ocscully
Member
No the Reduction unit on the Honda is the Grubee III Gearbox which has a 3.7:1 Reduction. I switched to the Grubee 4G drive for Honda motors in October which is a 5:1 reduction Unit.
ocscully
Looking for a gearbox to fit Titan 49cc and SBP shift kit
- Thread starter breaksalltherules
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No the Reduction unit on the Honda is the Grubee III Gearbox which has a 3.7:1 Reduction. I switched to the Grubee 4G drive for Honda motors in October which is a 5:1 reduction Unit.
ocscully
Skyliner70cc
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So, it is possible to use a Honda and install it on a shifter kit? If so, what, if any fabrication, did you have to do? Was the engine mount part of the SBP shifter kit? Please provide us additional info and/or pics. Is the Grubee 4G drive working well or is it loud, noisy, and unreliable?
I really wish someone comes out with an easy bolt on 4 stroke shifter kit with a reliable and quiet gear box.
I really wish someone comes out with an easy bolt on 4 stroke shifter kit with a reliable and quiet gear box.
MotoMagz
Active Member
Yes the shift kit will work with the Honda with no fabrication needed.The engine mount comes with the SBP shift kit.The 4G is very quiet.It has a couple of issues one being the oil lite bushing which is not a true oil lite bushing.The second being the clutch springs,which can be changed.Then it will engages like it should.
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Knuckle_Duster
New Member
I'm running a 5:1 4G on a SBP shift kit (using 5/8" shaft HS motor) and will add a few issues you might see:
1), the clutch drum. The front gear is pressed on the drum and subject to separation when you least expect it. I had to get mine welded after much headache.
2), 3 chains and slack happens. Not easy to keep all of them chains happy without resorting to an idler on both the longer chains. Lacking any idlers, when any of the chains are loose you can get "drivetrain wobble", like letting the clutch out too fast on a manual transmission vehicle. Wommm wommmmm wommmmmmm
3), the mount. It can twist/tweak easily under high power in low gears. 'Keep it tight!' one might say, but that's hard when you have to loosen 9 nuts/bolts for second chain adjustment only to find the adjustment may be off upon tightening due to mount tweak. An idler is practically a must-have for jackshaft-to-outer ring chain.
4), the 30T gear supplied with SBP kit is, IMHO, too small for 5:1 gearbox. I'm using a 36T and wish SBP had a 40T. Gear ratios vary of course, but if you have a 5:1 gearbox I'll bet you'll be happier with a 36T or higher. SBP made the 4-stroke shift kit with 3.7:1 Stage III in mind, so keep that in mind if you're using a 4G. Newer 4G may have diff ratio.
1), the clutch drum. The front gear is pressed on the drum and subject to separation when you least expect it. I had to get mine welded after much headache.
2), 3 chains and slack happens. Not easy to keep all of them chains happy without resorting to an idler on both the longer chains. Lacking any idlers, when any of the chains are loose you can get "drivetrain wobble", like letting the clutch out too fast on a manual transmission vehicle. Wommm wommmmm wommmmmmm
3), the mount. It can twist/tweak easily under high power in low gears. 'Keep it tight!' one might say, but that's hard when you have to loosen 9 nuts/bolts for second chain adjustment only to find the adjustment may be off upon tightening due to mount tweak. An idler is practically a must-have for jackshaft-to-outer ring chain.
4), the 30T gear supplied with SBP kit is, IMHO, too small for 5:1 gearbox. I'm using a 36T and wish SBP had a 40T. Gear ratios vary of course, but if you have a 5:1 gearbox I'll bet you'll be happier with a 36T or higher. SBP made the 4-stroke shift kit with 3.7:1 Stage III in mind, so keep that in mind if you're using a 4G. Newer 4G may have diff ratio.
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Skyliner70cc
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Moto,
Your bike is awesome. What frame/suspension is it? I'm glad folks like you paved the way and I think I'm going to make an identical one and I'm going to start saving up for it starting today. Please let us know if you develop any issues.
Knuckle, thanks for the info regarding improving reliability.
MotoMagz
Active Member
Thanx but I can not take the credit.OCSCULLY is the one who shared his knowledge and know how with me.I found using the shims between the motor mounts on the frame has kept my mount from moving and chains tight.
