After trying various methods with varying success, I have found a great way of removing seized pedals from cranks, cobbled together from various tips on here and YouTube. I hope it helps someone.
But first, hat tip to @KondratievsBike, who very kindly gave me the Suntour cranks and Shimano SPD pedals as Karma. These parts were properly seized, as KB had promised in his advert, which meant the 'extreme force-swearing-shedding of blood' method failed totally. The one below worked in four steps:
1. Dismantle the pedals. Not sure this is even totally necessary but meant smaller bits of metal going into the freezer in step 2. It also made access to the flats for a big adjustable spanner easier, and meant the grease in the pedals didn't get contaminated in step 3.
2. Freeze 'em. I wrapped each crank and pedal axle combo in a plastic bag as a nod to domestic responsibility and froze them for a few hours.
3. Boil 'em. I poured a full, just boiled kettle of water all over the axle and crank end. This went into a bucket so the crank/axle could then sit in it and get really hot. This combination provided the thermal shock and differential expansion/contraction in the alloy and steel to break the corrosive bond.
4. Mount them on a bike, any bike. This gave the leverage to work with, whilst holding the back brake on and turning the big spanner towards the back wheel. One way of turning that big spanner is stepping back on the end of the handle with your heel, whilst the ball of your foot sits on the axle. Ok, this is hard to describe but hopefully the photos will give you the idea.
You have to imagine my foot in the trainer!
Done! Happily both cranks and pedals remain fully intact and usable .
But first, hat tip to @KondratievsBike, who very kindly gave me the Suntour cranks and Shimano SPD pedals as Karma. These parts were properly seized, as KB had promised in his advert, which meant the 'extreme force-swearing-shedding of blood' method failed totally. The one below worked in four steps:
1. Dismantle the pedals. Not sure this is even totally necessary but meant smaller bits of metal going into the freezer in step 2. It also made access to the flats for a big adjustable spanner easier, and meant the grease in the pedals didn't get contaminated in step 3.
2. Freeze 'em. I wrapped each crank and pedal axle combo in a plastic bag as a nod to domestic responsibility and froze them for a few hours.
3. Boil 'em. I poured a full, just boiled kettle of water all over the axle and crank end. This went into a bucket so the crank/axle could then sit in it and get really hot. This combination provided the thermal shock and differential expansion/contraction in the alloy and steel to break the corrosive bond.
4. Mount them on a bike, any bike. This gave the leverage to work with, whilst holding the back brake on and turning the big spanner towards the back wheel. One way of turning that big spanner is stepping back on the end of the handle with your heel, whilst the ball of your foot sits on the axle. Ok, this is hard to describe but hopefully the photos will give you the idea.
You have to imagine my foot in the trainer!
Done! Happily both cranks and pedals remain fully intact and usable .