jospl

Dear Bike Forum Community,

I've had my road bike for 7 years now and determined it was time to overhaul my rear hub. Everything went well until it came time to unscrew the freewheel body fixing bolt as shown in the manual linked below. I hunted down the Allen socket bit after two hardware shop stops and went to work. Only, it didn't work. I might just take up unicycling because my 200lb self managed to balance on top of this thing while trying to unscrew it. I mean, this thing won't budge. My LBS sprayed some unscrewing compounds on it, we waited 30 minutes and still we could not get it to budge even with an extra long seat post stem being used for leverage.

Does anyone have any suggestions for how to unscrew the ununscrewable freewheel body fixing bolt? Inside there lies grinding grime... it's begging to come off!

Best regards,
John

Part manual: si.shimano.com/pdfs/dm/DM-HB0003-04-ENG.pdf

VegasTriker

You are more likely to get an answer in the Mechanics subforum https://www.bikeforums.net/bicycle-mechanics/ where a lot of wrenches lurk.

CliffordK

Ok, it looks like you have a Freehub, not a freewheel.

You've linked to a Shimano page. But, do you have a Shimano hub or another brand hub?

It should come out with the 12mm Allen Wrench. You said you've used a cheater and it still didn't budge. "foo"

Paint Stripper Heat Gun on the hub?

CliffordK

Upload some photos to your Gallery/Photo Album.

https://www.bikeforums.net/g/user/496311

Did your hub have loose bearings or sealed bearings?

JanMM

The linked pdf shows a freehub but refers to it as a freewheel, also. And shows that a 14mm hex wrench is used to remove the 'freewheel body'. States the freewheel body fixing bolt is not reusable and must be replaced.
I have no experience with shimano hubs like this. Sounds as if the fixing bolt has become permanently attached after 7 years.
Don't know if a hex adapter on a long socket wrench would work any better than the seatpost lever that was tried.

CliffordK

It showed 5800 and 6800 hubs which I believe are different.

We need photo confirmation of what the OP has.

JanMM

Right, multiple rear hubs shown. Which are all a bit different.

jospl

Dear Posters,

Thanks Jan & Cliff for your responses. I'll have to update my settings so I receive per-post email updates for each post (just received the bulk notification).

This is still a work in progress. I ordered an impact driver rated @ 1375 in-lbs. The hex adapter for the 1/2" socket comes in on Tuesday.

Heat gun... haven't tried that one yet. Good idea. Perhaps that's up next. Regarding the model, I think it's the FH-9000 / FH-6800 as depicted in the PDF although I don't really trust that manual since (1) it has the wrong hex sizes--it wasn't a 5mm or 10mm or 15mm (are really any 15mm? that's pretty big...)--it was a very awkward-to-find 11mm. And (2) the freewheel/freehub thing. Good catch @JanMM.

I uploaded the album w/ photos. Let me know if you have any troubles viewing the photos. Planning on giving the driver a go at it on Tuesday when the adapters come in.

Best regards,
John

andrewclaus

Usually heat and impact work. Impact could be a dead-blow mallet on the wrench handle. If you haven't broken spokes yet, you probably won't.

Spoonrobot 

Last OEM freehub fixing bolt I removed required a 60" cheater bar braced against the ground while I torqued the wheel with everything I had. When it finally gave there was a loud snap, I fell down and the wheel/hex key/bar assembly clanged all over the place. It was ridiculous.

Guy I work with now says they put the hex key in their vice, put the end into the bolt and have two guys turn the wheel. Apparently works pretty well because the bench the vice is on is locked to the cement wall with 32 tapcons.

aggiegrads

If you have a vise, hold the wrench in the vise and use the wheel to create torque. An inflated tire makes a good gripping surface.

Lemond1985

OP, I don't wanna see you break anything. I get the whole "never give up" attitude, but is there any specific reason that freehub needs to come off, other than pride? Might be a good time to "let sleeping dogs lie".

jospl

@Lemond1985 good call. Almost took a guy up on an offer to use his 12-ton hydraulic press (per craigslist by-owner post) for a 6-pack of beer. I've had a hub with grime in it before and it didn't last long. No worried though, a few days ago I ordered another wheelset. I just hate to throw a good wheel away, especially if it's a good excuse to grab an impact driver. I'll probably never need anything more than 1375 in-lbs though so if the driver doesn't work I'll open a craigslist post titled "Undo this bolt with bare strength and win $100!" and price the attempt at $5 a pop. Perhaps a fare or maybe even a farmers market...
@Spoonrobot -- Would have loved to see that. I wonder what the assembly line uses to put these things on that makes them so tight. I bet it felt good when it gave, other than the whole falling-on-the-ground thing.

A vise installation is a good idea but then the landlords would flip out on me.

davidad

I used a 4 pound hammer on Chuck's free hub the first time I worked on it. We boilermakers go for the big hammers.

leob1

1375 in-lbs is only 114.5 foot pounds, not really a lot for an impact wrench. Are you sure it's inch pounds and not foot pounds? Use 1375 foot pounds and SOMETHING will come loose(if you can hold the wheel)..

jospl

@leob1 I was wondering about that. I'm going to return the driver and grab a 4-pound hammer per davidad's suggestion.

