cassette for Dawes Super Galaxy 2011

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patpalloon
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Joined: 16 Jan 2011, 12:06pm

cassette for Dawes Super Galaxy 2011

Post by patpalloon »

I have a Dawes Super Galaxy that I bought in early 2012, but has a 9-speed cassette which makes it the 2011 model as ones after that have a 10-speed cassette. The original cassette on it appears to be the Shimano CS HG50 9 which is 11-32. Now I took it to my LBS for a service and it needed a new cassette and I asked for it to have the same one as the ratios are spot on. However, the ratios in the new one are too low and feel totally different from previously. The new cassette is a CS HG80 9 which is also 11-32, so I don't understand how it can feel so different, unless it's because it is a MTB one.

Obviously I will take back to the LBS to remedy, but wondered if anyone can shed some light on this?
I feel sure that the genius that did this, didn't even feel a thud as he drove by.
mercalia
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Re: cassette for Dawes Super Galaxy 2011

Post by mercalia »

well u also need to check the other 7 sprockets, not just the smallest and biggest. When I replaced my 8 speed I think there were 2 alternatives regarding the intermediate steps, the change in the number of teeth. Thats prob why it feels differnt - it is. You need to make a list of the teeth on each sprocket and get an identical set
Brucey
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Joined: 4 Jan 2012, 6:25pm

Re: cassette for Dawes Super Galaxy 2011

Post by Brucey »

HG50 and HG 80 11-32 share the same ratios

http://www.sjscycles.co.uk/shimano-deore-hg50-9-speed-cassette-11-32-prod8136/
http://www.sjscycles.co.uk/shimano-hg80-9-speed-cassette-prod17762/

so either they have in fact fitted an 11-34 or they have improved your bike so much that the gears now feel too low!

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~
OnYourRight
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Joined: 30 Jun 2013, 8:53pm

Re: cassette for Dawes Super Galaxy 2011

Post by OnYourRight »

Have you counted the teeth on the sprockets (at least the largest sprockets) of both cassettes? I ask because the sprockets on the 11–32T versions of both the CS-HG50-9 and CS-HG80-9 seem to go like this:

11–12–14–16–18–21–24–28–32

How can all the ratios be too low anyway? Can you not just change up a gear?

Maybe they’ve lubricated the chain for the first time in months, making the bike go easier? (But that’s a good thing!) Or maybe they’ve returned it to you in another chainring that you never used? It’s hard to guess without knowing what you know, i.e. your technical knowledge.
patpalloon
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Joined: 16 Jan 2011, 12:06pm

Re: cassette for Dawes Super Galaxy 2011

Post by patpalloon »

It's definitely different. Before I would be in the middle ring on the front and between 4 to 7th gear on the back for most riding on the flat, would only need the big ring at the front for downhills. Now even on the flat I need the big ring at the front and am flat out in top gear at 25mph, whereas before I wouldn't need top gear til around 35mph.
I feel sure that the genius that did this, didn't even feel a thud as he drove by.
OnYourRight
Posts: 283
Joined: 30 Jun 2013, 8:53pm

Re: cassette for Dawes Super Galaxy 2011

Post by OnYourRight »

Try counting the teeth on the sprockets. Maybe it’s not an 11–32T CS-HG80-9 at all? You seem to be concerned mostly with the higher gears, so pay particular attention to the number of teeth on the small sprockets.

Did they also change the chainrings or indeed the whole chainset? Why was the bike in the shop?

Are you sure the chainring selected corresponds with the one chosen at the left gear lever? (Sorry for asking this. Say something reassuring and I’ll stop!)

Other things to consider:

• the bike really does go better, whether because of a new and lubricated chain, better-adjusted gears, or something else
• you had a tailwind on your first ride after you got the bike back
• unrelated unhappiness with the bike shop, causing you to imagine problems with their work
• they’ve secretly swapped the wheels for 20-inchers. You never know!
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s1965c
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Location: Devon

Re: cassette for Dawes Super Galaxy 2011

Post by s1965c »

Have they changed the front rings too?

Either way, they seem to have done you a favour. What's the use of a top gear you can't use until 35 mph?
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OnYourRight
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Joined: 30 Jun 2013, 8:53pm

Re: cassette for Dawes Super Galaxy 2011

Post by OnYourRight »

s1965c wrote:Either way, they seem to have done you a favour. What's the use of a top gear you can't use until 35 mph?

I agree. A chainring for downhill use is pretty pointless, albeit nearly universal on bikes you can buy in a shop. I modified my own bike at considerable effort to make the big chainring more suited to cruising on flat roads.

