Maxi Car Front hub overhaul
 

Does anyone have experience wiht overhauling Maxi Car hubs?
I wanted to take the front hub apart today and followed the instructions from Yellowjersey. I started with the front hub but couldn't remove the non adjustable side (NAS) lock nut. After taking a better look at the axle on the NAS I wonder if that lock nut can be removed at all. The threads on the NAS look weird to me, like they somehow were modified after the lock nut had been installed. Is this supposed to be like that? This particular hub is from the 90's. Did Maxi Car use different axles on later front hubs?
The threads on the rear hub just look like normal threads but I haven't tried to take the rear hub apart yet.
The threads on the other side of the front hub are also just normal threads.

https://cimg3.ibsrv.net/gimg/bikefor...1325e37650.jpg

Bikes like the raleigh superbe had the axles ground flat on opposite sides to each other. They fit into specially sized fork ends with flats.

edit: it looked flat to me but it appears your threads are all flattened and the axle is damaged.

I've rebuilt Maxicar hubs and the DS (NAS) nut is indeed supposed to come off, and in fact it must if you want to remove the axle without destroying stuff inside. It appears the threads are mangled. You could force the nut off destructively, and replace it after re-threading the axle. There's a French bike shop on eBay that sells Maxicar hub parts, last time I looked they had axle nuts.

I would not attempt without the possible needed departs in hand.

I read long ago on the procedure to take these apart. Vintage Bicycle Quarterly I think even had an article on the task.

now bicycle quarterly, I think they still have back issues, a bit of a spend, but reference books cost.

You can find Maxicar rebuilding guides on other sites for free :).

The threads are probably mangled indeed. It just looks like it's been done on purpose...
My first idea was to leave the DS nut and only unscrew the dust cap and leave it hanging there and try to remove the whole axle like that. I would have to support the hub with a piece of a PVC pipe of bigger diameter so that the dust cap can go through it. There is probably a small chance of damaging those baffle washers this way, I don't know. Also, the hub will be supported by its flanges, probably not a big issue though I just don't know how hard I am suppose to tap the axle with a hammer, I am overhauling Maxi Car hubs for the first time. What do you think?

Removing that nut is a bit tricky, it requires so much torque to remove it that the axle just keeps rotating in my axle vice tool.
Or what do you mean by forcing it destructively?

That particular issue of VBQ (Summer 2004) is not available anymore, the website says it's out of stock..So it's nowhere to be found.

still try to get the axle out, to make it simpler to work on, and I'd be spending a few minutes on the threads with a good sharp swiss file before trying to take the locknut off. Do a bit, see how far the locknut goes, back it in and do a bit more.

If you can manage to unthread the dust cap with the locknut stuck on, great, that should do it. But your pin tool will have to fit without interference from the locknut. Sometimes those dust caps are stuck tight.

What I meant by removing the nut destructively is essentially sawing it off so that you can get a thread die on there and repair the axle threads, and then replacing nut with a new one. But as someone else pointed out, make sure you have a replacement nut in hand before you do that!

I built a crude wooden jig for tapping the Maxicar axle out, using two pieces of stacked 2x4s screwed to each other. One has a bore large enough to clear the hub bulge around the dust cap and the other has a bore for the axle to pass through when tapped out. This way, the majority of the hub body is supported by the wood jig. I have spare NOS dust shield/washers in case you mangle yours, I'd be happy to sell you them for what I paid.

Maxicar hubs are so different than any other hubs... like from another planet. But they're marvels of engineering, actually. Until you've rebuilt one once, there's a good chance of FUBARing something. Ask me how I know, or why I happen to have NOS spare dust shields :).

