Advertise on Bikeforums.net



User Tag List

Results 1 to 25 of 25
  1. #1
    Senior Member
    Join Date
    Sep 2010
    Posts
    59
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    Shimano Ultegra R603 gearing

    I've got a new set of Shimano R603 cranks I'm planning to install on our bike.

    Can anyone tell me if/where can I get a larger chainring? I want to put a 55 or 56 on it as we regularly run out of gears with an 11/52

    I'd ideally like one that still has that Shimano look to it.

  2. #2
    Clipless in Coeur d'Alene twocicle's Avatar
    Join Date
    Mar 2012
    Location
    Coeur d'Alene, Idaho
    My Bikes
    Calfee Tetra Tandem, Specialized Tarmac SL4 S-Works, other misc Road & MTB singles
    Posts
    883
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by jacks1071 View Post
    I've got a new set of Shimano R603 cranks I'm planning to install on our bike.

    Can anyone tell me if/where can I get a larger chainring? I want to put a 55 or 56 on it as we regularly run out of gears with an 11/52

    I'd ideally like one that still has that Shimano look to it.
    I believe this thread discusses your options...
    http://www.bikeforums.net/showthread...-Tandem-Cranks

  3. #3
    Senior Member jack002's Avatar
    Join Date
    Feb 2009
    Location
    Southwest MO
    My Bikes
    (1) 1993 Cannondale R900, red
    Posts
    593
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Whoa, 11/52 is not enough gear? You have 12" tires?
    Biking isn't a sport because anybody can do it. I can bike, you can bike. For goodness sakes, my mother can bike! You don't see her on the cover of Sports Illustrated, do you?

  4. #4
    Senior Member
    Join Date
    Sep 2010
    Posts
    59
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by jack002 View Post
    Whoa, 11/52 is not enough gear? You have 12" tires?
    700C wheels, we like to go fast. My stoker can't keep up with my cadence and as such we run out of gears around 40mph, this is close to the limit of the single riders we train with. If I can get another 5mph or so out of it that'll be enough to crack a lot of them, especially the ones who are on compact gearing.

  5. #5
    Senior Member Team Fab's Avatar
    Join Date
    Jan 2012
    Location
    Vancouver BC
    My Bikes
    Comotion Supremo, Trek T1000, Comotion Supremo Triple
    Posts
    174
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    What size cranks does your stoker and captain have?

    If you go 165 stoker and 175 captain that may help as well.

    It will make it easier for the stoker to spin up. And harder for the captain.

  6. #6
    Gear Combo Guru Chris_W's Avatar
    Join Date
    May 2007
    Location
    Switzerland
    My Bikes
    Spec' Tarmac (road), Spec' Secteur Disc (commuter & tourer), Salsa Mamasita (MTB), CoMo Speedster (tandem), Surly Big Dummy (cargo), Airnimal (folder), a train pass, and NO car :)
    Posts
    2,008
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Unfortunately, the R603 cranks only come in 170 and 175 mm lengths.

    The special design of all three chainrings on the R603 (and the new single-bike Ultegra and Dura Ace cranks) is the reason why I won't buy one of these cranksets - I like more choice in my gearing.

    Fortunately, TA Specialites and Stronglight are both making some specially-shaped rings that match those on the Ultegra single-bike cranks, and so should also match the R603s. However, information and availability on these options is still quite lacking. Also, you can mount any regular 130 mm BCD outer ring on the R603s using standard bolts - it won't look quite right but it should work fine.

  7. #7
    Senior Member
    Join Date
    Sep 2010
    Posts
    59
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Hmm. I'm not in a huge hurry as I havn't installed the cranks yet (still some life left in the existing chainrings). I got a killer deal on the Shimano cranks and didn't realise the chainring options were so limited. I might mothball these and get some Davinci cranks.

  8. #8
    Clipless in Coeur d'Alene twocicle's Avatar
    Join Date
    Mar 2012
    Location
    Coeur d'Alene, Idaho
    My Bikes
    Calfee Tetra Tandem, Specialized Tarmac SL4 S-Works, other misc Road & MTB singles
    Posts
    883
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Jacks, per the previous thread reference provided, see this:
    http://www.bikeforums.net/showthread...1#post14329184

    Simple enough if you want to stick with a Shimano big ring.

