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  1. #1
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    Minimal Q-factor of the cranks for Mojo

    Does anybody know, what is minimal Q-factor of the cranks, that could fit to the Mojo? I wonder, whether my Middleburn's RS-3 + 108mm BB would fit OK. Thanks. Peter

  2. #2
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    XTR 2007 pedal/chainstay clearance?

    To simplify the question a bit: What is pedal clearance between XTR 2007 cranks and Mojo chainstays (the gap between right crank and right chainstay, left crank/left chainstay gap, measured at the pedal thread)? This information helps too.

  3. #3
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    Caution;  Merge;  Workers Ahead! Can anybody help?

    Hi guys, can anybody help me? Please measure the pedal clearance between the crank (XTR 2007 type only!) and Mojo (SL) chainstay as shown in the picture (for left and right crank, please). There are plenty of you out there, who have XTR cranks on Mojo... Thanks.
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  4. #4
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    incomplete info

    12 mm non drive, 8 mm drive side.
    Not sure why that one's not centered, I think they usually are. The XT ones around the shop are perfectly symetrical.
    H

  5. #5
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    I have a middleburn rs-8 old school square taper with a 113mm bb.
    if that helps at all. the 113 is about the min width I would go with.
    Mitch

  6. #6
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    Many thanks. Both replies have helped me. So with my current cranks + BB the clearance would be ca. 5 and 6 mm. I've had approximately the same clearance on Spec Stumpy. Hans, do you think it's enough for Mojo?

  7. #7
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    So what is the q factor for the 08 XTR cranks, and what is the Ibis spec for the chainline offset on the driveside?

  8. #8
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    Quote Originally Posted by hanssc
    12 mm non drive, 8 mm drive side.
    Not sure why that one's not centered, I think they usually are. The XT ones around the shop are perfectly symetrical.
    H
    Mine's an early '06 model and about the same 11 mm non drive, 8 mm drive side with the original Mojo SX model OEM FSA Afterburner cranks.

    Picture from today:
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  9. #9
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    I think there are only 2007 XTR cranks, FC-M970. Q-factor is 170mm (crank to crank outer distance), crank to crank inner distance is 142mm.
    To complete the info, Q-factor of Middleburn RS-3 w/ Ti Middleburn 108mm BB is 160mm, crank to crank inner distance is 133mm, chain line 48mm.

  10. #10
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    my square taper with the middleburn rs-8 q factor is 168mm outside distance
    Mitch

  11. #11
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    Has anyone tried running a std. 74/110- 24/34/46 crankset on a Mojo? Seems the 46t chainring rubs the chainstay plate as the suspension cycles? Any ideas on how to make the setup work?

  12. #12
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    Chain suck

    Hi,

    I am suffering from a lot of chain suck and I suspect the clearance in the drive side is the problem. I have 6.5mm on a FC-M970 mojo SL frame (2007 swing arm)

    I have already replaced smaller front chain rings and chain and rear pully's but in rain/muddy condition the bike in un-rideable chain suck every 20-30meters, and this is when riding not even changing gears...

    before i replaced the pully on the 2007 XTR rearD i had the problem in dry too, when using the granny and changing gears.

    any suggestions please

  13. #13
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    Hello,

    Regarding the chain suck, I have a few questions:
    what is the arrangment of the spacers that go under the BB cups on your XTR BB? How many on the drive side?


    When you go to the large chain ring, largest cog combo, (plus let the air out of your shock and compress the rear suspension) does it look like you could take any links out without binding the suspension? If so, the shorter chain / higher chain tension is your friend in reducing chainsuck.

    Also the "b" tension screw on the RD can be tightened down increasing the chain tension.

    In muddy conditions the lube you use can make a huge difference as well..

    Please let us know how it goes.

    Take care,

    Hans

  14. #14
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    Concerning the chain: I use 54 links (pairs) for 22-32-44 chain rings setup and 11-34 cassette w/o any problems and chain sucks. For 11-32 cassette 53 chain links (pairs) work OK. Note: SRAM X.0 rear mech with medium cage is used.

