Groupset help please - all these numbers are baffling me!

[Tojo]

No one else has mentioned so I thought I'd just make it clear that Shimano 11 speed rear derailleurs have a different pull ratio to earlier derailleurs, so you can't use an 11 speed derailleur with a 9 or 10 speed lever and vice versa. (however there may be cable routings or devices that do make this possible but I've not come across them yet.)
According to Leonard Zinn (on Velonews website) all the 11 speed cassettes are interchangeable, and chainsets/front derailleurs will almost always work to a greater or lesser degree.

Yes,11sp has a shorter pull ratio on the cable each time you index because it has a narrower chain and the cassette spacing is also narrower, now though with 11sp it is cross compatible to an extent as in chains so therefore the sprockets have the same pitch, but I'm not quite sure about indexing as earlier Campag had different spacing on their cassettes, so therefore their shifters will take up a different amount of cable each shift. I haven't got enough money to experiment with Campag chainset and front DR and say Shimano rear set up..funds or just a build up of bits and bobs I come across may allow me in future...!
I think the cable routeing device you mention was like a pulley system that you fitted to to a Shimano RD to be able to run a campag cassette (or vice versa.. sorry cant remember) but that was pre 11sp, Also type this into google......shimergo.....!. Enjoy....Oh I just do love mechanical things.

 

[migrantwing]

I'm curious too as a lot of people have went back to 10sp as 11sp can be a bit finicky to set up and keep running right because of the closer tolerances....!. Cable run /routeing is different on frame to frame, maybe that is due to that deduction rather than the components of the groupset itself....! Also a big problem with any groupset is kinked outers/pinch points and using the wrong cabling..!

@Tojo

I run crossover on my 105 to alleviate sharp bends/kinks. I run the cables to opposite sides of the headtube, then crossover under the BB. Seems to shift great to me.

I realise that with the later version of 105 (5700) compared to the previous version (5600) the cable routing became 'aero' and routes under the bar tape. I don't know how shifting compares to 5600 as I haven't used 5600 enough to notice a difference.

 

[MichaelW2]

Back to the orignal question, you need a way of comparing the gear ratios and range given by all manner of different combinations of chainrings and rear sprocket clusers.
In the cycling world we do this by using "Gear Inches". This accounts for the size of the chainring, sprocket and wheel diameter, so you can compare 700c wheeled bikes to 20" folders.
Sheldon's calculator also includes a factor for crank length, which is useful but generally ignored.

Using graph paper or Excel, you can work out the "gear inches" of every combination in a transmission system, and note the overlaps.
Which gear inches you choose are a personal matter depending on strength, terrain, load. The aim is to maintain a fairly constant cadence/work-rate, and let your speed vary as it wishes. Gears can't make you any faster, only muscles do that.

 

[sabian92]

Just as a quick update - I've discovered that my current bike (a rather uncomfortable Carerra Virtuoso...) runs 12-25 at the rear and 50-34 at the front, so at least now I know where I'm aiming around (and below). Apparently according to bikecalc.com I should be flat out at 30mph using the top ratio (50x12 or something... I think), and even downhill I can't do that so for the time being it's far, far too high. Considering I'm carrying an extra 6st in weight as well (hence wanting lower gears so I can actually pull my own fat arse up a slight incline as I'm so unfit ) then lower ratios are what's needed I think.

I'm umming and ahhing over 105 or Deore XT - I haven't decided on flats/drops yet so I need to work out what direction I'm going in first.

 

[Eurostar]

Bear in mind that MTB rear hubs are longer than road ones. In other words the Over Lock Nut (OLN) measurement is greater. Check the Shimano site. I've been told that if the frame is steel and the difference is only 5mm it's not an issue, you just push the stays apart and muscle the hub in there. Probably best to check this with someone who really knows.

Edit: just looked at the Surly site and the Disc Trucker is built with XT rear hubs in mind, with 135mm OLD. Does that mean that all our discussions about 105 are irrelevant? Have a read of the Spacing section here http://sheldonbrown.com/frame-spacing.html. Maybe you just add some spacers.

 

[boydj]

If you need more teeth at the back you could always go for a Tiagra 12-30 cassette.

 

[sabian92]

Bear in mind that MTB rear hubs are longer than road ones. In other words the Over Lock Nut (OLN) measurement is greater. Check the Shimano site. I've been told that if the frame is steel and the difference is only 5mm it's not an issue, you just push the stays apart and muscle the hub in there. Probably best to check this with someone who really knows.

