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Has anyone ever decided to go sub compact, say 48/30, rather than change the rear cassette? 

I have moved to hill country. My rear cassette is 12-25 and I struggle on some of the steeper ascents. I have a compact on the front.

I have a Record rear derailleur (short) that won't cope with a larger ranging cassette. Instead of changing the rear derailleur and cassette I wondered if going to a sub compact would give me the equivalent of being in the 32 teeth sprocket?

I am crap at maths and struggled to grasp the tables that work it out for you.

 

31 comments

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rdmp2 [52 posts] 2 months ago
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I have a sub compact but on a heavy touring bike so not really a comparison. Would slightly reduce your gearing but at greater expense than changing cassette. If you can’t do the maths this website lets you compare 2 setups side by side

 

http://ritzelrechner.de/

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Canyon48 [1054 posts] 2 months ago
2 likes

Short answer; no, a subcompact would not give you an equivalent gearing as a larger cassette.

A subcompact 48/30 with an 11-25 would give you a much smaller range than a 50/34 with an 11-32.

In addition, 50/34 with 11-32 gives you a greater gear range, a lower low gear and a higher high gear.

 

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herrkaa [6 posts] 2 months ago
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I have a Chorus with a short cage and I've been running a 12-29 Miche cassette for years without any issues. Are you quite sure that your Record won't cope?

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darrenleroy [301 posts] 2 months ago
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herrkaa wrote:

I have a Chorus with a short cage and I've been running a 12-29 Miche cassette for years without any issues. Are you quite sure that your Record won't cope?

 

I'm not 100 per cent sure but my LBS has said it won't. It's quite a jump from 25 to 29. My rear derailleur is already pretty stretched out in the 25 cog.

I'm thinking I will have to replace the rear derailleur and cassette. Bummer. I might just go the whole hog and change up for an 11 speed Potenza. I hate wasting equipment that works perfectly but I suppose I could try and flog it on eBay. 

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TypeVertigo [428 posts] 2 months ago
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BikeCalc is an excellent tool for this.

Assuming you run a 700C x 28 mm tire:

Your current 12-25 x 50/34 drivetrain has a range of 36.30-111.31 gear inches

A 12-25 x 48/32 drivetrain will give you a range of 34.17-106.77 gear inches

An 11-32 x 50/34 drivetrain will give you a range of 28.29-121.45 gear inches

 

Going wider on the cassette yields more range both ways. You'll have an easier climbing gear and a harder top gear/higher theoretical top speed

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alotronic [575 posts] 2 months ago
2 likes

Cheapest way to get where you want is leave the 34/50 on the front and buy a £20 'road link' which is a thing that sits on the end of your mech hanger and pushes the rear mech further down. You can then use a 36 or even 40 as biggest sprocket on the back via a MTB cassette - gives you the same range as a subcompact with a 12-28 or 12-32. I put one on my bike for some welsh hills last week for a 34 x 36 granny gear and it worked a treat.

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LastBoyScout [464 posts] 2 months ago
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I've run 53/39 with an 11-32 cassette on a short cage Shimano Ultegra rear mech for a very hilly ride without any problems, even though it's not supposed to work - just adjusted the b-screw a bit.

I know it's not your Record kit, but have you actually tried it?

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maviczap [223 posts] 2 months ago
1 like
alotronic wrote:

Cheapest way to get where you want is leave the 34/50 on the front and buy a £20 'road link' which is a thing that sits on the end of your mech hanger and pushes the rear mech further down. You can then use a 36 or even 40 as biggest sprocket on the back via a MTB cassette - gives you the same range as a subcompact with a 12-28 or 12-32. I put one on my bike for some welsh hills last week for a 34 x 36 granny gear and it worked a treat.

This ⬆⬆⬆⬆⬆⬆⬆⬆⬆⬆

I'm running  praxis works 46/32 chainrings on the front, and my Ultegra GS cage just about managed to run a SRAM 36t largest sprocket without a roadlink. With a roadlink copy installed, then no problem running a 36.

