What cassette do I need??

TrekMan2014 · January 2015

Hi Im new to road biking,I bought a trek 1000 2004 model last year to do a charity ride palace to palace on I serviced it new saddle tyres bar tape fixed speedo etc,It currently has a 8 speed set up of sora front and rear mechs horrible sora 8 speed stis and I think a non shimano chainset which i think is a double not compact.I have managed to get a good deal of a friend of a mint pair of shimano 105 sti st-5510 s and a ultegra rd-6600 rear mech I wanted to upgrade the shifters as didnt like the thumbshifter on the 8 speed soras but got good deal on both what ratio cassette will I need for my 9 speed change 11-23 or 11-25 I have lots of hills and some flat where I live. Also im wanting to change the front mech but not sure if its a top or bottom pull and how to work out the size eg 34.9 etc..

ben@31 · January 2015

This is a Shimano compatibility chart, unfortunately it looks like it doesn't go back far enough for 5510.
http://www.celebrazio.net/bicycling/shi ... p_2014.pdf

Edit: I managed to find a chart with 5510. I had to look at archives as far back as 2003. Here it is http://www.celebrazio.net/bicycling/shi ... ility.html

Its worth thinking about if the freehub on the rear wheel can take a bigger cassette? Also you might need to buy another chain with different sized links.
Theres plenty of second hand groupsets on ebay (that come as a complete matching package).

TrekMan2014 · January 2015

Thanks for the above guide ^^^^ but my question is what ratio 9 speed cassette am i best going for? 11-25 11-23 or 12-25 as I have some steep hills and flats where i live and i have a standard double chainset not compact.I also know i will need to get a 9 speed chain . If i remove my seatpost and measure the diameter is that a good way of finding out the front mech size? main reason is for matching mechs as in all 9 speed.

dj58 · January 2015

Depends on what RD-6600 you have, SS short cage 25T max low sprocket or GS long cage 27T max low sprocket.
One of these http://www.wiggle.co.uk/shimano-hg50-9-speed-cassette/ should work.

What cassette ratio you need depends on your level of fitness, the general consensus is 11/12 - 27/28T or lower. You need to work what chainset you have 53/39T, 52/42T, 50/34T as that will determine what your lowest gear will be. If you are new to road biking you may find it beneficial to use a compact 50/34T chainset.

As for the FD what is the cable routing, down the down tube and under the BB, if so you need a traditional bottom pull model. If the cable runs along the underside of the top tube, the you need a top pull model. As for the size assuming it is a band on type, either measure the O.D. of the seat tube or take the existing FD off and measure the I.D. of the clamp. It will probably be 31.8mm or 34.9mm.

Also read the post Help I need smaller gears - what can I do? A GUIDE a lot of advice there.

TrekMan2014 · January 2015

Thanks

Im not sure if its a long or short cage any way of telling as i have the rear mech in front of me as not on the bike? :?: I am average fitness did a 40 mile charity event and was doing regulary 25-30 mile rides for training.
As for the chainset i have no idea what combination it is I will count the teeth tommorow and post when done.
Great thanks will also check the front mech tommorow and post the sizes on here. Also forgot to say im using spds on my road bike if it makes any difference mtb ones as can use my shoes on both bikes.

dj58 · January 2015

Hi,
You need to measure the centre distance between the two derailleur pulley mounting allen head bolts, then post it up on here and hopefully someone will be able to tell you which one it is. Don't worry about using your SPD pedals and shoes on your road bike, a lot of people do, including myself.

TrekMan2014 · January 2015

Thanks

I just measured bolt to bolt roughly its 4.8cm give or take a mm or 2 ?

ai_1 · January 2015

The best cassette for you will depend entirely on the specific terrain you ride, whether you like to keep your cadence high, or grind up hills and how good you are on hills. No one here will be able to tell you definitively. However 9-speed cassettes are pretty cheap so it's not a big outlay if you want to change later. If you'll be tackling some steepish hills and you're not certain what you want then I'd get a 12-27 or bigger providing your rear derailleur can handle it. I'd definitely stay away from 11-23 and I think 11-25 may be unnecessarily tough too. If you have a standard double chainset it's even more important to allow yourself a decent sized biggest sprocket.
What gearing did you have on the existing 8 speed setup? If it was alright then your best bet is to use this for guidance.

