Knackered bearings after 4,300 miles?

[Ajax Bay]

Would an 11 offer much more top end than a 12 anyway when teamed with a compact? I would have thought the difference would be minimal?

The difference is, with an 11t smallest sprocket vice 12t, you would be able to go 9% faster for the same cadence. Much more of a difference than your stated intent to go to 52t large chainwheel (vice 50t) which would give you only 4% more.

it's the big ring I'm more interested in changing, as I find myself spinning out sometimes with my current 50-12 ratios.

So it's a fair suggestion by @gbb to go for an 11-28 and you can find these second hand, if you try.
http://www.ebay.co.uk/itm/Shimano-1...720319?hash=item1c5f8648ff:g:~8sAAOSwaA5WkoqL

And I think @Pale Rider MUST be 'peddling' a canard:

Given that you are a fairly hard rider, an 11 could encourage slipping.

What, pray, do you think the pro peleton use, as the smallest sprocket on their 11sp Di2 Dura Ace? Perhaps they don't pedal hard.

 

[Globalti]

Hope is a well-regarded brand in this market, which leads me to suggest Hope Hoops, although others will have to point you in the direction of which of the many available would be most suitable.

I don't think Hope wheels are any better than any other with cartridge bearings. The four bearings in my Hope mountain bike rear wheel and freehub seem to last around a year. Luckily they can be bought cheap from local bearing stockists and if you can't be bothered to fit them yourself it's a five minute job for an LBS with a Hope service kit. In that case you might as well allow them to fit their own bearings and make at least a small profit on the job.

 

[the_mikey]

Hub bearings on these wheels are usually industrial sealed cartridge bearings, steel cartridge with steel bearings housed in a bearing race. In terms of maintenance, there is little that can be done with them, grease can be added or it can be washed out, but they're pretty much a disposable item.

Typically these bearings will start to fail once water is introduced, the water becomes trapped in the bearing and the steel parts will corrode, wear and tear is also a factor in bearing failure but worn out bearings tend to produce more play in the wheels causing brake alignment problems for example.

 

[Pale Rider]

And I think @Pale Rider MUST be 'peddling' a canard:

What, pray, do you think the pro peleton use, as the smallest sprocket on their 11sp Di2 Dura Ace? Perhaps they don't pedal hard.

A pro rider has limitless funds, can replace parts at will, his bike is constantly fettled by the finest technicians money can buy, and he rides for speed - nothing else.

The OP is self-funded, needs the parts to have a decent service life, does some home maintenance to save a bit of cash, and he rides for distance and other general purposes.

Thus what suits one is unlikely to suit the other.

Just because the pro peloton does it, doesn't make it a good for a general rider - often quite the reverse when it comes to kit.

But don't worry, you are not the first to fall for the 'ride like a pro' marketing bullshine.

 

[Ajax Bay]

You must also be driving on slightly less of the cog.

Given that you are a fairly hard rider, an 11 could encourage slipping.

My point was that elite riders would not use a sprocket size which had any risk of slipping.
Just so I get this right, then, you're suggesting that the use of an 11t smallest sprocket increases the chances of "slipping" (when the power goes on) as in, in @Yellow Saddle 's taxonomy, skating?
And are you suggesting ("needs the parts to have a decent service life") that a smallest sprocket which is 11t will likely wear out more quickly than a 12t?

 

[Yellow Saddle]

My point was that elite riders would not use a sprocket size which had any risk of slipping.
Just so I get this right, then, you're suggesting that the use of an 11t smallest sprocket increases the chances of "slipping" (when the power goes on) as in, in @Yellow Saddle 's taxonomy, skating?
And are you suggesting ("needs the parts to have a decent service life") that a smallest sprocket which is 11t will likely wear out more quickly than a 12t?

Small sprockets will skate easier than larger ones. If both sprockets have the same amount of wear, the smaller one, with less chain wrap will skate with less tension on the chain than the larger one.

