technical question.

[gavroche]

I have a Specialized Allez Triple with a 13-26 cassette and wonder if it is possible to change it to a 11-30 cassette to make it easier for hills. Would it affect the derailleur workings and would I need another chain? Thank you for your input and technical knowledge.

 

[simon.r]

A very similar issue discussed here: http://www.cyclechat.net/threads/gear-ratios-and-chain-sizing.120846/#post-2236012

 

[Broadside]

I have a Specialized Allez Triple .

I am guessing that as you have a triple you will already have a long cage rear mech, you should check the max cassette size that the mech can handle, check it in the relevant Shimano Tech Doc for your specific mech but I expect it will be fine. Always worth checking first though :-)

 

[MattHB]

I've run a 30 on a 105 with no troubles at all, I don't know what mech you have but I'm sure it'll handle it. IIRC shimano say the 105 will take upto 28, so clearly there's some flexibility in their warnings. Just check chain length and that you have the B screw adjusted properly for clearance.

 

[mcshroom]

You will need a new chain though as it needs to be longer than you currently have.

 

[Peteaud]

I am running a 30 on a 9 speed tiagra with no problems, ive even had a 32 on (there is a post on here somewhere about it with pics) so you should not have a problem.

You will need a new chain and worse case a new rear mech, such as a deore.

 

[gavroche]

Thanks everyone. I will go to my lbs sometime next week and make further inquiries with them, including costs and report back to you with the information.

 

[gavroche]

Been to my lbs and had new shimano 11-30 cassette fitted, new chain and bought a new tube as well, all for the price of £60.00 including labour. I am very pleased with that and can't wait to try it out now. The front rings are 52-42-30 and the lady in the shop assured me I should be able to tackle anything now. I told my legs and hope they got the message!

 

[Peteaud]

Been to my lbs and had new shimano 11-30 cassette fitted, new chain and bought a new tube as well, all for the price of £60.00 including labour. I am very pleased with that and can't wait to try it out now. The front rings are 52-42-30 and the lady in the shop assured me I should be able to tackle anything now. I told my legs and hope they got the message!

In low you are at 1:1 ratio so yes that should get you up anything.

 

[simon.r]

In low you are at 1:1 ratio so yes that should get you up anything.

Or, Schlumpf will do you a 27t ring on their mountain drive, which is equivalent to a 11t. Couple that with a 32t sprocket. Now you'll be able to get up anything