As for how much force it takes to remove the axle... that all depends on how frozen to the axle the NDS inner bearing cartridge race is. Because as you tap the axle out the DS end, the NDS bearing has to stay in place as the axle slides through it. I had to treat mine with PB blaster for a few days before I could get it out, and I'm afraid I had to use a 3-lb rubber sledge to get it to budge. Even after PB treatment. Granted, my hub is from the 1950s. Yours being newer, the axle might slide out with gentle taps. Just be sure to use a rubber sledge, or if not, then a block of wood between the sledge and the axle so as not to deform the end of the axle. And again, here's where there is risk of damaging the hub: If you tap too hard, you risk damaging the pressed in NDS bearing cup, which is pressed into the hub body (NOS replacements are available, but good luck extracting the original).

https://cimg8.ibsrv.net/gimg/bikefor...e60e939e16.jpg

need to ask on the CR group, at least one hoarder has a copy.

As mentioned earlier, there are several online guides, like this official Maxicar one reprinted on yellowjersey.com: Maxicar Wonderful French Hub Tech Page at Yellow Jersey

I am pretty sure that with a Park Tool pin spanner I would be able to unscrew the dust cap even with the lock nut still there. The spanner I own does not allow me to do that, so I just ordered two Park Tool spanners for the job, it's good to have them in any case. I'll have to wait around two weeks for them to arrive here though. In the meantime, I'll try to overhaul the rear hub and see if it goes any better.

I hope that those axles are not very stuck in there. In general, both hubs spin very smoothly, I could just leave them as they are. But I do want to open and service them mostly out of curiosity, you know :rolleyes:

Depending on which pin spanner(s) you got, they might not all work. I have the Park Tool pin spanner with the flat steel arms that pivot, and the pins that are screwed in. The arms interfered with the DS side axle shoulder and I had to grind the arms down just a tad closer to the pins for it to work. Also one of the dust caps was so tight that the pin tool couldn't keep its bearing in the bores, so I had to hold it laterally captive with a large axle washer and nut, which you can't do on your DS because of your trapped axle nut. So let's hope your dust cap isn't too stuck!

I referenced the Yellow jersey info, some is useful, but I recall much more annotated service guidance elsewhere. As I do not have an of these hubs, was not more than passing interest.

I ordered the SPA-1 and the SPA-2. The SPA-1 with 2.9mm pins should work I think, if not I'll use the SPA-2. It's handy to have them both anyways. I've got a similar pin spanner as yours but not made by Park Tool, that one doesn't work without modification, the arms are too wide. I did use it to remove the dust cup from the NDS, it was easy enough to do it. Maybe that's why you do have to overhaul these hubs from time to time, just to make sure that you can still disassemble everything without troubles.

There is not that much information online on servicing Maxi car hubs, the following links as well as the yellow jersey page are the only sources I am aware of:

https://restoringvintagebicycles.com...s-part-1-sigh/
https://restoringvintagebicycles.com...maxi-car-hubs/
https://restoringvintagebicycles.com...s-part-3-whew/
https://bike-cafe.fr/2015/06/maxi-ca...moyeu-vintage/

Yay! Both of the axles are out now!
I started with the rear hub which gave me quite some trouble as well. I can say with certainty now that tapping the axle out of the hub is the most difficult part of taking these hubs apart.
For the rear hub, I ended up using a piece of a 40mm (o.d.) PVC pipe which I also cut longitudinally on one side. This way, I could spread the tube a bit which allowed me to put the threaded part of the hub in it which provided very sturdy support for the hub. Okay, so far quite easy.. Now the hard part. After a lot of hitting and applying penetrating oil and letting it soak for a while and tapping the axle again I had no progress whatsoever:troll: The axle would't move at all. The thing is, I don't have a copper mallet but I do own a heavy 1kg rubber mallet. However, I don't think rubber mallets are very effective for this job. I think they are less efficient because of energy losses due to material of the mallet. You kinda hit the axle with it but it's not the same as hitting it with a proper hammer.
Anyway, not having a lot of a patience for soaking the hub for a couple of days in penetration oil or something like that, I was looking for another solution. Luckily, I had a piece of copper tubing around, I think 22mm. I flattened it on one side and used it to protect the axle by holding that bit above the axle. Now, I could use an iron hammer to tap out the axle :P After 4 or 5 blows in finally gave up and was out!