You can find these roadlink things on a well known auction site. The original roadlink things are overpriced for what they are, but cheaper than a new rear mech.

 

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VeloUSA [267 posts] 2 months ago
1 like

If you decide on a  Wolf Tooth Roadlink ensure the seller accepts returns because Wolf Tooth says

* Compatible only with Shimano 10- and 11-speed rear derailleurs

   * Not optimized for or recommended for use with other brands.

https://www.wolftoothcomponents.com/pages/roadlink-tech-page

 

 

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madcarew [786 posts] 2 months ago
1 like
darrenleroy wrote:
herrkaa wrote:

I have a Chorus with a short cage and I've been running a 12-29 Miche cassette for years without any issues. Are you quite sure that your Record won't cope?

 

I'm not 100 per cent sure but my LBS has said it won't. It's quite a jump from 25 to 29. My rear derailleur is already pretty stretched out in the 25 cog.

I'm thinking I will have to replace the rear derailleur and cassette. Bummer. I might just go the whole hog and change up for an 11 speed Potenza. I hate wasting equipment that works perfectly but I suppose I could try and flog it on eBay. 

It would be a rare derailleur that can't cope with an 18 tooth difference in the back. If your derailleur is already stretched out on the 25, it may be that your chain is too short.

Going from Standard to sub compact will give the equivalent of a 27 on the back (1 more gear) and going to a full compact will give the equivalent of  a 29 on the back ( 2 more gears). TBH, going full compact at 34/50 would be a good result, but for an awful lot cheaper, a 12 - 29 cassette would achieve a better result (you'd lose 1 top gear, but it doesn't sound like you're bothered by that having suggested a 48 would be ok). Get another opinion from a different LBS before taking the plunge on a new chainset. You can probably find the capacity of a record derailleur on line.

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alotronic [575 posts] 2 months ago
0 likes
VeloUSA wrote:

If you decide on a  Wolf Tooth Roadlink ensure the seller accepts returns because Wolf Tooth says

* Compatible only with Shimano 10- and 11-speed rear derailleurs

   * Not optimized for or recommended for use with other brands.

https://www.wolftoothcomponents.com/pages/roadlink-tech-page

 

 

 

 

Sorry, missed that the OP was talking Italian - worth a search to see if they work then!

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BehindTheBikesheds [2277 posts] 2 months ago
1 like

get a compact triple, 50/36/24, solves all your problems and you can keep the 11-25

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CXR94Di2 [2192 posts] 2 months ago
3 likes

I've got a triple crank to fit 48/36/26 with Di2 when I return home. I will run either a 11-32 or 11-40 Cass. I've been using a twin crank of 44/28 in the Alps this week and has been perfect for me to sustain 80rpm all the way up climbs like the Galibier with my 94kg weight.

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bobinski [294 posts] 2 months ago
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I changed from a 50/34 to a 48/32 with 11-28 for mountain riding. I thought close enough to a 50/34 11-28 without need to swap cassette and rear Ultegra short derailleur. It wasn’t enough and I ended up swapping in an 11-32 as well. What a huge difference. Had already ruined my legs at a cadence of 70 but now better able to spin at 75-80. No issues using short cage at all. 

The other riders were using a minimum of 50/34 and 11-32 or even 34

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darrenleroy [301 posts] 2 months ago
2 likes
BehindTheBikesheds wrote:

get a compact triple, 50/36/24, solves all your problems and you can keep the 11-25

 

I'm not getting a triple. I mean, I'm not Peter Sagan cool, but I have some dignity. 

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CXR94Di2 [2192 posts] 2 months ago
5 likes
darrenleroy wrote:
BehindTheBikesheds wrote:

get a compact triple, 50/36/24, solves all your problems and you can keep the 11-25

 

I'm not getting a triple. I mean, I'm not Peter Sagan cool, but I have some dignity. 

 

The word is vanity. 

