Wheel bearings? Bleeding lines? Aint broke don’t fix them?

Hi all,

I’m taking my bike down to the LBS to get some sus fitted and get a new BB installed.

I’ve got a pair of SRAM breaks and they’ve never been bled. I guess the bike is around 4-5 years old now and has seen a lot of use. Any point in getting them bled professionally or leave them alone?

Likewise, I noticed my wheel bearings are not buttery smooth. Is this a cause of concern? I’m doing a fairly decent trip soon and the bike will see a lot of hard milage, maybe around 300-400 miles. Again, should I have them changed out or whatever?

Advice welcome!

FM

Yes bleed them, the Dot 5 fluid will have absorbed some water by now

Yeah, do those things, but learn to do it yourself and save loads of money in the long run.

Brakes will be fine until they suddenly aren’t. That moment is usually at the worst possible time.

Levers to the bar when you’re dropping down a near vertical rock face with limited run out is the favourite.

Get them bled. Pray that leaving them untouched for 4-5 years hasn’t caused any damage/corrosion/general pain in the arse behaviour.

Same with hubs, a collapsed or seized bearing is pretty much a ride over event, might also damage other stuff in the hub (freehub, axle), or the bike in general (tyre rub, cassette gouging the frame, brake discs rubbing etc)

Good to know, thanks all.

Yeah, worth getting them bled…fresh fluid always helps make a brake feel very nice.

If the bearings fail completely the inner race and bearings can be come seperated and you end up with the outer bearing race stuck in the hub which is a massive ball ache.

Like they said… Basically all brake fluid has a lifespan, dot fluid soaks up any wter it comes across and once it’s done that it boils at much lower temps. And mineral oil doesn’t do that but that just means any water sits unabsorbed in the brake instead, and boils at 100 degrees, and can corrode stuff. So basically, every few years is a good idea.

Bleeding good brakes is pretty easy btw and the tools are usually cheap. I don’t know exactly which brakes you have but most SRAM for a long times has used the “2 syringes” approach which once you understand it, is really pretty great. It’s a useufl thing to be able to do and though it sounds scary it’s actually easier than most diy.

Wheel bearings, if they’re the sealed cartridge types, last a long time but also, they need to <really> fail before it’s a problem. Unlike cup-and-cone which you ruin the hub if you leave it too long or adjust them wrong, it’s the biggest advantage of cartridge.

Always check them out of the bike, there’s too much else going on when they’re in the frame. Hold the axle ends and spin, you’re listening and feeling for a low pitched rumble mostly, a bit like the sound of a drawer opening, that’s the early sign of wearing. Anything clunky, irregular, any cracking or bumping noises, tends to mean they’re getting properly worn. If you can, remove the freehub so that you can do this for just the hub bearings, and check the freewheel ones just by sticking your finger in them and turning (it’s hard to eliminate freewheel noises when testing bearings otherwise)

Quite often you’ll find bearings wear at different rates, this is probably the biggest advantage of DIYing- a shop will tend to replace the whole lot, I replace only worn bearings, on some hubs you find the most exposed ones live a third as long as the best protected ones in the middle.

Oh yeah you can extend this exact idea to frame bearings- it’s basically impossible to detect a worn frame bearing with the bike assembled, because of the weight and the forces involved, but take the rear wheel out and unbolt hte shock at one end so that it’s all free to move and you’ll feel things you can never notice therwise.

Surely the answer is “ask the bike shop whilst you’re there”?

I hate bleeding brakes.  I’m sure it’s simple once you ‘have the knack’ but I sadly do not, it’s been a right faff every time I’ve done it and I always wish I hadn’t started.  That’d be a trip to the LBS down the road for me next time.

I hate bleeding brakes. I’m sure it’s simple once you ‘have the knack’ but I sadly do not, it’s been a right faff every time I’ve done it and I always wish I hadn’t started.

I’ve found it much easier with newer brakes.

Hope brakes bleed conventionally ie just a bit of tubing and a jam jar needed.  Very simple to do  Another reason to like them.

Great timing, I was wondering the same about bearings. Bottom bracket feels fine, it’s five years old and been through numerous floods. Same with wheel bearings.

 I’m sure it’s simple once you ‘have the knack’

Some brakes are just crap to bleed. I mostly have “the knack”, i can do most (95+%) in minutes. Some i just *can’t* get a clean bleed on.

Did 3 bikes worth of hopes, one of shimano and one of magura in an hour before xmas, and one was a complete installation and fill from scratch (bag of bits, rather than preassembled from factory)

The SRAM things on one of my exes bikes, take an hour each end to get half way decent. If she sends them to a shop, it costs £60-70 and they aren’t even as good as i can get them. It’s the second or third set she’s had under warranty.

I like SRAM’s groupsets, but honestly their brakes…Anything that needs ‘a knack’ to it can get in the sea as far as I’m concerned. My experience is the same as @mert. It’s too fiddly, takes too long, and the results are variable, I’d get shot of mine, but they ‘mostly’ work for what I need, and I’m too miserly to change just for the sake of it.