Compact Crank vs Semi-Compact

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Comments

  • Alex99
    Alex99 Posts: 1,407
    Bobbinogs wrote:
    Webboo wrote:
    Alex99 wrote:
    t4tomo wrote:
    newcycle wrote:
    I have a currently 50/34 compact crankset, and everyone says I should buy a 52/36 semi-compact crank because I'm loosing speed on the flats compared to my friends.

    Sometimes it is true, I feel I can't keep up with the crowd on the peloton because of my 50/34.
    If i change to a 52/36, what difference will it make ?? on the flats ??

    thank you,
    I'm not sure he did get his answer. Whether he has compact or a Semi will make not difference, he is being left behind on the flats because his mates are more powerful than he is. Riding more will hopefully in time allow him to get fit and strong enough to keep up.

    OK, maybe he just gave up.
    and took up fishing.

    You think he's been left reeling then?

    Probably just netted a good deal on a chainring.
  • pinno
    pinno Posts: 52,184
    Fenix wrote:
    Alex99 wrote:
    Fenix wrote:
    If...10.

    Thought...flat.

    All very well for pros like Martin and Wiggins - but this is the beginners forum ? Anyone thinking they can push pro gears is mistaken.

    And what about jockey wheels ? They're 11 teeth aren't they ? If we're worried about smaller sprockets we should be oversizing those too ?

    http://www.bikeradar.com/road/news/article/ceramicspeed-oversized-pulley-wheel-system-claimed-to-save-three-watts-45108/

    1440533367213-104osy4zco3g1-700-80.jpg
    seanoconn - gruagach craic!
  • Alex99
    Alex99 Posts: 1,407
    Pinno wrote:
    Fenix wrote:
    Alex99 wrote:
    Fenix wrote:
    If...10.

    Thought...flat.

    All very well for pros like Martin and Wiggins - but this is the beginners forum ? Anyone thinking they can push pro gears is mistaken.

    And what about jockey wheels ? They're 11 teeth aren't they ? If we're worried about smaller sprockets we should be oversizing those too ?

    "...but this is the beginners forum ? Anyone thinking they can push pro gears is mistaken." I agree, but folks are looking for good advice.

    Ah, the big jockey wheels. Obvisously some deemed it a worthwhile thing to do. Didn't Shimano used to have 10t as standard and moved to 11? I believe they got Spinal Tap to launch the new range.

    Guess the main difference is that the chain isn't under the same tension as it would be over the sprocket.
  • fenix
    fenix Posts: 5,437
    A mere snip at almost £400. And if the marketeers claim 3 watts then who are we to argue eh ? ;-)

    LOL at Spinal Tap unveling the 11...


    I think the main thing I'd put over is that its silly to fret about efficiency of sprockets for us amateurs. It's not going to be measurable at our level.
  • pinno
    pinno Posts: 52,184
    Fenix wrote:
    A mere snip at almost £400. And if the marketeers claim 3 watts then who are we to argue eh ? ;-)

    LOL at Spinal Tap unveling the 11...


    I think the main thing I'd put over is that its silly to fret about efficiency of sprockets for us amateurs. It's not going to be measurable at our level.

    Not fretting, just stoking.
    seanoconn - gruagach craic!
  • Alex99
    Alex99 Posts: 1,407
    Fenix wrote:
    A mere snip at almost £400. And if the marketeers claim 3 watts then who are we to argue eh ? ;-)

    LOL at Spinal Tap unveling the 11...


    I think the main thing I'd put over is that its silly to fret about efficiency of sprockets for us amateurs. It's not going to be measurable at our level.

    There are people who want to know the ins and outs of equipment choice at all levels of ability. I'd rather not waste any of my limited power if I don't have to.
  • slowmart
    slowmart Posts: 4,516
    Ive just gone from a compact to a semi, why, I'm stronger than I was three years ago and the semi is fine for me now.
    “Give a man a fish and feed him for a day. Teach a man to fish and feed him for a lifetime. Teach a man to cycle and he will realize fishing is stupid and boring”

    Desmond Tutu
  • dennisn
    dennisn Posts: 10,601
    Alex99 wrote:
    dennisn wrote:
    Is it my imagination or are some people on this topic thinking that they must buy a new crankset in order to get this so-called semi compact gearing? As opposed to simply buying new rings?

    Some might be wrongly thinking it. Some, like me, would have to get new cranks though. As posted previously, no 36t chainring onto a 130 BCD crank.
    Right. For whatever reason I got the impression that a few people thought they needed to ditch their compact cranks for something called a semi compact crank.
  • MikeBrew
    MikeBrew Posts: 814
    Alex99 wrote:
    orraloon wrote:
    ^ :D I've enjoyed these 8 pages in the Beginners subforum.

