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Hello,

Sorry if this is in the wrong place.

This May I brought a Scott Speedster 60 to do my commute, being my first foray into road bikes it seemed reasonable and it did not have bad reviews, given its price bracket et al. However, I have recently been having issues with my chain skipping on the cassette while pushing hard in the smallest gear (Shimano HG41-7 7 Speed 11-28 tooth, full spec here http://www.evanscycles.com/products/scott/speedster-60-compact-2013-road...). I tried at first to re-tune my gears, but to no avail, the cable and the stops were all correctly aligned, I then noticed while replacing a broken spoke that the smallest gear the teeth are very worn I must have only done somewhere in the region of 2,000 miles on it. So I was wondering what people would recommend as a replacement. I am not overly concerned about the mass of the replacement and the 11-28 tooth gives me an ok range but would prefer something more hard wearing.

Thanks,

14 comments

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bazzargh [150 posts] 2 years ago
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How often did you replace your chain? (or clean it, for that matter?) If you keep using a cassette with a worn chain, the cassette will wear too. You can keep using the same cassette for much longer if the chain is in good nick. I don't think you'll find that different cassettes wear much better or worse than what you had (except that a 10 or 11 speed are thinner and will wear out faster if mistreated)

More on this topic here:
http://sheldonbrown.com/chains.html#wear

Other things that I'd wonder about - this is the smallest gear? So you spend all your time in top gear on a compact? Either you should be on normal 53/39 cranks (giving you more gear options at the top) or you're riding that cross geared (34x11) which would cause excessive wear - you'd be able to hear this!

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Wolfshade [162 posts] 2 years ago
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I tend to replace my cassette and chain together, but only being 5 months old I didn't really consider it needing to be done. I'll check tonight how much wear it has on it.

Yes its just on the smallest gear, and I spend most of my time on the top gear on my compact, when buying it originally I thought I might need the compact for hills having previously been on a triple ring (and the bike came with it as standard). I am thinking that I will just need to replace it for a standard 53/39 which as you say will give me more when I replace the cassette.
It's not been ridden cross-geared though if it had been it would be a simpler win I fear.

So with that in mind what do you think would be best? Currently I average around 18mph on my normal 10 mile commute if that makes any difference.

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TheHatter [770 posts] 2 years ago
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Bit confused when you say its on the 'smallest' gear and 'top' gear at the front but you're not crossing it- are you saying you're spending most of your time on 50 at the front and 11 at the back as thats a huge gear especially for commuting?

Either way as its a 7 speed I'd suggest going for a 'tighter' block and sticking with the compact chainset. Maybe 11-23 or even 11-19?

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Wolfshade [162 posts] 2 years ago
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Yes sorry for the confusion, I spend most the time on the 50 and 11 combo.

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bashthebox [751 posts] 2 years ago
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Fuck, if you're riding 50-11 and averaging 18mph then I fear for your knees! As well as hammering your joints, grinding out the miles at 50rpm also contributes to excessive chain and cassette wear. Riding at a higher cadence does a lot of things - it's more efficient, it's better for you in terms of fatigue and cardiovascular health, and it doesn't wear your components out as quickly.
You need to be spinning at about 90rpm... if memory serves, on the flat in the big ring, you'll be going at around 20mph in the third sprocket down from the top.

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notfastenough [3661 posts] 2 years ago
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That's about 51rpm! Nice quick spin of the gears is the order of the day, or your knees aren't going to thank you, in old age if nothing else.

It might seem difficult at first because you will start stressing the cardio system more than previously, but no worries it's all good.

Unless you live somewhere really flat, I think a compact is better for most of us. You'd need to be pretty competitive to need 53/39.

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Simon E [2541 posts] 2 years ago
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I normally change the cassette with every second chain. I replace the chain when it is close to or at 0.7 mark on a Park CC-3 and if it jumps then the cassette gets swapped too.

for 7 speed cassettes I have used Shimano 12-28 HG50 and HG20 on my commuter but there is a 11-28 version too (HG30, I think). All are solid, durable items. Keeping the chain and cassette reasonably clean and chain lubed will extend lifespan of both. IME the KMC Z82 chain is better than the Z51 and SRAM PC830, both of which must be made of cheese, as they doesn't last long
 22

I can't imagine many people being undergeared with 50x11, but there are plenty who claim to be 'spinning out' on the flat into a headwind and dragging a 18kg trailer with this combo (or whatever). Yeah, right! Make sure you keep your mobile phones on, Dave Brailsford is sure you be calling you with an offer very soon...