 

What ever get you up the hills in the most comfortable way

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darrenleroy [301 posts] 2 months ago
1 like
CXR94Di2 wrote:
darrenleroy wrote:
BehindTheBikesheds wrote:

get a compact triple, 50/36/24, solves all your problems and you can keep the 11-25

 

I'm not getting a triple. I mean, I'm not Peter Sagan cool, but I have some dignity. 

 

The word is vanity. 

 

What ever get you up the hills in the most comfortable way

 

You're quite right, it is vanity. Last summer I met a middle aged Belgian chap in Le Bourg-d'Oisans who was doing some riding, He had a triple on the back. At dinner I was sat next to a British marine and his girlfriend (ex-Wales international runner turned very keen cyclist). The marine fancied himself a bit; you know the type; buff, very focussed, very dull.
We were comparing times. When the Belgian chap told us his time the marine went quiet. The Belgian was riding a triple. He explained that it allowed him to spin at his preferred cadence whatever the incline, thus maintaining rhythm. I'm still not fitting a triple though. 

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BehindTheBikesheds [2277 posts] 2 months ago
2 likes
CXR94Di2 wrote:
darrenleroy wrote:
BehindTheBikesheds wrote:

get a compact triple, 50/36/24, solves all your problems and you can keep the 11-25

I'm not getting a triple. I mean, I'm not Peter Sagan cool, but I have some dignity. 

The word is vanity. 

What ever get you up the hills in the most comfortable way

Absolutely, many a time I've watched pros come to a standstill and almost falling off due to running out of gears. Tour of Britain a couple of years back and suprisingly it was raining in the Lake District, watched with great hilarity as an old codger with a walking stick outpace the chasing bunch up a wet steep bit., it was comedy gold

 

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maviczap [223 posts] 2 months ago
0 likes

Back on topic.

My first trip to the Pyrenees I used 9 speed triple 50/39/30 with 28 biggest. I was able to spin up the climbs, as a rider from flat East Anglia, I was able to climb better than my mates from Wales who were on compact. To be fair they were carrying more body weight than my 67kg

Next few years were on 10speed 50/34 with a 30, which I managed, but couldn't spin up like the triple.

Upgraded to 11speed and the last 2 trips, I used a 50/33 with 32, but probably due to a lack of miles ,getting older and weighing 70kg I did struggle on my last trip.

I'm back in the Pyrenees next weekend, and ilI' be using 46/32 and a 34, with more miles and weighing 67kg, so let's hope I can spin up, rather than grind up.

I'd quite happily use a triple but I'm using Di2, anyone using Di2 with a triple, and I don't mean using 2 two of the three?

I have in my parts locker, a Tiagra triple and 105 triple shifter, which will be deployed once age overtakes ability, which won't be long

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CXR94Di2 [2192 posts] 2 months ago
0 likes
maviczap wrote:

Back on topic.

My first trip to the Pyrenees I used 9 speed triple 50/39/30 with 28 biggest. I was able to spin up the climbs, as a rider from flat East Anglia, I was able to climb better than my mates from Wales who were on compact. To be fair they were carrying more body weight than my 67kg

Next few years were on 10speed 50/34 with a 30, which I managed, but couldn't spin up like the triple.

Upgraded to 11speed and the last 2 trips, I used a 50/33 with 32, but probably due to a lack of miles ,getting older and weighing 70kg I did struggle on my last trip.

I'm back in the Pyrenees next weekend, and ilI' be using 46/32 and a 34, with more miles and weighing 67kg, so let's hope I can spin up, rather than grind up.

I'd quite happily use a triple but I'm using Di2, anyone using Di2 with a triple, and I don't mean using 2 two of the three?

I have in my parts locker, a Tiagra triple and 105 triple shifter, which will be deployed once age overtakes ability, which won't be long

I'd quite happily use a triple but I'm using Di2, anyone using Di2 with a triple, and I don't mean using 2 two of the three?

Yes yes

I built my Tripster V2 last year for mountain climbing using XT di2 groupset, initally with 40/28 crank, a 11-32 or 11-40 cassette.  I modified to get 44/28 crank to give a little more flat down hill speed.  