  9. #9
    Senior Member longbeachgary's Avatar
    Join Date
    Sep 2008
    Location
    Beautiful Long Beach California
    My Bikes
    Eddy Merckx MXL; 2012 CAAD10; 2013 CAAD10 - The Silver and Black; Cannondale CAAD10 DI2 - The Black Dahlia; 2013 Cannondale CAAD10 DI2, The Black Mambo
    Posts
    3,202
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by jacks1071 View Post
    700C wheels, we like to go fast. My stoker can't keep up with my cadence and as such we run out of gears around 40mph, this is close to the limit of the single riders we train with. If I can get another 5mph or so out of it that'll be enough to crack a lot of them, especially the ones who are on compact gearing.
    You ride with single riders that can ride at 40mph? Radio Shack and Liqiugas could use these guys.

  10. #10
    Senior Member waynesulak's Avatar
    Join Date
    Jan 2008
    Location
    Ft Worth, TX
    My Bikes
    650B tandem converted from Santana Arriva, Santana Noventa, Boulder Bicycle 700C, Gunnar Sport, Trek TX700,
    Posts
    1,576
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by jacks1071 View Post
    Hmm. I'm not in a huge hurry as I havn't installed the cranks yet (still some life left in the existing chainrings). I got a killer deal on the Shimano cranks and didn't realise the chainring options were so limited. I might mothball these and get some Davinci cranks.
    daVinci's cranks are great.

    I understand why a company like Shimano or Campy will design proprietary components because they feel they tie the buyer to one vendor. On the other hand as an end user I appreciate standards and try not to reward companies for avoiding them.

  11. #11
    Senior Member
    Join Date
    Apr 2007
    Posts
    1,663
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by jacks1071 View Post
    700C wheels, we like to go fast. My stoker can't keep up with my cadence and as such we run out of gears around 40mph, this is close to the limit of the single riders we train with. If I can get another 5mph or so out of it that'll be enough to crack a lot of them, especially the ones who are on compact gearing.
    I love this post. I've been on the receiving end of that before, undergeared on a single with a compact trying to keep up. It's one of the reasons why I run a triple or 52/36 on my single bikes now.

  12. #12
    Senior Member
    Join Date
    Sep 2010
    Posts
    59
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by longbeachgary View Post
    You ride with single riders that can ride at 40mph? Radio Shack and Liqiugas could use these guys.
    Sitting behind us is like drafting a truck and really is pretty easy to sit on.

    The only way I'll crack some of them is if we out-gear them and they can't spin fast enough. I figure if we hurt them bad enough at the start of the rides we should have an easier journey through the hilly sections.

    They murder us in the hills, we've been getting in the habit of attacking prior to the hills and the group gets back on around the top otherwise we are off the back on any half decent climbs.

    Its a lot of fun :-)

    I see in the link above someone suggests a dura-ace 54 - thats only another 2 teeth though and I'd feel more confident knowing someone else had already done it. I really think I want a 56 ideally, anyone know if that would cause any issues with the front shifting? We have Shimano 105 5600 shifters (triple).

  13. #13
    Senior Member
    Join Date
    Nov 2011
    Posts
    119
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    There are both 7800 and 7900 Dura Ace 56T chainrings on eBay right now, FWIW.

  14. #14
    Clipless in Coeur d'Alene twocicle's Avatar
    Join Date
    Mar 2012
    Location
    Coeur d'Alene, Idaho
    My Bikes
    Calfee Tetra Tandem, Specialized Tarmac SL4 S-Works, other misc Road & MTB singles
    Posts
    883
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by WheelsNT View Post
    There are both 7800 and 7900 Dura Ace 56T chainrings on eBay right now, FWIW.
    Correct. More to the point it was a nudge to look at these rings.

    Play with http://sheldonbrown.com/gears/ to find your desired gear/mph setup.

  15. #15
    Senior Member
    Join Date
    Sep 2010
    Posts
    59
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by WheelsNT View Post
    There are both 7800 and 7900 Dura Ace 56T chainrings on eBay right now, FWIW.
    Wow they are expensive. Has anyone fitted the Dura Ace 7900 outer ring to an R603 crank? They are too expensive for me to buy and find it doesn't work.

    I've read through the other threads linked and find people talking about this but I can't recall anyone who has done it and posted the results.

    The Davinci cranks are looking better by the minute.

