Experimenting with a drivetrain: a rear derailleur, a shitfer, a cassette

Discussion in 'Cycling Equipment' started by KROSS, May 16, 2014.

  1. KROSS

    KROSS New Member

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    Hello there,

    There's a set of 3 chainrings on my bike, a cassette of 8 cogs, and a little bent rear derailleur which made me wanna go for some changes. I could just get a new rear derailleur but I've come up with an idea of experiencing a new ride. I've never used 2 chainrings ("granny" and middle) and will barely ever use any cog of a cassette which doesn't provide you with good speed. All the time I've used my 3x8 gear and would like to know if it is possible:

    1. to get rid of a front derailleur (and its shifter as well), middle and "granny" chainrings;

    2. A: to add 1-3 more cogs cassette to have 9-11 cogs in total;
    2. B: or if possible to have fewer cogs than 8 but of smaller sizes so that it would result in having e.g. 3-4 cogs of small sizes with perfomance of range e.g. 3x8, 3x9, 3x10, 3x11 of a standart-sized cassette);

    3. If it's 2A: I just change my cassette to another one with 9-11 cogs, buy a rear derailleur which has a range of switching of 1-9or11, and probably I must get a new shifter of rear derailleur to make sure its N of "clicks" coincides with N of cogs and a range of switching of a rear derailleur.

    If it's 2B:
    3. I get a new e.g. 10-cogs cassette, get rid of 6 biggest cogs if possible (or just buy a small-cogs set cassette if they are on the market), get a new shifter of a rear derailleur with 10 N of "clicks", buy a new derailleur with range of switching of 1-10 and try to "suit" it a proper way on my bike. And it will probably result in shifting by clicking only the last four numbers (7, 8, 9, 10) of a shifter, dozens of "fun" of trying to configure the rear derailleur with switching range of 1-10 to work well on a 4-cogs cassette of small cogs.

    Extra question. If a shifter and a rear derailleur are by 1 manufacturer is there a need in checking for their ratio conciding?
     
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  2. dabac

    dabac Well-Known Member

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    Yes, you can run 1x9,1x10, or 1x11. MTB and CX people like that.

    You'd still need a new RD though.
     
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  3. KROSS

    KROSS New Member

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    So I will get a detached/separate/or-however-it's-called chainring of the same pattern my cranks have, get a new chain of a proper size, buy a 10-cogged cassette, and that's all. And what about a shifter? Have to get a new one with 10 clicks? And I should buy a RD and a shifter of the same manufacturer to make sure the ratio coincides?
     
  4. CAMPYBOB

    CAMPYBOB Well-Known Member

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    Quote by Kross:
    "And I should buy a RD and a shifter of the same manufacturer to make sure the ratio coincides?"

    Yes.

    Alf can tell you all the oddball combinations of cassette manufacturers and spacings that can be made to work well with a Campagnolo shifter, but it is almost always advised to use SRAM with SRAM, shimaNO with shimaNO, Campy with Campy, etc.

    Match the shifter brand and number of gears to your cassette. Front chainring choices can be more forgiving, especially if you are only going to use one chainring and no front derailleur/shifter. Try and use a chainring that is also the correct thickness for your new number of rear gears and chain.

    So...10 gears in the rear...10-speed chain...matching 10-speed rear shifter...matching 10-speed rear derailleur...9, 10 or 11 speed chainring 'should' work as long as the mounting bolt circle matches your current crank spider.
     
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  5. KROSS

    KROSS New Member

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    Thanks a lot guys. Just gotta look at budget and get components.

    Just 1 moment:
    Quote:
    Originally Posted by CAMPYBOB .
    shimaNO with shimaNO
    Is there something wrong with Shimano components?
     
  6. CAMPYBOB

    CAMPYBOB Well-Known Member

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    NO.

    Other than they're not Campy! Just kidding.
     
  7. KROSS

    KROSS New Member

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    And according to info here my rear hub is probably compatible with 9-10 cassettes? At least 9.
    (Joy Tech D041DSE.)

    I think it must be.

    UP Yes, figured it out.
     
  8. maydog

    maydog Well-Known Member

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    If you are such a beast with the gearing, you could go with a Swampy special - 52 teeth in the middle cog and 57 in the (very) big ring.

    What are your current chainring sizes?
     
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  9. KROSS

    KROSS New Member

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    Quote:
    Originally Posted by maydog .
    What are your current chainring sizes?

    http://www.universalcycles.com/shopping/product_details.php?id=46763&category=64 (48-38-28)

    Jesus, what an idiot I am. I just realised that there's no need in more cogged cassette if its last cogg already has 11th teeth unless you want a smoother shifting. It won't affect your max speed.

    God. Thank you guys for making me understand how stupid I am. If there are advises of something to deal with chainrings please let me know, however I'm sure there are already dozens of threads of the same contents...

    So my current chainring system linked above doesn't provide enough "fun".
    PS Interesting if it's possible to have 1 rear gear with 11th (a so-called single speed) teeth and 2-3 chainrings. What a shifting will be like then? As I don't find a use of any other rear gear except the one provided by 11th cog I see no need in having those components installed on my bike.

    Btw, my FD is Shimano Altus FD-M310.
    Seems I need to find out about the rest myself (SS, road bikes chainrings compatibility with MTB cranks). I'm sure I'll find what I need in other threads.

    Thanks one more time again, you saved me/my budget from my ignorance.
     
  10. maydog

    maydog Well-Known Member

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    What size are your wheels? What kind of bike is this that you want to modify.

    A 48x11 is still pretty fast. At an 80rpm cadence with 700x25 wheels that's 27mph, faster than most can handle for more than a few minutes.At a 100 rpm, thats 34mph.

    You may want to play with this calculator:to get an idea of gearing effects on speed.

    http://sheldonbrown.com/gears/
     
  11. KROSS

    KROSS New Member

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    The problem is that 48x11 is kinda easy to ride, not sure about my rpm and how efficient 100rpm can be but you just go to 44x11 max potential thereby it seems more rational to get a chainring with more teeth than 100+rpm'ing 48x11.

    http://www.2011.krossvelo.ru/p-level_a2_disc_xt/
    The second tab under the picture for specs. (The only I can say is that I have 26" wheels.)
     
  12. dabac

    dabac Well-Known Member

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    Bicycling is a lot more about stamina than strength. More huffing and puffing than grunting and straining. And the whole cycling community is surprisingly agreed that the sweet spot is an average cadence in about the 80-100 range. and that would bring your bike into the 30 mph range before an average rider spins out. So unless you're an anatomical freak, or spend important time at 25+ mph - work on pedalling technique, not bike technology. Mashing AKA pedalling hard-and-slow is a lot tougher on your knees than spinning. Upping the cadence and lowering the load is a stock recommendation for riders with knee trouble. It's possible to set a bike up to use a triple crank and a single sprocket. But as you still need to keep the rear derailer as a chain tensioner it's kinda pointless. You end up needing(almost) all the rear gear bits on the bike, and you have the slower shifting of the front. Big steps between gears, slow shifting and not much reduction in hardware. Single front or 3-speed IGH makes a lot more sense.
     
  13. alfeng

    alfeng Well-Known Member

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    Okay ...

    So, you are riding a MTB on paved roads ....

    You have a couple of options ...

    1. install a Road crankset ... for this frame, a standard length BB spindle was "okay" ... but, on some MTB frames you may need a BB which is capable of handling a Triple ROAD CRANKSET to ensure chainring clearance with the chainstays

    [​IMG]
    With a Road Crankset, you can install larger chainrings ... with 52t & 53t now being common sizes.

    • I recommend you opt for a Road crankset which uses "standard" 5-arm, 130BCD chainrings (e.g., Shimano or FSA)
    • larger size chainrings are available which are typically used on Triathlon bikes ... but, I think that the largest realistic size chainring which a MTB front derailleur can handle is a 53t.

    2. and/or, install 700c wheels/tyres on your current MTB Hardtail ...

    Here is one of my Hardtail frames which I converted to to a Road bike by installing a Road fork + 700c wheels/tyres + a Road Crankset with a "Triple" BB spindle due to the width of the chainstays ...
    [​IMG]

    And, here is another MTB frame which only needed a "standard" length BB spindle ...
    [​IMG]

    Because your KROSS bike has disc brakes, you can simply install a pair of 29er wheels & add the tyre size which you prefer (e.g., 700x28).
     
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  14. oldbobcat

    oldbobcat Well-Known Member

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    Be careful about installing road cranksets on mountain bikes. Often, especially on the newer bikes with 135 mm axle spacing and 73 mm bottom bracket shells, the inner chainring will hit the chain stay. Then you get a bottom bracket with a longer spindle so the ring clears the stays, and the chain line won't cross over to the inner cassette cogs correctly, and the front derailleur won't reach the outer ring. Not saying don't try it, just saying beware.
     
  15. alfeng

    alfeng Well-Known Member

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    FWIW. MY limited experience with installing Road cranks on aluminum frames (both MTB and Touring) which have 135mm dropouts is that it is the OUTER chainring which may-or-may-not come into contact with the chainstay if a longer BB spindle is not used and not any of the smaller, inner chainrings.
     
  16. KROSS

    KROSS New Member

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    Not sure I need a 29'er or a too-road bike (instead of road-riding I also like doing it on soil where roughness and drops of less than 2 meters meters can take place), just another chainrings with more teeth.

    I decided to buy another cassette of the same specs (8 cogs), and a new rear derailleur as the old is too bent to work well.

    So the questions are:
    — if my chainline is 50mm, do I need another BB for a set of 2-3 chainrings with the biggest having 52 (or 53) teeth?
    — If I need a road BB can it (a BB) be damaged by landing from lower-than-2-meter height?
    — Not sure but some people say that you can try to adjust the 28-38-48-FD for xx-xx-53.
     
  17. alfeng

    alfeng Well-Known Member

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    29er tyres are massive ... and, they probably will NOT fit in our bike's frame/fork ...

    You just want to consider a set of 29er wheels if you want to go faster when riding on pavement or hard-packed gravel/etc. ...

    • 29er rims are the same 700c spec as you would find on a Road rim ... the rim's width & hub used are typically the difference ...

    • The 29er wheelset would allow you to use Road tyres (probably 700x25 would be the smallest size unless you had semi-custom wheels laced up for your bike) ...

    • 700x28 tyres + a 48t chainring may be all you need to achieve the greater speed that you want ... most MTB frames can handle a 48t chainring
    • your crank has a 104BCD (Bolt Circle Diameter)
    • a 48t chainring is the largest (AFAIK) 104BCD chainring that is available
    • and therefore, is component in the combination of future parts which you may want to consider along with a 700c wheelset before fitting a Road crank on your bike.

    YOU will have to either measure the width of the chainstays and/or included a picture (here) where the teeth of chainrings are closest to allow a long-distance estimate of whether-or-not you will need a longer BB spindle ...

    OR, simply try a Road crankset on your bike and see if the teeth clear the chainstays with the 'normal' BB which yields a 145mm-to-150mm Q-factor (i.e., the distance between the outside of the crank arms where the pedals are attached) ...

    1.. As far as the spindle length, you should NOT have to worry about the chainline, per se ...that will take care of itself ... and (again), it is the chainring clearance which is your concern if you opt for a larger-than-48t outer chainring.

    2. Most of the Shimano & the FSA BBs are essentially the same (if External) and of the same design & material if cartridge regardless of whether it is cataloged in the Road or MTB category ... Downhill BBs may be another issue ... so the BB typically won't be ruined unless you get a BB with ceramic bearings ... however, I can't be sure about the crank or your pedals if you are planning on hucking a couple of meteres with a Road crank or with many MTB cranks.

    3. Despite what Shimano indicates, their MTB front derailleurs CAN accommodate a 52t chainring, and, while I don't recall trying a 53t chainring, I would presume a 53t chainring would be good-to-go with a Shimano MTB front derailleur because the lower arc of the outer cage is, by my reckoning (and, presuming that Shimano hasn't changed anything), THE SAME.
     
  18. KROSS

    KROSS New Member

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    I think the biggest chainring of 53t won't "touch" chainstays as the space (on my bike) seems big enough (2 sm at least with my 48t chainring, I can take a photo of it later).

    And what to 29er I have heard that when practicing landing, etc. the wheels consequently become more "flexible".

    As to MTB cranks, yea, they start spinning out from time to time (mine at least, the crank at left).

    LOL, just figured out my FC-M311 cranksets comes in both 28-38-48t and 42/32/22t variants, not yet sure about my specs. No more info on the official site stated, so gotta calculate those t myself. Anyway, I'd like to go for 53t so anyway I'll find some info about the q-factor.
     
  19. dabac

    dabac Well-Known Member

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    Spinning out is Bike Speak for when you can't turn the pedals any faster. W/o special training, this is generally agreed to happen somewhere above 100 RPM.

    You'd need to have a really weird crankset for only the left to spin out - so probably you're talking about something else.

    Even a 42T will let you reach 25MPH, and a 48T will take you to 30 MPH. Are you really that fast, often enough and long enough for an even higher gearing to make sense?
    I think you're about to spend considerable effort on something with very little payoff apart from pride on getting it done.

    And yeah, increase the wheel diameter and all other being the same - hub width, spoke count, spoke gauge - then the wheel will get flexier. Some DHers use 24" wheels for higher strength.
     
  20. alfeng

    alfeng Well-Known Member

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    FWIW. I doubt that your stock 26" wheels will survive repeated 2 meter drops ...

    Regardless, MY point was that you should use a second set of wheels which have 700c/29er rims for when you are on pavement & a set of 26" wheels for your off road riding.
     
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