The mounting holes of my rack have been drilled to 6mm. My frame has M5 eyelets, so I can only use M5 screws. I would like to reduce the 6mm holes to 5mm to remove any play around the screw. I even found washers with a flange (2nd photo) but they are nylon; couldn’t find steel/aluminium ones in the proper size (sometimes they come with QRs and axles).
Any other ideas? What is the best way to mount the rack?
Edit: It’s for my touring bike which will be heavily loaded. I want to make the connection as strong and safe as possible.
supertucan on
Just use a washer and be done with it
dadbod_beeblebrox on
McMaster-Carr sells M5 spacers with an outer diameter of 6mm, you could see if they come in the length you need.
hopefulcynicist on
Washer or the nylon bushing that you found would both be fine.
 The bolt should not be the main load bearing point in the setup or you risk shearing the bolt. The majority of the load should be handled by clamping force / friction between the rack and frame.Â
Yiplzuse on
Have someone 3d print them. Grainger catalog you basically are looking for a 5mm id and 6mm od. You can cut tubing or grind spacers to fit. You could have a machine shop make the parts. I would not drill and tap the frame. You could try filling in the 6mm holes with liquid steel and drill them to 5mm but I think that would fail.
64-matthew on
I had the same issue, and tapped the 5mm thread out to 6mm.
6 Comments
The mounting holes of my rack have been drilled to 6mm. My frame has M5 eyelets, so I can only use M5 screws. I would like to reduce the 6mm holes to 5mm to remove any play around the screw. I even found washers with a flange (2nd photo) but they are nylon; couldn’t find steel/aluminium ones in the proper size (sometimes they come with QRs and axles).
Any other ideas? What is the best way to mount the rack?
Edit: It’s for my touring bike which will be heavily loaded. I want to make the connection as strong and safe as possible.
Just use a washer and be done with it
McMaster-Carr sells M5 spacers with an outer diameter of 6mm, you could see if they come in the length you need.
Washer or the nylon bushing that you found would both be fine.
 The bolt should not be the main load bearing point in the setup or you risk shearing the bolt. The majority of the load should be handled by clamping force / friction between the rack and frame.Â
Have someone 3d print them. Grainger catalog you basically are looking for a 5mm id and 6mm od. You can cut tubing or grind spacers to fit. You could have a machine shop make the parts. I would not drill and tap the frame. You could try filling in the 6mm holes with liquid steel and drill them to 5mm but I think that would fail.
I had the same issue, and tapped the 5mm thread out to 6mm.