A QuickTrack rail for Topeak Panniers with clip.

I have a spring loaded pannier on my commuter bike with a large bag. On another bike I have a Topeak Uni Explorer pannier rack which fits a trunkbag which can hold 30L but doesn't hold as much as my spring large bag. This rail is designed so I can fit my larger bag onto a Topeak pannier so I can carry more stuff.

You'll need 6 m4x30mm bolts and m4 nuts for the clip and the rail, and 6.5x30mm compression spring for the clip. The spring needs to have relatively high spring constant (>1N/mm). The holes on the rail can be used to attach bolts to whatever container youre attaching to the rail. To attach to a fabric bag, I attached 8 eyelet holes using this eyelet kit. For added strength you'll either need to fix a sheet of plywood to the top of the rail using the m4 bolt holes or thread 3 m4x300m threaded bolts through the holes in the rail.

There are 2 different rails; 61mm and 59mm. 61mm means the rail is slightly wider than the 59mm. This means the 61mm cant be levered out of the track and must be fitted via the end of the track; it is a more secure fit than the 59mm rail. The 59mm rail can be clipped into the track from above the track and from the end of the track which is useful when converting pannier bags to the quickrail version (See images); its still a pretty secure fit with it clipped onto the pannier but its less so than the 61mm rail.

This rail also works with this pannier adapter.

Parts you'll need:

• 4 m4x30mm bolts
• 3 m4x300mm threaded rods
• 10 m4 nuts
• A spring with a spring constant >1N/m around 25mm in length and 8mm in inner diameter (although Im not too sure on these dimensions).

Tools you'll need:

• Grinder/hacksaw
• Screwdriver
• Spanner

Instructions

• Print the parts; print the rail so the front is on the build plate; Pause print at layer 68 to insert captive m4 nuts in Top Pin.
• Thread the thread rods into the holes running along the body of the rail part.
  • If using the bag clip, slide this onto the rails (I haven't checked if this goes onto the new design so if you're having problems let me know).
• Cut the rods to length using the hacksaw/grinder; tighten the rods onto the rail using the screw driver and spanner.
• Attach the Pin holder to the rail using the 2 m4 bolts and 2 m4 nuts.
• Slide the spring onto Top Pin
• Put the Top Pin into the pin holder, and secure it using Pin Bottom and 2 m4 bolts.
• Done!

28/02/2024 V1.1: Decreased pillars on pin from 9.5x15.5mm to 8.5mmx14.5mm and decreased circular pillar width from 6mm to 5mm as it was too tight on the pin holder. Increased the height of the pillars by 15mm as there wasn't enough clearance for the railing. Added a chamfer to the bottom of the top of the top pin so it can be printed without supports and also reduced the grip of the top pin height from 15mm to 5mm.

29/02/2024 V1.2: Added a shelf to the top of the rail to stop any of the bag from getting stuck between the rail and the pannier. Increased base width of rail from 60 to 62mm as 60 allowed the rail to be pulled out when at an angle, and increased nut cutout height on the rail from 2.5mm to 3.7mm as I have made a typo. Increased pillar sizes of top and bottom pin from 8.5x14.5mm to 9x15mm as V1.1 dimensions were a bit too loose.

29/02/2024 V1.3 : The rail was now too tight on the pannier rack, so I decreased the base width from 62mm to 61mm (surprising how much a millimeter can make). I had also made a mistake when changing the base width which caused the pilot holes for the bolt to move so I have fixed this so the bolts will go through the holder to the rail again. Decreased height of end of the rail by 2mm so the pin would go under the pannier rail easier. Added chamfer to pin bottom around the bolt holes so I don't have to print those bits with supports.

02/03/2024 V1.4: Added captive nuts to the end of the rail and made a bag clip which attaches to the end of the rail to hold my bag in place on the pannier. The pin would go under the bar but would struggle to release, so I redesigned the bottom pin to allow for more clearance on release.

13/05/2024 V1.5: Increased bottom pin height from 11mm to 14mm as it sometimes would fall out when hitting a pot hole. Decreased Rail width from 61 to 59mm as sliding the rail with the bag on was quite difficult; at 59mm, the rail can slot into the rail sideways which is easier. The side loading method means the rail is more loose but it doesnt seem to come out easily unless pulled up at an angle. Added extra support to rail to stop it snapping at clip end after rigorous testing (sending it over a speed bump).

07/06/2024 V1.6: Increased bottom pin height from 14mm to 16mm as it came out occasionally still. Added a 1.5mm 45' chamfer to the base of the pin to add strength to the part. Added 3 m4 threaded bolt holes to the rail to give it more strength as it would sometimes delaminate under heavy loads (Removed end nuts as rod can be installed). Added 61mm and 59mm rail versions as some users might want a more secure fit.