Ive now changed my front Di2 XT 2 gear derailleur to a XTR Di2 3 gear.  These are fully compatible with my set up.  I then fitted an XT triple crank 48/36/26. It works beautifully either in syncro mode or manual mode.

Shimano spec is that XTR will only take 40t max crank, this is rubbish as 48 fits easily.  Ive hear of 50t triple cranks being fitted with careful setup.

Having a band clamp for the front di2 derailleur is recommended so to allow fine adjustment

Here is shimano compatibility chart and a photo of my new crank with XTR di2 derailleur 

 

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CXR94Di2 [2192 posts] 2 months ago
1 like
maviczap wrote:

Back on topic.

My first trip to the Pyrenees I used 9 speed triple 50/39/30 with 28 biggest. I was able to spin up the climbs, as a rider from flat East Anglia, I was able to climb better than my mates from Wales who were on compact. To be fair they were carrying more body weight than my 67kg

Next few years were on 10speed 50/34 with a 30, which I managed, but couldn't spin up like the triple.

Upgraded to 11speed and the last 2 trips, I used a 50/33 with 32, but probably due to a lack of miles ,getting older and weighing 70kg I did struggle on my last trip.

I'm back in the Pyrenees next weekend, and ilI' be using 46/32 and a 34, with more miles and weighing 67kg, so let's hope I can spin up, rather than grind up.

I'd quite happily use a triple but I'm using Di2, anyone using Di2 with a triple, and I don't mean using 2 two of the three?

I have in my parts locker, a Tiagra triple and 105 triple shifter, which will be deployed once age overtakes ability, which won't be long

 

The gearing you found easy for the Pyrenees was down to your weight.  Ive ridden with a variety of riders of different weights.  Light riders, sub 75kg, can get away with compact 50/34 11-28/32 setups when climbing mountains.  When heavyweight riders try mountains they need alot easier gearing, I go upto 40t cass and now a 26t chainring to be able to spin for hours.  Ive seen 90+kg riders die a horrible slow grind death using a standard compact setup.  I weigh 94kg+bike+kit so easily nudging 110kg whilst climbing. 

Ive just come back from the Alps and was able to maintain a decent cadence of 80rpm for the like s of the Glandon, Galibier and Croix de fer, These are climbs of 25+km long average 7+%

 

Note 

light riders will climb faster than heavy riders on long climbs.  Either let them go or leave 10 mins earlier to meet near the top.

I and another chap left 15 mins earlier for the Croix de fer, we were caught up within a km of the top some 30km long climb

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CXR94Di2 [2192 posts] 2 months ago
2 likes

photo XTR Di2 triple with 48/36/26 gears

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maviczap [223 posts] 2 months ago
0 likes
CXR94Di2 wrote:
maviczap wrote:

Back on topic.

My first trip to the Pyrenees I used 9 speed triple 50/39/30 with 28 biggest. I was able to spin up the climbs, as a rider from flat East Anglia, I was able to climb better than my mates from Wales who were on compact. To be fair they were carrying more body weight than my 67kg

Next few years were on 10speed 50/34 with a 30, which I managed, but couldn't spin up like the triple.

Upgraded to 11speed and the last 2 trips, I used a 50/33 with 32, but probably due to a lack of miles ,getting older and weighing 70kg I did struggle on my last trip.

I'm back in the Pyrenees next weekend, and ilI' be using 46/32 and a 34, with more miles and weighing 67kg, so let's hope I can spin up, rather than grind up.

I'd quite happily use a triple but I'm using Di2, anyone using Di2 with a triple, and I don't mean using 2 two of the three?

I have in my parts locker, a Tiagra triple and 105 triple shifter, which will be deployed once age overtakes ability, which won't be long

 

The gearing you found easy for the Pyrenees was down to your weight.  Ive ridden with a variety of riders of different weights.  Light riders, sub 75kg, can get away with compact 50/34 11-28/32 setups when climbing mountains.  When heavyweight riders try mountains they need alot easier gearing, I go upto 40t cass and now a 26t chainring to be able to spin for hours.  Ive seen 90+kg riders die a horrible slow grind death using a standard compact setup.  I weigh 94kg+bike+kit so easily nudging 110kg whilst climbing. 

