Wheel Nightmare - Grubee HD Hub - Any Help?

klassard

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I apologize as this is mentioned in other threads but I haven't seen a resolution yet.

I purchased a grubee HD Axle/Hub from bicycle-engines.com a while back. I got it laced up with 10 gauge spokes by Wheelmaster and took it to the local bike shop to get a freewheel for the pedal side (the hub doesn't come with one).

Nothing fit. I tried another bike shop. Nothing fit. Tried a third bike shop. Nothing fit. The threads are close, but jam after a couple turns. The drum for the drum brake fits fine on the left and right side, so I know the threads are in good shape.

I checked the grubee site. It says the threads are 35x1. Unfortunately, this doesn't exist. There is I.S.O. = 34.92 x 1.048 mm
as well as Brittish = 34.80 x 1.058 mm and the far less common French = 34.7 x 1 mm.

I sent messages to bicycle-engines.com, and grubee. Don Grube responded with "It is 35x1" and the folks at bicycle-engines.com told me they've never had a problem before and sent me to another bike shop which has yet to respond to my messages.

Has anyone successfully screwed a freewheel onto one of these hubs? If so, can you tell me what kind of threads this thing has?

Any help would be great!

Thanks!

Kevin
 
Wow. This is a surprise to me. I just took a freewheel I had sitting around and screwed it on mine. I never even knew there were different threads.
 
Why doesn't this hub come with a pedal side freewheel? Is it the freewheel left hub btw?
 
Strange...i put a single speed freewheel on my hub & it went on perfect.
Something sounds wrong with your hub thread.
 
I agree. There must be something wrong with the thing. Maybe they make different threads for different markets. For example, in China, where the things are made, I imagine there are more metric and maybe even French threads than ISO. Perhaps I got one that was intended for another geographic area by mistake. This is insanely frustrating. Having the holes drilled out and laced up by wheelmaster wasn't cheap. Even if I get bicycle-engines.com to swap the hub out, I'll have to get the thing re-drilled. AAAARRRGH!!!
 
It is the hub with the freewheel for the engine on the left (that freewheel and sprocket came with the hub). On the right, there are threads to put a pedal freewheel, which doesn't come with the hub. The problem is that no pedal freewheels that I can locate fit the thing. Oddly enough, I have a freewheel from a chinese electric scooter that fits perfectly, but it doesn't have bicycle chain teeth. Hence, I think the threads are some odd foreign specification that found its way into birddog distributing's stock by accident.
 
I gave Jeremy at bicycle-engines a call today. I was told that he is their technical expert. He told me that it is normal for freewheels to get stuck on their hubs and that I should just chain them up and pedal them to force them on. Unfortunately, this solution damages the threads if they aren't correct.

I've confirmed today that the threads are not I.S.O. threads. I took a freewheel from a Chinese electric scooter and tried it. It went on like butter. Unfortunately, it didn't have bike teeth. So I ordered one from this site - http://www.scooterparts4less.com/web_electric/freewheel_hub.htm

It came in the mail today. It also went on like butter.

Here's the clincher:

The Chinese electric scooter freewheels don't fit on any of my normal bike hubs, but they fit perfectly on the Grubee axle. My other normal freewheels from my regular bikes are completely interchangeable with any of my hubs EXCEPT the Grubee.

The Grubee hub must have some kind of non-standard thread that is shared by Chinese scooter hardware and not by bicycle freewheels.

This means that either the 100's of people that bicycle-engines.com says buys their hubs are forcing freewheels on that don't fit and inadvertently ruining their threads or the hub I received was an anomaly that got shipped to bicycle-engines.com by mistake and the majority of their hubs do in fact have ISO threads and I was just unlucky.

Now, I have a freewheel that works but I am still hosed because I also bought a disk brake adapter to replace the band brake on the hub. The adapter has I.S.O. threads and will therefore not fit on the Grubee hub. If anyone is using a two-sided hub that actually has normal threads, this thing would be an awesome disk brake solution: http://www.sjscycles.co.uk/product-...c-Brake-Adapter-for-145mm-OLN-98-TD-12727.htm
 
It is normal to force freewheels on this hub(or any other hub) but ONLY at the end of their threading cycle,not the beginning.
Glad u found a solution though.........pity if u had to re-do that entire wheel.
 
I suppose if the builds always went as planned, it wouldn't be as much fun when I finally got them up and running :)

I just wish the folks at bicycle-engines.com were a little more receptive to what I was trying to explain. It may well be that the hub I received was an odd ball and not what normally comes out of the factory where they get them. I'd even be happy to send them the thing along with the freewheel I found so they could check it out. If the bulk of their hubs use the Chinese threads, it may ease some frustrations of potential customers if they disclose this upfront. If not, I'd sure like to swap mine out for a normal-thread version.
 
Hi Kevin, It could be possible that the chrome on this hub ended up being extra thick, I know I certainly had a HUGE amount of trouble drilling the holes to accept the #9 gauge spokes (took me all day Literally), Maybe the threaded erea could be wire brushed on a electric grinder with a wire wheel to slightly bring the diameter of the threads down to where the sprocket threads correctly ? just a thought, please keep me in the loop as I'll do everything in my power to get you through this issue.. thanks and good luck ! Jim........
 
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