Grubee G4 kit mounted on Grubee bike with 1 piece crank

[Irish John]

IrishJohn: No, not mpg, I meant range pertaining to the gears, low end for steep starts and high for more speed on the flats without haveing the motor wound up all the way.

If you get the sprocket combination right there's really no need for a shifter kit on a 4-stroke frame mount. They don't rev their guts out like the HTs and they sit for miles on end at a comfortable 45 - 50 km\hr. The frame mount can't take being smacked around on dirt roads so you won't be riding trails. A 11T front with a 48T back on the old GBs were good enough for all the big hills around here. The Honda makes a difference but the belt drive is yet to be tested. I very much doubt it fills the power difference between the HS & Honda but it may provide a little more power to the back wheel. We'll be the guinea pigs and we'll be the ones who find its best sprocket combination.
The trouble with a shifter kit is that the person who uses it is likely to want max speed all the time and will have the engine running at peak revs all the time anyway.
Believe me I reckon a shifter kit would slow you down and will present lots of nasty experiences just waiting to happen.

 

[Irish John]

IrishJohn

What is the width of the belt?

15.1mm

 

[highrider]

I'm thinkng of upgrading to a 4 stroke engine. DO the 4 stroke engines have gears or are they like the 2 stroke having only one gear throttle?

Also do the plastic engine covers come in any other colour besides red, I prefr black or silver?

 

[Irish John]

I'm thinkng of upgrading to a 4 stroke engine. DO the 4 stroke engines have gears or are they like the 2 stroke having only one gear throttle?

They have a gearbox on the horizontal shaft and they only have one gear which is quite adequate if you get the sprocket combination right.

do the plastic engine covers come in any other colour besides red, I prefr black or silver?

They come in red but you can easily pain them any colour.

 

[Irish John]

G4 & GT1 on trial run.

I tried the G4 out today and was thoroughly disappointed. The 44t doesn't feel right and the top speed is pretty useless - bit like an HT but quieter. The chain came off the tensioner cos I cant get the nylon wheel to line up with chain.
I'm looking at using a washer from a v-brake to help get the tensioner to go at same angle as chain. The problem is caused by the motor having to be mounted so high to let the pedals clear the pulley wheel. The chain line is never good like that. Back to the workshop to figure out a solution.
My opinion of this kit so far is that I'm glad I bought up the last of the old gearbox stock cos this one definitely isn't as good.

 

[fetor56]

A bit of a let-down so far....what's the rest of the bike like John(in particular the forks)?

 

[Irish John]

A bit of a let-down so far....what's the rest of the bike like John(in particular the forks)?

It's not bad for the price. Forks are OK but Zoom forks are the low end of the fork market. Wheels are nice but galv spokes will go grey and look naff pretty soon. Bike is pokey - too short between stem and seatpost and handlebars aren't as nice as a Schwinn. It's over designed because I think people who don't know think the standard bike frame is not strong enough so this one is really strong and consequently too heavy.
I like my Schwinns especially my own one that has no coaster brake. I wish someone would just make an honest to God cruiser with springer forks and V brakes and get it made outside of Asia.

 

[Deleted member 8310]

a G4 mod?

Looking at the pics of the G4 on the Grubee site it looks as if the drive could
be pivoted up and redrill some holes. Then the motor could be mounted level
and the drive clear the pedals.

You might have to grind some tach welds off but that's easy and so is a re-tack.

It looks as if the backing plate would pivot and that is the only part that
would need redrilling. Of course my assumptions are only from online images.

 

[Irish John]

Looking at the pics of the G4 on the Grubee site it looks as if the drive could
be pivoted up and redrill some holes. Then the motor could be mounted level
and the drive clear the pedals.

You might have to grind some tach welds off but that's easy and so is a re-tack.

It looks as if the backing plate would pivot and that is the only part that
would need redrilling. Of course my assumptions are only from online images.

There is a lot more problems with this G4 than just the angle of the gearbox. In typical Grubee fashion they never did the calculations to work out the sprocket sizes and if you get those wrong at the outset chances are everything else compounds the problems. I reckon he's out by about 10 teeth which breaks his previous record of 8 teeth. The width alone is a good enough reason to leave this gearbox sitting on the shelf. Lots of ideas really poorly executed add up to dog's breakfast of a kit. Not as bad as the JL Hoot (nothing will ever equal those turkeys for incompetence) but the G4 is a darn good attempt to steal the JL Hoot Perpetual Challenge Trophy from the Chinese.
If you kick the back of the GB upwards you end up with a drivetrain line that cannot be tensioned with the tensioner supplied and on some cruisers you may well saw the seat stay in two with the chain. They should go back to the drawing board and try again but without our help Grubee will always fail to get it right. What happened with that EZM GB. Don't hear a squeak out of them - once the motor gets above a certain width you are onto a real loser.

 

[Deleted member 8310]

bummer

"There is a lot more problems with this G4..."

How dissapointing, pretty sure hopes are dashed with alot of people due to
your reports. Your pics show just how wide it is. If it was the greatest who
would care, but considering your experience, well...