Shimano 105 5700 vs 5701?

[Nigelnaturist]

I suspect the move to a Compact is because a 42 or 39T inner ring on a Standard is too high for us mere mortals and "proper" cyclists don't ride Triples.

Not sure I agree, might be more to do with profits, do you not think pros's use a compact on some of the hills ( a compact is defined by the BCD on the crank not the teeth on the rings) a standard 130BCD cant fit less than 38th so if they want a 36 they have to use a compact 110BCD, my chainset is a compact triple 74/110BCD, I understand the weight issues for pros, but why dictate to the rest of us that we can only have a normal or compact double, in fact the new chainset by shimano is neither as both ring sizes fit the new chainset, so by definition is not a true compact, it a hybrid system, even on a 39x25 I would get most places round here, hills are not long though a couple a sharp bits, but that means losing the 18th I want, why give up a good set of gear ratios by dropping the triple. In other words I ride a double except where its difficult for me to do so, but it doesn't mean I wouldn't use the inner ring for better cadence control climbing.

 

[Nigelnaturist]

I suspect the move to a Compact is because a 42 or 39T inner ring on a Standard is too high for us mere mortals and "proper" cyclists don't ride Triples.

As for proper cyclists, are these the ones I don't see in winter.

 

[migrantwing]

I'll have to go out and make sure I know what gearing I'm using, I mean to scrutinise it, so that I can figure out if a change of cassette, a change of chainring, or both will be a better option.

 

[sittingbull]

I ride a 52/42/30 triple. I spend 90% of the time on the middle ring with a 12-26 on the rear. I rarely use the granny ring but there are times (well into a long ride) when I'm glad it's there. If I was 20 years younger and as fit/strong as the Pros I might never need it, but I'm not and I do. I have a compact chainset but it's still in the box, I agree a 16T step is significant but it will provide me with the option of the required range without resorting to a triple again.

As for proper cyclists, are these the ones I don't see in winter.

Yes

 

[Nigelnaturist]

I'll have to go out and make sure I know what gearing I'm using, I mean to scrutinise it, so that I can figure out if a change of cassette, a change of chainring, or both will be a better option.

Gearing really depends on your usual terrain, what I can get away with and what others need in hillier areas are two different things, I know if I am doing more hills I don't miss the 18th as much, but thought of losing the 16th as well ....... my fitness levels are that I could manage most things on my setup excluding the 26th inner ring,
These are the gear inches of what I am looking at doing next week when I can afford the cassette, the second table is what a typical compact would have to cover the same range

Like I said my average gear is 61" and my last chain lasted 3651 miles, mainly Autumn/Winter riding, I use the 38x24 I currently have which is 55" but not very often the 27th so for me the setup I propose should work better (best laid plans and all that) it might not work in the real world though, but you can see that almost all my riding is done with the chain in the middle and pretty straight. I really don't think people give it enough thought, only as after thought when things are tough.

 

[gjkathome]

Hi Nigel. What chain-rings are you using to get your 26 38 50 set-up?

 

[Nigelnaturist]

Hi Nigel. What chain-rings are you using to get your 26 38 50 set-up?

I use a UN55 BB square taper coupled with compact triple crank set, from spacycles in Harrogate about £22, the rings again their own are 110mm BCD (this is what makes it a compact not the chainring teeth count i.e. 50/34) for the middle and the outer and 74mm for the inner, their prices are £10-15-20 inner to outer I think I will check, different sizes made from Zircal Alloy so are quite durable, and look pretty good too.



Chainrings
Crankarms
Then the BB which on this set is 113mm.