Project Big Bore

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Step 13 : Bit of butchery of the frame to put the new swing arm pivot in.

Very awkward to get into the area. Ended up using gas to cut the centre out and the grinder.

Used a stepped drill bit to bore out the right diameter for the pivot. I won't weld it up yet until the swinging arm is complete.

Frame cut for swinging arm pivot Swinging Arm Pivot in place


Step 14: Cut, Drilled / Tapped and welded on clamps for eccentric holders. Welded down one side of them as well to give strength that won't be see on the bike. Just have so slit them now. If I can get my hands on an accurate bandsaw I will get them done. If not I'll try and get a slitting saw for the milling machine.

Clamp for Eccentric Welded on Clamp for Eccentric Welded on plus eccentrics in place

Step 14b: Got a bandsaw to slit the clamps. Tried them out and they seem to be clamping the eccentics really tightly.

Finished Eccentric Clamps Spacers

Step 15: Bored the 1st swing arm. Trying to figure out now if I leave the clamps horizontal to the ground or leave them in line with the flow of the swing arm.

Swing Arm Eccentric in place Close up of Eccentric in the swing arm

New Kit: Got new Rental bars and a second hand R1 shock that looks like new for a price I couldn't pass so if it works out bonus.

Swing Arm Eccentric in place

Step 16: Welded up both sides of the swing arm. Have to link them together and figure out where the shock is going to go.

Swing Arms Welded up

Step 17: Put it together to test that all measurements were correct and everything is in line before welding swing arm tube to the frame. Have to adjust the back wheel alignment slightly to centre on the frame which can de done with spacers and possible modification to the wheel. But main thing is chain alignment is spot on.

Mock up with swing arms and handlebars

Rear swing arm mockup Front swing arm mockup

Step 18: More Hacking, this time to get the rear shock in.

Fitting Rear Shock Rear Shock mockup

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