Will this crank arm fit this spindle?

[dpopz123]

Crank arm - https://www.ebay.ie/itm/Bicycle-Alloy-C ... SwmJRazkei

Spindle - https://www.ebay.ie/itm/Complete-Bike-b ... ySE5S0SW4Q

I was just wondering will this crank arm fit this spindle ? I brought the same spindle with the code '3RMC' as it is displayed on the broken one and it says it is a square taper spindle but my crank arm seems to be a diamond taper ? Not sure if I brought the right one. Could I just turn the spindle 90 degrees to make it a diamond taper ?

[Brucey]

the 'square vs diamond alignment' thing is only a problem if you have one of each on a BB spindle. Both use a square taper BB spindle.

For the bottom bracket you will need to get the threading correct where it fits into the frame (most bicycles in the UK use a 68mm shell and BSC threading) the taper type correct (JIS or ISO) and you will need to make sure you have the correct length for your specific chainset; just because the old cranks have the same number of chainrings etc is no assurance that the BB spindle should be the same length as the old one.

cheers

[dpopz123]

The original crankset for my mountain bike is diamond taper and the spindle is 134.5mm I only needed a left arm crank 175mm. Do you think I made the right purchase? My only worry is the spindle saying it’s square taper but it looks identical to my broken spindle.Thanks for your reply!

[LollyKat]

Yes, it will fit. The "diamond" is only a reference to the orientation of the square hole in the crank - both fit the square taper of the spindle.

Diamond square taper:


"Square" square taper


Welcome aboard!

[Brucey]

The original crankset for my mountain bike is diamond taper and the spindle is 134.5mm I only needed a left arm crank 175mm. Do you think I made the right purchase? My only worry is the spindle saying it’s square taper but it looks identical to my broken spindle.Thanks for your reply!

there are two things

1) taper
2) orientation (square or diamond)


both square and diamond orientations fit onto square taper cranks, and you only run into trouble if you have one of each. There is no such thing as 'diamond taper' that is someone getting muddled.

cheers