Differences in Cassettes? Shimano HG50-8 and HG51-8?

[RideToWorky]

Hi All,

RE: Changing rear cassette from Sunrace (12-25) to Shimano (11-28)
Happy that cheap and cheerful local bike shop is willing to change the rear cassette for me, on my road bike.
Nice honest kinda shop, working in a run down kinda area.

£5 labour to swap over!
£ more if need adjust gear changes, if need new chain and rear derailler etc


The cassettes they have on the shelf is a Shimano HG50-8 (11-28) and a Shimano Alivio HG51-8 (11-30)
Can't find the HG50 on Google. Only the HG51


Are these HG50's simply last years stock , or are they "budget economy" ones, and I should ask the shop to order in some better spec ones, and I'll pay in advance?



Hope you can advise
I've no idea!


Regards
Martin


PS:
My bike details:
http://www.gtbicycles.com/gbr_en/2014/b ... -gts-sport

[Freddie]

Cassettes are much of a muchness, the more expensive ones might be a little lighter for much more money. You should pick a cassette depending on the gearing you want; most important is that the lowest gear is low enough. I think your rear derailleur can handle a 32t sprocket, so if I had any significant climbs, I'd plump for a cassette with a 32t large sprocket.

[cycleruk]

Not sure but I think that the HG50/51 range is the highest specification that Shimano now do in 8 speed. (There are lower ranges of 40 & 30 as well.) There used to be other series such as HG 70/72 (?) which where slightly higher spec' (lighter). There is nothing wrong with the HG50's so as advised above just chose the gearing that suits. It may be that HG50 is the road range and the HG51 is MTB but both will work with the Claris dérailleur. The one thing to watch out for is the largest sprocket that the Claris will work with! According to what I have just read it is 32T so there should be no problem choosing how low a gear you want/need.
Obviously the larger the big sprocket the higher the jumps between each sprocket.

[mercalia]

I have both. Without looking at mine the HG50 has separate locking ring and the 2 small separate cogs, the HG51 has the lock ring part of the smaller cog? Other than that they look the same. The HG50 is an older design I think - my Dawes 1-Down of 1999 vintage came with the HG50

You could say that the separate lock ring of the HG50 and lose small cogs serves no purpose? I assume was to allow you to replace the very small cogs that wear the most? or maybe a separate lock ring is better in engineering terms ( but costs more, the HG51 is normally cheaper)

I bought 2 of each a short time ago - the HG50 shimano boxed while the HG51 was bulk packed

look on Amazon eg

I think they are as good as one another

http://www.amazon.co.uk/Shimano-HG50-Speed-Cassette-Silver/dp/B00D9LFQAQ/ref=sr_1_1?ie=UTF8&qid=1455741203&sr=8-1&keywords=Shimano+HG-50

Dont know why your Google cant find them - I had no trouble.


https://www.google.co.uk/shopping/product/14618431456863615379?q=Shimano+HG50+8+Speed+Cassette&prmd=ivns&prds=paur:ClkAsKraX6IVUzwfSwFHo5cXZEIHg3wbpzs5NtAYS_cZsYQB60flaZoCNV2D0iSKphZgv37KSfzT2f69Hr7U7GmrAFlsmZMLIl7nm18sotxMmMKAP6KvN-f51xIZAFPVH71ecla18s1h6dRUPdBdXWAT-_Tylw&sa=X&ved=0ahUKEwiFyN3a1__KAhVMOBQKHTPPAeUQ8wIIMjAF

https://www.google.co.uk/shopping/product/11086685597282093947?q=Shimano+HG50+8+Speed+Cassette&prmd=ivns&prds=paur:ClkAsKraXyyep8yec9H5ihpEkE8TKSzeNvd78QOSvtslmkT8ka9vtI4LmmqxZ-8qAPT3gjc5bDQDhzXsnmVP4VdeXBR89dTL5PTcOGBvNWseK9512gSeAT5eRRIZAFPVH72n7Hrg96OBjn_LzZY3lxRiaZYTJA&sa=X&ved=0ahUKEwiFyN3a1__KAhVMOBQKHTPPAeUQ8wIIIzAB

[CREPELLO]

If the cassette finish has a slightly golden hue, it's nickel plated. If it's got a cool silver hue, it's chrome plated. They are nominally a harder finish than the nickel plated cassettes, but I'm not sure it really makes that much difference to longevity in reality.

Having said that, I have noticed XT/Ultegra grade cogs on the same cassette in both the chrome and nickel look/finish . Anyone care to suggest what that may be about?

[Brucey]

didn't they go through a phase of fitting some Ti sprockets?

These look a lot like Ni plate at a glance.... Does a magnet stick to the ones you are referring to?

cheers

[CREPELLO]

Hmm, I will have to check that out tomorrow, but in the meantime I will withdraw what I said about finish v's quality, as I honestly don't know what's going on in the mid/hi level Shimano cassettes. Here's an SLX 10 speed cassette with a big transition in finish..

For once, the oversized picture only makes it even clearer what I was referring to!

[Brucey]

well those certainly are not Ti sprockets in that position, they have to be steel...

Another thought is that the Ni plate is actually electroless Ni plate; this is a different beastie entirely, since it is actually an alloy of Ni and other things (N for example, IIRC). Using such plating enhances wear resistance (for a while) because it is very hard (harder than chrome plate). After a while it wears through and then it can flake off. I had a set of 10s Dura Ace chainrings that were similarly plated and that is what happened to those. I think the plating sticks better to steel though.

cheers

[CREPELLO]

Ah, right, makes sense. I have some Record chain rings that are the same and it has peeled off in one or two places.

[RideToWorky]

Thanks for the advise guys!

Martin

[hamster]

didn't they go through a phase of fitting some Ti sprockets?

These look a lot like Ni plate at a glance.... Does a magnet stick to the ones you are referring to?

cheers

Ti ones were only ever on HG9x for XTR or Dura Ace.

[Sweep]

Encouraging responses from this thread which seem to say (apologies if i am misinterpreting) that any shimano cassette will be fine as long as it has the ratios you need. But gotta ask, is it possible to buy separate 11T cassette rings? I think they are usually loose and just fastened by the lockring,