Viewing 40 posts - 1 through 40 (of 45 total)
  • shimano cranks to dub, what do i need?
  • howsyourdad1
    Free Member

    Hi, replacing my XTR m9000 crnaks and shimano threaded BB with  SRAM DUB GX eagle with threaded BB.

    What tools do i need?  ideally from a european online shop please, i’m in sweden.

    dangeourbrain
    Full Member

    You’ll need a new BB tool, Bike 24 link assuming you have the kit for the shimano BB that will be it.

    If not I’m guessing they came OE so the shimano one could need one or other of two tools depending on which BB you have.

    Why are you swapping over though? Seems an odd change?

    PrinceJohn
    Full Member

    A stiff drink to help with the regret when you decide to remove the DUB bb

    PJM1974
    Free Member

    First off, you’ll need a DUB BB removal tool – SRAM helpfully went with a new standard that means your existing BB tool won’t work Wiggle

    My M8100 groupset came with a BB tool included – this has a dual use in that it is used to torque the lockring that holds the chainring in place.

    ebennett
    Full Member

    Probably just a set of allen keys and a BB removal tool that works for Shimano and SRAM. Park Tool Bottom Bracket Tool (BBT-9) should do the job. You’ll need a Torx screwdriver as well if you need to attach the chainring to the cranks.

    martinhutch
    Full Member

    First thought was patience of a saint and a five foot long breaker bar for when you want to remove the dub cranks. 🙂

    Just type SRAM Dub bottom bracket tool into google, you just need a big (and tiny) allen key for fitting the crankset.

    chakaping
    Free Member

    Why are you swapping over though?

    +1

    Don’t do it to yourself OP.

    dangeourbrain
    Full Member

    SRAM helpfully went with a new standard

    Well in their defence its the same as a lot of 30mm threaded tools and it wouldn’t fit the normal 24mm tool due to the bigger bearings.

    Shimano OTOH changed theirs from the standard tool to silly small one for no good reason.

    davros
    Free Member

    Don’t forget a torque wrench and a breaker bar for installation and removal of the dub cranks.

    alan1977
    Free Member

    Counselling, you need counselling

    i don’t know why you would? you can happily run the sram chain on the shimano chainring

    PJM1974
    Free Member

    Why are you swapping over though?

    Exactly this – I’ve had my bike for three months and have swapped from DUB to XT given my historic distrust of anything made my SRAM that contains bearings.

    Well in their defence its the same as a lot of 30mm threaded tools and it wouldn’t fit the normal 24mm tool due to the bigger bearings.

    Shimano OTOH changed theirs from the standard tool to silly small one for no good reason.

    Yep – The Shimano BB tool has a dual use in that it also torques the chainring retainer thingy and in the case of the XT groupset that I bought, the required tool was shipped in the box with the cranks.

    stanley
    Full Member

    Sram DUB here on a few of the bikes. No problems. All good.

    Lol at the mention of breaker bars and the like… it’s only 50 odd Nm… that’s not that tight really!!

    beamers
    Full Member

    Don’t forget a torque wrench and a breaker bar for installation and removal of the dub cranks.

    In my experience you don’t need a torque wrench when installing the cranks. The bolts torque themselves up to way beyond the prescribed 50nm within a couple of pedal revolutions.

    Removal only possible with a 3 foot section of scaffolding pole on the end of a long allen key, every couple of hundred miles to avoid disappointment.

    Apart from that – great system.

    dangeourbrain
    Full Member

    it’s only 50 odd Nm… that’s not that tight really!!

    It is if you’re using a normal allen key, and as you’re no doubt well aware, the willingness to buy appropriate tools is inversely proportional to the value of your bike.

    davros
    Free Member

    To be fair I haven’t used dub, but have had SRAM 30mm and still have gxp. From what I’ve read, people have the same issues. I can live with the gxp now but the Shimano system and their bbs are so much easier to live with.

    ballsofcottonwool
    Free Member

    In my experience you don’t need a torque wrench when installing the cranks. The bolts torque themselves up to way beyond the prescribed 50nm within a couple of pedal revolutions.

    How does a bolt on a splined axle tighten itself?

    beamers
    Full Member

    How does a bolt on a splined axle tighten itself?

    One of the great mysteries of the DUB system I guess.

    Yak
    Full Member

    Nothing. Well maybe a pen to fill in the returns form for the dub stuff. You have the best already. Don’t change!

    joebristol
    Full Member

    I have dub and gxp and unless you’re chasing weight loss by going XX1 Xd Ebony cranks I wouldn’t swap from xtr ht2 tbh. The 24mm axle system from Shimano is just a more user friendly design.

    I’ve had one Sram dub bb last really well and one go all loose and gritty in short order. My dub cranks are now running in a wheels manufacturing dub bb to see if those bearings last longer. Annoyingly the wheels one has a different bb tool again from the Sram dub size – cost a fortune to change!

    chakaping
    Free Member

    The Shimano BB tool has a dual use in that it also torques the chainring retainer thingy

    Nah, it’s a bit bigger than the DM chainring one. You can do them up “finger tight” with the BB tool, but you need a specific tool to do it right (there are cheap CNC alloy tools for it on ebay tho).

