high flange/mtb rear hub overhaul information

The Profile MTB Cassette hubs (150mm, 8-9 speed 135mm, 6-speed, and single speed) all have the same basic components, as does the BMX High Flange hub with a 3/8" axle. The majority of the 8-9 speed, 6 speed, and single speed hubs we sell are of the 3/8 axle stud type, and of course all of the BMX High Flange Hubs have the 3/8 axle studs, but the QR axle ends used in these instructions are no differently attached.

Of course, It's preferred that you use an arbor press or a bearing press to install new bearings in your hubs, but since we recognize that not everyone has access to those, we provide these instructions to make things easier for you. We are happy to overhaul your hubs here at Profile for a small fee. Please contact us for details.

click to enlarge

Pictured is an MTB 8-9 speed hub. The BMX High Flange 3/8 hub assembles the exact same way, but obviously the hubshell, axle, and driver are different cosemtically.

• a. non-drive axle end (the larger of the two) (1)
• b. non-drive cone spacer (1)
• c. hub bearings ( #6903) (2)
• d. aluminum center axle (1)
• e. hub body (1)
• f. driver spacer (1)
• g. driver (1)
• h. drive-side spacer (1)
• i. drive-side axle end (the smaller of the two) (1)

Bear in mind that rushing this process can lead to damaging your hub. Take your time and make sure that the bearing press or axle and the bearings are aligned correctly at all times as you press them in.

Overhauling your hubs is not something that needs to be done more than once or twice a year, unless you ride 3 or 4 hours a day, everyday. Then you might need to do it 3 or 4 times a year, but my point is that you shouldn't take your hubs apart just for the sake of taking your hub apart.

You will need new bearings, two 3/16" allen keys for the cone spacers, a hammer, possibly a bench vice, and a rag. Of course, you should inspect all of the hub's parts before you begin to reassemble it, to ensure that the hub will perform as close to new as possible when you're done. Inspect the hub flanges for cracks, and make sure that the aluminum center axle doesn't appear bent, bashed, worn, stripped, or cracked. Also make certain that your cone spacers aren't crushed or otherwise deformed. If they are difficult to remove from the axle or hub, that's a pretty good indication that they are damaged. you can purchase Profile Hub Small Parts in our online store, or your local bike shop can order the parts for you.

To disassemble the hubs, loosen one of the axle ends about half way, and hit the axle end with a hammer. Loosen the axle end a bit more and hit it again- repeat the process untill the bearing drops out the other side. Clamp the center of the axle in the bench vise, and remove the axle end that's still attatched to the center axle. Slide off all of the parts. Slide the axle back into the hubshell into the bearing that remains in the hub. Screw one of the axle ends about halfway into the alxe end on the opposite side of the bearing, and hit the axle end to pop the bearing out.

Clean and inspect all of the hub's components for wear and damage. Carefully remove the springs and pawls from the driver, and set them aside in a safe place so you don't accidentally knock them off your work area and lose one of them forever.

To reassemble your hubs, slide the non-drive bearing (c) and cone (b) on the non-drive side of the axle (d), and thread the axle end all the way down. You can clamp the center of the axle in a bench vise to keep the axle from rotating while you tighten the axle end all the way down. You can use a bit of blue loctite on the threads of the axle end if you like.
Slide the axle assembly into the hub. You can tap the axle end with the hammer to begin to seat the bearing on the non-drive side, but you don't need to press the bearing in all the way, just enough to get it started. IMPORTANT : Make sure the axle is square to the hub and isn't going in crooked. Then, on the drive side, slide on the hub bearing (c),and the driver spacer (f).
Slide the driver (g) on to the hub body, followed by the drive side axle end(i). Turn the axle ends with your allen keys a few turns, and then back the axle end(i) out. You should now have room to fit the drive side spacer(h) on under the drive-side axle end, continue to tighten the axle end (i).
Continue to tighten the axle end down. You can clamp the other allen key in the vice if you like. Take your time, and don't force it.
The axle ends have been tightened all the way onto the axles at this point. The non-drive side cone spacer (b) is flush with the hubshell (e), and if you remove the drive side axle end (i), the drive side spacer (h) is only a mm or so above the end of the axle.
Spin the axle. It will probably feel a bit rough, so you should perform the "shocker" on the hub to cure this. Strike the axle against a hard metal surface, or use a hammer, and strike both axle ends about as hard as you would hit a nail into soft wood. This should equalize the bearings in their bores and get rid of the roughness. If it does not, you may have to start the entire rebuild process over, or just perform the "shocker" a little bit harder. You're not trying to hit a home run with the force of the blow, you're trying to hit a bloop single, to put it in baseball terms.

If you are unable to resolve an issue with your hub, we do perform repairs here for a nominal fee. Please don't hesitate to contact us if you run into difficulties. Riding a poorly performing hub is never a good idea.

DISCLAIMER: These instructions are provided as a service. The best way to install sealed bearings is always a bearing or arbor press. The methods discussed here are alternatives for the home bike mechanics with home bicycle tools. If you are not careful, you will damage your hubs and bearings. Profile cannot be held responsible for any damage caused by attempts at repair attempted by anyone other than employees of Profile racing.

If you are unsure of your abilities, take your bike to a local bike shop, or contact us at Profile. We are happy to overhaul your hubs for you here. Contact Shane at Profile at 727.391.7370 for details.