Thinking of buying my first road bike which has a compact 34 / 50. Currently using 30/39/50 on tourer, being pretty useless on the very steep bits I need the lowest gear on the triple. I have been informed by changing the cassette on the compact I can achieve the same lowest gear - is this correct ? Any advice would be very welcome, many thanks. (Age 53 - recreational rider).
Triple v Compact advice please
- Thread starter Eddigrae
- Start date
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Hacienda71
Mancunian in self imposed exile in leafy Cheshire
- Location
- Wilmslow, Cheshire
You need to make sure your rear mechanism can take the size of cassette you would change to. You may need to change the rear mech on the bike to one that can accommodate the bigger cog of the lowest gear. Also you will need to change the chain as you will need a longer one if the two biggest cogs change.
gbb
Legendary Member
- Location
- Peterborough
I'm trying to visualise what intermediate cogs would be on the back and if this would help or hinder you when shifting onto the 34
I dont like compacts...maybe its just me but i find when you shift onto the 34, you have to shift up on the rear at the same time, otherwise you're suddenly spinning like the clappers. I found the drop from 50 to 34 to be too big...i just find it messy.
Plenty here like them, so maybe its just me, but be aware some don't like compacts for the above reasons.
Thinking about it, perhaps its the terrain round here...a reasonable amount of rolling hills, not too steep, but it involves plenty of shifting to keep momentum.
I guess if theres not constant shifting up and down, thats why some people dont mind them.
Just thinking out loud...don't mind me
I dont like compacts...maybe its just me but i find when you shift onto the 34, you have to shift up on the rear at the same time, otherwise you're suddenly spinning like the clappers. I found the drop from 50 to 34 to be too big...i just find it messy.
Plenty here like them, so maybe its just me, but be aware some don't like compacts for the above reasons.
Thinking about it, perhaps its the terrain round here...a reasonable amount of rolling hills, not too steep, but it involves plenty of shifting to keep momentum.
I guess if theres not constant shifting up and down, thats why some people dont mind them.
Just thinking out loud...don't mind me
GrasB
Veteran
- Location
- Nr Cambridge
YMMV, genrally a road triple gives you 1 more gear down compared to a 34/50 compact. So it does come down to what you prefer. Generally compacts need more double shifting, if you're using ergo shifters this can be an issue but with bar end shifters on bullhorn bars I don't find it any more problematic.
if you're need the lowest gearing on a triple why are you wanting a double?
extending a double that low is going to have consequences I'd have thought unless you have one single big gear on the cassete but the hill
or get some better legs, there's an argument that you only get as good as the lowest gear make you
extending a double that low is going to have consequences I'd have thought unless you have one single big gear on the cassete but the hill
or get some better legs, there's an argument that you only get as good as the lowest gear make you
Randochap
Senior hunter
- Location
- British Columbia, Canada
There is a discussion of double and triple at VeloWeb, in the Randonneuring section.
Basically, the advantage of a triple is keeping shifts closer on wide range gearing.
Basically, the advantage of a triple is keeping shifts closer on wide range gearing.
With a 34 x 27, when you come to a 14% hill, you stand up and turn the cranks at less than 40 rpm ( which requires less than 300 Watts ).
It is the equivalent of picking the bike up and carrying it. So, hills steeper than 14% ( the ones with one chevron on the Ordnance Survey map ), may as well be walked.
Triples are liked by the Randonneurs because ( e.g. ) the middle 7 on a 9 cassette are coupled with the middle chainring, so we can ride almost anywhere without touching the front changer. This makes life a lot easier.
Doubles can be set-up, however, to have the 'normal' gears coupled to the big ring if the bike is damned light and you can ride up an 8% on 53 x 21.
But seeing there are more 7 - 10% hills than 12 - 14% hills, the middle ring on a triple is used instead of doing the change on a double.
It is the equivalent of picking the bike up and carrying it. So, hills steeper than 14% ( the ones with one chevron on the Ordnance Survey map ), may as well be walked.
Triples are liked by the Randonneurs because ( e.g. ) the middle 7 on a 9 cassette are coupled with the middle chainring, so we can ride almost anywhere without touching the front changer. This makes life a lot easier.
Doubles can be set-up, however, to have the 'normal' gears coupled to the big ring if the bike is damned light and you can ride up an 8% on 53 x 21.