    Don’t get me started on the multitude of DM chainring “standards”.

    alan1977
    Free Member

    singletrackworld.com/forum/topic/shimano-cranks-to-dub-what-do-i-need/#post-12441620

    By using disimilar metals (ally bolt, steel shaft)..
    to be fair.. 50n/m is no wehre near as tight as what ive seen people having to do to release it.. its approx one ugga on a foot long ratchet to me
    I annually loosen and retighten that bolt

    PJM1974
    Free Member

    Nah, it’s a bit bigger than the DM chainring one. You can do them up “finger tight” with the BB tool, but you need a specific tool to do it right (there are cheap CNC alloy tools for it on ebay tho).

    How odd. Just a fortnight ago I used my M8100 chainring / BB tool that came in the box to fit a 30T chainring to my new cranks and to torque my new BB cups?

    howsyourdad1
    Free Member

    ok i get the picture!  My XTR cranks are perhaps 5 years old now and creak like hell after a few rides, despite greasing the chainring bolts, which seem to be the culprit.  Any tips on no creaky goodtimes?

    The weird bcd chainring is also annoying

    dangeourbrain
    Full Member

    Any tips on no creaky goodtimes?

    Avoid DUB bottom brackets?

    Have you tried replacing the crank bolts and receivers (I can’t say I’ve ever had a creaky crank that wasn’t dirt, or pedals, or BB, or knackered ring etc.)

    beamers
    Full Member

    My DUB chainset / BB doesn’t creak.

    When I slacken the chainset bolts regularly (see above) I whip the chainset off and grease up all of the contact points to keep the creaks at bay.

    In a way then its a bonus that I have to slacken the chainset bolt regularly in order to have any hope of getting the ****ing thing undone without getting the local strongman and some medieval torture devices involved to release it.

    Great system.

    dangeourbrain
    Full Member

    Great system.

    You know, I think you may have mentioned that before.

    Scienceofficer
    Free Member

    Ok. Here’s what happens with both these systems.

    The bearings die. They may seize (and do) and because the crank axles are carried on plastic spacers in both systems it’s perfectly possible to keep turning the cranks without really noticing.

    Shimano use a 24mm steel axle which means the bearings in the BB are bigger and tend to last longer before they seize and the steel axle is much more resistant to wear when the bearings do eventually seize.

    The crank axle on a DUB crank is aluminium. When the bearings seize and you don’t notice, you wear a groove in the axle. The system has slop because the axle is loose on the bearings, it feels like you’re bearings are worn and the additional load from the sloppy axle fit wears bearings down at record speed.

    ampthill
    Full Member

    But 2 bottom brackets so your ready to fit the new one after a couple of months. They are terrible

    jeffl
    Full Member

    shimano cranks to dub, what do i need?

    Walk up to a mirror and have a word with yourself 😁

    Stick with the Shimano crankset.

    howsyourdad1
    Free Member

    Haha thanks for the advice!

    beamers
    Full Member

    Great system.

    You know, I think you may have mentioned that before.

    I’m trying to convince myself.

    I’m running a Nukeproof press fit BB and that’s actually been pretty good. 1500 miles on it and its still smooth.

    nickc
    Full Member

    Sram DUB here on a few of the bikes. No problems. All good.

    Same here. the only real difference is the axle material, everything else functionally the same – look after them the same way you’d look after any part on a MTB with a bearing in it.

    chakaping
    Free Member

    Consider SLX cranks mate – cheap, easy to fit & remove and surprisingly competitive on weight (crankarms lighter than XT IIRC).

    rootes1
    Full Member

    if you do go dub….

    use their cheaper / heavier bolt instead of the alu one:

    https://www.sjscycles.co.uk/chainsets/sram-dub-crank-arm-bolt-kit-m18-m30-self-extracting-steel-black/

    will help in the future when you have to removed the cranks.

    weeksy
    Full Member

    Plenty of Dubs here, my Trek is a PF Dub !!!! beat that… however, it’s also completely silent and lovely.

    The Status is also a Dub… and silent…

    Can’t fault Dub

    ampthill
    Full Member

    Firstly I think the DUB threaded bottom bracket is the issue. I think the larger diameter ones will have space for better seals bearings


    @nickc
    what should I be doing to look after my bottom bracket?

    dangeourbrain
    Full Member

    what should I be doing to look after my bottom bracket?

    look after them the same way you’d look after any part on a MTB with a bearing in it.

    So fit it, ignore it, pressure wash occasionally then complain bitterly when it fails after 4 months 18 months but you’re sure it’s not that long.

    nickc
    Full Member

    @amptill, look after it the same way you’d look after your headset? Take it apart every now and again, inspect it and grease it if it needs it. Bottom brackets are directly in the firing line of all the crap, that folks expect them to just go on and on regardless is a bit fanciful.

    My previous DUB did over 5500 miles.

    ampthill
    Full Member

    I suppose it might help. But I haven’t needed to give any bottom bracket any maintenance since they stopped having loose balls

    nickc
    Full Member

    yes, you’re probably right, there’s no reason that the DUB may have gone on to do 5K miles without me touching it.

Viewing 40 posts - 1 through 40 (of 45 total)

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