Compact Double to Triple

TinyExplosions

Right, mostly I'm doing research, but it's not entirely out of the quesation that I may want to upgrade to a triple at some point. My Focus has Ultegra shifters and Derailleurs, and a 10 speed rear casette. Would I be right in thinking that I could pick up an ultegra triple crankset and stick it on with no problem at all, or is there something hidden I don't know about? Would I need a new bottom bracket as well or not?

(I don't need a debate on whether this is a good or bad idea, just really looking for the techie advice )

tunney

Surely you mean downgrade to a triple

New shifters (only come in pairs) - expensive
New crankset.

Not sure on the BB but maybe.

I don't understand why people change to triples. If you constantly ride hilly get a compact, or a 27 on the back.

penexpers

The shifters are expensive alright. Would you need to buy a whole new crankset? I thought you could just bolt the granny ring onto the existing crankset?

kenmc

yeah it depends on if you have a triple or double shifter already....
possibly also a new front mech if it doesn't have the travel.
Maybe a new chain depending on the size of the new chainwheels.
possibly also a long-cage rear mech.
The BB might need to be changed to give the clearance on the frame for 3 chainwheels - i.e. to push the chainwheel out far enough.
$$$$$$$

TinyExplosions

The front mech, and the shifters are all Ultegra which (as far as I know work just fine for triples as doubles)

It's more of a thought exercise than something I'm actually going to do, but I was curious as to what is involved!

Hermy

Ultegra front derailleurs are numbered 6600 for doubles and 6603 for triples. I know this after wasting an entire day trying to set up a derailleur made for a double on a triple crank set. The shop that supplied me didn't know there was a difference!

kenmc

TinyExplosions wrote: »

The front mech, and the shifters are all Ultegra which (as far as I know work just fine for triples as doubles)

It's more of a thought exercise than something I'm actually going to do, but I was curious as to what is involved!

Not quite, depends on the 'model' of ultegra - there's different shifters for doubles (ST6600) and triples (ST6603). Same with the deraileurs as Hermy pointed out.
See here for compatability charts.

Raam

What is the ratio of your cassette?
12/27 would be more than enough with a compact.

niceonetom

this triple talk is madness. madness i tell you. no good can come of it.

honestly - i have the same ratios as you, tiny, and i have yet to need the 27, exactly what mountain are you intending to climb? K2?

edit- and think of all the other lovely upgrades you could make for the money...

sorry, i know you weren't looking for a us to talk you out of this 'upgrade' but my techie advice goes no further than: don't.

TinyExplosions

Cheers for all the replies folks... like I said though, It's not something I'm looking to do, just something I was wondering about... don't worry, I'm staying a compact double man

blorg

Tiny- I have a Focus Cayo Triple; you'd be welcome to try it out on some hills if you like (what size are you? I've got a 58.)

Generally a different cassette is the first suggestion but the Cayo already has a 12-27 on the back so your only option would be the 11-28 that SRAM do (certainly worth a try before you consider the triple; a lot cheaper and would also give you more on the high end.)

I got a triple as I was used to it and wanted less of a jump between the rings on the front. When I change the front I shift maybe 1 or 2 at the back for an acceptable change and I felt the space between 34 and 50 was a bit extreme. This was really the key issue.

In terms of the lowest gear, I find I really don't need it- I am more than OK even on the steepest climbs with my second lowest, 30-24, which is almost exactly equal to the lowest on the compact (34-27.) On the other hand the 30-27 does allow me to spin up 15%+ gradients at the same cadence I would be using on the flat. I could also see it being useful towards the end of a long cycle when I'm wrecked; I cycled past a fair few double-equipped walkers on Slieve Mann during the W200.

I didn't really see a lot of disadvantage; the weight difference is neglible, and weight only matters when you would most benefit from the triple in any case. Shifting is fine although I can believe that a compact is a bit better, and easier to adjust. Q factor I was used to. A compact does look better, no question. If I was going again, I think I might try the compact, it was a close decision.

One thing I would consider on my own bike would be swapping the big ring for a 52 or 11.25 at the back as I do find myself spinning out with 50.12 on descents or with a strong tailwind (have a 52 on another bike.) Not a frequent problem though! This would be an advantage the triple would have over the compact.

I would be very slow to change a compact for a triple though (or vice versa) - it's a lot of stuff needing changing and would be expensive. All this would only inform the decision if buying new, otherwise I'd just stick with what you have (other than tweaks like the cassette, etc.)

bunnygreen

Nice one Blorg,at last some rational response to the old triple chestnut.

niceonetom

blorg wrote: »

...I do find myself spinning out with 50.12 on descents or with a strong tailwind...

i've found that too, and i've considered getting the sram 11-28 cassette because of it, though i don't think i'd use the 28 much. i think i really want an 11-26, but there's no such thing as far as i can see.

Question:
do any of you know what would be necessary to go from a compact double to a standard double? is it simply a question of new chainrings and moving the front dérailleur up the seat-tube a bit- or would it be more difficult? this is an academic enquiry, i doubt i'd actually do it.

TinyExplosions

niceonetom wrote: »

i've found that too, and i've considered getting the sram 11-28 cassette because of it, though i don't think i'd use the 28 much. i think i really want an 11-26, but there's no such thing as far as i can see.

Question:
do any of you know what would be necessary to go from a compact double to a standard double? is it simply a question of new chainrings and moving the front dérailleur up the seat-tube a bit- or would it be more difficult? this is an academic enquiry, i doubt i'd actually do it.

Academic queries don't seem to matter round here mate

blorg

niceonetom wrote: »

Question:
do any of you know what would be necessary to go from a compact double to a standard double? is it simply a question of new chainrings and moving the front dérailleur up the seat-tube a bit- or would it be more difficult? this is an academic enquiry, i doubt i'd actually do it.

I think most compact chainsets use a 110 bolt circle diameter (BCD) while standard doubles use 130 so you might have issues finding standard chainrings with a 110 BCD. In that case you'd have change the whole chainset including the cranks. Other than that I don't think you would need to do anything other than get a slightly longer chain. The front derailleurs are the same, with a 16 tooth range. You might want to swap the rear derailleur for one with a shorter cage to get some of the improved shifting benefits but this would be optional. Note this answer is also "academic" and open to correction by someone who has actually done this!

Chips Lovell

Most people just just swap out the entire cranksets, because as blorg said, there's usually different bolt circle diameters between compact and full size sets. Having said that, I think you can get bigger rings with 110 BCD, but you'd have to check that. Aside from that, nothing else really needs to be changed.

niceonetom

thanks, that's good to know should i miraculously develop into a racer type person. you never know. Ultegra HT cranks are only about €100 euro so it would be a cheap move to make.

trek climber

Apologies in advance if this seems a silly question - but what is the difference between a standard double and a compact double ??

niceonetom

basically a standard double has bigger chainrings (usually 52 and 39) and a compact has smaller ones (usually 50 and 34). a compact is usually used with a wider range cassette too. the idea is to give you the range of a triple but to look like a real double so proper cyclists won't point and laugh and call you mean names. it's also mechanically a bit simpler and easier too use becuase the front dérailleur doesn't need to be trimmed as often. i like it.

trek climber

niceonetom wrote: »

basically a standard double has bigger chainrings (usually 52 and 39) and a compact has smaller ones (usually 50 and 34). a compact is usually used with a wider range cassette too. the idea is to give you the range of a triple but to look like a real double so proper cyclists won't point and laugh and call you mean names. it's also mechanically a bit simpler and easier too use becuase the front dérailleur doesn't need to be trimmed as often. i like it.

Well explained - cheers