CliffordK

If you want an impact driver, purchase a 1/2" impact driver. Air or Electric.

https://www.amazon.com/DEWALT-DW292-.../dp/B0009HM5OI

Listed at 345 ft pounds torque.

Hmmm... so much is going cordless.
https://www.amazon.com/DEWALT-DCF897.../dp/B01H0UJE5Y

Listed as an impressive 700 ft.lbs of max torque and 1200 ft.lbs of max breakaway torque.



Still, if you can't get it off with a long breaker bar, then something sounds like it is wrong.

jospl

The impact driver wouldn't get it off. Sure made me put on ear protection though. That thing hammering on the bolt was really loud.

I really don't need that much power, this is definitely an edge case. If the hammer doesn't work I'm calling it quits on this thing.

Thanks everyone for your help--I really appreciate the suggestions.

a2e

Right at page 16 of the manual, you can see the FH-9000 has a "not reusable" bolt. Anyone knows why Shimano came up with this ****?
Also the you need a M14 Allen wrench, not 10 nor 15.

HillRider

Yes indeed there are 15mm L-hex wrenches but they aren't common. The only one I was able to find is sold by Park Tools and it rather pricey. The freehub body bolts on Shimano GRX gravel wheels like my WH-RX570 wheels require it. Home Depot sells a 1/2"-square drive 15mm hex bit for $10. I have one of those but haven't used it yet so I don't know if the hex is long enough.

mpetry912 

well you gotta love Shimano, at least they have documentation with exploded drawings.

I don't care for the one shot threaded barrel nuts that are of indeterminant size and threading.

the comparable Campagnolo hub retains the freehub body with 3 set screws. Much easier.

If the impact didn't budge it you either were turning the wrong way - or you were just holding the wheel and the force of the impact was not being transferred into the part.

I think if you clamp the tool (12 or 14 mm allen) in a vise and use the wheel as your leverage you might get it.. pretty sure the barrel nut will be convention RH threads (lefty loosey).

or just build a new wheel

/markp

mitchmellow62

Everyone knows this is an old thread from 2019? The OP never posted if he solved it or not. He also never said if it really was a shimano hub. I'm betting it wasn't and the hub body was attached in a different way. Happened to me once. His personal info says he owns a Scott Speedster. Most speedsters came with Scott hubs.

jgwilliams

Indeed. My Fulcrum wheel needed a 17mm spanner and a 5mm hex key. It wouldn't take me above 5 minutes to change it now that I know what I'm doing. I gather the same free hub is used on a lot of Fulcrum and Campag wheels, which would definitely tend me towards buying them in the future.

jospl

I believe the hub was a "vuelta hub" per this product ad "Aeromax Alloy Wheelset Road Bike Comp 700c" wheelset:
https://www.amazon.com/gp/product/B002XOJD9A/

I could not find any literature on the "vuelta hub" since there are no markings on the hub itself and no hubs listed on their website which I could find, so I found what I thought was the closest match (looks like the same hub per diagram, and it sounds like a shimano). My guess is that it's probably a shimano design licensed and built by Vuelta. Other than not being able to tear it down, it is a pretty high quality hub from what I can tell. Smooth riding.

Solution: no solution. I ended up buying another one of the same wheelset. It is cheap, so it is not a big loss. Sold the old wheels on craigslist to someone who was going to give it a try. I'm not sure if they succeeded or just lived with the rattling / grinding noises. The eight-pound sledge didn't work & that was my limit.

But, yea, a cheap wheel. I think that pretty much sums it up.

mitchmellow62 - if you have another idea how this hub would be attached per the photos here (e.g. https://www.bikeforums.net/g/picture/13206583) I am idly curious as to what the process would be. I agree it feels like it doesn't open this way. Perhaps it's like a2e said... "not reusable". Perhaps glued for a solid, cheap seal.

If anyone can find the Vuelta hub manual, that would be solid, but it's no longer a problem so no worries.

mpetry912 indeed, shimano spoils us. It's probably unreasonable to expect the same level of attention by other brands.

Thanks again guys. Happy holidays.

mitchmellow62

Thanks for posting. I purchased a rear hub at a local coop for almost nothing thinking I would harvest the 8/9/10 speed hub body. The hub was unlabeled and I assumed it was a shimano knockoff. I don't remember sizes but the right hex wrench (12 mm?) fit into the axle space in the hub body just like a shimano hub. I couldn't move it. I took it to the LBS and we used their longer wrench with the hub in a vice. We started to bend the wrench. I took it home and was looking at it a little closer. I discovered that a hex wrench inserted from the non drive side (different size but I don't remember exactly what) unscrewed a very short bolt that threaded into the underside of the hub body. The hub body was removed with very little effort. Unfortunately, I had no use for it. It was a cheap lesson that not everything is shimano.

And Merry Christmas to you also!