although given the amount of cameras around they are useful if you know what I mean.
No lights required if you only want a daytime mot, although it is prudent to have a rear brake light for obvious reasons.
Indicators are not law on a bike because you can use hand signals, however, if the bike was built with them then they are supposed to be there and working for mot purposes.
As for the extra wiring, use a deep dished headlight with the chrome bowl at the back and insulate all the wiring and tuck it into there.
Some aftermarket digital speedos allow you to adjust the speedo ratio via the tyre size. That is you select the size of the tyre, say 17", and go through the speedo selections to get to that one. Theoretically it should be close. I did it on something or other a couple of years ago, but used a GPS to set up the near enough correct speed read-out. Most GPS systems get within a couple of miles an hour these days so its good enough.
The best advice is go talk to your local bike mot bloke about what they expect to see on a custom build so it doesn't fail on something stupid.

 

Thanks for the replies, I'm setting up a single speedo dial with a neutral warning light set into the top of the headlight bowl. Changing lamps and indicators out for smaller retro looking ones. I've managed to reduce wiring down to just the one warning light but somehow managed to stop my speedo backlight from working, well done me! All good fun. I've just seen a bike called a 'mutt Mongrel' Anyone heard of them? That's the look that I'm after.

 

Here you go, looks good

 

That's the kind of look I'm heading for.
Headlights from china? New thread alert!