But seeing there are more 7 - 10% hills than 12 - 14% hills, the middle ring on a triple is used instead of doing the change on a double.
jimboalee said:
Absolute spot on are these comments, I know from experience, that when you run out of gears on a hill and you can only crawl up it at 4mph or less then it is just as easy to walk, I gave it a try one day when I thought to myself, I'm cycling at walking speed and killing myself trying to turn the pedals, lets get off and walk the hill. When I got home and checked my times from my Garmin with earlier rides, I found that walking it was only very slightly slower than cycling, but I put it down to struggling with cleats on and not getting a good grip as I walked.
Riding in the middle ring, I do most of the time and cruise along efforrtlessly as I find I can keep up a good high cadence and I have all the gear ranges that I need. Its only when I hit 20mph that I change to the high ring to keep my speed up along with a high cadence.
On group rides, other riders on occasions comment as to why I am on the middle ring on my triple or the inner on my double, but they cannot seem to grasp how much easier it is to ride with a higher cadence than pushing a higher gear. The proof of the pudding which they do not twig on is that I am still with them riding alongside but soon as the pace hits 20mph+ then I'm away, still feeling fresh as I have not been slogging the higher gears and tiring myself out needlessly.
wafflycat
New Member
- Location
- middle of Norfolk
All my steeds have triple chainrings. I much prefer a triple to a double.
GrasB
Veteran
- Location
- Nr Cambridge
For solo riding I don't like triples my self. I find that one chainring ends up being left in no mans land & is unused or just gets in the way.
Tigerbiten
Guru
I use a triple in front as there is no way a double will give me the range of gears I use.
My top gear is ~100" and my lowest is only ~12", 48-36-22 on the front, 9-32 on the back useing 20" (18.5") wheels.
Luck .........
My top gear is ~100" and my lowest is only ~12", 48-36-22 on the front, 9-32 on the back useing 20" (18.5") wheels.
Luck .........
Paul_Smith SRCC
www.plsmith.co.uk
- Location
- Surrey UK
I have posted this before but may be of interest here so I have repeated it for you:
What you need to do is work out what gear ratios you like to use and then try and achieve them, making sure they are correctly positioned, no point if mathematically you can only get your most common used gear in largest ring largest sprocket.
By way of an example that is all I have done on my current tour bike, I use a 13t-29t Campagnolo 10 speed cassette set up with a chainset that 26-36-46t chainrings to give the the gear ratios I am after
I like gears of around 60”, you will see that I have got those on both middle and outer ring. I have done this essentially because this is a bike I use for two roles, solo rides of 15-20mph and touring rides of 12-15mph, to save repeated chain ring changes I can essentially use the big ring mainly for solo rides and the middle ring for more sociable rides. Even though it only has a 96" top gear I find that easily high enough for a mid 20-25 mph work out, for 15-20mph cruising I have ratios that I like available mid cassette on the 46 ring, this I find is the perfect set up for me. Of course everyone is different, some prefer a lower low gear and a higher high gear, horses for courses as they say
It does take a bit of thought as to what you need both in terms of ratios and then equipment choices to achieve them, but it can nearly always be done. In my case for example I did invest in a high quality chainset to get the ring combinations I wanted, as for me personally I find many road specific triples have ring choices too large yet the ATB chainsets too small for what I wanted.
Note I said 'wanted' not 'needed', my tour bike is used for tours, often I want to climb a long mountain pass with little effort to take in the scenery, so I chose lower gear ratios on that bike. Sportive bikes by comparison are normally ridden with no luggage, plus set up generally for riding at a higher speed than a touring bike, you can see from that gear chart above that a 34t inner chain ring with a 27t largest sprocket, a common combination on a sportive bike with compact transmission, will give a lowest gear ratio of approx' 34", on that style of bike that is low enough for most riders, even on a mountain pass.
To try and explain what a 34" gear ratio equates to you will see a red Audax bike in my tour write ups under my signature below, the 'Lejog' write up had a higher gear than that and I rode up every climb, in that specification I also toured the High Alps with two full panniers and again rode every climb.
However, I realised when I was riding in a group I had to keep the gear turning on the climbs and ride quicker than many of my new friends, who were using lower gear ratios than me and able to ride at a slower more socialble pace, that along with wanting to take in the scenery is why you will now see that bike had a triple in some of the later tour articles. As I said gear ratio choices can take some thought, the decision may not always be down to ability.
