# Upgrading chainrings and rear cassette on my CAAD10



## Conviccted (Jan 3, 2012)

Hello everyone I have a cannondale Caad 10 3 ultegra road bike,with a compact crank. I'm looking into changing my chainrings to 53/39 and my rear cassette to a shimano dura ace 11-28. My crank lenth is a 170,will these upgrades be possible with out any issues. I was told that I need a 172.5 crank lenth and can only go as high as a 11-27 rear cassette....any help would be appreciated,thanks


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## Propofol (Jul 5, 2005)

That is a compact crankset with a 110mm BCD. In order to fit 53/39 chainrings you should use a crank spider with a 130mm BCD or you'll have too much lateral flex from the 53 chainring.

Your only realistic option is to buy a new crankset.


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## CAADEL (Jul 23, 2011)

Alternatively you can use 52/36T on the 110mm BCD. 
Your new generation (7900, 6700, 5700) shimano rear derailleur has the capacity to work with 28T. Older generation short cage shimanos could handle up to 27T and a medium cage was needed. But that's not your case here.


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## Conviccted (Jan 3, 2012)

Thanks everyone for the info,I'm gonna order the 52/36 chainrings with the 11/28 cassette...hope I like them


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## redondoaveb (Jan 16, 2011)

Curious. Why do you want to change? What is your existing cassette?


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## Conviccted (Jan 3, 2012)

My original cassette is a 12/25 shimano ultegra 6700....I'm struggling a lot on a fast group ride that does lots of hills and after asking a few friends they are using the standard gears with 12/27 rear cog set.....when we do longer rides with less people I watch them only using there small crank gear and struggling less than me on my small crank gear.I'm also switching to a lighter cog set eighter dura ace or SRAM red. I'm open to any suggestions


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## redondoaveb (Jan 16, 2011)

Why not save some money and get an 11/28 cassette and use your 50/34. That will give you the 11 for a little higher gear if you really feel you need it. Personally, I like a 12 as I can't spin an 11 on the flats and get closer gear spacing with the 12. With the 28 you should be able to climb a brick wall. I was running a 50/34 with a 12/25 and haven't had any problems on hills except that I have to do a lot more standing in the steep sections. I just switched to a 12/27 though. I like it because the ratios are 12-13-14-15-16-17-19-21-24-27. I lost the 23 and 25 tooth of my 12/25 but I can pretty much climb anything on the 24 and I have the 27 as a bail out gear.

IMHO, I think the 12/27 with the 50/34 is a great setup if you do a lot of hills. If most of your riding is flats then the 53/39 is great, but then you wouldn't want the 28. Keep the 25.


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## Newnan3 (Jul 8, 2011)

OP, how do you like the Ultremo zx tires??


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## Conviccted (Jan 3, 2012)

Your right maybe I'm rushing into things my friends do have much lighter bikes and I'm gonna wright the gears down on paper it make a lot of sense about the spacing of gears...our group rides are always hills and every now and then when we don't make the group ride we hit the reservoir for long flats,that's when I long for the higher crank gears....my friends said I will feel a big difference with the standard gears.


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## Conviccted (Jan 3, 2012)

The ultremo zx tires are great,real light and very fast....I run them to the max pressure 145 and they made a big difference, I have 3 friends that are using them also and they all like them a lot


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## redondoaveb (Jan 16, 2011)

Conviccted said:


> Your right maybe I'm rushing into things my friends do have much lighter bikes and I'm gonna wright the gears down on paper it make a lot of sense about the spacing of gears...our group rides are always hills and every now and then when we don't make the group ride we hit the reservoir for long flats,that's when I long for the higher crank gears....my friends said I will feel a big difference with the standard gears.


The 50/12 will give you a top speed of 32.6 mph at 100 rpm. Not a lot of people can spin that for very long on the flats The 53/12 would give you a top speed of 34.5 at 100 rpm. 2 mph difference. Don't know if that's worth the expense of a new crank, especially when it sounds like most of your riding is hills, where a 34/27 or 28 would really benefit you.


