New CX frame and questions!

[Tim O'Reilly]

Hi All,

Finally got my new CX frame, a Kinesis Pro6 kit and now starts the painful job of buying the components.
What I would like to know is, I have decided on a FSA compact crank with 34/50 rings. My qustion is, could I run a Shimano XT 10 speed cassette 34/11 with XT rear mech with the crank and with Shimano 105 STi's, all would be 10 speed stuff, but is this normal behavour? My mate who is into CX has told me to buy a 29/11 cassette, but the 34/11 or possibly a 36/11 cassette would give me a better range for the steep Yorkshire hills.
Thanks.

 

[Alun]

If the rear mech is XT "dyna-sys" then the cable pull will be incompatible with 105 shifters. You need a non dyna-sys rear mech such as a Deore, doesn't matter if its 9 or 10 speed one.

 

[Tim O'Reilly]

If the rear mech is XT "dyna-sys" then the cable pull will be incompatible with 105 shifters. You need a non dyna-sys rear mech such as a Deore, doesn't matter if its 9 or 10 speed one.

Alun, Even if the 105 shifters are 10 speed as well to match a 10 speed rear mech?

 

[Alun]

Alun, Even if the 105 shifters are 10 speed as well to match a 10 speed rear mech?

Yep, Dyna-sys is a MTB system and wasn't designed for 105 (road) shifters. Non dyna-sys MTB rear mechs happen to use the same cable pull as road shifters and are compatible. Obviously a 10 speed cassette needs a 10 speed shifter, but rear mechs can be either 9 or 10 speed. You will need an inline cable adjuster unless the rear mech has an adjuster which the 9 speed Deore does.

 

[Tim O'Reilly]

Thank you Alun!

 

[Howard]

What I would like to know is, I have decided on a FSA compact crank with 34/50 rings. My qustion is, could I run a Shimano XT 10 speed cassette 34/11 with XT rear mech with the crank and with Shimano 105 STi's, all would be 10 speed stuff, but is this normal behavour?
Thanks.

The answer is... it depends. I'd lean towards 'No'.

If you are touring the alps with it, with 50kg of luggage, it's possibly a justifiable choice. In the UK, for general road riding, you'd find the gaps between the ratios very, very irritating. For cross racing it would be a terrible choice as most of the ratios on the little ring would be slower than running.

For road riding stick with a normal road set-up - compact cranks and 11-28 if it's hilly. For cross, go for a cross chainset, 36/44.

 

[Tim O'Reilly]

Thanks Howard!
Another question if I may? What stem length is considered normal for CX and bar choice as riding drop bars is going to be a new experience for me as I only ride flat bars/mountain bikes?

 

[black'n'yellow]

there is no 'normal' length for any stem - you need to work out what is the best length for you.

 

[jdtate101]

Most cross bikes come with a cross specific crankset 46/36 with something like a 11-28 on the back, this give more than enough range to cope with most hills. Now, if you're going to use this mainly on the road and not across fields then a compact 50/34 may give you more range top and bottom, but either will be fully compatible with a 10 speed front and rear derailleur set. Pair these with your 105 shifters and you're good to go.
If your frame supports disc brakes, look at avid BB5 or BB7, if rim brakes look at tektro CR720's. For the stem, one thing to remember is that cross bike geometry is genrally more upright, so don't get a stem that racks you out too much, I think mine is a 90mm. Pair the stem with a good Alu bar like a deda RHM01 or newton should see it complete. Saddle wise, well thats a personal choice, so go with what's comfortable and what you have used before on other bikes.
Tyres....If you are going to use it mainly on road, then look at something like Conti speed kings (good road compromise tyre), or if you want some off road capability then something like Vittoria CX Pro XG's. Wheels....I would get some good, strong 36 hole rims for strength with sealed hubs.

 

[Howard]

Stem length - as above - you want to be aiming for something that gives you an upright posture in comparison to the 'long and low' road bike posture. Start with something short and see how it feels in comparison to your MTB - 70, 80 or 90mm. Make sure the bar you get isn't too narrow or it will make the bike feel twitchy with the short stem. 42 or 44cm if you are a big chap.

This all depends on how well the frame you bought fits you though. Good luck!

 

[Tim O'Reilly]

Thanks All.
Gone for a standard 90cm stem to see how that feels!
I've now ordered my wheels! I've gone for Mavic Open Pro's in silver with red 36 hole Hope pro 2 evo hubs. I've chosen these rims because I wanted a rim that I could swap between road and cross tyres! They are also very versatile and light.
The handlebar will probably be wider rather than narrower.

 

[black'n'yellow]

most road rims will take a cross tyre without issue...

 

[Tim O'Reilly]

Now got most of the parts except the wheels which will be ready next week.
A few pictures to take the Michael.

 

[Tim O'Reilly]

If the rear mech is XT "dyna-sys" then the cable pull will be incompatible with 105 shifters. You need a non dyna-sys rear mech such as a Deore, doesn't matter if its 9 or 10 speed one.

I ended up with this mech. I'm not sure if this is Dyna-sys? The info on the mech doesn't mention it.

http://www.chainreactioncycles.com/Models.aspx?ModelID=20698

 

[Alun]

I ended up with this mech. I'm not sure if this is Dyna-sys? The info on the mech doesn't mention it.

http://www.chainreactioncycles.com/Models.aspx?ModelID=20698

That should be OK, Dyna Sys are 10 speed like this one, http://www.chainreactioncycles.com/Models.aspx?ModelID=83162
You'll probably need an in-line cable adjuster !