11-28 SRAM Cassette

sweep

Hi all,

I am thinking about buying a Planet X Sportive Ti which comes with a Shimano R600 Chainset 50/34 170mm, Shimano Ultegra 10 Rear Mech and Shimano 105 10spd Speed Cassette 12-25.

http://www.planet-x-warehouse.co.uk/aca ... Large.html

I would primarily be using the bike for 100/200/300k audax and sportive rides.

I am not sure that the lowest ratio of 34/25 would allow me to tackle some of the hills on these rides comfortably, particularly 200k into a longer ride.

I notice that SRAM do a Shimano compatible 11-28 cassette which would give me something approaching the lowest gear of 30/25 provided by my current bike (triple chainset).

Would I just be able to replace the 12-25 Shimano cassette with the 11-28 SRAM one or would I need a new rear mech etc?

I guess a slightly longer chain would be required but should everything else be ok?

dennisn

I'm thinking that your thinking is OK. Should work.

Dennis Noward

antfly

A better idea would be to have a mountain bike rear mech put on then you could go down to 34, 25 to 28 is hardly worthwhile.

nickwill

antfly wrote:

A better idea would be to have a mountain bike rear mech put on then you could go down to 34, 25 to 28 is hardly worthwhile.

On the contrary, you would find a major difference with a 28 sprocket on the back. With that and a compact you should get up anything!

antfly

Well the difference would be 12% but it just depends how good he is on hills.I know I need my 32 ring.

dennisn

Nickwill wrote:

antfly wrote:

A better idea would be to have a mountain bike rear mech put on then you could go down to 34, 25 to 28 is hardly worthwhile.

On the contrary, you would find a major difference with a 28 sprocket on the back. With that and a compact you should get up anything!

I'm with you. Going from a 25 to a 28 is very helpful. I have gone so far as to put a 33 tooth front ring on my compact. Athough a mountain bike rear mech would certainly get you a whole bunch more gearing. Still, I have done a far share of climbing in the Colorado Rockies and find that my 33-27 tends to get my fat *ss up prettty much anything and I am not a climber by any stroke of the imagination.

dennis noward

antfly

What sort of incline are you talking in the rockies?The hills here might be low but a lot of them are pretty damn steep compared to other places.

antfly

Well seeing as you didn`t answer I did a little research and they don`t look very steep,the hills there, {correct me if I am wrong} typically 7% with a very maximum of 14%.We have hills here over 30% and over 20% is pretty common.

dennisn

antfly wrote:

What sort of incline are you talking in the rockies?The hills here might be low but a lot of them are pretty damn steep compared to other places.

Most of the major passes are not overly steep, just very long and lots of switchbacks.
However, some of the "back" roads can be very steep. So steep in fact that they make you wonder how they were paved. But overall most of the roads need to accommodate
big truck rigs and 10% seems to be about as steep as trucks can go safely. At least that's what I'm told. Altitude is another factor. With most passes being at least at the 10,000 foot mark and a few over 12,000 feet, all the gearing you've got is often needed.
It feels so good to decend for a really high altitude down to say 8000. You can breathe again and start to come back from the dead.

Dennis Noward

Nuggs

You'll be fine.

My Roubaix had a 105 group set and a, 11-28 SRAM OG cassette.

TheStone

I have 50-34 and the SRAM 11-28 on my Ultegra setup. Works fine.