Triple crankset to Single crankset

[blbaszis]

I have an old mtb that I would like to change from a 3x8 to 1 1x8. I use the bike as a commuter and have no need for the extra gears. It has a Sakae xr100 crankset wit the gears riveted on. Otherwise I would just remove the inner and outer gears and keep the middle gear scince it is a low enough range for my needs. Can I use a Shimano crankset on this bike? Checking the specs on line says the pedal spindle is square taper and is 124.5 wide. Hope this info helps

[nfmisso]

Maybe. It depends on what BB axle length the new crankset is intended for. You may have to replace the BB as well.

You need to know couple things to determine if it will work as intended:
* Over Locknut Dimension (O.L.D.) of your rear wheel.
* Design BB axle length of your new crankset.
* Is the new crankset intended for MTB or road bike

New MTB cranks are intended to work with 135mm OLD, new road cranks with 130mm OLD. Once upon a time, almost all bikes had 120mm OLD, which grew to 126mm, then 130mm; MTBs continued to 135mm.

Also note that the manufacturer's recommendation for BB axle length should be considered as a guideline, not the absolute. And for example, if the crank is intended for 130mm OLD, and your frame is 135mm OLD, you might want 5mm longer BB axle than recommended for it to match the MFG's recommendation.

[blbaszis]

Thank You! This info helps a lot, stuff I did'nt know about. If there was a way to just remove the inner and outer chainrings on my present crank, I would do that and save some time and Money. sadly, they are rivited together.

[DaveM]

A little careful work with a hack saw (or better yet, dremel tool) and you can probably cut off the extra chainrings. If you want to get real fancy, cut off just the teeth of the outer chainring and leave the rest as a chainguard which protects your pants leg from the chain. Of course, file any cuts carefully so that you don't have sharp edges spinning around your ankles.

If you do get a new crank, there's quite a few single cranks out there that should fit fine. Try to get one suited for the BB spindle length you have, but it doesn't need to be exact. Worst case, you have to get a new BB as well.

[RBurrelli]

Why not just keep it on the middle ring and remove the front derailleur or shifter?

[blbaszis]

Thats what I am doing currrently but I would like to upgrade to something a little better. If anything upgrade to a diffrent triple setup where the outer chainring is no larger than 44t. I prefer the lower gears because my knees have been acting up, part of getting over 50 years old I guess. these rivited chain rings just look cheap that all.