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Old 10-09-2009, 07:17 PM
WayneC WayneC is offline
Motorized Bicycle Elite Member
Join Date: Aug 2009
Location: Clearwater, FL
Posts: 173
Thumbs up I'm Freewheelin' Now!

Hey Guys, (long post warning)
I had been wanting to do this upgrade since I built my 4 stroke RS/CVT cruiser. I finally got around
to putting on the Grubee HD Freewheel hub kit complete with band brake.
I tried searching this site for anyone else actually [I]using[I] one of these for some feedback
and found nothing in that regard. Only a few posts mentioned them and a lot of people
were/are wanting them but not much feedback so in case I missed something, I'll give you my
Building/installing wasn't a cakewalk but wasn't difficult either. My first obstacle was reaming
out the hub flange spoke holes. It comes set up for 12ga. but I have 11ga. and my rim was already
drilled for the 11s. That hub, in addition to weighing a ton, is tough! I broke 3 drill bits (one of
which broke and went through my thumb; in-and-out). Gave up on it for a few days and was
ready to take it to a machine shop when I got the notion to try and use a needle file to open
them up. Mounted that in my drill and presto! Problem solved.
Next was the threads of the hub. It came complete with a few nicks that wouldn't let the
freewheels thread on. Needle file to the rescue again. Cleaned up the threads and back in business.
This hub takes a scooter freewheel on the crank (pedal) side. My yankee threaded freewheels
didn't fit so I ordered a Chinese thread one from a scooter place.
The hub is extremely W I D E so I had to spread my frame. If you do this, pay attention to the hub
spacing and notice that it is offset to the right side. I spread ONLY my left chain stay to accomodate
the width.
Now for the freewheel and brake assembly. I don't think the person that wrote the instructions on
Grubee's website ever actually put one of these together successfully because they tell you to
grind off the mounting bolts and "lock" the brake durm onto them to prevent them from backing off.
?what? If you do that, there goes any freewheeling!!!??? AND all of the pictures I've seen of this
hub show the sprocket mounted INBOARD of the freewheel hub. That is BETWEEN the freewheel and the spokes!. Well, once the freewheel is threaded on and the motor torques it down tighter, it ain't comin' off and you're stuck with your selection of rear sproket forever. I mounted my sprocket (56T)
on the outboard side to allow me to change to the 44 or 48 which I will probably do soon. I had to still grind the bolts down (and the heads as well) to clear the brake drum but it's good now.
The band brake went OK 'cept for the nut that holds it to the axle has a small shoulder on it and that shoulder was SLIGHTLY too deep which didn't allow the nut to seat against the brake. A few minutes with a file solved that problem and all went well. I added the cable and my brake lever and after a few minutes of adjusting...TADA! However, Grubee or the China factory don't quite get the idea of a pinch bolt. The hole is too far away from the head (should be up against it) so the cable doesn't really get pinched until you really lay into torquing the nut. I may add another layer of cable stop to this in the near future.
Further impressions... Staying with the brake for a moment, it looked iffy but works surprisingly well. I would put it on par with a "good" side pull caliper brake. I know, kind of an oxymoron. But it stops the bike well and in conjunction with my S/A front drum, I can stop when I need to.
So! If I may toot my own horn here, I got one heck of a truing job on that wheel. It is so smuuuthe to ride on. Sometimes I scare me. The 56T with the CVT jumps off the line (especially after tuning the CVT to work with the little Subaru) and gets me goining about 25 on the flats. I'll be looking into the 44T-48T for improving that figure as well as further CVT tuning for those sprockets, but that's another thread for another time. The KICKER is when you let off the throttle--the chain stops turning and the motor goes to idle in about 3 seconds and you're smoothly and quietly sailing along at the same 25MPH!!!!!! WHOA! 10 kinds o' cool! This leaves the possibility of a STEALTH maneuver if needed when the man may be around. I.E. kill the engine and ghost pedal at 20MPH hahahaha Then...
...reach back when the coast is clear and pull the starter cord and continue on. SBD!
Now, I don't know if this next thing is due to the freewheel or the CVT or both. When I let off the throttle and coast, then hit the throttle again I can feel a clunk/push in the seat of the pants when the clutch engages about 3000-3500RPM. It's not a BAD type of feeling. It's like a POWER type of thing. If I ease on the throttle it still pushes but smoother. Probably a combo of things including gearing. With the CVT I'm kicking in at 32:1
The other thing I really like about the hub is the double sealed bearings. That's 2 sets of cartridge bearings on either side of the axle! They are smooth running and (I hope) long lasting. So between the rear hub and the aforementioned S/A hub which also has sealed bearings, I like the ride of this cruiser and hi speed downhills don't worry me so much anymore.
All-in-all, I give it a big thumbs up.
If pics, further explanations, or parts sources/locations are needed let me know; I'll do what I can.
NOW, is anyone else using this hub? Impressions? Ideas?
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