Happy with the result, I decided to attempt to open up the front hub as well. I followed southpawboston's advice and modified my cheap pin spanner in order to be able to unskrew the dust cap without removing the stuck axle nut. A bit of filing here and there and the spanner was ready for the job. This time I used a piece of 50mm (o.d.) PVC tubing. Knowing how to approach the tapping step this time, I gave the axle a couple of blows and it was out. :)
I am in the middle of cleaning all the parts now and I will be assemling the hubs back very soon. I feel like I am getting pretty confident at servicing Maxi Car hubs :)

https://cimg6.ibsrv.net/gimg/bikefor...5d2b9c1593.jpg
Modified pin spanner
https://cimg6.ibsrv.net/gimg/bikefor...2ab42af602.jpg
The front axle
https://cimg0.ibsrv.net/gimg/bikefor...d89072daf1.jpg
A piece of copper tubing to protect the axle
https://cimg3.ibsrv.net/gimg/bikefor...72b20ee075.jpg
Bonus picture. Hauling the "tools"

Well done. And it's possible now to rebuild that DS cartridge bearing that's still on the axle. Now that it's separated from the outer race (which is pressed into the hub body), the inner race can remain on the axle. Taking care not to bend or distort the outer dust shields, which are held in place between the axle flange and the cartridge inner race, you can just pull the cartridge away from the inner race toward the NDS side of the axle. The balls will shift radially outward as you slide the cartridge (more like ball cage at this point, actually) over the raceway (channel) of the inner race that's pressed on the axle. Then you can clean/degrease the ball cage and inner race separately without ever removing the inner race. Then reassemble.

Good luck!

Thanks! I already figured out that the bearing cages can be removed from the axle like that. It's pretty straightforward. I thought that the bearing cages were symmetrical but they are not, one side of the cage is thicker than the other one. And it seems that the thicker side should face the NDS, and that's the case for both cages! It is at least like that on the front hub, I didn't pay attention how the bearing cage was installed on the DS of the rear hub. The cages are also a bit different from the ones I see in the manual on YellowJersey. They are almost flat on both sides, I guess the bearings changed in those later hubs.

Heck, the funniest thing about the bearings is that the inner race on the rear hub is marked with 4GPZ 6010. The secret of Maxi Car is solved, they used Soviet bearings in their hubs, of course! :o
4GPZ (The Forth Governmental Bearings Plant) was an important bearings manufacturer based in Kuibyshev, USSR (later renamed as Samara) which existed from 1941 till 2001. Apparently, they numbered all bearings plants in the USSR from 1 (obviously in Moscow) to 34. I grew up not so far from the still existing 11GPZ in Minsk, where they also produced those magneto bearing, and still most likely do.

https://cimg7.ibsrv.net/gimg/bikefor...a7a450df46.jpg
Note that the bearing cage is thicker on the right hand side
https://cimg7.ibsrv.net/gimg/bikefor...701bf63779.jpg

https://cimg6.ibsrv.net/gimg/bikefor...d715e1eb8c.jpg
4GPZ 6010. Apparently, the forum doesn't support Russian letters, so I can't type it in Russian

I will look in my old issues, see if I have it.

Thanks, let me know if you find it

Hope this helps....

https://cimg9.ibsrv.net/gimg/bikefor...90c94d51f.jpeg
https://cimg1.ibsrv.net/gimg/bikefor...788ab4882.jpeg
https://cimg4.ibsrv.net/gimg/bikefor...f4a0bc616.jpeg
https://cimg5.ibsrv.net/gimg/bikefor...9e8d6009b.jpeg

https://cimg4.ibsrv.net/gimg/bikefor...01b1cf249.jpeg

santa fe 2926 Thanks! Very much appreciated! Could you also post a photo of p.28? I think that one is missing..

Sorry about the order, and double posting page 26, there aren’t any more pages on the overhaul, the last page (28) of Summer 2004 is about steel frames by Mike Kone. I got the issue to learn about MaxiCar, but working on them is probably beyond my cup and cone skills. Admire those on the forum that can do the work!

Just wondering if any shops or individuals performs overhauls on maxicar hubs.