Advertise on Bikeforums.net



User Tag List

Page 1 of 2 12 LastLast
Results 1 to 25 of 35

Thread: Compact gearing

  1. #1
    tx7
    tx7 is offline
    Newbie
    Join Date
    Feb 2006
    Location
    Texas
    My Bikes
    Giant Raliegh
    Posts
    1
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    Compact gearing

    Does anyone here have experience with compact gearing. I am 53 and ride a giant with standard gearing(53/39 chainring 12/25 casette) It seems I hardly use the 53/12 combo. I have read about the 50/34 compact chainrings but wondered if a noticable differance could be felt.

  2. #2
    so whatcha' want? bigskymacadam's Avatar
    Join Date
    Mar 2005
    Location
    Charlotte, NC
    Posts
    1,709
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    here's sort of a FAQ from the road forum. lot's of info ....

    Compact Crank Overload

  3. #3
    OM boy cyclezen's Avatar
    Join Date
    Jul 2005
    Location
    Goleta CA
    My Bikes
    a bunch
    Posts
    3,011
    Mentioned
    2 Post(s)
    Tagged
    0 Thread(s)
    compact - good stuff, if you want to have a wide gearing spread and still have close jumps, without the need for a triple.
    I now have 2 bikes with compact (2 still with trips and 2 with 53/39) and am changing my race bike from 53/39 to a 50/34 or 50/36 compact (not sure which I want yet...). The remaining STD 53/39 is a vin-Tahge Garage Queen with C-record stuff for poseuring...
    if you live and ride only in Florida, Kansas, or other flatutious areas, don't bother...

  4. #4
    Senior Member Raketmensch's Avatar
    Join Date
    Jan 2006
    Location
    Upstate New York
    Posts
    367
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    No personal experience yet, but it's pretty easy to see that the difference has to be significant when you do the math. Right now I'm riding a vintage steel touring bike with a triple, and I'm about to get my hands on a carbon rocket with a 50-36 compact up front. Work out the gear ratios and you'll see that there's a substantial difference at the low end between your current setup and a compact. You won't feel a big difference at the high end (53/12 is not all that different from 50/12, and as you say you probably don't use the 53/12 combo all that much anyway. I know I wouldn't, except on scary-fast downhills.) But 34/25 is way different from 39/25, and you'll for sure feel the difference if you climb hills much where you ride.

  5. #5
    Roadie
    Join Date
    Jun 2004
    Location
    israel
    My Bikes
    kestrel
    Posts
    370
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Seems like a good idea. I was just wondering if chain angle is not an issue, i.e., since the chain drives at an angle between the chainwheel and the lower cogs (as opposed to the middle cogs where the chain is straight), and more riding will naturally be done in the lower cogs with a compact. Anyone have experience with this?

  6. #6
    Senior Member Retro Grouch's Avatar
    Join Date
    Feb 2004
    Location
    St Peters, Missouri
    My Bikes
    Rans Enduro Sport, Hase Kettweisel Tandem, Merin Bear Valley beater bike
    Posts
    23,718
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by berts
    Seems like a good idea. I was just wondering if chain angle is not an issue, i.e., since the chain drives at an angle between the chainwheel and the lower cogs (as opposed to the middle cogs where the chain is straight), and more riding will naturally be done in the lower cogs with a compact. Anyone have experience with this?
    Yup. The issue is chain rubbing on the inside of the big chainring when using the small chainring and the smallest two or three rear cogs. I get just a touch of chainrub in my third smallest cog with my Klein and generally hunt for a different combination rather than ride in the second smallest. I still like it better than any of the alternatives that I've considered.

  7. #7
    sch
    sch is offline
    Senior Member
    Join Date
    May 2003
    Location
    Birmingham. AL
    Posts
    2,591
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    I too have been pleased with my compact conversion from Ultegra triple/12-27. Long experience showed that I rarely used the 30t cog, though when needed it is needed but this amounts to perhaps 5mi out of 4000 each year. My conversion included a switch to Campy shifters and der as I am bummed out on Shimano for reasons posted elsewhere. The large adjustment range of the Campy shifters is really made for compacts and allows minimizing the cage rub easier than Shimano does. One thing you have to get used to is double shifting: when you drop from the 50 to the 34 you have to up shift in the rear one or two sprockets. I found on the triples that I spend 80% of my time on the 42t CW and almost never use the 52-12. For me 34-25 is low enough for all but the very rare hills. I am still accumulating experience at the 50-12 end and may ultimately look at a 13-26 or a bit wider, I understand a 13-27 is out there somewhere. Shimano is introducing a compact, soon... Haven't heard whether SRAMs road group, if and when, will include a compact.
    I like it a lot. Weird to look down at the bars and not see any cables though.
    Steve

  8. #8
    Senior Member
    Join Date
    Aug 2005
    Posts
    2,413
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    I have a lot of experience with Compact gearing and it's the cat's meow.

