# Rear Rack Mounting



## Vetteman61 (Jun 10, 2020)

I'm looking to put a rear mount on a 1964 Space Frame bike (1964 Foremost).  I've noticed that the rear seat clamp uses a carriage bolt and that the original racks mounted to this bolt.  I've looked online and seen that the original racks just have a round hole here, but I don't understand how a rack mounts to the bolt and does not interfere with the carriage bolt going through the bike to hold itself in place.

would anyone have some close up pictures on how this works?

thanks,
Brandon


----------



## Vetteman61 (Jun 15, 2020)

Anyone?


----------



## AndyA (Jun 16, 2020)

I'm away from home so I can't check this right now, but I think that my Flightliner has a carriage bolt on the seat clamp.The rack support has a round hole but the seat clamp has a square hole. Maybe the square shank of the carriage bolt is long enough to extend into the clamp. When I get home, I'll take a look and confirm (or not).


----------



## Roger Henning (Jun 16, 2020)

The seat post clamp has holes on both sides for the bolt to go through.  One is square to hold the the bolt from turning and the other side is round for the threaded part of the bolt to go through.  Tighten with a nut.  I have had a bike(s) with this system all were low end K Mart quality bikes.  Roger


----------



## Rivnut (Jun 16, 2020)

I have some Murray made bikes with the "carriage" bolt in the seatvtubevclamp.  Just take a small triangle shaped file and open up the hole in the rack to match the hole in the clamp.


----------



## Vetteman61 (Jun 17, 2020)

Thank you for the reponses.  I'm curious, did any of the bike with the carriage bolts come with a rear rack?


----------



## AndyA (Jun 18, 2020)

Oops, memory failure. Flightliner (red bike below) has a hex bolt thru the rack support and seat clamp. Same arrangement on a Spaceliner (silver bike). I can't say for sure that this is the original setup. They work fine; the only drawback is that adjustment requires two wrenches.


----------



## Sven (Jun 18, 2020)

This is what's on my '59 Flightliner , a carriage bolt


----------



## AndyA (Jun 18, 2020)

Uncle Sven:
Does the square shoulder on the bolt fit into a square hole in the seat clamp?


----------



## Rivnut (Jun 18, 2020)

These are racks that are on  "in process" bikes - ones that I did not have to disassemble to photograph

Prewar Elgin - one of two but I only took one picture.  Came as part of the original bike, not added-on.


Post war JC Higgins. Againg, part of the bike as it came from the factory




These line up with the carriage bolt square hole in the seat post bracket.
I looked at a Schwinn wire rack and it has the same hole in the rack as in the seat post clamp.  A hole with a couple of reliefs at 3 and 9 o'clock where ears on the AS bolt lock in and keep the bolt from turning as you tighten the nut. Hope this helps.

Ed


----------



## Sven (Jun 19, 2020)

AndyA said:


> Uncle Sven:
> Does the square shoulder on the bolt fit into a square hole in the seat clamp?



To my favorite Nephew.  
Yes sir, very snuggly I might add.





As you can see in the picture below, Murray Jet Fire rack has square holes in both rack and seat clamp.


----------



## AndyA (Jun 19, 2020)

So my memory is OK, sort of. Original bolts on Flightliner and Spaceliner were slotless, square-shouldered, pan heads (almost like carriage bolts), as shown in Sven's pics. They were in crummy shape, so I replaced them with nice, shiny hex heads. Hence the need for two wrenches.
Wow, we can sure get into some esoteric stuff on this forum.


----------



## Vetteman61 (Jun 19, 2020)

Thanks everyone for the photos.  Given the info here I suppose I'll try the carriage bolt and if the shoulders won't make it to the square hole I can just switch over to a regular bolt with a nut.  

thanks!


----------

