high flange/mtb front hub overhaul information

The Profile High Flange BMX front hub uses the same center axle as the QR or 10mm axle MTB front hub, so you can follow these instructions for both hubs. The only difference is in the hubshells. The 20mm front MTB hubs are completely different, but those instructions will be found on this page as well.

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

• a. axle studs (2)
• b. cone spacers (2)
• c. hub bearings (2) (front #6903)
• d. aluminum center axle (1)
• e. hub body (1)

Bear in mind that rushing this process can lead to damaging your hub. Take your time and make sure that the bearing press 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 bench vice to hold the lower nut on the threaded rod, a wrench that fits the upper nut on the threaded rod, and a rag. Of course, you should inspect all of the hub's part 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 Fixed Hub Small Parts in our online store, or your local bike shop can order the parts for you.

To disassemble the hubs, remove the axle bolts, and loosen one of the cone spacers about half way. Thread an axle bolt back in the loosened conespacer, and hit the bolt with a hammer. Loosen the cone spacer a bit more and hit the bolt- repeat the process untill the bearing drops out the other side.

Clean and inspect the hubshell, center axle, and cone spacers for damage.

To reassemble your hubs, we will thread a nut onto the threaded rod about 5 or 6 inches down, and clamp the nut in the jaws of a bench vice as shown.
Place, in this order, a steel 3/8" washer (q), a 3/8" aluminum washer (r) and either the 14mm steel washer (s) (for rear hubs) or the aluminum 3/8 cone spacer (u) for front hubs. We'll be working on a front hub in the pictures, so you'll put the aluminum cone spacer on the threaded rod next, then the hub bearing, and the aluminum center axle.
Place the hubshell on top of the bearing. We're going to press one bearing in at a time, so place the aluminum cone spacer directly onto the bearing seat of the hubshell, then the 3/8" aluminum washer (r), the steel 3/8" washer (q), and finally, a 3/8 bolt.
IMPORTANT! Make sure the bearing is straight! Make certain the cone spacer is square to the bearing! Begin to tighten the bolt on top, making sure that everything is aligned properly. If the bearing isn't straight, you can damage your hubshell.
When the bearing is installed completely, it will be recessed slightly into the hubshell
Place the other bearing on top of the hub, followed by the 3/8" aluminum washer (r), the steel 3/8" washer (q), and finally, a 3/8 bolt.
The bearings should not slide into the hubshell at this point- if they do, or if you can slide them in and out of the hubshell with your bare hands, there is an issue with your hubshell. Call us and discuss it.
You will ideally have 2 8mm allen wrenches for this step.Snug up the bolt that's in the fork, and use the bolt on the far side to hold the axle steady. Make sure that the bearings and conespacers are lined up square to the hub. As you tighten the bolt that's in the fork, the bearings should be drawn into the hub. It shouldn't take a great deal of force or pressure.
You will feel a definite stop when the bearings are completely inserted. The edges of the conespacers should also be more or less flush with the curve of the hubshell as well. Loosen the axle bolts and place the wheel normally in the fork.
Tighten the bolts as you normally would, and check the wheel for side to side play and smoothness. If you have side to side play, then you should start over, paying special attention to the inspection stage. If you still can't get rid of the side play, contact us, and we'll get it fixed. If you feel roughness, but no side to side play, remove the wheel from the fork, and snug both bolts to the hub. They should be maybe a half a turn past finger tight. Hit one of the bolts with your mallet sharply, but not like you're trying to ring the bell at the county fair. One or two taps should completley seat the bearings if they weren't seated before. Anything more than that, start the process over.

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.

The principals of overhauling all Profile Front Hubs are basically the same, with axle dimension and cone spacers being the primary difference.

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.