    All of my times have improved over my local rides because I'm spinning up the hills more and I am using the upper gears and the closer spacing now where I used to be always in the 21, 19 or 17 when I rode the 53.

    Anyone that isn't racing criteriums that isn't using compact gearing probably doesn't have a clue.

  9. #9
    OM boy cyclezen's Avatar
    Join Date
    Jul 2005
    Location
    Goleta CA
    My Bikes
    a bunch
    Posts
    3,011
    Mentioned
    2 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by berts
    Seems like a good idea. I was just wondering if chain angle is not an issue, i.e., since the chain drives at an angle between the chainwheel and the lower cogs (as opposed to the middle cogs where the chain is straight), and more riding will naturally be done in the lower cogs with a compact. Anyone have experience with this?
    like RetroG i was getting a little rubbage on the large ring when on the 2nd cog in rear (on my 8 spd 130mm - but no problems on the 7 spd 126 rear).
    I went to the local hardware store and bought 1 mm nylon washers that fit over the ring bolts. After some experimentation I settled on using them between the large ring and the spider (as opposed to the small ring & spider). No more rubbage and better chainline for the big ring (on my bike).
    Since I'm using a straight 13-19 then 21, I really needed that 2nd position cog - 34/14...

  10. #10
    Roadie
    Join Date
    Jun 2004
    Location
    israel
    My Bikes
    kestrel
    Posts
    370
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by cyclintom
    I have a lot of experience with Compact gearing and it's the cat's meow.

    All of my times have improved over my local rides because I'm spinning up the hills more and I am using the upper gears and the closer spacing now where I used to be always in the 21, 19 or 17 when I rode the 53.

    Anyone that isn't racing criteriums that isn't using compact gearing probably doesn't have a clue.
    Well I'll be - if that doesn't sell me on compacts nothin will. The idea of spinning up hills is an intriguing thought. The final issue is cost/benefit, i.e., is it worth the output (if it is $200 in the states it is twice as much here for the same thing). It sure is a long shot from the gearing we rode back in the '70s (52/48 double chainwheel) 12-25 cluster.

  11. #11
    Time for a change. stapfam's Avatar
    Join Date
    Jan 2004
    Location
    6 miles inland from the coast of Sussex, in the South East of England
    My Bikes
    Dale MT2000. Bianchi FS920 Kona Explosif. Giant TCR C. Boreas Ignis. Pinarello Fp Uno.
    Posts
    19,915
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    To me- compact gearing is a lot lower than you roadies use, but just a couple of point.... Triple crankset of 48/36/24 Rear sprocket of 11/32-- Completely different gearing to the rest of you but it is surpising that on the road- we use that 36/32 a lot, and surprising how few occasions we use the 48/11. Alright its a mountain bike- but a very fast tandem one with slicks fitted so does not hang about. If we are using 48/11 it will be downhill and on the flat we will be lower geared and still be pushing at 25-30mph- possibly with a higher cadence than others but leaving some very fit roadie's. On a mixed ride with the roadies we find that it has to be top club racers to push us at that speed aswell.

    I have tried some of the road gearing on a lightweight road bike, but never used that tallest gear, and always felt that a lower gear should be available.
    How long was I in the army? Five foot seven.


    Spike Milligan

  12. #12
    Let's do a Century jppe's Avatar
    Join Date
    Oct 2004
    Location
    North Carolina
    My Bikes
    Pinarello Prince/Campy SR; Cervelo R3/Sram Red; Trek 5900/Duraace, Cervelo P2C/Duraace
    Posts
    6,017
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    My bike is outfitted with a triple-52/42/30 and I use a 12/27 rear cassette. If I were doing it over I'd do a 50/34 with a 12/27 rear cassette. I really need the "easy gears" for some of the longer climbs in the mountains. Lately I've found I'm spinning more in my middle chain ring so a 50 would probably be just the ticket......My brother has made the switch along with several others around here and have nothing but good things to say about it.

    I can't justify making the change until my kids get WAY out of college and start sending me money instead of bills..........