It's also worth considering whether your proposed change is really a worthwhile upgrade. The hardware your mate is selling you is rather old and while it's a step up from your 8 speed Sora it's still going to be fairly mediocre compared to middle of the range current groupsets. For example current Sora is 9 speed and has moved away from the thumb-shifter. Current Tiagra is 10 speed and current 105 is 11 speed and again all have the same shifting functionality as the top end groupsets. That's not to say your proposed solution is a bad choice, just that it's worth considering the alternatives.
The biggest question is whether other components also need replacing. Are the chainrings, BB etc on your existing setup okay or heavily worn and in need of replacing too? If they are it may be more economical and simpler to buy a complete groupset. www.merlincycles.co.uk and others routinely sell complete Sora, Tiagra, 105 & Ultregra groupsets heavily discounted from RRP. Again, I'm not suggesting this is a better option and I don't know if it will be cheaper or not, but worth considering if you haven't already.

markhewitt1978 · January 2015

TrekMan2014 wrote:

Thanks for the above guide ^^^^ but my question is what ratio 9 speed cassette am i best going for? 11-25 11-23 or 12-25 as I have some steep hills and flats where i live and i have a standard double chainset not compact.I also know i will need to get a 9 speed chain . If i remove my seatpost and measure the diameter is that a good way of finding out the front mech size? main reason is for matching mechs as in all 9 speed.

If you have some steep hills the answer is none of those. You're going to need at least a 28 with a standard double - unless you're some semi-pro

.

cadseen · January 2015

I would go for 12-25 gives you more options for lower gears, you wont need a 11

Ribble are doing some good affers on cassette atm eg. http://bit.ly/18jbFm7

markhewitt1978 · January 2015

For many 25 is still quite a high gear - depends on the rider of course. But totally agreed about the 11T gear, that's why I run a 12 even then I don't often use it.

dj58 · January 2015

TrekMan2014 wrote:

Thanks I just measured bolt to bolt roughly its 4.8cm give or take a mm or 2 ?

I measured my Ultegra RD-6700-A-SS short cage derailleur, which will take a max. of 30T low sprocket.
6.0cm between pulley bolt centres, so I would hazard a guess that you RD-6600 is a short cage model.

TrekMan2014 · January 2015

will my ultegra mech be able to do a 12-28? as i think thats what im going to go for? I will count the teeth on my chainset and post up when iv done.

ForumNewbie · January 2015

If you have a standard double at the front (say 52/39), that would mean even with a 28t biggest cog at the back, it will be tough on steep hills unless you are very fit. Many bikes now are sold with compact doubles at the front (50/34) and an 11-28 cassette at the back meaning a smallest gear of 34/28. I'd be looking for at least that if you ride on hilly routes.

dj58 · January 2015

TrekMan2014 wrote:

will my ultegra mech be able to do a 12-28? as i think thats what im going to go for? I will count the teeth on my chainset and post up when iv done.

Not sure that your mech could take a 28T low sprocket, I'll do some digging on here and try and find out. Also I think you should seriously consider getting a compact chainset.

TrekMan2014 · January 2015

If you can do some digging be appriciated

As would like a 28 if possible.On my current 8 speed set up back in september i was getging used to the bike managed to get up a steep hill i wasnt able to do before think it was standard 8 speed ratio. Will defo check what chainset i have tommorow.

ai_1 · January 2015

TrekMan2014 wrote:

If you can do some digging be appriciated As would like a 28 if possible.On my current 8 speed set up back in september i was getging used to the bike managed to get up a steep hill i wasnt able to do before think it was standard 8 speed ratio. Will defo check what chainset i have tommorow.

Is there a "standard" 8 speed ratio"? I doubt it. Presumably 8 speed cassettes come in various ranges just like 9, 10 and 11 speed cassettes. If you knew the size of the biggest sprocket on your 8 speed cassette, then once you check your chainset you'd know exactly how new and old compare in terms of smallest gear.

markhewitt1978 · January 2015

ForumNewbie wrote:

If you have a standard double at the front (say 52/39), that would mean even with a 28t biggest cog at the back, it will be tough on steep hills unless you are very fit. Many bikes now are sold with compact doubles at the front (50/34) and an 11-28 cassette at the back meaning a smallest gear of 34/28. I'd be looking for at least that if you ride on hilly routes.

Agreed. A standard with a 25T cassette is higher than even pro riders use on hilly routes. For the rest of us it's way way too high.

ai_1 · January 2015

markhewitt1978 wrote:

ForumNewbie wrote:

If you have a standard double at the front (say 52/39), that would mean even with a 28t biggest cog at the back, it will be tough on steep hills unless you are very fit. Many bikes now are sold with compact doubles at the front (50/34) and an 11-28 cassette at the back meaning a smallest gear of 34/28. I'd be looking for at least that if you ride on hilly routes.

Agreed. A standard with a 25T cassette is higher than even pro riders use on hilly routes. For the rest of us it's way way too high.

