Understanding Metro Gear Conversions
May 3, 2006 12:03:30 GMT -5
estemanito and Greasetank like this
Post by Dandy Dan on May 3, 2006 12:03:30 GMT -5
This thread is intended to provide information to anyone who is interested in gearing their Ruckus taller to increase their top speed (provided you have the power).
A 2006 Ruckus has a redline of 8850rpm which it reaches at about 43mph. Prior to 2006, the redline was 8000rpm which is reached at about 39mph.
All Ruckus's are geared using 4 gears in addition to their variator and clutch system and these gears are found behind the rear clutch in the 'transmission' which also contains 0.1L of SAE 90 Hypoid Gear Oil
The 4 gears, starting with the gear on the end of the clutch (drive) shaft and finishing with the gear on the end of the main axle are 12 Teeth -> 42T -> 12T -> 47T
The first 2 gears (12T and 42T) are identical on both the Ruckus and Metro so they will be ignored other than to state that they reduce the rotation speed to 0.286 (12/42) so that means that the first gear has to spin roughly 4 times before the 2nd gear makes it around once.
The 2nd gear is connected directly to the 3rd gear so they both spin at the same speed. The 3rd gear has 12T in a Ruckus and it meshes with the final gear on the axle which has 47T. This 12T to 47T gearing reduces your gearing further so that the 47T gear spins only 0.2553 (12/47) times for every time the 3rd gear spins. The result of all 4 gears working in combination is that every time the first gear on the clutch shaft spins your rear axle only spins 0.073 times which means it takes about 13.5 rotations of the clutch shaft to spin the rear wheel once.
With that out of the way, I'll now discuss why the Metro gears can be helpful. The Metro gears are perfectly compatable in that they fit perfectly into the Ruckus case but the gearing is different because the Metro uses small wheels so it needs taller gearing just to reach equivilent speeds. (Note: The Restricted Metro II uses the same gears as the Ruckus due to it's lower top speed, don't buy these).
The Metro uses the same first 2 gears as the Ruckus (12T drive/clutch shaft and 42T 2nd gear) but the 3rd and 4th gears are 13T (instead of 12T) and 45T instead of 47T. This gives you the same 0.286 reduction between the first two gears but instead of the final two gears creating a 0.2553 reduction they only create a .289 reduction (13/45) which means that your intial gear only has to spin 12.1 times to rotate the rear wheel completely instead of 13.5 times like a Ruckus.
So what does this all mean? Well, if you swap your final two gears in your Ruckus to the Metro ones your final gear ratio will be 13% taller. So for a 2006 Ruckus that hits the 8850rpm at about 43mph it will now hit the redline at 48.6mph. A pre-2006 Ruckus with a 8000rpm redline will be able to reach 44mph before it reaches 8000rpm instead of about 39mph.
There's still more to consider though, like what if you just want to swap one of the 2 final gears. To keep a long explaination short, just swapping the final gear will gear you 4.5% taller which means a pre-06 Ruckus will redline at 41mph and a 2006 Ruckus will redline about 44.9mph.
If you just swap the third gear (which is a lot cheaper than the final gear, about 1/3 the cost) you'll end up geared 7% taller which will net you 46mph with an 06 or about 42mph with an older Ruckus. So this is actually more bang for less buck.
As for the compatability, Doctavious has swapped the final gear while continuing to use the stock 3rd gear and he was amazed by how perfectly they mesh together and he's currently using that with a noticably increased top speed and no problems to date. I can't say for sure that you could just swap the 3rd gear with equal results but I would guess that it will mesh fine too. If you swap both you'll for sure have no problems.
FYI, the first gear (drive shaft) costs about $25 US, the 2nd gear will set you back about $18, the third one $20 and the final gear about $60 US. You can gain a better understanding of what these gears look like by going to:
RonAyers.com -> OEM Parts -> Online Microfiche -> Honda -> NPS50 -> NPS50 2005 -> Transmission
Lastly, the final gears are backordered because of the recent demand for them so expect a bit of a wait. In the mean time, someone should try just swapping the 3rd gear and see how well that works.
Oh, one question people may have is why should they do this if they already have a CDI? Well, a CDI is kind of cheater way to increase your top speed because it just eliminates the redline which lets you reach crazy speeds downhills but it's a bad idea because it lets you abuse your engine by revving it too high and it revs you right past your peak power so you won't gain as much top speed compared to gearing it taller. A Ruckus peaks around 8000rpm and you'll have a better chance of cruising at 45mph if you are at 8000rpm instead of 10K. In my experience, a CDI lets you go faster down hills but it doesn't do much on flats because your Ruckus doesn't make enough power above 8K to really go any faster.
