Going somewhere hilly - what to swap?

[mountainrman]

Am going somewhere with substantial hills and thinking of taking my Boardman Pro Carbon with me. It is based on the air 9 frame, with ultegra 6700 , Fsa Energy 53/39T and standard 12/25 cassette, which is fine for I where I live.

Am wondering whether to swap the 53/39 for a triple 53/39/30 , and wondering how hard it is to set up with the Ultegra mech I have. Is it straightforward or should I leave it to a bike shop?

Alternatively wondering whether to swap for an 11/28 instead. Or as well maybe?. Which would others do? The 12 seems limiting on serious downhills.

I tend to hire bikes abroad rather than pay for shipping.which in hilly places already tend to have a triple, so more used to a triple than a bigger cassette.

Any help appreciated...

 

[King Boonen]

If you're running a double I'm 99% sure you can't run a triple with the levers that will be on your bike, you'll have the 6700 levers on the bike but you need the 6703 to run a triple, same with the front derailleur.

Is the 12 really that limiting? I'd maybe look at the 12-30, that low gear will come in handy, particularly at the end of a long hard day. I think you'll be more thankful for having the 30 than regretful for not having the 11.

 

[mountainrman]

If you're running a double I'm 99% sure you can't run a triple with the levers that will be on your bike, you'll have the 6700 levers on the bike but you need the 6703 to run a triple, same with the front derailleur.

Is the 12 really that limiting? I'd maybe look at the 12-30, that low gear will come in handy, particularly at the end of a long hard day. I think you'll be more thankful for having the 30 than regretful for not having the 11.

Thanks for that.
I never knew such a big cassette existed outside mountain bikes!
Presume a standard 6700 mech can handle it?
That will probably do the trick: Gives me 20% more "granny gear" - thanks.

 

[King Boonen]

Thanks for that.
I never knew such a big cassette existed outside mountain bikes!
Presume a standard 6700 mech can handle it?
That will probably do the trick: Gives me 20% more "granny gear" - thanks.

I found it on wiggle and Merlin, it is pretty big!

Gear spacing in the cassettes should be exactly the same, so you may not even need to fine tune the rear mech after replacing it. always ask at the point of sale to make doubly sure, you never know when something might change, Merlin are very good for helpful advice but yes, I'm sure it will work absolutely fine.

Enjoy the trip, I'm jealous!

 

[Giuseppe Magnetico]

Converting to a triple you'd need a new front shifter, BOTH front and rear derailleurs, and a new crank. A 6700 short cage rear der max cog is 28t. The solution to your conversion without having to go triple is the 11-28 cassette, and a compact crank. You give up descending gears, but it seems your main concern is to be able to go up easier instead of come down faster. Even living here in the Rockies I have no need for anything more than 50-11 on the descents, rarely get above 45mph before you have to downshift into the next turn anyway.

 

[mountainrman]

Converting to a triple you'd need a new front shifter, BOTH front and rear derailleurs, and a new crank. A 6700 short cage rear der max cog is 28t. The solution to your conversion without having to go triple is the 11-28 cassette, and a compact crank. You give up descending gears, but it seems your main concern is to be able to go up easier instead of come down faster. Even living here in the Rockies I have no need for anything more than 50-11 on the descents, rarely get above 45mph before you have to downshift into the next turn anyway.

Thanks for the experience.

Hadn't realised I would need to change the rear mech to use a triple out front.

Useful to know it works in the Rockies, so I am thinking a bigger cassette is the answer - the shimano 28/11 was the one I knew about, , that 11 certainly has enough high end speed - a bit more than I have.

 

[Giuseppe Magnetico]

Thanks for the experience.

Hadn't realised I would need to change the rear mech to use a triple out front.

Useful to know it works in the Rockies, so I am thinking a bigger cassette is the answer - the shimano 28/11 was the one I knew about, , that 11 certainly has enough high end speed - a bit more than I have.

Yep, the short cage der only has so much range that it can effectively take up the massive amount of chain slack required for the granny gear, so the GS cage der is required.

