Results 1 to 9 of 9
  1. #1
    mtbr member
    Reputation:
    Join Date
    Jan 2013
    Posts
    35

    Dura Ace Cassette with Saint Short Cage Derailleur

    Hi everyone,

    I'm contemplating switching my cassette from a 11-32t SRAM PG970 to a Dura Ace 12-25t 9 speed on my mountain bike.

    I have a Shimano RD-M810 Saint shadow derailleur (short cage) on my bike right now. It doesn't take up chain slack when I'm in granny, which is one of the main reasons I want to go with this change. Another reason is that the gearing is just too low with the 11-32t.

    So the question is, will this work? I've heard Shimano road/mountain cog spacings are the same, but maybe there is some other reason for this to be incompatible.

    Also, I have a Shimano XT M765 dual control shift lever, if that matters.

  2. #2
    mtbr member
    Reputation:
    Join Date
    Nov 2011
    Posts
    2,483
    Should work OK but why not just stop using the granny?

  3. #3
    mtbr member
    Reputation:
    Join Date
    Feb 2009
    Posts
    877
    Why do you have a granny gear with a short cage derailleur in the first place?

  4. #4
    mtbr member
    Reputation:
    Join Date
    Mar 2011
    Posts
    979
    It would be cheaper to buy something like an SLX/XT M662 M772 RD than a DA cassette - they are very pricey if I remember correctly.
    I sometimes run a 10 speed Shimano 11-34 MTN cassette on my cross bike for off road touring when loaded and it works fine with 10 speed road STI shifters and a M772 RD the sprocket spacing for each spacing is he same for road and mountain

  5. #5
    mtbr member
    Reputation:
    Join Date
    Jan 2013
    Posts
    35
    I originally had a long cage XT on there (it broke when my old chain snapped). I switched to the Saint cause I scored it cheap NOS on fleaBay.

    I actually never thought about taking out the granny gear, would it be possible to lock the 3 speed dual control shifter to 2 speeds up front (I have an XT front derailleur)?

    Anyhoo, as an update. I went out and got a 400 mile old 12-25 ultegra cassette for like $15. Took out a few links from the chain and now everything works perfectly. =) Spin out a bit faster on descents cause of the 11t v 12t thing but that's just nitpicking.

    I might actually still take out the granny gear like you guys suggested.

  6. #6
    mtbr member
    Reputation:
    Join Date
    Jan 2013
    Posts
    35
    Here are some pictures from today of the new drive train =)Dura Ace Cassette with Saint Short Cage Derailleur-8631506567_9ce36b3fff_b.jpgDura Ace Cassette with Saint Short Cage Derailleur-8632614538_a2da8ae0a7_b.jpgDura Ace Cassette with Saint Short Cage Derailleur-8631509343_09b6d46aa0_b.jpgDura Ace Cassette with Saint Short Cage Derailleur-8632617156_342b7028a8_b.jpg

  7. #7
    mtbr member
    Reputation: Handy's Avatar
    Join Date
    May 2011
    Posts
    52

    Shimano Saint RD-810-A-GS

    Dear Crank Monkey,

    Correct me if I am wrong, reward me if I am correct...

    First of all, great idea ! I have been thinking along similar lines, but I couldn't put what was wrong into words until a change was made with the equipment. Imagine, each rider has their own riding style. My riding style with the equipment I was using, over the terrain I was riding, was leading me to overshifting. When I changed gears, I would change too many gears and then I would have to come back to the gear I wanted. Perhaps some riders would say, change your riding style and stop overshifting, but, not so easy.

    Other riders may know, let your style flow, change your equipment to suite your style and terrain. Enter, the Shimano Ultegra CS-6500 12-23 cassette. The cassette this cassette replaced was a HG-80 11-28 cassette. The new rear derailleur is a Shimano Saint RD810-A-GS, the front derailleur is XT-FD-M771 high clamp, low swing, the chain is a Sram PC-991, and the shifters are XTR SL-970, the crank is a Shimano FC-590, 22, 32, 44, and the distance from crank to rear axle is about 16 1/2 inches.

    While riding before the cassette switch, I would be approaching a hill, let's say a small hill, and there are not many small hills and not any big hills. So I am riding along, begining to go uphill, more, downshifting while in my middle chain ring(32), downshifting more, until I reach the top of the cassette in the 28 tooth cog, now I want to down shift more, I " bail out" to my small chain ring(22), now I am in 22 x 28 and this gearing is too low and does not produce the result I was looking for. Equipment change...now, you can guess the rest of the story.