Rather than trying to remember combinations it makes sense to reduce it to a single number.
e.g. in the example above a standard (39T small chainring) and cassette with a 25T biggest sprocket equates to a gear ratio of 39/25 = 1.56.....bigger number = lower cadence for a given speed, or "harder" gear.

When I got started I had a 50/39/30 triple and 11-32 cassette on a Specialised Tricross (30/32 = 0.94). Even with that my cadence was dropping dramatically on steep climbs but that's because I was going so slow, as in walking pace when the slope got to 10%+. However on the flat the gaps on a 9 speed 11-32 cassette were a little bigger than I liked so after a few months once I'd gotten some semblence of fitness I changed to a 12-27 (30/27 = 1.11). I have now converted my Tricross for use as a TT bike (bizarre choice for a TT conversion I know!) and it's got a 13-25 cassette (30/25 = 1.2). Now I've got a new road bike with a compact double (34T) and 11-28 cassette (34/28 = 1.21) and I've gotten a bit lighter and fitter so I can now get up climbs with gradients close to 20%.

My cadence is still low on really steep slopes but that's unavoidable since cadence is a function of speed and gear ratio. The steeper the slope the more energy it takes to hit a given speed, regardless of the cadence. So as you get better the gradient of the slopes you can comfortably ride with a given ratio will increase but there'll always be a climb capable of slowing you to a crawl.

P.S.
It's common practice for cyclists to refer to gears as a length in inches. What they're doing is combining the ratio as I've calculated it above, with the circumference of the wheel since this is also proportional to the distance you travel per pedal revolution. So my current road bike has a minimum gear length of about: 1.21 * tyre circumference. Lets say the tyre circumference is about 2200mm or 86.6". 1.21*86.6" = 105"

thegibdog · January 2015

TrekMan2014 wrote:

will my ultegra mech be able to do a 12-28?

Yes. I am running a 12-28 (paired with 34/50 up front) using a short cage Ultegra RD6600.

TrekMan2014 · January 2015

I have just measured my chainset outer ring is 53 teeth inner ring is 39 will 12-28 still work ok with the ultegra rd? Also discovered fd is a bottom pull but no size i measured seatpost will it be the same size as mech?? 34.9

ai_1 · January 2015

TrekMan2014 wrote:

I have just measured my chainset outer ring is 53 teeth inner ring is 39 will 12-28 still work ok with the ultegra rd? Also discovered fd is a bottom pull but no size i measured seatpost will it be the same size as mech?? 34.9

Well, if it will work with a 50/34 and 12-28 then I would expect it'll work with 53/39 and 12-28 too. The difference between 53 and 39 is only 14 teeth and it's 16 between a 50 and 34 so the derailleur has to take up more slack in the compact setup.
Unless you're a very strong rider, I think you should definitely go with the largest sprocket you can since you've got a standard double up front. 39/28 = 1.39 which is a slightly bigger (tougher) gear than 34/25 = 1.36. A novice would typically struggle with either on very hilly terrain.

As mentioned earlier a compact double with a 12-27 or 11-28 cassette is probably the current typical set-up for most middle of the road cyclists wanting relatively easy gearing for hilly rides. That gives a ratio of 1.21 or 1.26 either of which is significantly easier than the 1.39 you'd get with a 28T sprocket.

dj58 · January 2015

TrekMan2014,

OK I found the post I was looking for, viewtopic.php?f=40004&t=12952412

If you read through it you will see that richiebones says that you can run the older model Ultegra with a 30T sprocket if you use a longer B tension screw. The standard B-Tension Adjusting Screw is (M4 x 13.5mm)

So as thegibdog confirms you should be ok with a 28T sprocket. If your seat tube is 34.9mm then yes order a 34.9mm FD.

simon_masterson · January 2015

markhewitt1978 wrote:

ForumNewbie wrote:

If you have a standard double at the front (say 52/39), that would mean even with a 28t biggest cog at the back, it will be tough on steep hills unless you are very fit. Many bikes now are sold with compact doubles at the front (50/34) and an 11-28 cassette at the back meaning a smallest gear of 34/28. I'd be looking for at least that if you ride on hilly routes.

Agreed. A standard with a 25T cassette is higher than even pro riders use on hilly routes. For the rest of us it's way way too high.

Not really a valid comparison. For a start, I'm guessing that they might be riding at a higher intensity than you do, but Chris Froome does not opt for a 28t rather than a 25t because he won't get up that hill if he doesn't; and there are plenty of classics and other events with decent sized hills in them that they'll do on standard chainsets. I'd be more inclined to attribute the available ratios on 11 speed to the increased use of wide range cassettes; the jumps really aren't very large on an 11 speed 11-28.