Just yesterday I modified my 11-28 Ultegra to a 12-28, got rid of the 11t and added a 16t from a different cassette which is absent from the stock 11-28. There's just some things I can't live without..

 

[rph1960]

Going 25 to 28 not alot of difference. Definitely get compact 34/50 with 11-28. I run this on road/TT bikes no problem. Can never have low enough gear in mountains. Amazing how much I use 16t as GM said above.

 

[rgmerk]

Other options

If you need even lower gears than that, Shimano have now released the RD-5701 rear derailleur (105-level), which officially supports running a 10-speed 11-32 (or 12-32) rear cassette. It should work with any Shimano 10-speed road setup.

Might be useful if you need even lower gearing for some particularly brutal climb, or if you don't want to go to the expense of a new crank. Compromise is big gaps between ratios, of course.

 

[richwagmn]

Yep, the short cage der only has so much range that it can effectively take up the massive amount of chain slack required for the granny gear, so the GS cage der is required.

Just yesterday I modified my 11-28 Ultegra to a 12-28, got rid of the 11t and added a 16t from a different cassette which is absent from the stock 11-28. There's just some things I can't live without..

This used to be easier before Shimano starting riveting some of their gears together.

Does Shimano still stamp their cogs with letters indicating compatibility? I seem to remember the 7spd cassette cogs being stamped with letters which would let you build custom cassettes assuming you could match the letters (some had 3 letters stamped on them).

 

[Giuseppe Magnetico]

This used to be easier before Shimano starting riveting some of their gears together.

Does Shimano still stamp their cogs with letters indicating compatibility? I seem to remember the 7spd cassette cogs being stamped with letters which would let you build custom cassettes assuming you could match the letters (some had 3 letters stamped on them).

Largest 3 cogs are stamped together, the rest are singlets.

 

[dsut4392]

Agree with the compact crank recommendation. Ride it with your 12-25 first to see if you even need a bigger cog on your cassette.

We live at the base of a 1270m climb (average grade only 5.7% but some significant stretches at 10% and a few hairpins much steeper) and my wife seems happy with her 11-25 and 34/50 combo. Even though 25/34 is only 6% lower than the 27/39 low gear I have on my bike with a standard crank, the difference is noticeable on the bike.

 

[42x16ss]

Agree with the compact crank recommendation. Ride it with your 12-25 first to see if you even need a bigger cog on your cassette.

We live at the base of a 1270m climb (average grade only 5.7% but some significant stretches at 10% and a few hairpins much steeper) and my wife seems happy with her 11-25 and 34/50 combo. Even though 25/34 is only 6% lower than the 27/39 low gear I have on my bike with a standard crank, the difference is noticeable on the bike.

The other thing I've noticed with compact cranks is that even though there may be little or no difference in the rollout of your lower gears, the perceived exertion is less with compact cranks as you are turning a slightly smaller chainring.

 

[winkybiker]

Amazing how much I use 16t as GM said above.

I gave up having any clue about precisely what gear I am in since I got more than 6 sprockets at the back and moved to STI.

 

[dsut4392]

The other thing I've noticed with compact cranks is that even though there may be little or no difference in the rollout of your lower gears, the perceived exertion is less with compact cranks as you are turning a slightly smaller chainring.

I think that must be psychological - If the gear inches are the same and the crank length is the same, physics says the size of the chainring makes no difference [excluding negligible differences in chain friction].

NB this does not necessarily hold for suspension bikes which have a pivot point that is not concentric with the BB. In designs where compression of the suspension leads to "chain growth", variation in the angle at which that tension is applied will have varying effect on extension of the suspension. This can affect drivetrain efficiency as the bike may be more prone to "bobbing" in small chainring vs larger chainring even given the same gear inches.

 

[42x16ss]

Possibly, I wouldn't rule it out. I'm just going by my own experience. I think the late great Sheldon Brown had some kind of theory regarding this.

 

[mountainrman]

Thanks all - advice appreciated.
I am tempted by the combination of dropping to a compact 50/34 with a 28/11 on the back to give me the granny gear and also get back high end speed lost when I lose the 53., and as someone suggested will take it to some local hills and try it with the 25/12 before changing the cassette. I am not confident enough to go messing with the cassette build, but maybe consider that later!

