'76 speedo and tach ratios

Discuss everything about Honda GoldWing. Feel free to ask any question related to GoldWing.

Moderators: CYBORG, Oldewing, robin1731, Forum Moderators

Post Reply
jimbonaut
Chrome Member
Chrome Member
Posts: 121
Joined: Sat Dec 19, 2020 3:08 pm

'76 speedo and tach ratios

#1

Post by jimbonaut »

Pretty sure on the CB750's I've worked on the ratio was 4:1 but no idea if the same applies these 'wings. Shopping around for an aftermarket replacement as the speedo/tach on mine is shot...
Last edited by jimbonaut on Wed Feb 08, 2023 4:05 pm, edited 1 time in total.
User avatar
Lucien Harpress
Honored Life Member
Honored Life Member
Posts: 4077
Joined: Sat Dec 24, 2011 11:41 am
Location: Michigan

Re: '76 speedo ratio

#2

Post by Lucien Harpress »

I could be wrong, but I'm fairly certain the CB750 and the GL1000 both run a 2240:60 speedometer ratio (along with many other Japanese bikes of the time). If you're looking to replace with stock, or at least close to, 4 into 1 sells some VERY nice replacements.

The tachometer is a different story (that's where the 4:1 or the 7:1 makes more sense), but I'm even less sure about that one.
1997 Valkyrie- Light Cutomization, but Too Busy Riding
1980 KZ1300- Bike's Haunted
1976 GL1000 (Yellow)- It Runs (Poorly) and Doesn't Leak (Mostly)
1974 Velosolex 3800- Better Than Walking
1972 CB750- Broke the Chain And Ate the Motor
1969 CT90- The Most Fun You Can Have on 90ccs.
1965 CA77 Dream- Needs a Full Teardown, but Complete

All advice I give is only valid until an expert corrects me.
jimbonaut
Chrome Member
Chrome Member
Posts: 121
Joined: Sat Dec 19, 2020 3:08 pm

Re: '76 speedo ratio

#3

Post by jimbonaut »

Thanks for the pointer Lucien and you're right, those replacements do look very nice. Did you try removing your speedo/tach from the original housing and replace it with a new set? The OEM housing looks fairly secure and I don't want to break anything by whaling on it too hard. Are the units fairly easy to swap out?
jimbonaut
Chrome Member
Chrome Member
Posts: 121
Joined: Sat Dec 19, 2020 3:08 pm

Re: '76 speedo ratio

#4

Post by jimbonaut »

Checked the 4into1 website again and seems they no longer sell the replacement tach? Or maybe it's just out of stock...
User avatar
Sidecar Bob
Honored Life Member
Honored Life Member
Posts: 7634
Joined: Sun Jun 11, 2006 10:14 pm
Location: Kawartha Lakes, Ontario

Re: '76 speedo ratio

#5

Post by Sidecar Bob »

Speedometers are usually rated by the cable RPM at a specified speed and all of the Japanese bike makers use the same speedometer ratios:
2240 RPM = 60 MPH
2330 RPM = 100 Km/h

This means that you can use any speedometer intended for a Honda, Yamaha, Suzuki or Kawasaki.
Note that the gear ratio in the drive gear on the wheel varies depending on wheel size.

Tachometers are rated with simple ratios
Yamaha and Kawasaki used 1:5 tachs
Suzuki used 1:4
Honda used 1:7 for engines below 750cc and 1:4 for 750cc and larger. I am unsure which the 700cc "Harley tariff" versions of bikes that were 750cc in the rest of the world had and to add to the confusion Motofaction says that the CX family use 1:4 but other sources indicate that they need 1:7.
Mr. Honda ('83 GL1100/Dnepr) summer How a motorcycle evolves thread
The Famous Eccles ('84 CX650EI/VeloUral) winter Never Ending Build (CX500forum)
Click: Colour schematics for all GL1000 & GL1100 and GL1200 standard models plus instructions on how to download the full size version
"A guy with two sidecars can't be all bad." - Cookie
Another guy with two sidecars..... Hmmmm... must be something to that....
jimbonaut
Chrome Member
Chrome Member
Posts: 121
Joined: Sat Dec 19, 2020 3:08 pm

Re: '76 speedo and tach ratios

#6

Post by jimbonaut »

Any idea if this tach would work? It's listed as fitting a CB750 but no mention of a Goldwing. Sure looks the same...

https://www.cb750supply.com/products/99 ... cho-speedo
User avatar
pidjones
SUPER BIKER!!!!
SUPER BIKER!!!!
Posts: 3237
Joined: Wed May 22, 2013 4:06 pm
Location: East TN

Re: '76 speedo and tach ratios

#7

Post by pidjones »

Should. I used a GL1000 tach on a CB750F.
"Love 'em all.... let God sort 'em out!"
Ex 2006 GL1800 - the Black Pearl SOLD! to make room for:
2021 Can-Am Spyder RT Limited Dark Chalk Metallic
1975 Red GL1000 project - ex Pistol Pete project
1972 Triumph T150V Trident rescue - finished and FOR SALE!
1976 Yamaha RD400c
1978 GL1000 with '75 engine - the Hunley
Ex 1978 GL1000
Ex 1979 GL1000
Ex '79 CB750F rat bike
Ex '86 SEi
Ex '77 GL1000
Ex '76 RD400
Ex '72 Penton 125 set up for flat track
Ex '73 RD250
Ex '68 TR6C - chopped
jimbonaut
Chrome Member
Chrome Member
Posts: 121
Joined: Sat Dec 19, 2020 3:08 pm

Re: '76 speedo and tach ratios

#8

Post by jimbonaut »

Thanks pid, good to know - wonder if the housing/mounting holes etc are the same on the CB's and GL's?
User avatar
pidjones
SUPER BIKER!!!!
SUPER BIKER!!!!
Posts: 3237
Joined: Wed May 22, 2013 4:06 pm
Location: East TN

Re: '76 speedo and tach ratios

#9

Post by pidjones »

Don't remember that. I do remember that the bezels are different. Here are '79 CB750F and GL1000 tachs.
79cb750ftach.jpg
79cb750ftach.jpg (24.42 KiB) Viewed 257 times
79gltach.jpg
79gltach.jpg (61.32 KiB) Viewed 257 times
"Love 'em all.... let God sort 'em out!"
Ex 2006 GL1800 - the Black Pearl SOLD! to make room for:
2021 Can-Am Spyder RT Limited Dark Chalk Metallic
1975 Red GL1000 project - ex Pistol Pete project
1972 Triumph T150V Trident rescue - finished and FOR SALE!
1976 Yamaha RD400c
1978 GL1000 with '75 engine - the Hunley
Ex 1978 GL1000
Ex 1979 GL1000
Ex '79 CB750F rat bike
Ex '86 SEi
Ex '77 GL1000
Ex '76 RD400
Ex '72 Penton 125 set up for flat track
Ex '73 RD250
Ex '68 TR6C - chopped
Post Reply
  • Similar Topics
    Replies
    Views
    Last post

Return to “GoldWing Tech Discussions”