But generalising about this is silly. It depends on your health, fitness, your preferred climbing style, and the geography of where you live - as well as your inclination to climb big hills. Eg. if you are reasonably fit and live in a largely flat area, you may well not find yourself in need of really low gears. Not everyone is interested in climbing Hardknott. Times change - the 39t is a bit like yesterday's compact - go back long enough and you couldn't fit a smaller inner ring than 42t, and 28t was something you would find on a touring freewheel (on 5-7 speed the jumps are huge), whereas racing-oriented bikes would generally have a 12 or 13 up - so 18-20 as the largest cog.

All that's not to say that the compact doesn't make sense (it does), but to say that a standard double with a cassette that goes to 25 is something that only professional cyclists should use is a ridiculous statement. Personally, I'm currently using 52/39 with 13-20. I don't live in the Lakes!

ForumNewbie · January 2015

Simon Masterson wrote:

markhewitt1978 wrote:

ForumNewbie wrote:

If you have a standard double at the front (say 52/39), that would mean even with a 28t biggest cog at the back, it will be tough on steep hills unless you are very fit. Many bikes now are sold with compact doubles at the front (50/34) and an 11-28 cassette at the back meaning a smallest gear of 34/28. I'd be looking for at least that if you ride on hilly routes.

Agreed. A standard with a 25T cassette is higher than even pro riders use on hilly routes. For the rest of us it's way way too high.

Not really a valid comparison. For a start, I'm guessing that they might be riding at a higher intensity than you do, but Chris Froome does not opt for a 28t rather than a 25t because he won't get up that hill if he doesn't; and there are plenty of classics and other events with decent sized hills in them that they'll do on standard chainsets. I'd be more inclined to attribute the available ratios on 11 speed to the increased use of wide range cassettes; the jumps really aren't very large on an 11 speed 11-28.

But generalising about this is silly. It depends on your health, fitness, your preferred climbing style, and the geography of where you live - as well as your inclination to climb big hills. Eg. if you are reasonably fit and live in a largely flat area, you may well not find yourself in need of really low gears. Not everyone is interested in climbing Hardknott. Times change - the 39t is a bit like yesterday's compact - go back long enough and you couldn't fit a smaller inner ring than 42t, and 28t was something you would find on a touring freewheel (on 5-7 speed the jumps are huge), whereas racing-oriented bikes would generally have a 12 or 13 up - so 18-20 as the largest cog.

All that's not to say that the compact doesn't make sense (it does), but to say that a standard double with a cassette that goes to 25 is something that only professional cyclists should use is a ridiculous statement. Personally, I'm currently using 52/39 with 13-20. I don't live in the Lakes!

Hi Simon, a 39/20 seems to be quite a tough lowest gear unless you live in a very flat area or are a very strong cyclist. Looking at gear ratios I see that 39/20 is 2.0 which would be the equivalent of me using my 42 (middle ring) and 21 at the back on my steel Audax bike. I'd certainly find it hard climbing anything over 10% in that gear.

I would still say for a beginner a 39/25 is a tough lowest gear, that will make it very difficult to spin up any significant hills.

simon_masterson · January 2015

ForumNewbie wrote:

Simon Masterson wrote:

markhewitt1978 wrote:

ForumNewbie wrote:

If you have a standard double at the front (say 52/39), that would mean even with a 28t biggest cog at the back, it will be tough on steep hills unless you are very fit. Many bikes now are sold with compact doubles at the front (50/34) and an 11-28 cassette at the back meaning a smallest gear of 34/28. I'd be looking for at least that if you ride on hilly routes.

Agreed. A standard with a 25T cassette is higher than even pro riders use on hilly routes. For the rest of us it's way way too high.

Not really a valid comparison. For a start, I'm guessing that they might be riding at a higher intensity than you do, but Chris Froome does not opt for a 28t rather than a 25t because he won't get up that hill if he doesn't; and there are plenty of classics and other events with decent sized hills in them that they'll do on standard chainsets. I'd be more inclined to attribute the available ratios on 11 speed to the increased use of wide range cassettes; the jumps really aren't very large on an 11 speed 11-28.

But generalising about this is silly. It depends on your health, fitness, your preferred climbing style, and the geography of where you live - as well as your inclination to climb big hills. Eg. if you are reasonably fit and live in a largely flat area, you may well not find yourself in need of really low gears. Not everyone is interested in climbing Hardknott. Times change - the 39t is a bit like yesterday's compact - go back long enough and you couldn't fit a smaller inner ring than 42t, and 28t was something you would find on a touring freewheel (on 5-7 speed the jumps are huge), whereas racing-oriented bikes would generally have a 12 or 13 up - so 18-20 as the largest cog.