I was amazed by the variety of gears used by the Tour of Romandie uphill trial. Froomey was using a 56 up front?? Did I mishear that? - don't think I have seen a gear that big.

 

[King Boonen]

Check out Tony Martins chain ring at the London Olympics...

 

[Bustedknuckle]

Am going somewhere with substantial hills and thinking of taking my Boardman Pro Carbon with me. It is based on the air 9 frame, with ultegra 6700 , Fsa Energy 53/39T and standard 12/25 cassette, which is fine for I where I live.

Am wondering whether to swap the 53/39 for a triple 53/39/30 , and wondering how hard it is to set up with the Ultegra mech I have. Is it straightforward or should I leave it to a bike shop?

Alternatively wondering whether to swap for an 11/28 instead. Or as well maybe?. Which would others do? The 12 seems limiting on serious downhills.

I tend to hire bikes abroad rather than pay for shipping.which in hilly places already tend to have a triple, so more used to a triple than a bigger cassette.

Any help appreciated...

First, is the LH shifter double only or triple/double?

Need a new front der for a triple. You can 'make due with a shoft5 cagerder with a triple but you get droopy chain in small/smallish combos so that you have enough chain length for big-big.

Cheapest is just get a shimano 12-30..for more $, get a compact crank(50/34 and then use a 11-28. No need to change any derailleurs.

 

[durianrider]

I can hold 5.88 watts per kg for 10mins. I run a 50/34 with a 12/28.

Contador often runs a 34x32.

Ive riden most of the big cols with a 39x21 whilst wearing a 10kg back pack. I got up em cos Im fit and carbed up BUT would have been better enjoyed had I not had to grind my knees up every col I rode that trip.

Because I use a power meter I can objectively say that my preferred climbing cadence for peak wattage output is 80+. I like to ride steep climbs and climb with power that drops everyone else but the pro's I train with. Compact cranks let me hit my sweet spot cadence to produce that power again and again.

Remember if you run sram road shifters that you can use a sram mountain bike RD to get even higher cassette ratios. Use the gears that let you sit above 80+ or just grind your knees up the climb and make it a less enjoyable trip.

 

[Bustedknuckle]

Yep, the short cage der only has so much range that it can effectively take up the massive amount of chain slack required for the granny gear, so the GS cage der is required.

Just yesterday I modified my 11-28 Ultegra to a 12-28, got rid of the 11t and added a 16t from a different cassette which is absent from the stock 11-28. There's just some things I can't live without..

6700 RD handles the ultega 12-30 w/o issue.

 

[ustabe]

If you need even lower gears than that, Shimano have now released the RD-5701 rear derailleur (105-level), which officially supports running a 10-speed 11-32 (or 12-32) rear cassette.

Following SRAM's marketing lead, I see.

With a 34/32 combination you'll be able to climb trees. Even a 39/32 will be pretty low. Just be sure to watch your chain length.

 

[Bustedknuckle]

Following SRAM's marketing lead, I see.

With a 34/32 combination you'll be able to climb trees. Even a 39/32 will be pretty low. Just be sure to watch your chain length.

I think mostly because for 11s Ultegra, shimano has abandoned the triple, and sram never had one. When 105 goes to 11s, the triple will leave with that one as well. At least Campagnolo makes triples, just re-introduced in 2012..a good thing, even an 11s.

sram can barely manage front shifting with a double, let alone with a road triple.

 

[Giuseppe Magnetico]

6700 RD handles the ultega 12-30 w/o issue.

No thanks, I'll sick with my 12-28. Was never a fan of maxing out B-limit screws to stuff massive cogs back there that rarely get used.

 

[42x16ss]

Following SRAM's marketing lead, I see.

With a 34/32 combination you'll be able to climb trees. Even a 39/32 will be pretty low. Just be sure to watch your chain length.

34x32 is utter overkill unless you are climbing Angliru or Zoncolan. Or riding a MTB.

Didn't Cobo use 34x32 on the Angliru in 2011?