Ive just come back from the Alps and was able to maintain a decent cadence of 80rpm for the like s of the Glandon, Galibier and Croix de fer, These are climbs of 25+km long average 7+%

 

Note 

light riders will climb faster than heavy riders on long climbs.  Either let them go or leave 10 mins earlier to meet near the top.

I and another chap left 15 mins earlier for the Croix de fer, we were caught up within a km of the top some 30km long climb

Yep, I get that and take my hat off to you, as you're nearly 30kg more than me. I've done all those climbs, bar Galibier the long way up the telegraph. Croix der Fer was a big test, just because of the length of the climb.

Thanks for the photo, I might experiment with my Tiagra triple. Any issues with chain rub on the front mech?

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CXR94Di2 [2192 posts] 2 months ago
1 like

No issues with rubbing, first the Di2 front derailleur self trims as you move across the cassette gearing. Second, I ensured that the spacers on the bottom bracket, were spot on to give the correct alignment. I think I sanded down one spacer removing 1mm of thickness

Avatar
alexb [187 posts] 2 months ago
1 like
darrenleroy wrote:
herrkaa wrote:

I have a Chorus with a short cage and I've been running a 12-29 Miche cassette for years without any issues. Are you quite sure that your Record won't cope?

 

I'm not 100 per cent sure but my LBS has said it won't. It's quite a jump from 25 to 29. My rear derailleur is already pretty stretched out in the 25 cog.

I'm thinking I will have to replace the rear derailleur and cassette. Bummer. I might just go the whole hog and change up for an 11 speed Potenza. I hate wasting equipment that works perfectly but I suppose I could try and flog it on eBay. 

If you are using Campag 10 speed (which I guess you are), and a 53/39 then the 11-25 gives you the following gear range:

127.1"-41.2"

Compared to:

115.1" to 31.7" using the 48/30

Using a 13-29t 10 speed cassette on a standard 53/39 gives you 

107.5" - 35.5

Using a 50/34 combination with the 13-29t cassette will give you

101.5" - 30.9" - so lower than the sub-compact with a slight loss at the top end

So I'd suggest first trying a new chain and cassette (13-29), then maybe fitting smaller chainrings.

There's quite a lot of gear duplification, but this seems normal for compact doubles.

Unless you are completely spinning out the 53 on the flat, I'd suggest trying the larger casette first (a Veloce cassette and KMC chain are going to cost you less than £50).

The smart way to use a double is with an ultrawide cassette and a very narrow double - it's possible to find gear combinations that allow the  front chainring to fill the gap between ratios in the rear cassette with no duplications at all. 

 

Avatar
CXR94Di2 [2192 posts] 2 months ago
1 like

Nobody spins out a 53t crank on the flat, even the pros, unless it's on a long steep descent.

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maviczap [223 posts] 2 months ago
1 like
CXR94Di2 wrote:

No issues with rubbing, first the Di2 front derailleur self trims as you move across the cassette gearing. Second, I ensured that the spacers on the bottom bracket, were spot on to give the correct alignment. I think I sanded down one spacer removing 1mm of thickness

Having read your posts properly,  I saw you're using an xtr front mech, which is very useful to know, I did wonder if it was possible.

Not sure if I can do this on my carbon Battaglin, which has a fixed mech hanger in the front, but my Ti bike does use a band on mech, so ilI' be trying your mod out for sure.

As you correctly said, it's all about getting up the climbs comfortably, rather than worry about how your bike looks or what people say.

I remember seeing someone back in 2009  ono the Tourmalet with a dinner plate rear cassette, which must have been a mountain bike cassette, as no one did big sprocket cassettes for road bikes then, he looked comfortable, so I thought why not.

