MBc-Member Product Review: GruBee Solid Hub Heavy-Duty Axle Kit

A

alesterfeind

Guest
Ok, I got my new axle, hub and sprocket yesterday by FedEx from bicycle-engines.com. I called them on Tuesday and got it on Saturday. This is the 2nd order I have made with this vendor, and they have been very quick to deliver both times.

Now, about the hub:

It's HUGE! The picture on the website does not really give you an idea of the size of this thing. I had planned on threading and building my own wheel. After getting it, I realizd the diameter is bigger than my other axle, so I have to replace the spokes as well. I took it up to the bike shop along with my wheel to talk to the techs about it. And, just so everyone knows, the guys at Bicycle's Plus here in Flower Mound were really cool about it being a motorized bike. One guy mentioned, "I have seen a guy riding one of these going north on FM-2499." I said, "That was me!" They can't wait to see the bike once it's put together.

After talking about options, I decided that if I am going to put any more money into this, then I am going to do it right. I purchased a heavy duty rim, (2 ply), new spokes, and I am letting a tech build it so it will be true when I put it on. It was $35 for the rim, $18 for spokes, and $45 for labor. So, it's going to cost about $100 to build the wheel around this new hub, and the hub cost about $50 with S/H. I really think the end result will be worth it in the long run. This new wheel should last forever and run much smoother compared to using the assembly kit we get with our engines that compresses and bends the spokes.

One great thing about this hub is how easy it will be to interchange different size sprockets since it just screws onto the axle. My hub kit came with a 44T. When Andrew gets his, I am sure he can come up with some custom sprockets to fit. I really want a 36T or 32T for my bike.

I should have it ready by this next weekend, and I will post pictures of the parts and the final result.
 
Alaskavan, I thought about that idea of somehow locking up the freewheel. However, for now, I am going to search for a solid hub alternative if one exists. If not, at some point I will be getting the 4-stroke Honda anyway, so I wouldn't want to ruin this good hub. In the meantime, I will just put my bike together the old fashioned way with the assembly we all know and love. As soon as one of us gets this hub on to the axle, maybe we can get this review going. haha
 
I forgot. Ocscully asked if it had cones. It doesn't. I don't know exactly how the axle is held in there. The threads run right on down into the bearings. I took all the nuts off and the axle didn't want to budge. I wasn't willing to take a hammer to it.
 
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Both sides are Driven?

Mickey,

Any one who builds a multi geared motored bike with anyone of the many kits available is going to have a rear wheel where the high tension side of the wheel is on the right the pedal drive side and the motor driven side of the wheel the left side will have less tension inherently weaker. The hub that this thread is about is delivered to be set up with a single speed freewheel on the right for the pedals and comes with a large flanged Left hand thread freewheel for the left side that a final drive sproket is bolted to. There are very few multi gear rear hubs available for bicycles that build up a dishless rear wheel. I can think of only two Wilderness Trail Bikes and Phil Wood and both of these hubs cost in the $300.00 range. There are track and BMX flip/flop rear hubs that are symmetrical and can be respaced and would build up dishless. My original comment was that this HD Hub from GRUBEE reverses the normal build and puts the higher tensioned spokes on the left motor driven side of the wheel rather than the pedal driven side. I was also asking about the spacing of the hub to determine weather or not spacers could be added to the right to allow room for a multi geared freefwheel and also to get the amount of dish that I feel this hub is going to have reduced.

I just did some quick measurements using the photos shown earlier in this thread and this hub with pretty much any rim you choose to use is going to be virtually flat on the left side, This means that virtually all the strength for the wheel is coming from just the spokes on the left side. The center of hub to flange measurement ratio is almost 3:1 that doesn't bode well for building a bullit proof wheel in theory. We'll all know soon as folks get these hubs built up into wheels and on their bikes.

ocscully
 
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ocscully

I was just pointing out that since the hub is designed to be driven hardest from the left side, having the dish, and hence, the highest tensioned spokes on the left is correct.

I'm interested in these hubs as well. I notice that a frame spreader is available so I'm betting the hub is at least a 120mm. I'm thinking that threading a freehub won't be possible but would be sweet.

Mickey
 
Alternative Hub Choices?

alestarfeind,

I'm not sure this is the right thread to post this but since you mentioned you were going to be looking for an alternative hub for your project I thought I might pass along some possabilities. Thru normal LBS channels or thru the on-line bike store network there many Single Speed rear hubs that accept disc brake roters. It would be very simple to adapt one of these hubs to take the rear drive sproket for a motored bike. These hubs range in price from the High End $280.00 for a WTB Laser Disc Single Duty Hub to the lowest price I found yesterday $35.00 for a Nashbar Single Speed Cassette HUB-Disc. Falling in between these extremes are any number of hubs, Paul Component Engineering's Disk WORD rear hub @ $165.00, FUNN Bullet Single Speed Cassette Hub @ $124.00, Surly New Disc Hub @ $79.00, and DMR Revolver SS Rear Disc Hub @ $53.00. There are others as well but these pretty much cover the range. The $35.00 price on the Nashbar Hub is a 50% off sale price. I came across several reviews on that particular hub and the consensus seems to be that it is a really great hub for the money. I ordered one today for myself. The other thing that is a major plus about any of these hubs is that they are all pretty much symmetrical and the wheels you will end up with from any of them will be dishless/equal spoke tension on both sides. One other plus to the hubs mentioned above that are of the cassette type is that you will have a bit of chain line adjustment for your pedal drive cog.

ocscully
 
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HD Hub disassembly

The axle for the hub is asymetrical, and from the distributor, mine had a Lot of extra threads on the left side. Much more than required for the freewheel and strap brake. I finally got around to taking it apart to see if I could reverse it to gain room for multiple gears on the right side.

It looked like the bearings were pressed in, so I pulled the nuts off one side (leaving one on there to protect the threads on the end of the axle. Then, since I had all sorts of tools handy, I applied measured pressure to the end of the axle (I beat it on a rock). The bearing popped out of the other end.
IMG_2034_1.jpg

IMG_2035_1.jpg

The bearings are sealed, so inferior grease or not, I'll just use them. It should be easy to find replacements if/when needed.
IMG_2036_1.jpg

I just flipped the axle around, stuck it back in there, and beat it back together.
IMG_2037_1.jpg

It looks like I still have plenty of threads on the left side, and I gained a bunch of room on the right.
IMG_2038_1.jpg
 
Very cool, Van. Thanks for the pics! Do those Grubee driven sprockets and freewheel really need all that thread on the left side of the hub? Did they get them backwards in production?
 
I don't know why it comes like that. Even with the strap brake on there, I'll have enough thread on the left side, and as you can see, my frame is pretty beefy.
 
Van, Thanks for taking the chance with the precision pressure process. It helps all to see the actual innards in order to understand process.
Makes sence.
Doc
 
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