Hub Overhaul Tech



Hubs-Wheelbuilding	Hubs-Axles	Crank Installation	Spline Drive Spider

This page contains instructions for overhauling hubs with True 3/8's axles. If you have the older Standard axles, those instructions can be found here.

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.

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.

Overhauling Profile Mini Front Hubs is easier than you might think it is. You just need new bearings, two 8mm allen keys (but you can make do with one), your bike's forks, 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.

click to enlarge

Profile Fixed Hub parts:

a. 3/8"(10mm) axle bolts (2)
b. Cone Spacers (2)
c. Hub Bearings (mfg #6903 - front, mfg #6902 - rear) (2)
d. Aluminum Center Axle (1)
e. Hub Shell (1)

Taking Profile Fixed Hubs apart is simple. Remove the wheel from the bike, and back one of the bolts out until it's 2/3's of the way out of the hub. Then hit the bolt with a rubber mallet, and the bearing should pop out the opposite side.
Remove the bolt, cone spacer, and bearing, and thread the bolt back into the side of the axle opposite the bearing, and use the mallet to remove the bearing that's still in the hubshell.
Once you have the hub completely apart, clean the bearing seats, axle, bearings (externally only, if you're keeping the old ones,) and inspect all components for damage. If you see any cracks, crushing, distortion, or deformation then you should replace that part. Inspect your bearings for side to side play. Then, slide your bearing (c)onto the axle (d). If you are installing shims, they should go on the axle, followed by the bearings. After the bearing, slide on a cone spacer (b), and tighten the axle bolt (a) all the way down, finger tight is fine.
Insert the axle assembly through the hubshell, and again, insert the shim (if needed), the bearing, the cone spacer, and use the axle bolt to hold it all together, leaving the bolt sticking far enough out that you can put the hub into the dropout on your fork as shown. 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 frame or 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.

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 or contact us for details.