    The OP got his answer and cleared off a long, long time ago :D

    Perhaps he sold the bike, bought some silly checked trousers, a set of clubs and went Dolphin instead............. :arrow:
  • Pinno wrote:
    Alex99 wrote:
    Fenix wrote:
    If you look at beginners they are usually pedalling about 60rpm. If anything they learn to spin faster as they get better. 40rpm would be very much at the lower end of the spectrum but it's your knees....

    As to racing a 10 with a 53 11 - that's no problem.
    Unless that's your lowest gear. You're not going to be pushing that on a 10.

    Thought that sprockets smaller than 14t start to drop off in efficiency. There is discusison about that in Obree's book where he reccommends using the largest chainring possible. Also Wiggin's choice of 58x14, no conincidence... 50x12 is very close to the same ratio. Hmm. I also remember the same from an article with analysis of derailier gears vs hub gear efficiency.

    Tony Martin running a 56(?) or 58t ring is to have a better chainline and a really big gear for down hill. Even he's not riding 58x12 on the flat.

    In the case of Wiggo and O'Bree, I wonder what the difference in cadence is between the 58 x 14 and the 50 x 12 is. These things were probably tested and calculated to the nth degree.

    When Cadel Evans won the TdF and won the TT on the penultimate day was done at an average 105 rpm on a rolling course which lasted just over an hour.
    Almost 3 weeks of pedalling over huge mountains and long stages in all conditions, yet he still managed that average cadence. His legs probably weren't that strong at that point which underlines the importance of cadence and top notch CV fitness. My supposition about his ability to sustain power at that point in the race as opposed to a lower gear but high cadence surely has some merit.
    After all, what are gears for - they act as a torque multiplication device.
    If we as amateurs use the excuse that they are pro's and we can't learn from them, then it's BS.

    Or consider Boardman's 25 mile record - 45:57 on 110 inches.
  • webboo
    webboo Posts: 6,087
    All this talk of semi's won't look good if some one looks at your internet history.
  • pblakeney
    pblakeney Posts: 27,139
    Slowmart has a semi.
    Titters........
    The above may be fact, or fiction, I may be serious, I may be jesting.
    I am not sure. You have no chance.
    Veronese68 wrote:
    PB is the most sensible person on here.
  • pinno
    pinno Posts: 52,184
    Pinno wrote:
    Alex99 wrote:
    Fenix wrote:
    If...10.

    Thought...flat.

    In...BS.

    Or consider Boardman's 25 mile record - 45:57 on 110 inches.

    Which could have been 50 x 12 or 46 x 11. Semi compact and compact? :D
    seanoconn - gruagach craic!
  • darkhairedlord
    darkhairedlord Posts: 7,180
    Pinno wrote:
    Fenix wrote:
    Alex99 wrote:
    Fenix wrote:
    If...10.

    Thought...flat.

    All very well for pros like Martin and Wiggins - but this is the beginners forum ? Anyone thinking they can push pro gears is mistaken.

    And what about jockey wheels ? They're 11 teeth aren't they ? If we're worried about smaller sprockets we should be oversizing those too ?

    http://www.bikeradar.com/road/news/article/ceramicspeed-oversized-pulley-wheel-system-claimed-to-save-three-watts-45108/

    1440533367213-104osy4zco3g1-700-80.jpg

    The transparent aluminum gear cables certainly help.
  • pinno
    pinno Posts: 52,184
    ^ Those teeth look shot despite only been back pedalled out of the factory for the photo shoot and I think that there is a mechanical efficiency conflict with the 11 tooth sprocket...
    seanoconn - gruagach craic!
  • pblakeney
    pblakeney Posts: 27,139
    The transparent aluminum gear cables certainly help.
    Going single speed without the expense.
    The above may be fact, or fiction, I may be serious, I may be jesting.
    I am not sure. You have no chance.
    Veronese68 wrote:
    PB is the most sensible person on here.
  • milemuncher1
    milemuncher1 Posts: 1,472
    Fenix wrote:
    A mere snip at almost £400. And if the marketeers claim 3 watts then who are we to argue eh ? ;-)

    LOL at Spinal Tap unveling the 11...


    I think the main thing I'd put over is that its silly to fret about efficiency of sprockets for us amateurs. It's not going to be measurable at our level.

    That's it.
  • milemuncher1
    milemuncher1 Posts: 1,472
    As an experiment, I rode all the way home from w*rk last night, on about 120 gear inches. Admittedly it was only 8 miles, and a few down hills, and a few very slightly uphill bits, with a flat bit at about the half way point. I didn't find it massively difficult, and there was no way I was going to be able to get to spin out on the downhill bit ( and not just because it was dark and damp ). The drive train was not happy though :wink: .
  • Alex99
    Alex99 Posts: 1,407
    MikeBrew wrote:
    Alex99 wrote:
    orraloon wrote:
    ^ :D I've enjoyed these 8 pages in the Beginners subforum.