Note my bike is an Audax bike, I have mentioned it purely to illustrate the thought process that can go into deciding what gear ratios to go for.
Hope this helps
Paul_Smith
www.corridori.co.uk
What you need to do is work out what gear ratios you like to use and then try and achieve them, making sure they are correctly positioned, no point if mathematically you can only get your most common used gear in largest ring largest sprocket.
By way of an example that is all I have done on my current tour bike, I use a 13t-29t Campagnolo 10 speed cassette set up with a chainset that 26-36-46t chainrings to give the the gear ratios I am after
I like gears of around 60”, you will see that I have got those on both middle and outer ring. I have done this essentially because this is a bike I use for two roles, solo rides of 15-20mph and touring rides of 12-15mph, to save repeated chain ring changes I can essentially use the big ring mainly for solo rides and the middle ring for more sociable rides. Even though it only has a 96" top gear I find that easily high enough for a mid 20-25 mph work out, for 15-20mph cruising I have ratios that I like available mid cassette on the 46 ring, this I find is the perfect set up for me. Of course everyone is different, some prefer a lower low gear and a higher high gear, horses for courses as they say
It does take a bit of thought as to what you need both in terms of ratios and then equipment choices to achieve them, but it can nearly always be done. In my case for example I did invest in a high quality chainset to get the ring combinations I wanted, as for me personally I find many road specific triples have ring choices too large yet the ATB chainsets too small for what I wanted.
Note I said 'wanted' not 'needed', my tour bike is used for tours, often I want to climb a long mountain pass with little effort to take in the scenery, so I chose lower gear ratios on that bike. Sportive bikes by comparison are normally ridden with no luggage, plus set up generally for riding at a higher speed than a touring bike, you can see from that gear chart above that a 34t inner chain ring with a 27t largest sprocket, a common combination on a sportive bike with compact transmission, will give a lowest gear ratio of approx' 34", on that style of bike that is low enough for most riders, even on a mountain pass.
To try and explain what a 34" gear ratio equates to you will see a red Audax bike in my tour write ups under my signature below, the 'Lejog' write up had a higher gear than that and I rode up every climb, in that specification I also toured the High Alps with two full panniers and again rode every climb.
However, I realised when I was riding in a group I had to keep the gear turning on the climbs and ride quicker than many of my new friends, who were using lower gear ratios than me and able to ride at a slower more socialble pace, that along with wanting to take in the scenery is why you will now see that bike had a triple in some of the later tour articles. As I said gear ratio choices can take some thought, the decision may not always be down to ability.
Note my bike is an Audax bike, I have mentioned it purely to illustrate the thought process that can go into deciding what gear ratios to go for.
Hope this helps
Paul_Smith
www.corridori.co.uk
Deciding what gears to install.
1/ Weigh yourself.
You can use your bodyweight to calculate the MAX torque that can possibly be applied to the B/B.
Take a safety factor. 75% is about right. ¾ of the MAX is what you can reasonably expect to generate with every successive pedalstoke when you are standing out of the saddle.
2/ Decide on your favourite cadence ( when you are standing out of the saddle).
3/ Use ‘Powercalc.xls’ off the CTC website to find out how much power is required to climb a hill at various speeds.
On a separate sheet, juggle the figures to get a speed, gear and cadence which will generate the required power to climb the hill.
Or, you can reciprocate the weight of the bike in lbs, multiply this by 1000 and subtract 6 ( 2 x 3" steps) for a 14% hill.
1/ Weigh yourself.
You can use your bodyweight to calculate the MAX torque that can possibly be applied to the B/B.
Take a safety factor. 75% is about right. ¾ of the MAX is what you can reasonably expect to generate with every successive pedalstoke when you are standing out of the saddle.
2/ Decide on your favourite cadence ( when you are standing out of the saddle).
3/ Use ‘Powercalc.xls’ off the CTC website to find out how much power is required to climb a hill at various speeds.
On a separate sheet, juggle the figures to get a speed, gear and cadence which will generate the required power to climb the hill.
Or, you can reciprocate the weight of the bike in lbs, multiply this by 1000 and subtract 6 ( 2 x 3" steps) for a 14% hill.
Landslide
Rare Migrant
- Location
- Called to the bar
Maybe you could try asking the shop if they'd convert it to a triple before you buy it.Eddigrae said:
