Compact/ Semi Compact is this the emperors clothes of cyclin

tim_wand

There's a lovely DI2 Venge on " your bikes" Fantastic looking build and obviously just what the OP wanted.

Its got a Compact chainset on it and some of us Nay sayers have suggested that this does not look right on such a bike.

Now obviously Function is more important than the Aesthetic. and I m probably not qualified to comment as I live in the flat lands of Lincolnshire and I m certainly no Contador or Schleck.

However I ve just switched back to a standard chainset and whilst its not affected my climbing one bit (still rubbish) my average ride speed is up, and I can hold my turn on the front a lot easier.

Now they are marketing Semi Compact 53/36 at us as the answer to our "problems"

Now I m also no Sheldon-Brown ( Nicklouse et al correct me if I m wrong) by why is the P.C.D always different .

Cannot most things in the UK be dealt with just by changing the Casette ratios around, I know its usually the upper three rings to give higher gearing, and the cassette needs to be solid at the wheel to give stability at the base, but surely engineering tech and Pawl strength could give us a free hub where you could swap out the whole cassette.

Sram Wi fli and Tiagra , now go 32 and 30 teeth respectively on a mid cage mech. and by 2013 end I m sure the big S will have a 12 cog groupset so the jumps wont be so big.

So what do most people see as the best soloution or is it really Horses for Courses.

Yossie

53/39, run whatever cassette you want at the rear and a large dollop of Rule 5. I've used a compact front before (as it came with the bike) but really couldn't see any advantage whatsoever, so changed it to 54/39 (there was deal on the 54 as opposed to full retail on the 53) and all is fine and dandy, so said Amos and Andy.

But that s just me.

napoleond

I use 52/36 on my 110BCD crank, it's ok. I have 53/39 on my winter bike, I prefer it.

keef66

And I use 50/39/30

edhornby

dunno about 12 speed, I seem to recall an interview with the guy from campagnolo who said that going from 10 to 11 was a big challenge, like watchmaking getting the precise small movements

the BCD can be a small inconvenience but it's a stable system so not as bad as all the different bottom bracket types (let's not go there...), but you are right that the cassette changes give you the bigger benefits

Monty Dog

To say that you can hold a higher average speed with a standard chainset sounds that being in the bigger gear is forcing you to push harder rather than shift down?
I have a compact on my racebike which works out fine as I can leave it in the big ring for the duration of the race and 50x11 is higher than 53x12 - I usually run out of legs before I run out of gears.

displacedaussie

Does it really matter? Doesn't the choice of chainset and cassette just give you a big old handful of ratios, with the main thing being the ones at either end, and second the distance between the ones in the middle? Most of the possible ratios overlap anyway.

For those who never need a 53x11 or 53x12 (53x11 @90rpm = 34mph), which I'm pretty sure is a _huge_ number of people, then the compact chainset just gives a different set of more useful gear ratios, particularly at the lower end to use, along with smaller jumps in the middle, which might make it easier to "find the right gear". I don't see what can possibly be bad about this?

tim_wand

Monty Dog wrote:

To say that you can hold a higher average speed with a standard chainset sounds that being in the bigger gear is forcing you to push harder rather than shift down?
I have a compact on my racebike which works out fine as I can leave it in the big ring for the duration of the race and 50x11 is higher than 53x12 - I usually run out of legs before I run out of gears.

I dont race (any more) other than the odd sprint tri, When I m talking about holding my turn on the front its club runs and fitness rides with mates, I just find it easier with the 53 ring, but its rare that I ll take a turn on the front on climbs as I m 14 stone but I can certainly produce and hold a higher average speed with the standard chainset.

I ve never measured cadence but I would Imagine mine is relatively low, I ve always prefered to push a big gear hard rather than spin and my knees seem to take it (despite 30 years plus of footballing) touch wood I m the only one of my peers who's never had knee problems.

And yes Monty dog (p.s my new dogs named after you) I run out of legs before I run out of gears, Want to do a RAID Pyreneen this year so will be spending a lot more tme in the peaks and dales, so maybe both my thinking and chainset will change.

napoleond

I find myself changing gears more with a compact than a standard. Dunno why.

smidsy

NapoleonD wrote:

I find myself changing gears more with a compact than a standard. Dunno why.