Chain wrap is the number of teeth engaged with the chain at one time. If a 24 sprocket is wrapped halfway, 12 teeth engage with the chain. If a 11 sprocket is wrapped halfway, only 5 teeth are engaged.

Further, smaller sprockets wear quicker than larger ones but there are a bunch of riders to "quicker". Basically, for the same number of wheel revolutions performed with a large and a small sprocket, the smaller one will wear quicker. This however does not show up in everyday cycling because most of us don't sit in the 11 all day. We generally favour another sprocket higher up on the cassette.

A small number of people, men and women, have a different muscle composition than most of us and have more fast-twitch fibres than us mere mortals. These people are gear grinders. You come across them from time to time. They are the ones always in 53/11 combos. As a mechanic, when you deal with them you have to keep in mind that normal wear patters don't surface with them. Their big advantage is that they can fix their skating cassettes with other people's throw-away 11 sprockets.

I didn't read the entire thread, so I hope the context on my answer based solely on what you asked makes sense.

 

[EasyPeez]

I don't think you can get an 11-28 Tiagra cassette but you can get a 105 11-28 cassette. The downside is they cost a bit more.

Thanks. Looks like they go for about £20 so nearly double what I paid for my Tiagra cassette. At a current rate of one cassette every 2 years though, I reckon that's an extra expense I can absorb!

Given that you are a fairly hard rider, an 11 could encourage slipping

Thanks. I appreciate less teeth engage with an 11, increasing wear, but I don't see me using the 11 enough to wear it down very fast. Skating shouldn't occur on an 11 sprocket, even ridden hard, unless it starts to wear, should it?

The difference is, with an 11t smallest sprocket vice 12t, you would be able to go 9% faster for the same cadence. Much more of a difference than your stated intent to go to 52t large chainwheel (vice 50t) which would give you only 4% more.

I'm surprised adding a sprocket with 1 less tooth at the back gives over twice as much potential extra speed per cadence as adding a ring with 2 more teeth at the front. I am going to show myself up for the dullard I am here, but how do you do these calculations? I'd be interested to compare the ratios on 50-12/50-11/52-12/52-11
Thanks.

 

[Ajax Bay]

Thanks to @Yellow Saddle . I can see that in theoretical terms if an 11t wears then it's more likely to skate than a 12t with the same wear. But in practice, the smallest sprocket does not wear nearly as much as others in the cassette so only occasionally does the extreme case (as he articulates) occur.

I don't see me using the 11 enough to wear it down very fast. Skating shouldn't occur on an 11 sprocket, even ridden hard, unless it starts to wear, should it?

I agree with your premise and the answer is 'No'.

@EasyPeez You get the ratio of a gear (chainwheel/sprocket) by dividing the sprocket size (number of teeth) into the number of teeth in the chainwheel. This is the number of times a rider drives the rear wheel round for one full turn of the pedals. I'll leave you to do the maths but 50/11 is ~9% greater than 50/12. You may notice there's a slightly bigger gear change at the point on your cassette where the difference in teeth between sprockets changes from one to two, for example the difference in ratio between the 15t and the 16t is 6.6% and between the 16t and the 18t is 12.5%. Switching the chainwheel from 50t to 52t gives you 2/50 additional fraction of a wheel turn per one full turn of the pedals: 4%.

Recommend a read of this recent thread:
http://www.cyclechat.net/threads/opinions-sought-on-this-drivetrain-change.193432/
@Smurfy 's post (edited) gives the 'gear calculator' which I think you'd find interesting.

Here is 34-50, 12-25, where the jump is expressed as 'Gear Step %'.
http://www.gear-calculator.com/?GR=...16,17,19,21,23,25&UF=2125&TF=90&SL=2.6&UN=KMH
http://www.gear-calculator.com/?GR=...16,17,19,21,23,25&UF=2125&TF=90&SL=2.6&UN=KMH

 

[EasyPeez]

Thanks to @Yellow Saddle . I can see that in theoretical terms if an 11t wears then it's more likely to skate than a 12t with the same wear. But in practice, the smallest sprocket does not wear nearly as much as others in the cassette so only occasionally does the extreme case (as he articulates) occur.

