Bigger Sprockets

duncan.willey

Hello,

I've got a road bike with a 52,39 on the front chain ring and my biggest sprocket on the back is a 25. I've got skinny legs and I think I would like a lower gear if I can. I've been told that 39 is as low as i can go on the front without going to a compact and I don't really want to spend that kind of money.

Can i get a bigger sprocket on the back, say a 27 or 28 and how much difference would it make. By my calc (sorry to my physics teacher) a 28 would make the gear about 10% lower. Is that right?

Its shimano 105 throughout if that makes a difference.

Hope you can help because I am off to the lakes and I will keel over with my feet clipped in otherwise.

Thanks in advance!

Dunc

P_Tucker

1. You could put a 38 on the front, but it won't make much difference
2. Your maths is broadly right, but it doesn't really mean much. Basically, the difference will be almost exactly the difference between the 23 and the 25 that you currently have. You can't go bigger than 28 without changing your rear mech.

petemadoc

A 27 or 28 on the back will definitely help. I think a compact chainset is more suitable for most situations other than racing. I live in mountainous Wales and have a compact 50/34 with a 12-27 cassette on the back. Does the job

JRooke

Just get a 12-28 105 Cassette on the back, you can get one for £30 and it will make a very noticeable difference.

duncan.willey

Excellent, thank you for quick responses. So a 28 12 it is then.

Is fitting a difficult job?

P_Tucker

duncan.willey wrote:

Excellent, thank you for quick responses. So a 28 12 it is then.

Is fitting a difficult job?

If you have the tools, no. If you don't, it's impossible

duncan.willey

Im guessing that it fits the critical point that all bike jobs seem to fall into where it is £5 cheaper to buy to the tools and do it yourself rather than give it to the lbs. At which point I have a go and then have to ask the lbs to do it anyway which in the end costs me

1 - the cost of the tool
2 - the cost of the lbs to fit it
3 - my pride when I have to go back to ask them!

Thanks all

Dunc

sloppyschleckonds

http://bit.ly/q607jf

arlowood

Hi Dunc

By my calculation the total cost would be around £46 to buy the new cassette and the tools for the job. viz:-

Cassette - about £34 from Chain Reaction Cycles

http://www.chainreactioncycles.com/Mode ... roducts-UK
.
Cassette Lockring Tool (to remove old cassette and refit new cassette) - about £5 from Evans

http://www.evanscycles.com/products/ice ... gn=froogle

Chain Whip (to anchor freewheel whilst you remove cassette lockring) - about £7

http://www.edinburghbicycle.com/ebwPNLq ... tVersion=1

I am assuming that you will have a suitable spanner to use on the lockring tool or a standard socket set bar end will fit the lockring tool also.

So you could ask your LBS to quote you for the job and see where the difference lies.

IMHO swapping a cassette is one of those relatively basic jobs that most cyclists should tackle at least once in their lives. Once successfully done it gives you the confidence to move on and tackle more complex jobs - which ultimately will save you money.

Plenty of advice and tutorials out there on the web to talk you through the cassette removal and replacement

http://www.youtube.com/watch?v=C9Oek25xKJ0

petemadoc

duncan.willey wrote:

Im guessing that it fits the critical point that all bike jobs seem to fall into where it is £5 cheaper to buy to the tools and do it yourself rather than give it to the lbs. At which point I have a go and then have to ask the lbs to do it anyway which in the end costs me

1 - the cost of the tool
2 - the cost of the lbs to fit it
3 - my pride when I have to go back to ask them!

Thanks all

Dunc

Totally agree with Arlowood.

Get the tools and do it yourself. I'd recommend investing in a full toolkit , something like this

http://www.merlincycles.co.uk/Bike+Shop ... it_327.htm

Once you've changed the cassette you'll have the tools to do the next job.

If you have use of both your hands then you can change a cassette, no problem!

SteveR_100Milers

Don't forget that shimano cassettes on shimano fit hubs require a thin spacer to be fitted before you fit the cassette. Leave this out and you will never be able to set up the shifting properly!