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## Conviccted (Jan 3, 2012)

redondoaveb said:


> The 50/12 will give you a top speed of 32.6 mph at 100 rpm. Not a lot of people can spin that for very long on the flats The 53/12 would give you a top speed of 34.5 at 100 rpm. 2 mph difference. Don't know if that's worth the expense of a new crank, especially when it sounds like most of your riding is hills, where a 34/27 or 28 would really benefit you.


I really appreciate the great info,how did you come up with the mph/ speed formula? I think I'm going with the 11/28 cassette and some new wheels instead


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## redondoaveb (Jan 16, 2011)

Conviccted said:


> I really appreciate the great info,how did you come up with the mph/ speed formula? I think I'm going with the 11/28 cassette and some new wheels instead


Sheldon Brown's Bicycle Gear Calculator


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## Conviccted (Jan 3, 2012)

redondoaveb said:


> Sheldon Brown's Bicycle Gear Calculator


Cool...thanks again


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## redondoaveb (Jan 16, 2011)

Conviccted said:


> Cool...thanks again


Yeah, it's a great site. I think you're making the right choices, but again, just my opinion. There are a lot more experienced cyclists on this site that may not agree. Hopefully some of them will chime in on this.


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## Propofol (Jul 5, 2005)

Additionally, if most of your riding is on hills, running a chainring larger than 50T on a 110 BCD spider would not be optimal due to the increased lateral flex.


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## milkbaby (Aug 14, 2009)

Conviccted said:


> My original cassette is a 12/25 shimano ultegra 6700....I'm struggling a lot on a fast group ride that does lots of hills and after asking a few friends they are using the standard gears with 12/27 rear cog set.....when we do longer rides with less people I watch them only using there small crank gear and struggling less than me on my small crank gear.I'm also switching to a lighter cog set eighter dura ace or SRAM red. I'm open to any suggestions


Are you struggling to keep up going UP the hills? If so, then you probably don't want to change your set up other than possibly the cassette. If your pals are riding 53/39 with 12-27t, and you are on 50/34 with 12-25t, your lowest/easiest hill climbing gear (34 front, 25 back) is actually EASIER to spin than theirs (39 front, 27 back). And your cassette spacing is closer, so it may be easier to find the best gear to stay in good cadence than on a wider cassette. The compacts are designed for climbing, so definitely don't go to the larger chainrings!

Shift more/into the right gear and get into better shape if the above is the case. Your pals are dropping you because they are in better hill climbing shape. If you are having trouble keeping up on the downhills, then disregard... Good luck and enjoy the ride!


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## Yamabushi (Sep 30, 2008)

Conviccted said:


> I run them to the max pressure 145 and they made a big difference, I have 3 friends that are using them also and they all like them a lot...


Why are you running them at such high pressure? How much do you weigh?


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## mimason (Oct 7, 2006)

I hope you are still not considering changing to a standard crank. It will not help you or make you faster. Alternatively, getting an 11-26 in the rear with the 50/34 it an ideal setup. The 34/26 gives you the low end of a triple and you'll be popping wheelies on steep climbs if you don't balance your weigh forward.

Getting dropped is not about the crank or the weight of your bike most likely. You may be simply trying too hard on the climbs and you are not riding your ride or pace but theirs. I recommend that you settle in to your rhythm and establish a cadence where you can maintain power and hold it. Find out if you are a spinner or a masher. If you are a spinner then the higher cadence climbing will suit you better. How much do you weigh?


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## Conviccted (Jan 3, 2012)

I weigh 155 lbs....Should I run them at a lower pressure?,that's what my friend said to run them @ max


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## Propofol (Jul 5, 2005)

Conviccted said:


> Your right maybe I'm rushing into things my friends do have much lighter bikes and I'm gonna wright the gears down on paper it make a lot of sense about the spacing of gears...


