ValVal

Ok, so after two years of daily use of my rear surly hub, i'm ready to make a review and a step by step how-to for bearings replacement.
I live in Montreal, QC and use my bike all year round, ride maybe 100km/week, so i guess the hub has seen at least 10000km in all kinds of conditions, including heavily salted roads. Two weeks ago during a spring check-up, i realized that the bearings were shot, and had to replace them.

What you need :
- bearings, (enduro 7901 max, 10$ each at my LBS), since surly uses an axle that doesn't have shouldering, these are angular contact bearings (asymetric), and have an inside and an outside, the black face goes outside.
- cone wrench, 15mm and 17mm
- axle vise or adjustable wrench
- wooden or hard plastic mallet
- large flat screwdriver

Step 1 : Remove axle.
Clamp the axle with the vise or the lock-nut with the adjustable wrench, on the other side, unscrew the other lock-nut with the 17mm cone wrench, while holding the cone with the 15mm cone wrench. Then remove the cone, and the axle.

Step 2 : Remove the bearings.
Use the axle and the mallet to tap out one bearing from the inside. The inner race should come out, destroying the bearing. Push also the seals and the balls, so that there's only the outer race left in the hub. Turn the wheel and use the screwdriver like a lever to tilt the outer race from side to side and pull it out. Repeat with the other bearing.

Step 3 : Place the new bearings.
Place the new bearings on the cones, center them in the cups, and tighten the cones until the bearings are fully inserted in the hub. Remember that the black side goes out.

Step 4 : Replace lock-nuts.


This was easier than i expected, and i was happy with the result until one of the lock-nut broke while I was tightening it. Fortunately I had a spare from another hub.

IMHO, this hub suffers from a design flaw. The angular bearings are difficult to find. Moreover, they are very thin serie, which make them less reliable especialy in a fixie which endures heavy treatments.

I would not recommand this hub, and would prefer Formula or any hub with a shouldered axle.

Hope this helps.

renton20

check out the ultra new surly hubs. Despite all their talk of how their hubs give the best of both loose ball and cartridge hubs they have gone to a shouldered axle.

https://surlybikes.com/blog/post/were...u_up_hub_style

Dannihilator

They probably found another way to make their hubs aggravating. Watch, the axle threads strip out easily.

CliftonGK1

My sarcasm meter is off tonight and I'm having a tough time deciding if you're actually serious.

2 years of zero-maintenance all-weather riding and you're complaining that the bearings aren't reliable?
You're removing the bearing by gutting the thing and prying at it with a screwdriver, yet you're claiming the hub has a design flaw?
A quick search for 7901rs bearings turns up a few dozen sites where they're available, including ceramic bearings (if you want to spend $43/ea on them). Plus, you may consider a bearing removal tool to do it right an avoid scarring up the bearing seat, and a bearing press to get the new ones in without forcing them by the inner race.

Dannihilator

It is a flawed design, I've already gone through 3 sets of bearings(2 in the front) and have only had the wheels since late november and have used the proper tools to do the job each time, the hubs work themselves loose or tight, the rear one I have works loose, the front one I have works tight. But I've figured out a trick that has worked on them. Took the middle spacer out and put in a washer that had some serration to it. Been a month and a half since the hubs last went out of adjustment.

ianjk

Need to adjust the bearings properly or they will die fast...

Dannihilator

Hard to do when the front one came messed up right out of the packaging. Of course bearings being adjusted properly will last forever. I've adjusted and serviced shimano, campy hubs and have them run like they were freshly new.

ValVal

I admit that I dont have a bearing extractor, but in my case it wouldn't have been of any help since pulling them out from the inner race destroys the bearings, and leaves the outer race stuck in the cup, hence the design flaw. With symetrical bearings and shouldered axle, the bearing pops out in one piece when you push the axle.
I say they are difficult to find because i've asked a dozen shop (including specialized bearing shop) before finding someone who could order them. By the way Phil Wood doesn't have them anymore.
60XX or 68XX serie are beefier, and more reliable IMHO.

mihlbach

Two pairs of surly hubs and never had a problem. My oldest pairs has the original bearings and is still smooth. For my second pair, I replaced the rear bearings only after ~10,000 miles. Front bearings are still original. I am also using a Surly front disc hub on my FG MTB, with an ISO cog bolted onto the disc mount. Surly hubs work fine if you know how to set them up. It there is a flaw, its that they aren't idiot proof. Its too bad they are going to a shouldered axle...there's now very little to make the Surly hubs worthwhile. Now its basically the same as a cheaper Formula hub.