  16. #16
    Senior Member waynesulak's Avatar
    Join Date
    Jan 2008
    Location
    Ft Worth, TX
    My Bikes
    650B tandem converted from Santana Arriva, Santana Noventa, Boulder Bicycle 700C, Gunnar Sport, Trek TX700,
    Posts
    1,576
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by jacks1071 View Post
    Sitting behind us is like drafting a truck and really is pretty easy to sit on.

    The only way I'll crack some of them is if we out-gear them and they can't spin fast enough. I figure if we hurt them bad enough at the start of the rides we should have an easier journey through the hilly sections.

    They murder us in the hills, we've been getting in the habit of attacking prior to the hills and the group gets back on around the top otherwise we are off the back on any half decent climbs.

    Its a lot of fun :-)

    I see in the link above someone suggests a dura-ace 54 - thats only another 2 teeth though and I'd feel more confident knowing someone else had already done it. I really think I want a 56 ideally, anyone know if that would cause any issues with the front shifting? We have Shimano 105 5600 shifters (triple).
    That kind of speed it out of our league but it is nice that you have a 105 FD. It has a good steel cage and it should be able to stand some trimming to fit a larger diameter ring. I use a 105 FD just to have that nice stiff steel cage.

  17. #17
    pan y agua merlinextraligh's Avatar
    Join Date
    Aug 2005
    Location
    Jacksonville
    My Bikes
    Wilier trestina Zero 7; Merlin Extralight; Co-Motion Robusta; Schwinn Paramount; Motobecanne Phantom Cross; Cervelo P2
    Posts
    26,711
    Mentioned
    3 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by longbeachgary View Post
    You ride with single riders that can ride at 40mph? Radio Shack and Liqiugas could use these guys.
    Downhill is when you need the big ring. As I posted in another thread, I didn't think we needed anything bigger than 53-11 until racing on a mountainous course.

    At Masters Nationals, we tried to attack coming down Mt Bachelor. Got a bit of seperation, but we were spinning almost 140rpm in the low 50's, and it was just too unstable to try to pedal faster.

    In that admittedly rare circumstance, a 56, or even a 60 would have been handy.
    You could fall off a cliff and die.
    You could get lost and die.
    You could hit a tree and die.
    OR YOU COULD STAY HOME AND FALL OFF THE COUCH AND DIE.

  18. #18
    Clipless in Coeur d'Alene twocicle's Avatar
    Join Date
    Mar 2012
    Location
    Coeur d'Alene, Idaho
    My Bikes
    Calfee Tetra Tandem, Specialized Tarmac SL4 S-Works, other misc Road & MTB singles
    Posts
    883
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by waynesulak View Post
    That kind of speed it out of our league but it is nice that you have a 105 FD. It has a good steel cage and it should be able to stand some trimming to fit a larger diameter ring. I use a 105 FD just to have that nice stiff steel cage.
    Here's a cheap upgrade for ya'll. I have 2 new Ultegra 6703 triple FDs with 34.9mm clamp size sitting here if anyone wants them. I switched to the braze-on FD type and using the K-Edge clamp and chain keeper, so the Ultegra FDs are not needed. Ended up with one extra that remains brand new, the other has a couple rides use only. $40/ea. PM me if interested.
    Last edited by twocicle; 10-10-12 at 12:40 PM.

  19. #19
    just another gosling Carbonfiberboy's Avatar
    Join Date
    Feb 2007
    Location
    Everett, WA
    My Bikes
    CoMo Speedster 2003, Trek 5200, CAAD 9, Fred 2004
    Posts
    7,550
    Mentioned
    1 Post(s)
    Tagged
    1 Thread(s)
    Is the OP saying that he could ride singles off his wheel on the flat if only he had bigger gears? I've ridden my single behind some strong tandem teams, including 2 captain with a strong stoker. It's pretty hard to do. I he's talking about during descents, very shallow descents where one can gain speed by pedaling beyond 40 are rare. I've never seen one, though I understand they do exist, like on the east slopes of the Rockies. Most descents, when we hit about 35 we're faster if we stop pedaling and tuck, pedals level, knees in, flat back, chin on stem, elbows under diaphragm, stoker's head on my butt. We're gone. If there's a single that knew to be abreast of us as we went over the top, a quick swerve left and they're gone, though we usually don't do that.

    The problem with trying to drop people on the flat is that power required for the lead bike goes up as the cube of the speed. So when you hit the climb, you're already cooked. Smarter to let them pass you on the climb, then sprint over the top and crush them on the descent. They can't get on because you're going 10 mph faster than they are. Then you never have to ride them off your wheel. You'll each be putting out less average power than they will on the flat, heading for the next climb. This is all, needless to say, dangerous, which is why people don't recommend racing tandems against singles, unless the singles know the routine and will stay the heck right.