Your CAAD 10 is no slouch when it comes to weight. Stock weight is what, maybe 17-17.5lb? Even if your friends are riding 13lb bikes it's not the weight that's making the difference.



> The ultremo zx tires are great,real light and very fast....I run them to the max pressure 145 and they made a big difference, I have 3 friends that are using them also and they all like them a lot


Like the other poster I'm wondering why you are running such high pressures. I'm a clyde and I usually don't run higher than 115.



> I weigh 155 lbs....Should I run them at a lower pressure?,that's what my friend said to run them @ max


Did you happen to ask your friend why? Doing things blindly on the recommendation of others is going to get you in trouble.


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## redondoaveb (Jan 16, 2011)

mimason said:


> I hope you are still not considering changing to a standard crank. It will not help you or make you faster. Alternatively, getting an 11-26 in the rear with the 50/34 it an ideal setup. The 34/26 gives you the low end of a triple and you'll be popping wheelies on steep climbs if you don't balance your weigh forward.
> 
> Getting dropped is not about the crank or the weight of your bike most likely. You may be simply trying too hard on the climbs and you are not riding your ride or pace but theirs. I recommend that you settle in to your rhythm and establish a cadence where you can maintain power and hold it. Find out if you are a spinner or a masher. If you are a spinner then the higher cadence climbing will suit you better. How much do you weigh?


I don't believe Shimano has an 11-26 Dura Ace cassette.


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## bon_gabs (Feb 2, 2010)

or just buy this one,to match your frame,,its all over ebay..

https://a3.sphotos.ak.fbcdn.net/hph...0216502736910_606701909_7658407_3726460_n.jpg


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## Conviccted (Jan 3, 2012)

mimason said:


> I hope you are still not considering changing to a standard crank. It will not help you or make you faster. Alternatively, getting an 11-26 in the rear with the 50/34 it an ideal setup. The 34/26 gives you the low end of a triple and you'll be popping wheelies on steep climbs if you don't balance your weigh forward.
> 
> Getting dropped is not about the crank or the weight of your bike most likely. You may be simply trying too hard on the climbs and you are not riding your ride or pace but theirs. I recommend that you settle in to your rhythm and establish a cadence where you can maintain power and hold it. Find out if you are a spinner or a masher. If you are a spinner then the higher cadence climbing will suit you better. How much do you weigh?


I appreciate the good advice I weigh 155 lbs,what do you think about the 11/28 with my compact crank?


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## Conviccted (Jan 3, 2012)

bon_gabs said:


> or just buy this one,to match your frame,,its all over ebay..
> 
> https://a3.sphotos.ak.fbcdn.net/hph...0216502736910_606701909_7658407_3726460_n.jpg


Wow...thanks nice


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## Conviccted (Jan 3, 2012)

Yamabushi said:


> Why are you running them at such high pressure? How much do you weigh?


I weigh 150-155 lbs ....what should I run them at ?


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## Conviccted (Jan 3, 2012)

Propofol said:


> Your CAAD 10 is no slouch when it comes to weight. Stock weight is what, maybe 17-17.5lb? Even if your friends are riding 13lb bikes it's not the weight that's making the difference.
> 
> 
> Like the other poster I'm wondering why you are running such high pressures. I'm a clyde and I usually don't run higher than 115.
> ...


I think he said it prevents flats and you ride faster at higher psi,what's your opinion....I appreciate the help


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## Propofol (Jul 5, 2005)

Conviccted said:


> I think he said it prevents flats and you ride faster at higher psi,what's your opinion....I appreciate the help


Higher pressures may help against pinch flats and you may ride a little faster, but given your weight and skill you won't feel a whit of difference between 145psi and something more reasonable like 100psi.