Edit: just looked at the Surly site and the Disc Trucker is built with XT rear hubs in mind, with 135mm OLD. Does that mean that all our discussions about 105 are irrelevant? Have a read of the Spacing section here http://sheldonbrown.com/frame-spacing.html. Maybe you just add some spacers.

I didn't know that, bloody complicated bikes! Not entirely irrelevant, I can still use XT hubs with a 105 though can't I?

 

[Eurostar]

Dunno...this is making my head hurt. Will the 105 cassette attach to the XT freehub? I would have thought not. Plus there's the question of what shifters you can use. You could google "mixing 105 with XT". And look up the dimensions and diagrams of freehub and cassette on the Shimano site. Ask someone here more knowledgeable than me - maybe start a new thread. Or ask a Surly dealer. Or go to the yacf forum and ask there - one of them is bound to know.

Also have a look at the components which Surly fit to the bike http://surlybikes.com/bikes/disc_trucker/bike_specs There might be some clues there as to what's possible.

 

[MichaelW2]

I mix Tiagra 9 with LX hubs and Deore rear mech.
The MTB front mechs are not compatible with road levers.

In Shimanoland, 9 is 9, but 10 road is different to 10 MTB.

"It is correct that a Shimano 10-speed MTB rear derailleur will not work with a Shimano 10-speed road shifter. And you definitely cannot expect a 10-speed shifter to work with a nine-speed cassette. However, you can use a 10-speed cassette and 9-speed Shimano MTB rear derailleur with your 10-speed 105 shifter (and a 10-speed chain)."
― Lennard Zinn

 

[Nigelnaturist]

This what I did with my 105 5700 triple, I got a Compact triple chainset from Spa which is a light as the 105 triple but standard BCD 74/110, which means I can fit virtually any chain ring I want, it is currently fitted with a 26/38/50 and a 12-27 cassette giving a range of 25-110" approx, as @Eurostar pointed out, I spin on the 38x15-19 range and have just got 3,500 miles out of my last chain, (with virtual no noticeable wear). My next cassette will be 12-23 on the same set up, giving 30-110" or a 34x30 the reason is I hate the gap between 17-19 and I hardly use the 38x27 combination, if I am that low I will be using the inner ring as I have better choices, i.e. 26x16-19, and round here thats as low as I usually go and thats spinning up hill.

 

[Eurostar]

It's horses for courses, innit? Sabian, if your current cruising speed is 10-12 mph it's probably safe to say that when you have lost the weight and are fitter your cruising speed will be 14-17. In all honesty those are fairly low speeds compared to the roadie/club member type who cruises at 20-22 mph and sprints at 30. That's who 105 is designed for. 105 is just Dura Ace but lighter, and Dura Ace is what the pros use. So don't be surprised if you can't get closely spaced cruising ratios with 105. Many of us (me included) use some MTB components on our touring bikes for this reason. (I have MTB cranks with an old Dura Ace cassette). Look at Nige's post above - he's mostly on a 38T ring, and he's about to change his cassette because he's fed up with not having an 18 cog between his 17 and 19. So forget about a big chainring, focus on a cassette with only 1 tooth gaps at your cruising speeds and you'll be happy as larry.

 

[sabian92]

Scrambling my own brain with this stuff!

I might just go for XT stuff all round - saves having to find out what mixes and matches, gives me the option of discs that won't bankrupt me, plus the gearing is lower (and after my little fact finding yesterday with my current bike the gearing would be the same on a heavier bike, although admittedly with smaller wheels) and it's slightly cheaper anyway.

Still, I've learned a lot about gearing even if I don't end up using 105 so thank you very much to those who contributed.

 

[Sunny Portrush]

Yeah, Ive just read this thread and my brain hurts. Just come back from doing alot of climbing on the Bealach Beag and whilst I was pleased with my speed on the flats and on descent, my climbing ability was power-puff lol. As far as I can work out, the cassette is 12-30 and the chainset 50/35 so I have no idea if they ate good for climbing.

Someone will probably point out that these are the easiest possible combinations and that I just haveto train harder for next year lol

 

[raleighnut]

You need a triple on the front.

 

[uclown2002]

You need a triple on the front.

Or you could take the advice on your other thread; ride your bike more and lose some kilos.