A 2006 Ruckus has a redline of 8850rpm which it reaches at about 43mph. Prior to 2006, the redline was 8000rpm which is reached at about 39mph.
All Ruckus's are geared using 4 gears in addition to their variator and clutch system and these gears are found behind the rear clutch in the 'transmission' which also contains 0.1L of SAE 90 Hypoid Gear Oil
The 4 gears, starting with the gear on the end of the clutch (drive) shaft and finishing with the gear on the end of the main axle are 12 Teeth -> 42T -> 12T -> 47T
The first 2 gears (12T and 42T) are identical on both the Ruckus and Metro so they will be ignored other than to state that they reduce the rotation speed to 0.286 (12/42) so that means that the first gear has to spin roughly 4 times before the 2nd gear makes it around once.
The 2nd gear is connected directly to the 3rd gear so they both spin at the same speed. The 3rd gear has 12T in a Ruckus and it meshes with the final gear on the axle which has 47T. This 12T to 47T gearing reduces your gearing further so that the 47T gear spins only 0.2553 (12/47) times for every time the 3rd gear spins. The result of all 4 gears working in combination is that every time the first gear on the clutch shaft spins your rear axle only spins 0.073 times which means it takes about 13.5 rotations of the clutch shaft to spin the rear wheel once.
With that out of the way, I'll now discuss why the Metro gears can be helpful. The Metro gears are perfectly compatable in that they fit perfectly into the Ruckus case but the gearing is different because the Metro uses small wheels so it needs taller gearing just to reach equivilent speeds. (Note: The Restricted Metro II uses the same gears as the Ruckus due to it's lower top speed, don't buy these).
The Metro uses the same first 2 gears as the Ruckus (12T drive/clutch shaft and 42T 2nd gear) but the 3rd and 4th gears are 13T (instead of 12T) and 45T instead of 47T. This gives you the same 0.286 reduction between the first two gears but instead of the final two gears creating a 0.2553 reduction they only create a .289 reduction (13/45) which means that your intial gear only has to spin 12.1 times to rotate the rear wheel completely instead of 13.5 times like a Ruckus.
So what does this all mean? Well, if you swap your final two gears in your Ruckus to the Metro ones your final gear ratio will be 13% taller. So for a 2006 Ruckus that hits the 8850rpm at about 43mph it will now hit the redline at 48.6mph. A pre-2006 Ruckus with a 8000rpm redline will be able to reach 44mph before it reaches 8000rpm instead of about 39mph.
There's still more to consider though, like what if you just want to swap one of the 2 final gears. To keep a long explaination short, just swapping the final gear will gear you 4.5% taller which means a pre-06 Ruckus will redline at 41mph and a 2006 Ruckus will redline about 44.9mph.
If you just swap the third gear (which is a lot cheaper than the final gear, about 1/3 the cost) you'll end up geared 7% taller which will net you 46mph with an 06 or about 42mph with an older Ruckus. So this is actually more bang for less buck.
As for the compatability, Doctavious has swapped the final gear while continuing to use the stock 3rd gear and he was amazed by how perfectly they mesh together and he's currently using that with a noticably increased top speed and no problems to date. I can't say for sure that you could just swap the 3rd gear with equal results but I would guess that it will mesh fine too. If you swap both you'll for sure have no problems.
FYI, the first gear (drive shaft) costs about $25 US, the 2nd gear will set you back about $18, the third one $20 and the final gear about $60 US. You can gain a better understanding of what these gears look like by going to:
RonAyers.com -> OEM Parts -> Online Microfiche -> Honda -> NPS50 -> NPS50 2005 -> Transmission
Lastly, the final gears are backordered because of the recent demand for them so expect a bit of a wait. In the mean time, someone should try just swapping the 3rd gear and see how well that works.
Oh, one question people may have is why should they do this if they already have a CDI? Well, a CDI is kind of cheater way to increase your top speed because it just eliminates the redline which lets you reach crazy speeds downhills but it's a bad idea because it lets you abuse your engine by revving it too high and it revs you right past your peak power so you won't gain as much top speed compared to gearing it taller. A Ruckus peaks around 8000rpm and you'll have a better chance of cruising at 45mph if you are at 8000rpm instead of 10K. In my experience, a CDI lets you go faster down hills but it doesn't do much on flats because your Ruckus doesn't make enough power above 8K to really go any faster.