Because you have a closer spread of gears so it allows you to find the perfect gear more without having to make a bigish step between gears?

tim_wand

NapoleonD wrote:

I find myself changing gears more with a compact than a standard. Dunno why.

Me too. 95% of the time with a standard I m in the same cog but not with a compact. I m aware that I ve got very low cadence and if riding on my own will drop into lower gears to delibertley work at higher cadences but I dont like it.

They say practice what your bad at not what your good at , but I d rather spin the a big gear with a low cadence all day long (I wish) than spin my legs off with a lower gear. I expect thats why I ve turned into a one pace wonder.

Its the same with my running though, I can run at a fairly decent pace (but only that pace for ages) but cant sprint or accelerate for long. I think its an age thing (42) and you just get one paced compared to your younger days.

Im going to make a concerted effort to train at different intensities this year . I dont have a power metre only a HRM and Cadence would you guys use HRM or Cadence as a guide.

It scares me how high my HR will go with only the slightest increase in cadence, but I can ride a 25 minute 10 without hitting more than 85% MHR. Whereas 3 minutes at a high revs produces figures which make me think I m going to have a cardiac arrest.

Ultimately I want to be a better climber so I suppose I ve just got to head to the hills more, Drop weight and increase power (Simples!!!!)

Any way I m stopping there I m beggining to sound like BHIMA ( and my Strava and Nike+ will always be private)

desweller

With a compact you have compromised the gap between chainrings in order to achieve that low gear. So, if you run a close-ratio back block, the gap covers more sprockets and you sweep a long way across the cassette when you change chainrings. If you run a wide-ratio back block you can avoid doing this, but now that you have bigger gaps between gear ratios on the cassette you find yourself shuffling between gears a lot because you can no longer find a comfortable gear.

On a standard double the gap between chainrings is not compromised, so you don't sweep through a lot of gears at the back when you change chainrings. Of course, you now can't have a really low gear without running a really wide-ratio back block.

The catch-all solution is, of course, a triple. Low gears, small gaps between chainrings, close ratios and a really good chainline on that convenient 40T middle ring.

FatTed

Tim
If you are going to do the RAID I suggest lower gears are required, not necessarily a compact, but something equivalent to a 34/27 you don't really need a 53/12 you wont be pedaling down the mountains.
this is a good crowd http://www.pyractif.com/cycling-package ... coast.html

tim_wand

FatTed wrote:

Tim
If you are going to do the RAID I suggest lower gears are required, not necessarily a compact, but something equivalent to a 34/27 you don't really need a 53/12 you wont be pedaling down the mountains.
this is a good crowd http://www.pyractif.com/cycling-package ... coast.html

Thanks Fat Ted, I ve looked at these guys before and had some contact with Paddy at Velopeleton. I like the way you can schedule his trips to suit ability and not be fixed to the requirements of the RAID and avoid some of the busier sections. I have a couple of mates who hit 40 this year and either want to do this or LEJOG. I ve done LEJOG but it will ultimatley be their choice depending on passes from Wives and funds.

StillGoing

tim wand wrote:

I dont have a power metre only a HRM and Cadence would you guys use HRM or Cadence as a guide.

It scares me how high my HR will go with only the slightest increase in cadence, but I can ride a 25 minute 10 without hitting more than 85% MHR. Whereas 3 minutes at a high revs produces figures which make me think I m going to have a cardiac arrest.

Ultimately I want to be a better climber so I suppose I ve just got to head to the hills more, Drop weight and increase power (Simples!!!!)

I'm 51 and like you have a HR that goes beserk with exertion especially when climbing so use a compact and Wifli RD. However, my cadence is always around 90-100 rpm on a ride which doesn't raise my HR above my targeted zone. The easier the gear the easier it is to have a good cadence, the harder the gear the tougher it is to have a good cadence. If I hit a climb it will rise to a highest of 179 bpm so far.