Zoomer37

How about option B.

Leave the 25 on there and just tell yourself thats all the gears you have to work with and build a set of thighs that would make an onion cry.

Then train, train, train and pretty soon you'll be able to ride up walls.

petemadoc

Zoomer37 wrote:

How about option B.

Leave the 25 on there and just tell yourself thats all the gears you have to work with and build a set of massive thighs that would make an onion cry.

Then train, train, train and pretty soon you'll be able to ride up walls.

I read in cycling weekly that cancellara runs a 32 on the back for some hilly races. Made me feel better.

duncan.willey

Thanks to all for your responses.

I am feeling brave and so I am going to go for it (i've ruled out training because it is too hard!). I've hit my next blocker.

Is there a difference between shimano 105 5700 and 5600. I presume that there is and I want to buy the right one. How can I tell which one is fitted on my bike?

Thanks agaiin, this is my first post and I am delighted about the amount of support i have received.

Dunc

petemadoc

duncan.willey wrote:

Thanks to all for your responses.

I am feeling brave and so I am going to go for it (i've ruled out training because it is too hard!). I've hit my next blocker.

Is there a difference between shimano 105 5700 and 5600. I presume that there is and I want to buy the right one. How can I tell which one is fitted on my bike?

Thanks agaiin, this is my first post and I am delighted about the amount of support i have received.

Dunc

If you're only buying the cassette there will be no difference between 5700 and 5600. The differences are in the shifters and front mech so no problems if you buy either, in fact any 10 speed shimano or sram cassette should be fine

arlowood

Hi Dunc

5700 was a redesign of the 105 Groupset introduced in 2011 - effectively replacing the earlier 5600 series. The changes were largely aesthetic to bring the look of the crankset and other components more into line with the higher spec Ultegra and Dura Ace groupsets.

However the basic cassette design has not changed so as long as you are replacing a 10-speed 5600 cassette with a 10-speed 5700 cassette there should be no problems

derbygrimpeur

with a 12-28 cassette you're going to have some massive jumps between sprockets.

I've recently converted to a triple, 53-42-30 12-23. Sprockets are all nice and close together and I've got plenty of gears to get up the steepest of climbs. Converting the chainset & cassette is obviously more expensive than just the cassette, but it's better than struggling to find the right gear (IMO)

Down the Road

Just man up !!!!

25 is ALL you ever need in the UK come to think of in the Alps as well.

derbygrimpeur

depends on riding style. I can get up all the climbs I've ridden (up to 25% gradient) in a 25, but I prefer to spin a higher cadence rather than grinding. This allows me to go quicker and laugh at all the knobheads that sneer at a triple as I fly past.

janwal

Down the road- I don't think so.Contador has used 11-32 in the Giro in the past! If it's good enough for him........

duncan.willey

Right I am still confused. I've counted my current cassette and it has 9 sprockets yet I can only find 10sp cassettes for sale. Are 10sp compatible with my existing shifter and deraileurs?

Sorry for being a bore

duncan.willey

Right I am still confused. I've counted my current cassette and it has 9 sprockets yet I can only find 10sp cassettes for sale. Are 10sp compatible with my existing shifter and deraileurs?

Sorry for being a bore

Lookyhere

All the responses assumed you had a 10 speed set up, as you mentioned 5600 and 5700.

9sp is not compatable with a 10speed setup.

You ll need a 9 speed 12 27 and i believe it will have to be a Shimano Ultegra 6500 i dont know if 105 12 27 in 9sp is available.

I f i wuz you, i would take it to a bike shop, i m sure you can buy the tools to remove it but refitting (and you will not need a spacer) will require that the lock ring is done up to the correct torque... or the cassette will come loose, only you know your own mechanical ability

Also, if the chain is worn, you will need a new chain as well, as an old chain on new Cassette will be at best noisey and poor shifting, you will need a chain splitter for that job and a quick link or 9sp pin to rejoin.

Given all that and the marginal gains of a 27, a compact might work out better and cheaper for you? it can be a 9 or a 10sp chainset, it doesnt matter