    The OP got his answer and cleared off a long, long time ago :D

    Perhaps he sold the bike, bought some silly checked trousers, a set of clubs and went Dolphin instead............. :arrow:

    A Dolphin is NOT a fish. AAAAAHHHHH
  • Alex99
    Alex99 Posts: 1,407
    As an experiment, I rode all the way home from w*rk last night, on about 120 gear inches. Admittedly it was only 8 miles, and a few down hills, and a few very slightly uphill bits, with a flat bit at about the half way point. I didn't find it massively difficult, and there was no way I was going to be able to get to spin out on the downhill bit ( and not just because it was dark and damp ). The drive train was not happy though :wink: .

    What was the experiment designed to test?
  • Alex99
    Alex99 Posts: 1,407
    PBlakeney wrote:
    Slowmart has a semi.
    Titters........

    Is that a semi, or are you pleased to see me? No it's actually a full compact :oops:
  • Alex99
    Alex99 Posts: 1,407
    Pinno wrote:
    ^ Those teeth look shot despite only been back pedalled out of the factory for the photo shoot and I think that there is a mechanical efficiency conflict with the 11 tooth sprocket...

    They seem to have covered the chain in sherbet too. Probably OK until it rains.
  • pinno
    pinno Posts: 52,184
    They eat fish.
    seanoconn - gruagach craic!
  • MikeBrew
    MikeBrew Posts: 814
    edited March 2016
    Alex99 wrote:
    MikeBrew wrote:
    Alex99 wrote:
    orraloon wrote:
    ^ :D I've enjoyed these 8 pages in the Beginners subforum.

    The OP got his answer and cleared off a long, long time ago :D

    Perhaps he sold the bike, bought some silly checked trousers, a set of clubs and went Dolphin instead............. :arrow:

    A Dolphin is NOT a fish. AAAAAHHHHH

    OK , like George Michael's downstairs toilet, Dolphins have a blow hole, so no - they're not fish in the strict sense. Pretty sure that they spend most of their time in the sea though, I mean, it's been a while since I've seen one (a Dolphin or George Michael) cruising the aisles at the local Tesco, that would be a Sardine nuisance.....Luckily it is about as likely as riding uphill in a 120 inch gear !
  • MikeBrew
    MikeBrew Posts: 814
    Pinno wrote:
    They eat fish.
    And not the tinned variety from Tesco !
  • MikeBrew
    MikeBrew Posts: 814
    Alex99 wrote:
    dennisn wrote:
    Is it my imagination or are some people on this topic thinking that they must buy a new crankset in order to get this so-called semi compact gearing? As opposed to simply buying new rings?

    Some might be wrongly thinking it. Some, like me, would have to get new cranks though. As posted previously, no 36t chainring onto a 130 BCD crank.


    Shirley this is about compacts verus semi compacts. Isn't throwing a 130 BCD into the mix something of a Red Herring ?
  • 97th choice
    97th choice Posts: 2,222
    Here's a typical 44-16 single speed ride

    https://www.strava.com/activities/493338938

    I was invited to ride the Tour of Britain London stage last year, because I am a Skyride social ride organiser

    https://www.strava.com/activities/391338390

    That was the 50-11 equipped Carbon bike,

    https://www.strava.com/activities/190333400

    London and back on the 50-11 equipped bike


    There are loads of others, but that's a mixture of lengths and bikes and gears and stuff.

    what point are you proving with those strava rides? I fail to see how riding at 10mph on a flat course proves the efficiency of a low cadence?
    Too-ra-loo-ra, too-ra-loo-rye, aye

    Giant Trance
    Radon ZR 27.5 Race
    Btwin Alur700
    Merida CX500
  • MikeBrew
    MikeBrew Posts: 814
    This thread is addictive, I think I might be Hooked.........
  • milemuncher1
    milemuncher1 Posts: 1,472
    Here's a typical 44-16 single speed ride

    https://www.strava.com/activities/493338938

    I was invited to ride the Tour of Britain London stage last year, because I am a Skyride social ride organiser

    https://www.strava.com/activities/391338390

    That was the 50-11 equipped Carbon bike,

    https://www.strava.com/activities/190333400

    London and back on the 50-11 equipped bike


    There are loads of others, but that's a mixture of lengths and bikes and gears and stuff.

    what point are you proving with those strava rides? I fail to see how riding at 10mph on a flat course proves the efficiency of a low cadence?

    I think you need to look up the term "flat course". It wasn't mountainous, but "flat" :lol:
  • Alex99
    Alex99 Posts: 1,407
    MikeBrew wrote:
    Alex99 wrote:
    dennisn wrote:
    Is it my imagination or are some people on this topic thinking that they must buy a new crankset in order to get this so-called semi compact gearing? As opposed to simply buying new rings?

    Some might be wrongly thinking it. Some, like me, would have to get new cranks though. As posted previously, no 36t chainring onto a 130 BCD crank.


    Shirley this is about compacts verus semi compacts. Isn't throwing a 130 BCD into the mix something of a Red Herring ?

    You have to consider such things when tunaing up your bike. Don't shrimp on such things.