  13. #13
    hello roadfix's Avatar
    Join Date
    May 2003
    Location
    Los Angeles
    My Bikes
    thank you for asking
    Posts
    18,502
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by jppe
    My bike is outfitted with a triple-52/42/30 and I use a 12/27 rear cassette. If I were doing it over I'd do a 50/34 with a 12/27 rear cassette. I really need the "easy gears" for some of the longer climbs in the mountains.
    I'm sorry but I don't get it. You already have "easy gears" for longer climbs.....you currently have a triple...
    I'm sure you know you'll lose a couple of your lowest climbing gears by going to a 50/34.
    .cinelli.olympic.surly.long.haul.trucker.kona.ku.surly.steamroller.
    .litespeed.classic.litespeed.firenze.bianchi.pista.dean.colonel.plus.more.

  14. #14
    Senior Member
    Join Date
    Aug 2005
    Posts
    2,413
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by berts
    Well I'll be - if that doesn't sell me on compacts nothin will. The idea of spinning up hills is an intriguing thought. The final issue is cost/benefit, i.e., is it worth the output (if it is $200 in the states it is twice as much here for the same thing). It sure is a long shot from the gearing we rode back in the '70s (52/48 double chainwheel) 12-25 cluster.
    I don't know what import duties are in Israel but I just bought a Campagnolo Centaur Compact crank for about $140 American and it is a NICE aluminum crank that uses a square taper bottom bracket. I will probably install these exclusively whenever I have to buy a crank from here on out.

  15. #15
    Senior Member
    Join Date
    Aug 2005
    Posts
    2,413
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by The Fixer
    I'm sorry but I don't get it. You already have "easy gears" for longer climbs.....you currently have a triple...
    I'm sure you know you'll lose a couple of your lowest climbing gears by going to a 50/34.
    If you have a triple already and you're used to the shifting problems there's really no sense in installing a Compact setup.

    But you only lose one ratio at the bottom and a double shifts a great deal better than a triple so if you're thinking of installnig a triple you're probably better off going with a Compact.

    48:11 = 4.4
    50:11 = 4.5

    30:32 = .92
    30:28 = 1.07

    34:32 = 1.06

    So you see that the lowest of your low gears is missing but let's think about this: the difference between the lowest triple gear and the lowest Compact is hardly noticeable in use.

  16. #16
    hello roadfix's Avatar
    Join Date
    May 2003
    Location
    Los Angeles
    My Bikes
    thank you for asking
    Posts
    18,502
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by cyclintom
    So you see that the lowest of your low gears is missing but let's think about this: the difference between the lowest triple gear and the lowest Compact is hardly noticeable in use.
    jppe (poster) is currently using a 12/27 cassette with his triple and is thinking about switching to a compact set with the same 12/27 cassette. His 30 ring granny currently yields 30 gear inches with the 27 cog while the 34 small compact ring will give him 34 inches with the same cog. Now that is a big difference.
    .cinelli.olympic.surly.long.haul.trucker.kona.ku.surly.steamroller.
    .litespeed.classic.litespeed.firenze.bianchi.pista.dean.colonel.plus.more.

  17. #17
    Rides again HiYoSilver's Avatar
    Join Date
    Oct 2004
    Location
    W. Sacramento Region, aka, Nut Tree
    My Bikes
    Giant OCR T, Trek SC
    Posts
    3,259
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    I just don't get it. How is "compact gearing" better than a triple? The weight difference between a double and a triple is very small % of total bike && rider weight.

    I'm running a 26-42-54 x 12:27. My range is 26 to 122GI average GI change between gears being only 10.4% Very nice. If I had to do it over, I'd replace the 42 with a 39ish ring. But even that leave some hills too steep to ride easily. Next time I'ld do it right. But no more digressing. It seems like switching from a triple to a double, even compact double means I will lose
    [pick all that apply]
    [ ]1. easier transitions between gears
    [ ]2. low end GI
    [ ]3. high end GI

    Am I missing something that makes the compact double appealing to you?
    Hi 'o Silver away

  18. #18
    Let's do a Century jppe's Avatar
    Join Date
    Oct 2004
    Location
    North Carolina
    My Bikes
    Pinarello Prince/Campy SR; Cervelo R3/Sram Red; Trek 5900/Duraace, Cervelo P2C/Duraace
    Posts
    6,017
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Sorry for the confusion!! I'm happy with my triple and certainly can't justify the changes and do not plan to. However, if I were getting a new bike and had to choose between a triple and a compact double I'd go for the latter. For the riding I do, there would be less shifting from the big chain ring to the middle chain ring plus I'd be using a higher percentage of of the "gears overall".