  20. #20
    Senior Member waynesulak's Avatar
    Join Date
    Jan 2008
    Location
    Ft Worth, TX
    My Bikes
    650B tandem converted from Santana Arriva, Santana Noventa, Boulder Bicycle 700C, Gunnar Sport, Trek TX700,
    Posts
    1,576
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    I agree with Carbonfiberboy. We don't have the power to overcome the drag but have learned to tuck nice and tight.

  21. #21
    Gear Combo Guru Chris_W's Avatar
    Join Date
    May 2007
    Location
    Switzerland
    My Bikes
    Spec' Tarmac (road), Spec' Secteur Disc (commuter & tourer), Salsa Mamasita (MTB), CoMo Speedster (tandem), Surly Big Dummy (cargo), Airnimal (folder), a train pass, and NO car :)
    Posts
    2,008
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by jacks1071 View Post
    Wow they are expensive. Has anyone fitted the Dura Ace 7900 outer ring to an R603 crank? They are too expensive for me to buy and find it doesn't work.

    I've read through the other threads linked and find people talking about this but I can't recall anyone who has done it and posted the results.

    The Davinci cranks are looking better by the minute.
    I believe that the ridges on the 7900 and 6700 cranks are different, so that 7900 rings won't look right on 6700 cranks (and therefore also not on the R603 tandem cranks). However, I've never actually seen anyone mount this combination, so I don't know just how odd it would look.

  22. #22
    Senior Member
    Join Date
    Dec 2005
    Location
    London, UK
    My Bikes
    Trek T200 plus enough others to fill a large shed
    Posts
    562
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Correct. It wil mount but the shape is different. Close inspection of photos somewhere like competitive cyclist will confirm.

  23. #23
    Newbie
    Join Date
    Jul 2013
    Posts
    1
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    need a 6503 fd 34.9 as my current is 31...what are my options

    Quote Originally Posted by twocicle View Post
    Here's a cheap upgrade for ya'll. I have 2 new Ultegra 6703 triple FDs with 34.9mm clamp size sitting here if anyone wants them. I switched to the braze-on FD type and using the K-Edge clamp and chain keeper, so the Ultegra FDs are not needed. Ended up with one extra that remains brand new, the other has a couple rides use only. $40/ea. PM me if interested.
    hi
    can anyone help with suggestions
    i have a new 6503fd but the wrong size for seat tube.
    they are old components so its hard to find a triple for a 9 ring.

    the forums i read mention a 10 ring will be fine...but my mechanic disagrees...
    if anyone has a 6503 for sale or recommends an alternative appreciate links or advice

  24. #24
    Member
    Join Date
    Oct 2012
    Location
    Bruce, ACT, Australia
    Posts
    33
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Hi Gazlas,

    what sizes do you have? There are shims that exist for making the tube fatter to fit a bigger diameter derailler clamp band.

    I haven't seen the specs but it is possible that the side plates for a "10 spd" front derailler are a bit narrower than for a "9spd" front derailler. If so you are more likely to have problems with rubbing when the chain is on a bigger angle. This might be what your mechanic is referring to. If your bike has a long chainstays this will minimise this effect.

    I happen to use a 10spd front derailler with a 9spd system, however I also use a friction shifter, so I can trim to solve any problems. I can say with the deeper inner plate of the new derailler it shifts really well, but I suspect that others won't be fitting friction levers anytime soon.

    Cheers,

    Cameron

  25. #25
    Tandem Vincitur Ritterview's Avatar
    Join Date
    Sep 2005
    Location
    Northern California
    My Bikes
    BMC Pro Machine SLC01, Specialized Globe, Burley Rock 'N Roll tandem, Calfee Dragonfly tandem.
    Posts
    3,159
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    I have a Shimano Dura Ace FD-7703 that I'd love to replace with the Campy Athena triple 11-speed FD, but I can't get the Athena FD to work with the Lightning crank, and non-Campy (TA) 9-10 speed chainrings. If Lightning would get around to making its 135 BCD (Campy) spider, I would have a virtual Athena crank, Campy 11-speed chainrings, the Athena FD, and I'd renoice to send this DA FD to the first tandem that asks for it!


Posting Permissions

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