But this is kind of beside the point. I just can’t think of any plausible reason things could have changed so much on your bike, patpalloon. Gears are fixed things: there’s no possibility of slippage causing the ratios to be anything other than what the teeth counts suggest. So either the number of teeth is different, whether at the front or the rear – and determining that with absolute certainty merely requires you to count them – or you’re imaging things. The latter is not so hard to do if you’re human.
fatboy
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Re: cassette for Dawes Super Galaxy 2011

Post by fatboy »

If my experience with Dawes is anything to go by the cassette on your bike may not have been an 11-32 but something else. My Horizon was supposed to have 11-32 but had 11-30 and my Century was supposed to have 12-25 but has 11-25.
"Marriage is a wonderful invention; but then again so is the bicycle puncture repair kit." - Billy Connolly
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531colin
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Re: cassette for Dawes Super Galaxy 2011

Post by 531colin »

I think we need the name of this miraculous bike shop....as a public service to all the people who buy a road bike and find they can't push most of the gears... :wink:
jb
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Re: cassette for Dawes Super Galaxy 2011

Post by jb »

Perhaps they also mended your speedo!
Cheers
J Bro
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timdownieuk
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Re: cassette for Dawes Super Galaxy 2011

Post by timdownieuk »

patpalloon wrote:It's definitely different. Before I would be in the middle ring on the front and between 4 to 7th gear on the back for most riding on the flat, would only need the big ring at the front for downhills. Now even on the flat I need the big ring at the front and am flat out in top gear at 25mph, whereas before I wouldn't need top gear til around 35mph.


Okay, there really aren't too many options. Either the cassette has very different ratios (but that's easy to check, just count the teeth), the bike shop fitted much smaller wheels (not a serious suggestion), sneakily changed your front chain rings for another smaller set they had lying around OR (and this is my favourite theory) something's happened to your front changer and despite what any gear indicator is saying on your handlebars (or appropriate number of clicks of your lever) you're riding around on the smaller of the two front chain rings and can't get it to change on to the largest ring.

So, just for clarification, have you looked down to ensure that you are using the largest ring when you think you are? Have you counted the teeth on your cassette?

If, for the sake of argument, you were running a 52x11 as your highest gear before you went to the bike shop and you still have 52x11 now, any difference that you're perceiving now has got to be, um, in your head.
patpalloon
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Joined: 16 Jan 2011, 12:06pm

Re: cassette for Dawes Super Galaxy 2011

Post by patpalloon »

fatboy wrote:If my experience with Dawes is anything to go by the cassette on your bike may not have been an 11-32 but something else. My Horizon was supposed to have 11-32 but had 11-30 and my Century was supposed to have 12-25 but has 11-25.


This has to be the explanation. I know what the new cassette is because I've counted the teeth and the serial number is on the smallest ring. I didn't check what the old cassette was, I'm just going on what I can see online.

I took the bike in for a service because it's done nearly 4000 miles. I can't fault anything else, it's beautifully smooth and clean. He did ask me if I wanted a different cassette, one with easier ratios. I said no, because the existing one was perfect. I can get up any hill fully loaded, so it's low enough, but the top end is really good, had 50 mph out of it. Now my legs are flailing around at 25mph. And I'm in a much higher gear just going along on the flat. The front mech rings haven't been changed, just a new chain and cassette. And I do know what gear I'm in and it's not due to the wind, credit me with some intelligence!
I feel sure that the genius that did this, didn't even feel a thud as he drove by.
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531colin
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Location: North Yorkshire

Re: cassette for Dawes Super Galaxy 2011

Post by 531colin »

patpalloon wrote:
fatboy wrote:If my experience with Dawes is anything to go by the cassette on your bike may not have been an 11-32 but something else. My Horizon was supposed to have 11-32 but had 11-30 and my Century was supposed to have 12-25 but has 11-25.


This has to be the explanation. I know what the new cassette is because I've counted the teeth and the serial number is on the smallest ring. I didn't check what the old cassette was, I'm just going on what I can see online.

I took the bike in for a service because it's done nearly 4000 miles. I can't fault anything else, it's beautifully smooth and clean. He did ask me if I wanted a different cassette, one with easier ratios. I said no, because the existing one was perfect. I can get up any hill fully loaded, so it's low enough, but the top end is really good, had 50 mph out of it. Now my legs are flailing around at 25mph. And I'm in a much higher gear just going along on the flat. The front mech rings haven't been changed, just a new chain and cassette. And I do know what gear I'm in and it's not due to the wind, credit me with some intelligence!


OK, so you counted the teeth on the current smallest sprocket (top gear) and it came to 11 teeth.
The smallest they make is 11 teeth.
The chainrings are the same, so top gear is the same as it ever was......unless you have had a miracle.
PT1029
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Re: cassette for Dawes Super Galaxy 2011

Post by PT1029 »

Seemingly unrelated but in fact relevent point. How often do you pump your tyres up?, and do you use a pump with a pressure guage, and do you top up your tyres every 2 - 3 weeks?
Lots of people (ie, in my case, customers and a few CTC club members) run their tyres at 1/2 - 1/3 the rated pressure (but to the rider, they think the tyres are hard).
A friend (active CTC rider) always runs his galaxy tyres soft (he's noticably faster if I pump them up - for my sanity more than his benefit). He once came round on his old hack Galaxy bemoaning his rubbish delaminating (old) conti tyres. Got the pump out, 15psi on the guage....
Pumped up the tyres on an old lady's 3 speed, she came back complaining we had lowered the gears (bike came in for non gear work, gears weren't touched). We explained we had merely pumped the tyres up so would be easier to ride, if the gears were really now too low, she could book it in and we could fit a smaller sprocket on the 3 speed hub. A week later she booked it in and paid for a smaller cog to be fitted......
Yes, soft tyres really do slow your bike down. If you took your galaxy to a good shop, they probably doubled the tyre pressure to where it should have been!
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