    Ok, back to me riding along, going uphill, downshifting, downshifting, 32 x 23, top of my cassette, I "bail out" to my small chainring, and I am now in 22 x 23, sometimes, still too low, but much better then before. Perhaps, I need to go to a 12-21 cassette. I miss the number 18 tooth cog. I think, I will end up with a 13 - 23 cassette, remove the beginer gear 13, replace it with a beginer gear 12, and have a custom 12-23 cassette w/o the 13 tooth cog, 12, 14, 15, 16,17,18,19,21,23. All nine speed equipment.

    This change was made last Thursday, so I have only been testing for four days. Testing results so far, better intermediate upshifting while in the middle chain ring. Before, upshifting from 21cog to 11cog while in the middle chain ring, shift from 21 to 18 ok, shift from 18 to 16 ok, shift from 16 to 14 ok, shift from 14 to 13, sometimes slow to shift, shift from 13 to 12 often times would not shift, upshift again, the chain then drops to the 11 cog and I have to downshift back up to 12 and then again shifting from 12 to 11 often times not shifting up to 11. Sometimes then in extreme situations, I down shift back up to say 14 and then upshift three times fast to try to get the chain to jump to the 11 tooth cog. All of this shifting with the HG-80 11-28 cassette with a Shimano XT-RD-M772 SGS rear derailleur.

    Perhaps some riders are thinking, what about chain wrap capacity ? And this is a full suspension bike, some riders may think I am over taxing my rear derailleur and it will wear out sooner...and then I can put this derailleur in the box with all the other old derailleurs.

    Yours truly,



    Handy

    P. S. Don't mess with my middle chain ring, the magic of the 32.
    Attached Images Attached Images  

  8. #8
    mtbr member
    Reputation:
    Join Date
    Jan 2013
    Posts
    35
    Hey Handy,

    I couldn't agree more with matching equipment to riding style. I think when it comes to shifting, a lot of the "feel" comes from the type of shifter you are using and cassette choice needs to match the shifters. I haven't really had any experience riding the XTR SL-970 (rapidfire?) shifters, but the ultegra cassette + short cage saint derailleur combo is really working well for my dual-control XT M765 shifters.

    Usually when I come to a hill, I like to flick my rear lever up to upshift one gear; crank a few revs to gain some speed; press the lever down halfway to down shift 2 gears immediately as I get to the hill (so -1 from original) and mesh up as needed (sometimes I press the lever all the way down to downshift 3 gears). The XT M765 shifter is really good at upshifting under heavy pedaling, so if I need I can go up one more to compensate if I want. Also, I never touch my front derailleur when on a hill.

    Now here's where the cassette change comes in. Before, when I was on 11-32, dumping 3 gears at once can be very taxing on the rear derailleur when riding near the lower limit of the cassette. The biggest 3 rings on the old cassette were the ones giving me the most trouble. Even more annoying is when I'm shifting fast back up from those gears, sometimes the chain would skip a few clips before catching. I think the problem is that the teeth count rises too quickly for those 3 low speed rings.

    Now with the Ultegra 12-25, I can dump 3 gears no matter where I am on the cassette. The teeth count increase is much more linear, which makes it that much easier for the derailleur to move the chain.

    -----

    For the downhill, I like to shift my front and my rear at the same time for big hills. So when I'm on flat ground just before a descent, I would press down on the front lever to go up one ring, dump 3 gears on the rear at the same time. This way, when I'm on the descent and need to upshift to add some responsiveness to the pedals, I have +3 capacity on the rear derailleur compared to before without touching the front shifter. Again, with the ultegra cassette, dumping multiple gears feel much smoother than before.

    -----

    So yeah, I guess that's the most noticeable improvement for me when it comes to shifting with the new ultegra cassette.

    I think for your setup, maybe go for an actual 12-23 cassette, 12,13,14,15,16,17,19,21,23. I just fear that shifting might be less than smooth if you jump from 12 to 14 on the top end for your highspeed gears on a custom cassette.

  9. #9
    mtbr member
    Reputation:
    Join Date
    Jan 2013
    Posts
    35
    Also, I ride a hardtail, so I would imagine it climbs quite differently compared to a full sus bike. My chainstay is a little bit longer at 425mm, but the chain is still quite short. I always like to climb out of saddle with my fork locked out.

    My bike is here on the last page:

    Let's see your raw aluminium!

Posting Permissions

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