Avatar
CXR94Di2 [2192 posts] 2 months ago
1 like
maviczap wrote:
CXR94Di2 wrote:

No issues with rubbing, first the Di2 front derailleur self trims as you move across the cassette gearing. Second, I ensured that the spacers on the bottom bracket, were spot on to give the correct alignment. I think I sanded down one spacer removing 1mm of thickness

Having read your posts properly,  I saw you're using an xtr front mech, which is very useful to know, I did wonder if it was possible.

Not sure if I can do this on my carbon Battaglin, which has a fixed mech hanger in the front, but my Ti bike does use a band on mech, so ilI' be trying your mod out for sure.

As you correctly said, it's all about getting up the climbs comfortably, rather than worry about how your bike looks or what people say.

I remember seeing someone back in 2009  ono the Tourmalet with a dinner plate rear cassette, which must have been a mountain bike cassette, as no one did big sprocket cassettes for road bikes then, he looked comfortable, so I thought why not.

Check out the compatibility chart I posted. You can use XT with XTR front or rear derailleur.

What you can't do is mix road Di2 derailleurs with MTB derailleurs.

I think XTR in Di2 is the only triple front derailleur available currently.

Avatar
CXR94Di2 [2192 posts] 2 months ago
1 like
maviczap wrote:
CXR94Di2 wrote:

No issues with rubbing, first the Di2 front derailleur self trims as you move across the cassette gearing. Second, I ensured that the spacers on the bottom bracket, were spot on to give the correct alignment. I think I sanded down one spacer removing 1mm of thickness

Having read your posts properly,  I saw you're using an xtr front mech, which is very useful to know, I did wonder if it was possible.

Not sure if I can do this on my carbon Battaglin, which has a fixed mech hanger in the front, but my Ti bike does use a band on mech, so ilI' be trying your mod out for sure.

As you correctly said, it's all about getting up the climbs comfortably, rather than worry about how your bike looks or what people say.

I remember seeing someone back in 2009  ono the Tourmalet with a dinner plate rear cassette, which must have been a mountain bike cassette, as no one did big sprocket cassettes for road bikes then, he looked comfortable, so I thought why not.

Check out the compatibility chart I posted. You can use XT with XTR front or rear derailleur.

What you can't do is mix road Di2 derailleurs with MTB derailleurs.

I think XTR in Di2 is the only triple front derailleur available currently.

Avatar
darrenleroy [301 posts] 2 months ago
0 likes
alexb wrote:
darrenleroy wrote:
herrkaa wrote:

I have a Chorus with a short cage and I've been running a 12-29 Miche cassette for years without any issues. Are you quite sure that your Record won't cope?

 

I'm not 100 per cent sure but my LBS has said it won't. It's quite a jump from 25 to 29. My rear derailleur is already pretty stretched out in the 25 cog.

I'm thinking I will have to replace the rear derailleur and cassette. Bummer. I might just go the whole hog and change up for an 11 speed Potenza. I hate wasting equipment that works perfectly but I suppose I could try and flog it on eBay. 

If you are using Campag 10 speed (which I guess you are), and a 53/39 then the 11-25 gives you the following gear range:

127.1"-41.2"

Compared to:

115.1" to 31.7" using the 48/30

Using a 13-29t 10 speed cassette on a standard 53/39 gives you 

107.5" - 35.5

Using a 50/34 combination with the 13-29t cassette will give you

101.5" - 30.9" - so lower than the sub-compact with a slight loss at the top end

So I'd suggest first trying a new chain and cassette (13-29), then maybe fitting smaller chainrings.

There's quite a lot of gear duplification, but this seems normal for compact doubles.

Unless you are completely spinning out the 53 on the flat, I'd suggest trying the larger casette first (a Veloce cassette and KMC chain are going to cost you less than £50).

The smart way to use a double is with an ultrawide cassette and a very narrow double - it's possible to find gear combinations that allow the  front chainring to fill the gap between ratios in the rear cassette with no duplications at all. 

 

I'd happily just change my rear cassette for something ultrawide but my 10 speed Record rear derailleur won't allow much past a 12-25. According to my LBS anyway. 

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