I need some techie advice on shimano cassettes

[geoff m]

Some good specials on Wiggle. I am updating all my Ultegra stuff. Chain, front chain rings and cassette. 10 speed.

There are different Ultegra number series. Eg. Ultegra 6600, 6700 and 6500 etc, series. I think from memory 6600 is the right ones but I can't remember why.

Also, I'm definitely after a cassette with 25 ratio. I have choice between 14-25 and 15-25? I understand the 25 but not the significance of 14 or 15?

Can anyone help me on these?

[geoff m]

I just checked my current cassette. Its 12t-25 6600.

I do find especially on the mad mile I quickly run out of gears when racing at great speed.

25 I'm happy with for Artillery Hill. Much better than 23

Any thoughts

[weiyun]

There are 11-25 cassettes and you may want to consider them. Slightly wider gap for one of the steps, but perfectly liveable.

[geoff m]

So the lower the number at the pre-fix, the harder I can ride at high speeds?

If I'm 12 now and finding I'm running out of gears at high speed, then 11 is a bit better?

If so then 15 would be way to high? Also, what's the difference say in 6600 cassettes and 6700 cassettes which are a bit more expensive? ANd would I need a 6700 chain instead of 6600.

Weiyun, wasn't surprised you were first to come in with techno info...thanks

[geoff m]

OK problem solved. I rang Mr T-Bone. 6700 is a later model for Ultegra, bit more expensive, and slightly better.

I should be going with 12-25 or even 11-25.

[mikesbytes]

I run 11-25 cassettes (9 and 10 speed), but it does boil down to personal preference. For me the 11 provides significant benefit over the 12 from about 70kph. I don't notice any gaps in the gearing, even on the 9 speed.

However everyone is different, its a personal choice

[weiyun]

Correct, 11 (smaller cog) will give you a higher ratio for those ultra-fast sections. Whether it'll be better or not will depend on whether you have the leg power to push that gear ratio. 25 will allow you to spin more on Artillery Hill.

[mikesbytes]

Forgot to mention my figures above are based on 53T chain ring. If you are running a 50T, then the 11 will kick in a bit earlier.

[christian]

You don't even need to use Shimano parts, SRAM cassettes have the same spacing so are interchangeable. I'd check the price on the SRAM PG1070 as well. As for chains, you can use SRAM, Shimano, or any number of others. I've been using a YBN SFL101-DHA on my road bike and its been pretty bullet proof so far. You get the locally from http://www.yaban.webs.com/

[geoff m]

Thanks all,

I ended up getting Ultegra 6700 cassette 11T-25, and 6600 chain and 6600 big ring (52T only one available) and 6600 little ring. Whilst I was there I picked up some swimming goggles.

That should give me a bit more oomph at mad mile. Apparently 52T big ring and 11-25 cog is much better than 53T big ring and 12-25 cog.

So there you go........

I wonder what your technical views of the swimming goggles I bought - 1 x Zoggs Odyssey Max Goggles Smoke/Metallic Blue. I'm sure the triathletes will know about this one.

[Karzie]

1 x Zoggs Odyssey Max Goggles Smoke/Metallic Blue

Won't the smoke get in your eyes?

[Eleri]

Geoff if you are ever bored and want to work this stuff out yourself you can always go to http://www.sheldonbrown.com/gears/ enter your ring and cluster sizes, crank length and wheel size and away you go. Cut and paste into a spreadsheet and you're laughing. If you are like me, you won't remember any of the numbers later.

Amazingly, someone has given the site a big makeover. Presumably not Sheldon Brown himself.

[Karzie]

Amazingly, someone has given the site a big makeover. Presumably not Sheldon Brown himself.

"Web site by Sheldon Brown
Lovingly maintained by John Allen and Harriet Fell"

[geoff m]

Thanks guys for all the advice for basic blokes like me