New chain ... but do I need more

[summerdays]

I checked my chain at the weekend and it falls into the 1% with absolutely no problem , I had meant to check it before that. I normally use SRAM PC970 chains.

Now I've let it get to the 1% do I need to change anything else... (bike is 3 years old, and done about 7500 miles and had a couple of chain changes).

Here is a couple of photos of the cassette:







And the chainrings:





I have found a similar cassette on special offer at CRC ... for £18 ... currently I have a SRAM PG950 and this is PG970 ... but several reviews mention it is quite heavy ... would I actually notice the different (I usually have heavy panniers on the bike anyway).

Any advice gratefully received.

 

[GrasB]

Chainrings typically last a lot longer than cassettes. If I think I've left it to long I buy a new chain loop it round the chainrings & see how far out everything is & from there make a judgment call. On the cassette I do the same picking the most worn sprocket. If anything needs replacing I then buy them.

As for cassette weight... if you were that worried about weight, why you riding on a triple?

 

[summerdays]

I'm not worried by a few grams as such ... I'm definitely not a fast rider (and carry too many things under the "just in case" category) ... I was more worried whether it gives me problems putting more weight at the centre of a spinning wheel.. (physics isn't my greatest subject) - as I noted others commented on the weight - so if the only effect is for those really weight concious then it isn't an issue for me .

Do you think the cassette is worth replacing based on those photos?

 

[gbb]

Several ways of looking at it, depending what you require from the bike.
Change chain, leave the rest, see how it performs and replace anything IF there's an shifting problems.

Looking at you chainset from the front, there's quite a sharks fin effect at 4 oclock and 10 oclock, looks moderately bad.
On the cassette, you dont so much see sharks fins, but some of the sprockets do have an elongated botton which effectively allows the chain to 'slide' between each tooth.

TBF, if youve done 7.5K on it, youve done well...perhaps time to spend a little, reap the rewards of new components.

 

[RecordAceFromNew]

Just from observation your cassette looks ok to me. None of the sprocket appears to have teeth with the tell-tale asymmetric (shark tooth shaped) wear.

By the same measure, the small ring of the chainset appears more worn than anything else. If you use it quite a bit it is worth getting a replacement, but no great hurry.

The official difference between the PC950 and PC970 is that the latter has nickel plating. They weigh the same at 297g. You can get lighter chains (often with hollow pins), saving circa 50g for an additional 50%+ in cost. Unless you are a weight weenie, there are cheaper and better ways to save weight.

 

[summerdays]

There are the occasional shifting problems but that could also be due to needing to fiddle with the cables... which I put off I case I make it worse (then I go and smile nicely at my LBS). But I'm only get better at this stuff by trial and error (probably loads of those!!!).

I think I will go for changing it... just got to decide whether I do it ... or LBS it... and what cassette and chainrings to go with...

 

[summerdays]

Just from observation your cassette looks ok to me. None of the sprocket appears to have teeth with the tell-tale asymmetric (shark tooth shaped) wear.

By the same measure, the small ring of the chainset appears more worn than anything else. If you use it quite a bit it is worth getting a replacement, but no great hurry.

The official difference between the PC950 and PC970 is that the latter has nickel plating. They weigh the same at 297g. You can get lighter chains (often with hollow pins), saving circa 50g for an additional 50%+ in cost. Unless you are a weight weenie, there are cheaper and better ways to save weight.

I'm not bothered by weight at all really .. more concerned to have stuff that is reliable, lasts a reasonable time and changes nicely than how much it weighs.

And as for cost - don't want the cheapest if it means sacrificing on it it working better, but equally don't want to spend hundreds on a part.

 

[cyberknight]

TBF, if youve done 7.5K on it, youve done well...perhaps time to spend a little, reap the rewards of new components.

+1 put a newer rear mech on at the weekend and the bike is like new again

 

[2Loose]

Summerdays, your cassette has done well and so has your chainset.
Remember that I also had the same bike...I left my original chain on for 4.5k and the 'U' areas between teeth on the cassette were less wide than yours (where the rollers should sit), but when I changed the chain it didn't work very well at all.

I ended up replacing the cassette, but found the chainrings were also ruined so ended up buying a new chainset before it started shifting properly again.

Yours actually look worse...sorry. The teeth on your chainset look fairly fin-like imho.

Definitely change the chain and cassette, but prepared for replacement chainrings or chainset depending on how it feels afterwards.

 

[summerdays]

Annoyingly I didn't get around to ordering the cassette from CRC and its gone back up in price from £18 to £59 for the 11-34 one! Why am I a ditherer? I would probably have paid the £59 originally ... but I can't now I know it was on offer at the cheaper price (mad head I have on me don't I ) - it will have to be from somewhere else!.

Thanks for the advice ... I must remember to take photos of the new stuff when I get around to it... so that I have something to compare it to further down the line.

 

[2Loose]

Get the 32 tooth one, it is still cheap and it'll still get you up Everest. How often did you find yourself in 1st anyway, I thought Bristol was pretty flat?


Alternatively, the Deore cassettes are only £24quid...

(I concede that geography might not be my strong point, but I changed to a 32 and could get up everything around here with panniers fitted if I sat and twiddled - upto 22% locally.)

 

[summerdays]

Err I love my 1st gear ... have I told you how slow I go up hill!!!

 

[2Loose]

34T Deore 9spd cassette is on the same page too...