  15. #15
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    thanks for the advice.
    i have 54 links and when i let the air out of the shock and chain is on the bigger pair and compress i can compress half and then the chain is really thight, like single speed, so chain is not too long i think.
    next i went on the granny and big rear ring and compressed, it dont feel too loose and there is space for the chain to pass ok.
    I have 2 spacers on the drive side and as i read the shimano xtr instructions it is also as supposed to be.

    the only thing i have not replaced in the process is the rear casette. but i think i will change the entire drive train now.

    my question is being an XTR guy what should i choose for best shifting performance normal or shadow? will it make any difference using XT casette instead of XTR?
    now i have dual control shifters and i am happy with those, but if you say any other combination works better i will try.

  16. #16
    Grams Light Bikes
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    Like Hans was asking...

    1) how many spacers on the drive side of the BB? you said 2 so...might suggest adding a tiny spacer to see if that helps
    2) lube the chain to death
    3) suggest going to a 10 speed chain, lighter, thinner and stronger (works fine on 9 speed drivetrain)
    4) XTR vs XT cogsets, XTR shifts a tad better, nothing huge, the weight diff is large
    5) Shadow shifts better, I think it's the stronger spring? Also the clamp nut is hidden so less chance the a rock will hit it and loosen the cable (although today I did what I thought was not possible, I hit a set of rocks just right and loosened the darn cable, ugh), XT vs XTR shadow, never tried a comparison, but again I would think it's the looks (XTR has Carbon!) and the weight
    6) sounds like the front shifting and rear might need to be tweaked, take it to your local LBS wizard mechanic and they might be able to massage it, you can also play with it yourself tweaking it till it almost wants to over chainsuck (make sense?) and then back off from there
    7) dual controllers are fine

  17. #17
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    Hi

    I have mentioned before on this forum that I too get chain suck on my Mojo. My whole transmission came off my old Spesh enduro where I had no problems with chain suck. As soon as i transferred this onto the mojo I got chain suck. I had xtr rear, xt front mech and lx chainset with KMC chain. I tried both one spacer and 2 spacers on the drive side bottom bracket but it still sucked!
    I have now completely changed my transmission to xtr shadow rear, xtr front mech, xt cranks with wipperman connex chain and it still gets bad chainsuck. The only time I don't get the suck is in completely dry conditions. This happens both just riding in granny gear and changing from middle to granny.
    I have also swapped the chainset off of my hardtail(with which I have never had chain suck even in very muddy conditions) and I still get the chainsuck.

    I borrowed a demo bike 2 times from stif before buying mine and this got the suck on both test rides but I just put that down to probably being worn components being a demo bike. Obviously not.

    I would really appreciate some advice from hans or the Ibis crew if they have experienced this as this is really frustrating when riding and ruins a great bike

  18. #18
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    chain suck

    I have gotten chainsuck in wet conditions, also got it on my Blur and other previous bikes. I'm not sure why it's happening on your Mojo and not on your other bikes. There are some things that might be different -the chainstays might be shorter on the Mojo though that's doubtful if comparing to a hardtail. The chain tension might be lower due to the B tension screw / screw landing location. Lube is a big consideration.

    You could have a shop check your chain line and chain length... Shorter is better on the chain as long as you don't get into binding.

    Otherwise, I haven't a clue I'm afraid....

    H

  19. #19
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    I think running a slightly tighter chain and lubing it regularly is the only advice I can offer. Chianline is important so a really good mechanic can help determine if the chainline is perfect.

  20. #20
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    shorter is better

    I used to get quite a bit of chainsuck then I went to a 2x9 setup and with the shorter chain I have never had a problem. I run a very short chain with 22/34 up front and 11-27 or 11-25 cassette and a sram short cage. I'm just about to tryout 22/36 upfront.

  21. #21
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    Yesterday i participated in a XC race.

    i have just replaced the chain and a new XTR casette and took it for a spin on the same route as the race was going to be held. all was well lubed and the trail was dry. no problems at all, and i was very happy.

    during the night we had heavy rain so i installed my other wheels with more grippy tyres as i knew it would be muddy. the rear wheel had a brand new XT casette, so i was clearly a bit scared not to have run the components together allthough there was only 15km difference in the parts.

    during the race i did get some chain suck over the 3 laps but i keept my head cold and finished 8th place. the system was well lubed with wet lube.

    i agree with Hans, there must be something about the lube issue. what is the best and how much?

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