shimano cranks to d...
 

shimano cranks to dub, what do i need?

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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.

 
Posted : 28/06/2022 1:47 pm
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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?

 
Posted : 28/06/2022 1:52 pm
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A stiff drink to help with the regret when you decide to remove the DUB bb

 
Posted : 28/06/2022 1:52 pm
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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.

 
Posted : 28/06/2022 1:53 pm
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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.

 
Posted : 28/06/2022 1:55 pm
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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.

 
Posted : 28/06/2022 1:56 pm
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Why are you swapping over though?

+1

Don't do it to yourself OP.

 
Posted : 28/06/2022 1:57 pm
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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.

 
Posted : 28/06/2022 2:05 pm
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Don't forget a torque wrench and a breaker bar for installation and removal of the dub cranks.

 
Posted : 28/06/2022 2:08 pm
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Counselling, you need counselling

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

 
Posted : 28/06/2022 2:10 pm
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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.

 
Posted : 28/06/2022 2:19 pm
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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!!

 
Posted : 28/06/2022 2:24 pm
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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.

 
Posted : 28/06/2022 2:29 pm
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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.

 
Posted : 28/06/2022 2:29 pm
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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.

 
Posted : 28/06/2022 2:31 pm
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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?

 
Posted : 28/06/2022 2:43 pm
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How does a bolt on a splined axle tighten itself?

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

 
Posted : 28/06/2022 2:48 pm
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Nothing. Well maybe a pen to fill in the returns form for the dub stuff. You have the best already. Don't change!

 
Posted : 28/06/2022 2:57 pm
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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!

 
Posted : 28/06/2022 3:16 pm
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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".

 
Posted : 28/06/2022 3:29 pm
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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

 
Posted : 28/06/2022 4:14 pm
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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?

 
Posted : 28/06/2022 4:56 pm
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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

 
Posted : 28/06/2022 5:22 pm
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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.)

 
Posted : 28/06/2022 5:30 pm
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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.

 
Posted : 28/06/2022 6:04 pm
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Great system.

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

 
Posted : 28/06/2022 6:06 pm
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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.

 
Posted : 28/06/2022 6:44 pm
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But 2 bottom brackets so your ready to fit the new one after a couple of months. They are terrible

 
Posted : 28/06/2022 6:51 pm
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shimano cranks to dub, what do i need?

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

Stick with the Shimano crankset.

 
Posted : 28/06/2022 7:02 pm
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Haha thanks for the advice!

 
Posted : 28/06/2022 9:07 pm
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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.

 
Posted : 29/06/2022 9:27 am
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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.

 
Posted : 29/06/2022 10:11 am
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Consider SLX cranks mate - cheap, easy to fit & remove and surprisingly competitive on weight (crankarms lighter than XT IIRC).

 
Posted : 29/06/2022 10:21 am
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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.

 
Posted : 29/06/2022 3:55 pm
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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

 
Posted : 29/06/2022 3:57 pm
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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?

 
Posted : 29/06/2022 4:40 pm
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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 [s] 4 months [/s] 18 months but you're sure it's not that long.

 
Posted : 29/06/2022 5:39 pm
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@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.

 
Posted : 29/06/2022 6:36 pm
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I suppose it might help. But I haven’t needed to give any bottom bracket any maintenance since they stopped having loose balls

 
Posted : 29/06/2022 8:15 pm
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yes, you're probably right, there's no reason that the DUB may have gone on to do 5K miles without me touching it.

 
Posted : 29/06/2022 9:03 pm
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I’m on my third my first 2 lasting about 1000km. Both came out full of mud. The guy I sit next to at work is basically in the same boat

 
Posted : 29/06/2022 9:07 pm
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Does it seem right that i need new cranks due to creaking? I mean i strip them, lube 'em up, three days of hard riding later they creak again. Do cranks 'wear out' like that?

 
Posted : 29/06/2022 9:40 pm
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Do cranks ‘wear out’ like that?

Not normally no.

They can be damaged of course but not that often. usually in my experience it's something attached to them.

 
Posted : 30/06/2022 8:22 am
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Just a thought (and I might be barking up the wrong tree here), but Shimano have some issues with higher end road cranks where the hollowtech is in several parts bonded together. Pretty sure I’ve seen pictures of a number of split / failing Ultegra cranks. Are XTR built that same way and something like that could be happening?

Otherwise there’s no real reason I can think of for a ht2 crank to just start creaking over a few years as long as it’s all greased right / bearings are good / it’s all torqued up correctly

 
Posted : 30/06/2022 9:50 am
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Does it seem right that i need new cranks due to creaking? I mean i strip them, lube ’em up, three days of hard riding later they creak again. Do cranks ‘wear out’ like that?

Have you tried a new chainring? They can creak, especially if it's an older ring with a new chain.

 
Posted : 30/06/2022 10:01 am