Speedo too slow

[Kang]

Hi all. I have a 1983 CG125 that I’m giving the cafe racer treatment. I’ve fitted some much bigger tyres which look great (in my opinion) but have made the speedo show slower speeds than I’m actually going. Is there any way of adjusting this please? It’s a mechanical speedo that runs off a cable attached to the front wheel. Cheers. 

[Gerontious]

I wouldn't mess with it. I would just apply some markers. stickers or whatever to the speedo to give a more realistic speed.

[Tinkicker]

Or fit an electronic speedo with a magnetic pickup fastened to a spoke.

[Nick the wanderer]

Or get a battery powered GPS Speedo, give yourself a digital readout with no cables..

[geofferz]

Mine is the same - my speedo was showing 70mph buy I got clocked at 140? 

[RideWithStyles]

10 hours ago, Tinkicker said:

Or fit an electronic speedo with a magnetic pickup fastened to a spoke.

Yeah just got to a bicycle shop, pick one up. Find out that they clip on to tiny metal spokes not actually normal wheels, find super glue, stick roughly right and wonder why ur going 50mph in a 20zone and then why it doesn't register at about 55mph.... Peal off and retry, rinse and repeat and not worry about going above 60....

or find the sensor moved 1mm and wont pick up.

i joke as in principle it would to a point but realistically not worth it.

nicks idea isnt too bad but youll have to have more out lay and cost just for the sake of the tyres and if you go to a dead zone like i have near me it no workee..

you could in theory change the gears in the housing but ud need to work out the ratio of the tyres, wire and gears to do that which is tedious at best and realistically trying to find different gears to match while fitting in the original housing would be a real mare not worth it..

geros is probably the most sensible for those when your clocks didnt have a dual mph kphh read out background, you could just buy a mph one and just ride at what you know is 30mph by following some one , make a note then like up the 30 sticker to where it was.you could get a 

[keith1200rs]

Use a bicycle GPS. All the cycle speedos I have used will register 50mph at least - I haven't managed to go any faster.

[Kang]

I like the idea of using markers. Keep it analog. I guess I was hoping there was an adjustment screw or something. Thanks for the replies. 

[RideWithStyles]

Nope sorry its all hard core set.