14mm socket with thin enough wall to fit inside the crank. Unfortunately if they have started wobbling they might be rounding out – which would require replacing. Torque on those is ~40Nm or so if I remember correctly.
OkExplanation6405 on
Just a regular as-long-as-possible socket wrench. Before you do that, check the square hole in each crank arm to see if it’s rounded out. If so, they’ll just work themselves loose no matter what you do, so you’ll need new cranks.
If they’ve been loose for any amount of time it’s likely the crank arm hole is damaged and will never be secure no matter how much you tighten it and you’ll need to get a new crank set.
Feisty_Park1424 on
If both cranks are wobbly then perhaps the bottom bracket bearings are worn/need adjusting
Budget_Half_9105 on
A big socket
buildyourown on
If you have to ask it’s time to visit a bike shop. You need a new bottom bracket
beachbum818 on
If both wobble it’s not that bolt. It’s the Bottom Bracket bearings. You need to pull the cranks, pull the BB to check the bearings.
TheUnHun on
Most likely none of the above answers. These are tapered bottom bracket cranks. One properly torqued when new they stay tight on the tapers. If they were installed loose and ridden wobbly then the aluminum crank tapers have probably been damaged. If so, the only fix is new cranks. The BB itself usually survives this as it is much harder than the aluminum cranks. Before you give up you need a thin wall 14 or 15 mm socket to seat it. These look more like a 14.
8 Comments
14mm socket with thin enough wall to fit inside the crank. Unfortunately if they have started wobbling they might be rounding out – which would require replacing. Torque on those is ~40Nm or so if I remember correctly.
Just a regular as-long-as-possible socket wrench. Before you do that, check the square hole in each crank arm to see if it’s rounded out. If so, they’ll just work themselves loose no matter what you do, so you’ll need new cranks.
Usually a 14mm thin wall socket. Some crank puller tools have it on the back side, like this Sunlite one [https://www.scottscycleandsports.com/product/sunlite-series-i-crank-puller-298886-1.htm](https://www.scottscycleandsports.com/product/sunlite-series-i-crank-puller-298886-1.htm)
If they’ve been loose for any amount of time it’s likely the crank arm hole is damaged and will never be secure no matter how much you tighten it and you’ll need to get a new crank set.
If both cranks are wobbly then perhaps the bottom bracket bearings are worn/need adjusting
A big socket
If you have to ask it’s time to visit a bike shop. You need a new bottom bracket
If both wobble it’s not that bolt. It’s the Bottom Bracket bearings. You need to pull the cranks, pull the BB to check the bearings.
Most likely none of the above answers. These are tapered bottom bracket cranks. One properly torqued when new they stay tight on the tapers. If they were installed loose and ridden wobbly then the aluminum crank tapers have probably been damaged. If so, the only fix is new cranks. The BB itself usually survives this as it is much harder than the aluminum cranks. Before you give up you need a thin wall 14 or 15 mm socket to seat it. These look more like a 14.