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Shanefutcher [98 posts] 2 years ago
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50x11 on a commute averaging 18mph is like going in 5th gear in car around shopping centre.focus on high cadence.i stick middle ring on a triple on my commute and average 23mph with cadence always around 90rpm

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Wolfshade [162 posts] 2 years ago
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Shanefutcher I think your anology is slightly off. Just because an average is true it doesn't mean that it actually happens.
Consider if I were to drive to work along the motorway the journey is about 10 miles and takes 20 minutes, now that gives me a not too shabby average of 30mph however, for the majority of my journey I'd be in 5th gear, but in reality would I ever drive my car at 30 in 5th? no.
Similiarly I have yet to roll a 3.5 on a dice despite it being the average value.
It is also not like I treat it as a fixieit just happens that marge proportions of the journey are flat or decents.

It does sound like I am changing a little too early so this morning I stayed in gear and built up my cadence before shifting up. Bit more stressful on my cardio system but ho-hum. I'll give it a try.

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bashthebox [751 posts] 2 years ago
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Your car analogy doesn't hold up though - in a car, it's more fuel efficient, up to a point, to drive at lower revs. It's not on a bike. The very fact that the 11 tooth sprocket is the only one that's worn out and you're averaging just 18mph is proof that you can dramatically improve the way you ride... unless you're saying that all your commute is a fairly steep downhill all the way, save for a long period where you're not moving at all? Maybe it's a ladder to get up to the top of the hill.

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Chuck [521 posts] 2 years ago
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bashthebox wrote:

and you're averaging just 18mph .

18 mph average isn't too shabby is it? I rarely do that! Or are people using different averages again?

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Wolfshade [162 posts] 2 years ago
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The analogy had nothing do with the efficeny of the car or no. The reason why I tend to spend most of my time on the 11 tooth sprocket is because I don't stay in the others, I move through the other sprockets when I get to a certain cadance, which I have now been informed I've been doing too early. So perhaps in reality my "average" sprocket is somewhere like 16.7.

Incidentally, the trip this morning at the more efficient rate didn't manage to improve my commute time, nor beat any of my segments, though I did get a personal 2nd and two 3rd fastest times. Maybe it just takes time to build up my cardio.

Unfortunately there are loads of traffic lights on my route so that is a lot of rolling to the ASL death traps and sitting waiting for the lights to change.

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Colin Peyresourde [1636 posts] 2 years ago
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Typical Road.cc forum. You start off going to the shop looking for Oranges, but when you get there everyone starts telling you that you actually wanted guttering.

Just replace the rear cassette with whatever you have now (Shimano, SRAM, Campag etc). You're likely to get better quality if you pay more too - for price durability I would recommend Ultegra.

From what you have said though, it does sound like maintenance is an issue. Clean and oil your chain every 1-2 weeks (if not more - mileage is probably a better test of when, but regular and often). Dirt gets on oily chain and wears it, which then wears the gear too.

It sounds like you are changing down too quickly to your 11 if it is the worn gear, and as everyone has said, if your cadence is low and you are stressing the chain/gears you will get more wear from that. The base guideline is that you dictate to the gear, rather that the gear dictate to you. I always drop down at least 2-3 gears coming to a junction/traffic lights, if not a whole ring. It actually gets you out of the blocks quicker and at the correct cadence ASAP. If you spin out and then gear up you'll be breaking your 18mph average in no time. Your knees and bike will thank you for it.

If you are in London there is no way you can average 18mph. You may do between traffic lights, but the whole system is rigged to mean that you can go no faster than 12.5mph.

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jellysticks [94 posts] 2 years ago
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Colin Peyresourde wrote:

Typical Road.cc forum. You start off going to the shop looking for Oranges, but when you get there everyone starts telling you that you actually wanted guttering.

Hilarious