    My experience has been that when my triple front derailleur is adjusted "just right" it is wonderful. However I've had 3 different models of front derailluers and all three have required more maintenance/adjustment than I would like. It just seems I'm needing to adjust it more frequently than I should have to.

    As far as overall gear selection, when I'm in the big chain ring I mostly use the "harder" of 1/2 of the gears-I usually just drop down into the middle chain ring. Likewise I rarely use the large 1/2 of the gears when I'm in the small chain ring. But I definitely need something close to a 34-there's no way I could run a double with a 39 and do some of the climbs and stay on my bike (I'd be walking-or looking for detours!!). I have gotten a little stronger so that it's pretty rare when I drop all the way down into the 30/27. I think I could manage with the 34/27 now.

    I realize I'd give up a little on both the high and low end but I think that would be manageable for me.

    I haven't looked at the gear inches in a while but I would guess a 50/34 would be better suited for me because it would have less duplication of gear inches between the 3 chain rings if that makes sense. I just ask myself why have all those gears if I don't really use them?
    Last edited by jppe; 02-08-06 at 05:16 PM.

  19. #19
    hello roadfix's Avatar
    Join Date
    May 2003
    Location
    Los Angeles
    My Bikes
    thank you for asking
    Posts
    18,502
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by jppe
    Sorry for the confusion!! I'm happy with my triple and certainly can't justify the changes and do not plan to.
    Oops....actually, I'm sorry.. ...I misread your post.....you did mention if you "were to do it over again"...
    .cinelli.olympic.surly.long.haul.trucker.kona.ku.surly.steamroller.
    .litespeed.classic.litespeed.firenze.bianchi.pista.dean.colonel.plus.more.

  20. #20
    OM boy cyclezen's Avatar
    Join Date
    Jul 2005
    Location
    Goleta CA
    My Bikes
    a bunch
    Posts
    3,011
    Mentioned
    2 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by HiYoSilver
    I just don't get it. How is "compact gearing" better than a triple? The weight difference between a double and a triple is very small % of total bike && rider weight.

    [pick all that apply]
    [ ]1. easier transitions between gears
    [ ]2. low end GI
    [ ]3. high end GI
    Am I missing something that makes the compact double appealing to you?
    I'm using both and have, after some miles, been able to adapt to the triples. The compact, is of course just a double, so that is easy.
    Don't get me wrong, a triple is great. Especially since I use that setup like a 'double' (52/42) with kicker gearing for the really vertical stuff (the granny with the largest 3 cogs). The thing that got me when going to a trip was the physical spread between the pedals. Compared to my old Superbe & Campy C-record stuff, the triple was well over an inch wider at the crank arms. Thats a big deal for ergos, power production and possible ankle/knee issues. Going to a hyper-floating pedal setup like the Eggbeaters allowed me to finally adjust to the over-wide stance.
    A compact is a double and has the width of a double, nuf said.
    As for racing, I'm willing to give the compact a try, since even in my best years pushing a 53/12 was ridiculous. Anyone who says they spin out a 53/12 is full of **** and hasn't worked their cadence to a proper level for racing. So why carry a 12 when its not going to be of any positive value? Now a 12 with a 50 makes better sense for anyone racing with a 9 spd and a straight block thru the 19 with a 21.
    For general fun riding, even the performance side of rec riding, I can't imagine a 12 is anything other than bike jewelry.
    Multi-day Touring with a prospect for climbing and weighty full baggage - I'd be slappin on a triple without a 2nd thought.
    The bike universe is expanding with choices. MTB has created so many great 'bridge' developments (like compact frames) that have made road riding more enjoyable, we need to thank those guys even if we never go up a dirty driveway, much less a gnarly singletrak.
    Compact cranks were actually offered back in the 70's with dedicated touring componentry, but it wasn;t until the MTB Gen that it made the leap to real performance day riding.
    Given no need for a new BB, 'testing' / trying a compact crank is only a crankset swap, and with something like the Nashbar compact or the FSA Gossamer (at less than $100), its almost cheaper to try than a differnt set of pedals.

  21. #21
    Berry Pie..the Holy Grail GrannyGear's Avatar
    Join Date
    Nov 2004
    Location
    Weaving thru the cowpud outside Modesto CA
    Posts
    1,123
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    But will an inexpensive Nashbar compact crank fit my square taper bb? How easy (or hard) is it to find square taper compatible compacts?.....geezer rider/geezer bike.
    ..... "I renewed my youth, to outward appearance, by mounting a bicycle for the first time." Mark Twain, Speeches
    .