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## Conviccted (Jan 3, 2012)

milkbaby said:


> Are you struggling to keep up going UP the hills? If so, then you probably don't want to change your set up other than possibly the cassette. If your pals are riding 53/39 with 12-27t, and you are on 50/34 with 12-25t, your lowest/easiest hill climbing gear (34 front, 25 back) is actually EASIER to spin than theirs (39 front, 27 back). And your cassette spacing is closer, so it may be easier to find the best gear to stay in good cadence than on a wider cassette. The compacts are designed for climbing, so definitely don't go to the larger chainrings!
> 
> Shift more/into the right gear and get into better shape if the above is the case. Your pals are dropping you because they are in better hill climbing shape. If you are having trouble keeping up on the downhills, then disregard... Good luck and enjoy the ride!


Good advice...thanks!


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## redondoaveb (Jan 16, 2011)

Conviccted said:


> I appreciate the good advice I weigh 155 lbs,what do you think about the 11/28 with my compact crank?


Can't answer for Mimason but keep in mind that if you go with the 11-28 your gear spacing is 11,12,13,14,15,17,19,21,24,28. You won't have the 16 that is nice to have. The 12-27 has 12,13,14,15,16,17,19,21,25,27.


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## Propofol (Jul 5, 2005)

redondoaveb said:


> Can't answer for Mimason but keep in mind that if you go with the 11-28 your gear spacing is 11,12,13,14,15,17,19,21,24,28. You won't have the 16 that is nice to have. The 12-27 has 12,13,14,15,16,17,19,21,25,27.


Also if you switch to a 28 you will possibly need to increase your chain length.


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## Conviccted (Jan 3, 2012)

Propofol said:


> Also if you switch to a 28 you will possibly need to increase your chain length.


Yeah that jump from 24-28 is pretty drastic plus I'm already usto the 34/25,that means 34/27 should make a nice difference


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## Conviccted (Jan 3, 2012)

Propofol said:


> Higher pressures may help against pinch flats and you may ride a little faster, but given your weight and skill you won't feel a whit of difference between 145psi and something more reasonable like 100psi.


So is running 145 psi bad or is it just to hard on the body cause you feel the bumps more,I'd figure preventing flats and being a bit faster is good


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## Propofol (Jul 5, 2005)

Conviccted said:


> So is running 145 psi bad or is it just to hard on the body cause you feel the bumps more,I'd figure preventing flats and being a bit faster is good


You will feel bumps more, have an increased chance of an explosive blowout, and you won't be a "bit" faster.

From all of the questions you're asking, it really looks like you're still relatively new at this. Instead of swapping out components, making changes that you don't know will help, and following recommendations from friends without understanding why, it's probably a good idea to just stick with what you have and learn some more. You will save money and lots of grief that way.


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## mimason (Oct 7, 2006)

The poster was correct that Shimano does not have a 11-26 cassette. I run a SRAM 11-26. As far as 11-28 goes I am mixed. I actually have climbing wheels set up with an 11-28 cassette and I rarely ever use the 28. At most I ride the 25(the next ring down the cassette). Also, the 28 requires a significant RD adjustment to get it to work correctly as you will be at the extreme max allowable setup. That's why I like an 11-26. I think you could get an 11-27 if I am not mistaken. 

As far as tire pressure and your weight you can easily run 95 pounds in the front and 100 in the rear. I am 175-180 and normally ride 100/105.


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## Yamabushi (Sep 30, 2008)

Conviccted said:


> I weigh 155 lbs....Should I run them at a lower pressure?,that's what my friend said to run them @ max


With too much pressure you're effectively bouncing down the road. Gliding/floating down the road is faster and significantly more comfortable. To get an idea what pressure you should be running see this chart as an initial guide:Michelin Bicycle USA - A better way forward®


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## Yamabushi (Sep 30, 2008)

Conviccted said:


> Yeah that jump from 24-28 is pretty drastic plus I'm already usto the 34/25,that means 34/27 should make a nice difference


In actuality it's not as big a jump as it seems. I have full size crank and run a 12-28. I am an avid climber and feel the 21-24-28 spread is quite good.




Conviccted said:


> So is running 145 psi bad or is it just to hard on the body cause you feel the bumps more,I'd figure preventing flats and being a bit faster is good


Running too high a pressure will "feel" faster for most people, but the reality is that unless you have an absolutely smooth surface, it is slower than running the ideal pressure. You start to loose the beneficial and desired pneumatic effect with too much pressure and end up bouncing up and over all the imperfections in the road surface. Going up and over all the bumps is wasted energy that could have been used to propel you forward. Of course, conversely, too little pressure has its own set of problems.


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## sneakyracer (Dec 1, 2007)

On grades of about 8% or greater the compact crank is actually an advantage unless you have world class power! then the 53/39 would be sufficient. The 12-25 is a good match to those compact cranks. a 12-27 or 11-28 would help some on the very steep grades (10%+). I have a 53/39 and a 11-28 cassette and only wish for a compact crank on sustained climbs above 10% and I my V.A.M. is about 750.


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## redondoaveb (Jan 16, 2011)

redondoaveb said:


> Can't answer for Mimason but keep in mind that if you go with the 11-28 your gear spacing is 11,12,13,14,15,17,19,21,24,28. You won't have the 16 that is nice to have. The 12-27 has 12,13,14,15,16,17,19,21,25,27.


Oops, made a mistake. The 12-27 actually has 12,13,14,15,16,17,19,21,24,27.


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## lucyfek (Sep 1, 2009)

I can see nothing wrong with existing setup (and no wear judging from pics). I'd keep it until its done. Get yourself better wheels etc (or just keep money). I have DA at front (53 or 52) and have to say that small rear cogs (down to 12) get virtually no use (it's flat where I live). I actually switched to riding in small front gear to "wear level" my drive train (I keep replacing cassettes with middle cogs worn only - what a waste). Besides having more flexible gearing you'll get used to higher cadence (96+ will feel natural, no more grinding). This talk about 32mph maximum speed seems highly hypothetical - I can surely go faster than that without getting into smallest cog, definitely not sustainable speed regardless of gearing (I don't ride behind trucks).
Extreme tire pressure makes no sense - just because the tire is rated for it does not mean that you have to inflate it more than necessary. Also some rims may not like it (check the rating before it's too late).


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## redondoaveb (Jan 16, 2011)

lucyfek said:


> I can see nothing wrong with existing setup (and no wear judging from pics). I'd keep it until its done. Get yourself better wheels etc (or just keep money). I have DA at front (53 or 52) and have to say that small rear cogs (down to 12) get virtually no use (it's flat where I live). I actually switched to riding in small front gear to "wear level" my drive train (I keep replacing cassettes with middle cogs worn only - what a waste). Besides having more flexible gearing you'll get used to higher cadence (96+ will feel natural, no more grinding). This talk about 32mph maximum speed seems highly hypothetical - I can surely go faster than that without getting into smallest cog, definitely not sustainable speed regardless of gearing (I don't ride behind trucks).
> Extreme tire pressure makes no sense - just because the tire is rated for it does not mean that you have to inflate it more than necessary. Also some rims may not like it (check the rating before it's too late).


Lucy, I was using 32.6 as an example. That's what speed you will achieve with a 50/12 @ 100rpm. You can achieve a higher speed by spinning a higher rpm. My point was, an 11 cog is not really necessary for a lot of people, me included. Even downhill, above about 35mph I'm in a tuck and not pedaling so no real need for a taller gear. Take a look at Sheldon Browns Gear Calculator and it will give you real speeds, not hypothetical speed.


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## Shinjukan (Aug 22, 2011)

*max tire pressure*

Just to add to that, running the tire to its max (145psi is the example) might provide resistance to flats, but then the tradeoff is handling. The tire is as hard as wood so the rider is effectively losing that all-important road grip especially when cornering. As one gets more time on the saddle, they'll slowly formulate what setting they prefer, not what others are suggesting.


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