I agree with your premise and the answer is 'No'.

@EasyPeez You get the ratio of a gear (chainwheel/sprocket) by dividing the sprocket size (number of teeth) into the number of teeth in the chainwheel. This is the number of times a rider drives the rear wheel round for one full turn of the pedals. I'll leave you to do the maths but 50/11 is ~9% greater than 50/12. You may notice there's a slightly bigger gear change at the point on your cassette where the difference in teeth between sprockets changes from one to two, for example the difference in ratio between the 15t and the 16t is 6.6% and between the 16t and the 18t is 12.5%. Switching the chainwheel from 50t to 52t gives you 2/50 additional fraction of a wheel turn per one full turn of the pedals: 4%.

Recommend a read of this recent thread:
http://www.cyclechat.net/threads/opinions-sought-on-this-drivetrain-change.193432/
@Smurfy 's post (edited) gives the 'gear calculator' which I think you'd find interesting.

That gear calculator is brilliant, thanks!

Of course - now I understand that you obtain gear ratio by dividing the number of teeth on the cassette sprocket into the number on the chain ring it's obvious that a small change at the back will create more difference than a slightly larger change at the front. Feel daft for not working this out before - maths never was my strong suit!

I'm not sure exactly what sprockets a 10 Speed 11-28 will come with, as Shimano no longer list spec info for these on their website, but I suspect that if I were to change my current 12-28 for an 11-28 I would effectively be swapping a 14 for an 11 and the rest would stay the same.
If this is correct then according to the gear calculator that would mean a gear change % of 15 when going from the 13 cog to the 15. That sounds quite a bit, and potentially quite clunky...hmmm. There again, my current set-up involves a jump of 13% when going from 15 to 17, so maybe it wouldn't be that noticeable a difference.

I know @Pale Rider & @mrbikerboy73 both backed up my suspicion that a change from 12 to 11 wouldn't feel like a big gain. The gear calculator suggests 9%, or in other words a gain of 2-3 mph at the top end (depending on cadence). Although not a massive amount an extra 2+mph is significant when really pushing it and might be the difference between my legs outgunning the bike and the bike outgunning my legs?!
For the sake of an extra tenner on my next cassette I think it's worth a try before I start messing about with new chainsets, as that's a far more costly undertaking. An 11-28 might convince me that I can live with a compact after all?

Again, thanks for all the info and advice, and apologies for dragging this thread totally off its original topic!

 

[Ajax Bay]

Shimano Ultegra | 5700 10-Speed Cassette ... 11-28 : 11, 12, 13, 14, 15, 17, 19, 21, 24, 28

Seem to be half price now @:
http://www.ribblecycles.co.uk/sp/ro...gclid=CNL7gprVs8oCFVCZGwodN80Dpw&gclsrc=aw.ds

 

[EasyPeez]

Shimano Ultegra | 5700 10-Speed Cassette ... 11-28 : 11, 12, 13, 14, 15, 17, 19, 21, 24, 28

Seem to be half price now @:
http://www.ribblecycles.co.uk/sp/ro...gclid=CNL7gprVs8oCFVCZGwodN80Dpw&gclsrc=aw.ds

Ah, ok. So the ratios are closer through the cassette, same as the 12-28 in fact, but with the big jumps coming at the very bottom end (big cogs). I like the sound of that better I think.
A 17% hike between the lowest 2 gears is not likely to feel seamless I guess, but in my experience once you're getting into 34/24 - 34/28 territory smoothness of gear change tends to drop down the Maslow hierarchy as the pain builds and the wistful visions of a cassette the size of a dinner plate swim into view....

Cheers.