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Looking for aftermarket crank for original Fat.

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Hi Guys

 New here, but not to Sondors (own 3). Looking for replacement high-quality cranks with 40 Teeth (original size).

 I've searched and searched and it seems impossible to find! I don't want the orginal parts as they don't stand up to the use we give the bikes. I also don't wish to go with a larger or smaller chainring  as 40 is a perfect balance for our riding. I've tried epoxy to stop the clicking, but it only lasted 10 minutes.

Thanks VERY MUCH for any and all insite. I can't be the only one with this problem.


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While I would be hard pressed to argue that the cranks are not as basic as they come on these bikes, they *are* ordinarily quite adequate over the long term.  There's no reason for a crank to click, actually.  More details on that?  A crankset has no moving parts so there isn't anything to click. The thing that is moving is the bottom bracket and I can guarantee that epoxy is never the answer for repair if it needs it.  Whats going on down there?

Insofar as the cranks are concerned, the Origin8 Track/SS fixie crank is probably the highest quality to easily fit on a Sondors.  Bear in mind it also has straight crankarms which are great on a courier bike but only barely clear on a fattie.  But they do clear.


You can pretty much forget about finding a quality crank with a 40T chainring.  Nothing that is of good quality exists.  However, you can buy a Driveline chainring separately.  Those are sturdy 7075 alloy and you can even buy a pants guard for them.  Myself personally I buy them oversized by a couple of teeth so ther is still less chance of a snag.  So if you have a 40T ring, buy a 42T guard.

You will wind up with a very attractive setup but you'll probably be into it for over $100 total... which is not much as cranksets go.

On EBay I searched for "130 BCD 40T chainring" and this was the first result (there are plenty of others this was just the first):


Looks like no chain guards are made that fit with that 130 bcd.  You'd probably have to go to a 104 to get that.


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Thanks so much  MattRobertson for your kind and detailed response! Could you tell me if the MOJO chainring you mentioned would fit correctly on the  Origin8 crank (I assume it does,  or you wouldn't have recommended it!).

I definitely agree that it's the crank to bottom bracket interface where the movement (clicking) is occuring (and I pretty much knew epoxy wouldn't work, but had no other options).

I ride aggressively on hilly trails and weigh 200 lbs, so I'm putting more strain on the cranks than an average rider might., and yes, I've kept them tightened to spec. I'm looking for high quality parts and don't mind the cost.

Final question; I assume that I should replace the bottom bracket and not try to re-use the original in case it's worn a bit. I found this one below. Is it the correct sizing?


Thanks again for your valuable insite!

Edited by Roguewave

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The way you match up chainrings to cranks is to match the Bolt Circle Diameter from one to the other.  Since both are 130mm (BCD), they fit together.  I can't say I recommend it though.  It was just the first one to come up on the search results on EBay.

On the bottom bracket:  You have managed to find the one and only source for these brackets outside of Sondors themselves.  That is the seller everyone uses, including myself.  Two more of them just arrived in my mailbox yesterday.

I am working on an alternative unit consisting of a Cyclone sealed bottom bracket where you would have to drift in the sealed cartridges some on the drive side to get the proper extension for the drive side crankarms.  If you have the bearing drift tools, or your LBS can do this (I need to check with mine it may be a regular thing with a bike shop to have to do this) then the bottom brackets sold for a 120mm Cyclone installation will work and work *better* than that Chinese BB you linked.   The Cyclone BB has a 178mm hardened steel spindle and its meant to be used with a 3kw to 4kw mid drive... so its more than plenty strong.  Look for it at the Sick Bike Parts web site

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11 hours ago, Roguewave said:

Thanks again for your excellent advise! Please keep me posted about your Cyclone BB. I can arrange shipping to Canada when it's ready.

Hello, been following your discussion.  I bought a Sondors X in April 2018 and it appears that the bottom bracket has failed at 423 miles.  Does Sondors replace the BB?  If not, what do you recommend?  

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