# Bumper-Cyclotron Spacer/Screw **URL:** \ **Category:** Proton Packs\ **Created:** [October 5, 2014, 3:19pm UTC](https://forum.gbfans.com/t/bumper-cyclotron-spacer-screw/10712 "2014-10-05T15:19:14Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![theguitarman](https://forum.gbfans.com/letter_avatar_proxy/v4/letter/t/7cd45c/32.png) [@theguitarman](https://forum.gbfans.com/u/theguitarman)\ **Post date:** [October 5, 2014, 3:19pm UTC](https://forum.gbfans.com/t/bumper-cyclotron-spacer-screw/10712/1 "2014-10-05T15:19:14Z")
Hello! Working on my GB1 pack, about to mount the [bumper](https://www.gbfans.com/wiki/equipment/proton-pack/bumper), and I can’t find any info about the spacer between the back of the bumper and the front of the [cyclotron](https://www.gbfans.com/wiki/equipment/proton-pack/cyclotron) (in photo below) [http://www.gbfans.com/image.php?url=/images/equipment/reference/1/22.jpg](http://www.gbfans.com/image.php?url=/images/equipment/reference/1/22.jpg) From the posts, I have read it’s about 1/8" to 1/4", and I assume aluminum. Also looking for info on the screw that goes into through the bellows and into the cyclotron. The screw list has 10-32 socket cap screws for the sides of the bumpers, is it just a longer one of these through the bellows? Thanks in advance! ---
**Author:** ![bishopdonmiguel](https://forum.gbfans.com/user_avatar/forum.gbfans.com/bishopdonmiguel/32/188541_2.png) [@bishopdonmiguel](https://forum.gbfans.com/u/bishopdonmiguel)\ **Post date:** [October 5, 2014, 4:23pm UTC](https://forum.gbfans.com/t/bumper-cyclotron-spacer-screw/10712/2 "2014-10-05T16:23:43Z")
Photo link not working. Unsure what is screen accurate but I used a 3/4-inch steel spacer for a 1/4-inch bolt. For my nick-a-tron resin Shock Mount, I removed the faux bolt head and drilled a hole through. A 4-inch long 1/4-20 stove bolt passes through the Shock Mount, [Bumper](https://www.gbfans.com/wiki/equipment/proton-pack/bumper) and [Cyclotron](https://www.gbfans.com/wiki/equipment/proton-pack/cyclotron) center, secured by a washer & locknut inside the shell. I also used a thick rubber washer between the Shock Mount and Bumper. ---
**Author:** ![jackdoud](https://forum.gbfans.com/letter_avatar_proxy/v4/letter/j/6a8cbe/32.png) [@jackdoud](https://forum.gbfans.com/u/jackdoud)\ **Post date:** [October 5, 2014, 5:09pm UTC](https://forum.gbfans.com/t/bumper-cyclotron-spacer-screw/10712/3 "2014-10-05T17:09:32Z")
It kinda depends on what pack shell and [bumper](https://www.gbfans.com/wiki/equipment/proton-pack/bumper) combination you’re using. The gap can vary anywhere from 1/8" to 3/4" depending on how things line up and how far back you mount the bumper. Most hardware stores carry aluminum standoffs. ---
**Author:** ![theguitarman](https://forum.gbfans.com/letter_avatar_proxy/v4/letter/t/7cd45c/32.png) [@theguitarman](https://forum.gbfans.com/u/theguitarman)\ **Post date:** [October 5, 2014, 6:19pm UTC](https://forum.gbfans.com/t/bumper-cyclotron-spacer-screw/10712/4 "2014-10-05T18:19:26Z")
Thanks for the info! I know for a GB2 pack, they used a slot head screw. Did the GB1 packs use a carriage bolt? ---
**Author:** ![abaka](https://forum.gbfans.com/letter_avatar_proxy/v4/letter/a/f04885/32.png) [@abaka](https://forum.gbfans.com/u/abaka)\ **Post date:** [October 5, 2014, 8:22pm UTC](https://forum.gbfans.com/t/bumper-cyclotron-spacer-screw/10712/5 "2014-10-05T20:22:21Z")
The GB1 packs most likely just used a socket head screw mounted via the bottom. ---
**Author:** ![theguitarman](https://forum.gbfans.com/letter_avatar_proxy/v4/letter/t/7cd45c/32.png) [@theguitarman](https://forum.gbfans.com/u/theguitarman)\ **Post date:** [October 5, 2014, 8:30pm UTC](https://forum.gbfans.com/t/bumper-cyclotron-spacer-screw/10712/6 "2014-10-05T20:30:56Z")
I can’t seem to find a closeup photo of a GB1 pack [bumper](https://www.gbfans.com/wiki/equipment/proton-pack/bumper) to see how it looks. Anyone have one? ---
**Author:** ![PssdffJay](https://forum.gbfans.com/user_avatar/forum.gbfans.com/pssdffjay/32/6529_2.png) [@PssdffJay](https://forum.gbfans.com/u/PssdffJay)\ **Post date:** [October 6, 2014, 8:19am UTC](https://forum.gbfans.com/t/bumper-cyclotron-spacer-screw/10712/7 "2014-10-06T08:19:05Z")
If you look through my build thread, you’ll see how I did mine. Not sure what page. ---
**Author:** ![Grimmy\_GB](https://forum.gbfans.com/letter_avatar_proxy/v4/letter/g/dfb087/32.png) [@Grimmy\_GB](https://forum.gbfans.com/u/Grimmy_GB)\ **Post date:** [October 6, 2014, 3:00pm UTC](https://forum.gbfans.com/t/bumper-cyclotron-spacer-screw/10712/8 "2014-10-06T15:00:32Z")
This is from Jay’s build [http://www.gbfans.com/community/viewtopic.php?f=2&t=34784&start=120](http://www.gbfans.com/community/viewtopic.php?f=2&t=34784&start=120)