  22. #22
    Roadie
    Join Date
    Jun 2004
    Location
    israel
    My Bikes
    kestrel
    Posts
    370
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Cycle zen - a few questions:

    How do you compare your riding quality in terms of speed, endurance, power and enjoyment between the compact and regular cranksets?

    How do you rate the Gossamer?

    Do you ever "miss" the ability to spin in high gears going down hills?

    Do you find yourself using the smaller sprockets more often than with the regular crankset?

    thanks

  23. #23
    Rides again HiYoSilver's Avatar
    Join Date
    Oct 2004
    Location
    W. Sacramento Region, aka, Nut Tree
    My Bikes
    Giant OCR T, Trek SC
    Posts
    3,259
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    thanks cyclezen.
    Hi 'o Silver away

  24. #24
    OM boy cyclezen's Avatar
    Join Date
    Jul 2005
    Location
    Goleta CA
    My Bikes
    a bunch
    Posts
    3,011
    Mentioned
    2 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by GrannyGear
    But will an inexpensive Nashbar compact crank fit my square taper bb? How easy (or hard) is it to find square taper compatible compacts?.....geezer rider/geezer bike.
    that's a bit of a rub... Both are ISIS, but you can get an okay ISIS BB for under $40ish... I tried the Nashbar compact, liked it but didn't like their BB, swapped the BB for an FSA and that was much more solid.
    Now running FSA Gossamers, and so far in fast day riding and training group rides they work nicely - we'll see how they do in a race next weekend.

    I believe Stronglight makes a Sq Taper compact crankset, and it looks quite nice at a reasonable price. Now I'm not sure if its JIS (Shimano) or ISO (Campy & rest) taper...

    Of course Campy makes one at the usual steep tarif.

    sidebar - package in mail today - bars did their 1st race this past wkend.

  25. #25
    OM boy cyclezen's Avatar
    Join Date
    Jul 2005
    Location
    Goleta CA
    My Bikes
    a bunch
    Posts
    3,011
    Mentioned
    2 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by berts
    Cycle zen - a few questions:

    How do you compare your riding quality in terms of speed, endurance, power and enjoyment between the compact and regular cranksets?

    How do you rate the Gossamer?

    Do you ever "miss" the ability to spin in high gears going down hills?

    Do you find yourself using the smaller sprockets more often than with the regular crankset?

    thanks
    I'm noticing no discernable difference between the STD and compact setups. But because of the wider chaniring tooth spread, I have to have a 1 tooth rear block jump from 12 to 19, otherwise I lose very important gears in the low80, mid 70s and high 60s - can't ride effectively with those holes.

    I like the Gossamer! But then I'm not a big gear masher. My comfortable cadence is between 90-100.
    I'm not into the carbon 'Bling' thing, so a good Alloy set works for me. The set also has those pickup bosses that make shifting to the large ring a real joy.
    Only problem I had initially was chain rubbage on the inside of the large ring when the chainline was inner front ring to 2nd cog back. I put 1mm nylon washers between the outerring and the spiders and that solved the rubbage. I'm using 8 spd rear setups and Sram PC48/58 chains (nice).

    Not missing the topend so far. At about 40ish+ I'm usually coasting while fun riding. And Sheldon's gear calculator tell's me that I get 40 mph with at 50/12 at 120 rpm - we'll see how that works in the next RR I do.
    Most of the descents around here are technical and rarely allow much more than 35ish mph before the cornering speed becomes sketchy. The longer, straighter downhills are high spd, infernal combustion traffic laden and best keep to 40 or under for safety's sake.

    What I like about the compact is that most of the 'level' riding is done on the Large ring and using most of the rear cog assortment. Most of the real 'climbing' is done exclusively in the small ring. The 50/19 is a 69 inch gear and the 34/13 is also a 69. That coincides perfectly for where I normal go into a 'climbing mode. So flats/rolling all in the big ring, climbing all in the small ring. Otherwise actual gear selection hasn't changed for me.
    I do like the fact that I'm using the cogs more 'evenly', meaning the amount of miles/time is spread around much more. Back in the old days of 53/42, the 14-15-16 tooth cogs got all the use, while either in large or small ring. I'd be tossing out perfectly good freewheels cause the 15 and 16 were 'hooked' while the rest of the cluster was pristine.
    I'll report back after my 1st RR with any proper descending...

Page 1 of 2 12 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •