Search the forum using the power of Google

Viewing 33 posts - 1 through 33 (of 33 total)
  • Does 1:1 actuation mean cheap 10 speed?
  • mafiafish
    Free Member

    If I get a 1:1 shifter linked to a 9 speed mech say x7/x9, considering a 10 speed cassette is no wider than a 9 speed one as far as I know) would the rear mech shift at the correct increments?

    steveh
    Full Member

    The shimano and sram 1:1 rates are slightly different as I understand it so it won’t work.

    mafiafish
    Free Member

    This would be using a sram 1:1 10 speed shifter and an older x9 mech. Is it the mechanicals of the mech which mean the ratio won’t work i.e. pivots/ springs lengths of rockers etc?

    njee20
    Full Member

    Slightly confused by what you’re asking, but you can’t mix and match SRAM 9 and 10 speed stuff, the cable pull ratios are not the same, 10 speed is less than 1:1.

    It’s the actuation of the spring/pivots which defines this, you’d seriously struggle to alter it. If you want to go 10 speed just buy a new mech!

    mafiafish
    Free Member

    Thanks, that’s what I thought might be the case, think I’ll go the x7 10 speed route then.

    Babbel
    Free Member

    Unless I’m missing something the 9 speed mech will be fine. The shifter defines the increments the mech moves. The mech just does at it is told! So as long as the stops on the mech are set so they reach top and bottom sprockets you’ll be fine.
    I ran a 9 spd set up with a 7 spd mech for quite a while with no probs.
    This was with Shimano kit though. May be with SRAM they have kept the amount of cable pull per shift the same and altered the mech. Seems unlikely as 7/8/9/ speed are interchangeable.

    bigyinn
    Free Member

    babbel, im sory but i think youre wrong and njee20 has it right.

    ac282
    Full Member

    You are missing something.
    The shifter defines how much cable is pulled per click.
    The design of the mech defnines how much it moves for a given amount of cable pull.
    For most 7 – 9 speed stuff (eg shimano) the mechs moved the same amount for a given amount of cable pull.

    10 spd sram mechs are different to 9spd sram mechs but the same as their 10spd road stuff.

    10spd shimano mtb mechs have a different geometry to their other stuff.

    geoffj
    Full Member

    If the range the over which the mech moves is the same for 9 and 10 speed setups, then surely the mech will work with 10 speed shifter. I guess the jockey wheels may be too wide for 10 speed chains though?

    Confused.

    midlifecrashes
    Full Member

    But there’s more to it than cable pulled per click of the shifter. There’s also the ratio of how much side to side movement of the chain per unit pull of cable. 7/8/9 Shimano held these similar so lots of compatibility. SRAM 9 was different so you couldn’t mix and match. Shimano and SRAM 10 are both different again, as is Campagnolo 11! You could put some friction shifters on there and not bother with all this clicking, but rather you than me.

    geoffj
    Full Member

    So in simple terms, the actuation rate of a Shimano 10 speed mech is different to a 7/8/9 speed one?

    scottidog
    Free Member

    I don’t get it.

    The way I see it is that if 9 and 10 speed cassettes are the same width. Mechs move uniformly across this width and all the shifter does is divide that space up into 9 or 10 equal segments. Therefore the mech doesn’t matter.

    I’m pretty sure the 105 mech on my dh bike is a 9 or 10 speed.

    IdleJon
    Full Member

    I think that some of you need to read the question carefully and think about how your bike actually works.

    According to the SRAM website, 10speed Exact Actuation is 1:1, which is irrelevant anyway because the question is would the rear mech work.

    In theory, if you were to buy SRAM 10sp shifters and cassette, then ANY rear mech would do the job as long as it pulled across the cassette at the correct angle and as long as the chain would run through. (I’m assuming that Sram haven’t completely changed the angle that their rear mechs pull, which seems unlikely to me.)

    Cut through the marketing rubbish and that is all that is needed. Nothing to do with cable pull per click or ‘side to side movement of the chain per cable pull’ (huh?). Why would friction shifters work any better than the dedicated 10sp shifters given that any problem would be with the mech itself?

    I would give it a go, mafiafish. The worst that could happen is that you need to buy a new rear mech if you aren’t getting good shifts. Of course it may not work as perfectly as a complete new 10sp system but that doesn’t mean it won’t work satisfactorily.

    The same issue comes up every time 1 new cog is added, the same confusion every time.

    geoffj
    Full Member

    From Sheldon Brown – http://www.sheldonbrown.com/k7.html#roadmtb

    Note, also that most rear derailers do not care how many gears you have. You do not need to have a so-called “10-speed” derailer to use a 10-speed cassette. This is true of all Shimano derailers with the exception of 1996 and earlier (pre-9-speed) Dura-Ace units, and “Shadow” series derailers, which work only with XTR 10-speed shifters. (You also can do a minor modification to a traditional Deore MTB rear derailer to work even with a “Shadow” series cassette that has a 36-tooth large sprocket).

    I’m not saying I don’t believe that the actuation may be different, but it would be interesting to hear for definite. I suspect a whif of marketing ball cocks to some of this.

    midlifecrashes
    Full Member

    I think Shimano 9&10 roadie stuff has the same ratios at the dérailleur end as Shimano 9 (Mega9) MTB. Shimano 10(DynaSys) MTB has a different amount of cable pull per shift at the shifter and a different ratio of sideways movement of the chain per unit of cable pull.Shimano 10 speed roadie shifters pull less cable per click so rear mechs were compatible with 9 speed. Don’t ask me about SRAM road stuff though. The cable pulled per click isn’t even either, you get less cable pulled in the middle of the range than the ends. I don’t think either the Sheldon Brown (RIP) or Chris Juden at CTC are properly up to date with this stuff, but here’s the CTC page.

    CTC gear ratios page.

    IdleJon
    Full Member

    Don’t ask me about SRAM road stuff though. The cable pulled per click isn’t even either, you get less cable pulled in the middle of the range than the ends.

    According to the Sram website, it’s a 1:1 pull ratio with even gaps between the cassette cogs, so cannot possibly be as you describe.

    mafiafish
    Free Member

    Ok as far as I see it the build of the mech i.e where the pivots are, the distance between pivots and path of the ‘armature’ upon being pulled might be a bit different in the 10 speed than the 9. By this I mean a 1:1 ratio on a 9 speed is to move a 9 speed mech x mm across the cassette. Likewise for a 10speed pairing but if the mechanical method of achieving that shift of x distance is different a 9 speed mech my be shifted by a different amount?
    I will give it a go though!

    lunge
    Full Member

    Right, I will try and describe as best I can. Firstly, lets ignore pull ratios for the moment.

    The lever pulls a set amount of cable per click. This will not change, it is a set amount over every click.
    The mech is set to move within a set distance (basically the distance from the smallest cog to the biggest cog).
    Now the mech can be designed to (within reason) move any distance for a given amount cable pull. It could, in theory at least, be designed to move across the entire cassette with the cable pull from 1 click of a shifter, or it could be set up to move 1 tenth or 1 ninth of the distance per click.

    The reason 9 and 10 speed are not compatible is that the mechs are designed to move a different distance “per click”. You could put a 9 speed mech on but 1 click of the shift wouldn’t move it the correct amount to change cog (it may be to much, it may be to little, I don’t know, but it would not be right).

    I suspect Shimano could have designed the mechs and shifters to be cross compatible across ranges but they haven’t, so you can’t!

    Hope this helps!

    Keef
    Free Member

    why would anyone need a choice of 30 ratios ? (yes,I know there may be duplicates) ?

    27 is far too many anyway. 😆

    ac282
    Full Member

    You don’t but 20 would be good.

    Keef
    Free Member

    I reckon 5 or so would be enough personally,I just don’t understand the need for 30 !

    Coleman
    Free Member

    I’m afraid I don’t understand anything about all this ratio theorising, but I do know that a 10 speed cassete is slightly narrower than a 9 speed – hence the spacer supplied with 10 speed.
    All totally irrelevant to this discussion, but I now know why I fit groupsets – better value, look good and work faultlessly! Good luck.

    njee20
    Full Member

    Spacer only comes with 10 speed road cassettes.

    I really don’t get why so many people struggle with this. Everyone gets that SRAM and Shimano 9 speed mechs/shifters are not compatible, so why on earth do so many people not get the 9/10 speed incompatibility.

    There are 4 different cable pull ratios:

    1. Shimano 7/8/9 mtb and 10 speed road excluding 7900, 6700 and 5600.
    2. Shimano 10 speed Mtb and road groups above (although the road groups have a unique front mech pull)
    3. SRAM 9 speed.
    4. SRAM 10 speed road and mtb.

    Mechs and shifters must match in order for it to work to it’s full potential. Simple.

    nicko74
    Full Member

    Tell you what, can someone just get a 10 speed cassette and shifter and give it a go?

    While we’re at it, I have this plane, and unfortunately it’s currently parked on a conveyor belt. Can someone tell me how I can take off?

    scottidog
    Free Member

    Here: http://www.chainreactioncycles.com/Models.aspx?ModelID=13595

    9 & 10 speed compatible rear mech.

    Mister-P
    Free Member

    Yes scottidog, a road ten speed rear mech will work with a 9 speed road or 9 speed MTB shifter. It will not work with a 10 speed MTB shifter. Nor will a 10 speed MTB rear mech work with a 10 speed road or 9 speed road / MTB shifter.

    This is all for Shimano, I have no knowledge of SRAM.

    scottidog
    Free Member

    That’s not very sporting of them is it!

    njee20
    Full Member

    Read my last post, those are the 4 ratios.

    mattsccm
    Free Member

    I disagree. forgetting the differnt pull rates , virtually any shimano mech ( there are one or two exceptions) will work fine over a 10 speed cassette,road shifters work xt fine, so do campag. I use all sorts of combos.Avoid SRAM shifters aand it will probably work
    Search for shimergo on the web,espcially the CTC site and you’ll find away

    njee20
    Full Member

    There are bodges, running cables the wrong sides of pinch bolts are what not, but if you don’t want to be a bodger and want stuff to work perfectly it’s not great. I wasn’t getting into Campag incidentally, just mtb stuff, and acknowledging some road parts will work 9/10 speed.

    You could use road flat bar 10 speed shifters with a 9 speed mtb mech, be about the cheapest way of doing it.

    pdw
    Free Member

    1. Shimano 7/8/9 mtb and 10 speed road excluding 7900, 6700 and 5600.

    I believe that 7900, 6700, and 5700 use the same rear cable ratios as older stuff.

    If you look at the 2009 road charts, all the rear shifters, new and old, are in the same box on the left. The FD cable pull and brake pulls are different, but RD cable pull is the same.

    Hairychested
    Free Member

    I thought back in the day that SRAM Gripshift ESP system worked in such a way that when you pulled 1mm of the cable with the shifter the rear mech moved the same – 1mm to the side, whereas a Shimano rear mech would’ve moved 2mm. If I were correct I’d mean 10sp stuff with a 1:1 ratio should work together nicely, just the way XT rear mechs work with Rocket shifters. Am I totally wrong?

    Brycey
    Free Member

    Scottidog

    I’ve just had yet another Saint short cage implode on my DH, was considering a 105 as I know a lot of folk used to run them. Can you see any reason why a Saint (new range) shifter wouldn’t run a 105 on 9 speed?

    Cheers

Viewing 33 posts - 1 through 33 (of 33 total)

The topic ‘Does 1:1 actuation mean cheap 10 speed?’ is closed to new replies.

Search the forum using the power of Google

Thanks for popping by - why not stay a while?IT'S FREE

Sign up as a Singletrack Member and you can leave comments on stories, use the classified ads, and post in our forums, do quizzes and more.

Join us, join in, it’s free, and fun.