All that's not to say that the compact doesn't make sense (it does), but to say that a standard double with a cassette that goes to 25 is something that only professional cyclists should use is a ridiculous statement. Personally, I'm currently using 52/39 with 13-20. I don't live in the Lakes!

Hi Simon, a 39/20 seems to be quite a tough lowest gear unless you live in a very flat area or are a very strong cyclist. Looking at gear ratios I see that 39/20 is 2.0 which would be the equivalent of me using my 42 (middle ring) and 21 at the back on my steel Audax bike. I'd certainly find it hard climbing anything over 10% in that gear.

I would still say for a beginner a 39/25 is a tough lowest gear, that will make it very difficult to spin up any significant hills.

39x20 is a hard gear, no mistake. I don't think of myself of being especially strong, but it works for me; it wouldn't be at the top of my list of things to recommend to a new cyclist!

But suitable gearing is so subjective - to a certain extent pretty much anything that goes uphill is going to represent a challenge in the first few weeks and months while fitness develops, and in time what was once a 'climb' might become a lump in the road - for that reason, I tend to take very early performance evaluations with a pinch of salt - and where you ride is the deciding factor; there's a world of difference between Herts and Beds and Calderdale and the Lakes.

ai_1 · January 2015

Simon Masterson wrote:

markhewitt1978 wrote:

ForumNewbie wrote:

If you have a standard double at the front (say 52/39), that would mean even with a 28t biggest cog at the back, it will be tough on steep hills unless you are very fit. Many bikes now are sold with compact doubles at the front (50/34) and an 11-28 cassette at the back meaning a smallest gear of 34/28. I'd be looking for at least that if you ride on hilly routes.

Agreed. A standard with a 25T cassette is higher than even pro riders use on hilly routes. For the rest of us it's way way too high.

Not really a valid comparison. For a start, I'm guessing that they might be riding at a higher intensity than you do, but Chris Froome does not opt for a 28t rather than a 25t because he won't get up that hill if he doesn't; and there are plenty of classics and other events with decent sized hills in them that they'll do on standard chainsets. I'd be more inclined to attribute the available ratios on 11 speed to the increased use of wide range cassettes; the jumps really aren't very large on an 11 speed 11-28.

But generalising about this is silly. It depends on your health, fitness, your preferred climbing style, and the geography of where you live - as well as your inclination to climb big hills. Eg. if you are reasonably fit and live in a largely flat area, you may well not find yourself in need of really low gears. Not everyone is interested in climbing Hardknott. Times change - the 39t is a bit like yesterday's compact - go back long enough and you couldn't fit a smaller inner ring than 42t, and 28t was something you would find on a touring freewheel (on 5-7 speed the jumps are huge), whereas racing-oriented bikes would generally have a 12 or 13 up - so 18-20 as the largest cog.

All that's not to say that the compact doesn't make sense (it does), but to say that a standard double with a cassette that goes to 25 is something that only professional cyclists should use is a ridiculous statement. Personally, I'm currently using 52/39 with 13-20. I don't live in the Lakes!

I'd agree that the proliferation of wide range cassettes is largely due to the arrival of 10 speed and 11 speed systems. However, I would suggest that for many riders the broader range of gear ratios was always something they would have wanted but with 5, 6, 7, 8 speed systems you couldn't have it all. You could have relatively small gaps or a narrow range. Triples provided a sensible way to gain a broader range despite the restrictions of the cassettes.
I would argue that the current trend towards broad range cassettes is a positive development that allows most cyclists to ride most terrain without having to make big compromises. Those living in flatter terrain can still live with these cassettes they simply won't need the larger sprockets very often, or they can get a narrower range item. However the broader range cassettes may be the right solution for many who aren't really sure what best suits their needs. Some people, maybe most cyclists in fact, aren't particularly bothered what components they've got on their bike so long as it works and they can continue to turn the pedals. They don't want to figure it all out.
Compact doubles and broad range cassettes make fit and forget all round bikes suitable for most gradients a reality for most cyclists. That's a good thing surely. I would say that triples already solved this problem to some extent but recent developments have brought it further.
Sure, some riders will want narrower range gearing but they will generally be those who know that.

The OP says he's in a hilly area, doesn't indicate his level of ability and doesn't know what cassette he wants. It's a fair comment to say he may find the sort of combinations he had in mind rather tough going at times. If he's light and fit, is happy to grind and/or the hills aren't too steep then he might be okay with the bigger gears but if in doubt the broad range solution is the safer option to start with.

What cassette do I need??

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