# Shimano WH-R550 Hubs



## meeshu (Jan 31, 2008)

I have a set of Shimano R550 wheels on one of my bikes. However, the bike is sluggish while riding. On checking the bike, the front wheel is a bit slow to rotate and stops rotating faster than the rear wheel.

After removing the front wheel and turning the skewer assembly/hub nuts by hand, I can feel a slight bumping or clicking effect!? The hub does not rotate smoothly as I think it should.

I suspect that the 16 spoke front wheel hub _may_ have been damaged due to my weight (234 lbs). Or, I think the bike has always been a bit sluggish, so this suggests the problem with the hub may have been there right from the start (?)

Any ideas what may be wrong with the hub? Easily fixed?


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## wim (Feb 28, 2005)

*Some info.*

Most likely not the cause of the 'sluggishness' you perceive. But draggy wheel bearings should be readjusted anyway to extend bearing life. In spite of their unusual spoke arrangement, these wheels roll on traditional, adjustable cup-and-cone bearings. The cones are probably a bit too tight, meaning they exert a little too much pressure on the bearing balls. To fix that, you loosen the locknut (item 4 in the exploded view) on one side a bit, back the cone (item 5) on the same side away from the balls ever so slightly, then tighten the locknut again. No need to touch the opposite side at all.

http://techdocs.shimano.com/media/t.../EV-WH-R550-F-2336A_v1_m56577569830608666.pdf

While the process sounds easy, it takes some experience to get it right in a reasonable amount of time. Closing the hub quick-release (QR) also tightens up the hub bearings a little, so you want to have some bearing play with the QR open, then have it go away as you close the QR. It usually takes me 3-4 tries to get the cone adjustment exactly to that point, and I've been screwing with hubs a long time. You may want to have the hubs cleaned and repacked (sounds like they could use it) by a shop. Watch how it's done if all this is new to you.

I seem to remember that the WH-R550 front wheel cones are oversized, so you'd need larger-than-normal cone wrenches to do this job yourself. _Edit:_ I just measured a WH-R550 front cone and its locknut—both are 17 mm across the wrench flats, so you'd need two cone wrenches with a 17 mm opening.


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## meeshu (Jan 31, 2008)

Thanks for your comprehensive reply! Very useful information here! 

Adjusting and maintaining wheel hubs is one thing I have not done before. There's always a first time though!

I don't as yet have any cone wrenches. I'll be getting some of these wrenches together with some other tools soon.


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## wim (Feb 28, 2005)

Cool, glad you're trying to do this yourself. Rebuilding cup-and-cone hubs becomes a relaxing, zen-like activity for some, Im not joking.


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## Squidward (Dec 18, 2005)

The front hub was poorly adjusted from the factory on my WH-R550 wheels.


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## meeshu (Jan 31, 2008)

Interesting! So much for quality control! 

I've suspected that the bike may have had a bad or maladjusted front hub ever since I bought the bike! I found the bike not to be faster than a similar bike with slightly lower spec'd components. Plus, the bike with the suspect front hub seemed a bit sluggish anyway.

However, my heavy weight and with only 16 spokes on the front hub _might_ have aggravated the condition of the hub.


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## wim (Feb 28, 2005)

meeshu said:


> Interesting! So much for quality control!
> 
> .


My shop days are over, but for many years, I helped in checking and adjusting every traditional cup-and-cone hub of every bike before it was put out on the sales floor. I can probably count the bikes on one hand that had perfect bearing adjustment. Didn't matter what price level—$300 cruisers to $3,000 super-bling racer boy stuff: 99% of them had misadjusted hub bearings. (Curiously, always too tight.)


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## meeshu (Jan 31, 2008)

Interesting!

The LBS where I purchased the bike from is supposed to be fairly highly regarded. However, it's possible that the LBS may not have checked, or may not have correctly adjusted, the front hub before selling the bike!?

Anyway I'll be purchasing some 17 mm and 13 mm cone wrenches shortly for the WH-R550 hubs and for some other hubs I have as well. It should be interesting to see what the problem is with the front WH-R550 hub.


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## PeanutButterBreath (Dec 4, 2005)

Shimano hubs often require adjustment from the factory, and _any_ hub should be checked. Even high quality sealed bearing hubs from Chris King require preload adjustment on installation and over the the initial period of use.

A competent mechanic will know this. On the other hand, some shops may not invest a competent mechanic's time into a low-end wheel.


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