marcus11

These are pictures of my left crank arm. It is stripped and cant get a pedal in it anymore. The bike is a K2 Zed 3.2 series. I would like to try to replace it myself but I am not sure what type of crank I need to buy. I am currently looking at Amazon as I don't want to spend to much. Obviously I am new at this so please excuse my ignorance. are they generally universal?I have seen square and Hex style and to me this looks like Hex but not 100% sure. I just want to make sure when I get the bolt out I will be able to reattach it to the new crank.

Thanks for your help,

dsbrantjr

A good bike shop should be able to repair your crank arm with a Helicoil insert which will repair the threads stronger than the original aluminum. This is likely a bike shop-specific job since the threads are left-handed. Whether you repair or replace the arm, be sure to grease the pedal threads and torque them properly; insufficient torque and the resulting looseness is the usual cause of stripped threads, aside from cross-threading.

fietsbob

the look of any replacement wont match, so like above ,

bike shop service.. have a threaded insert installed.

there are oversize threads cut then a threaded sleeve or coil is screwed in ,
to allow you to screw the pedal in, again.

pdlamb

Bike shop, as djbrant said. It may be cheaper just to buy a new left crank, since they're standard service items, than pay the labor for the helicoil (assuming they have the helicoil and tools). I think I replaced one for $20 a few years back.

ksisler

OP; When I need a left crank arm, I look on ebay where they are widely available for cheep -- $8-25 or so new. Seems as if there is an industry of companies cranking out replacement left arms. If you just need a working arm that fits, it will be cheep. If you want exact original OEM matching one, that will be a few dollars more.

Of course you will need to know what you are replacing, but other posters will probably help with that info. Better pictures would help. Need to also know what length it is. On the back of the current arms it will have a number like 175 or 165 stamped on it. That should be the length. Confirm it with a metric ruler = center of crank spindle to center of pedal spindle.

marcus11

Thanks for the info, I have been looking at Amazon.com and see that they are easily purchased for cheap. I don't mind that it won't match exactly. I just want to get back on my bike lol! The only thing I am a bit confused on is if it matters if I buy one that is Hex or square or diamond etc...

Thanks again for the help.

RubeRad

Get the right size allen wrench (8mm?) and unscrew that crank bolt. If it comes out easy, you should see behind it is a square taper interface, then you'd need a crank extractor/puller to get it off, getting it back on just involves screwing down the crank bolt to press it onto the taper again.

If the crank bolt unscrews for a turn or two and then gets difficult, odds are you've got a "self-extracting" crank. Just keep unscrewing, and after a few more turns it will come off the interface, probably octalink or something similar. That plus the crank length should give you enough info for a replacement.

However, as recommended above, you may do fine taking it to a bike shop for a threaded insert (helicoil). Going rates for this simple job (that is quick and easy to do if you have invested in the tools, which most bike shops would have) are supposedly in the $15-25 range. You could get back on the road overnight, or maybe even on the spot if you can get to a bike shop apart from lunch/evening rush and they have time to do it.

3alarmer 

I've probably done about ten of these insert jobs. It's pretty simple, the tool is a combination
reamer/tap (oversized), and in all it takes maybe twenty minutes or a half hour.

If you get it done, make sure whoever does it uses Loctite on the insert threads to assist
with keeping it tight in its new home. The inserts are kinda pricey, about five bucks a pop, IIRC.

onespeedbiker

From what I can determine your crank is a variant of a SR Suntour XCC T202 https://www.mtbdeals.com/bikes-comple...n-bike-439-99/ (BTW SR Suntour cranks have a square oriented interface. While I can't find one with the particular look of your KS, cambriabike.com https://www.cambriabike.com/Sr-Suntou...r-89130170.asp sells a plain black or silver for $13.33. You can also pick them up on ebay or Amazon https://www.amazon.com/s/ref=nb_sb_no...ntour+XCC+left

linus

Sounds like you better of going to a bike shop.