Theoben Rapid Forum

Everything Technical About Rapid => Technical => Topic started by: Walk on May 10, 2026, 08:28:21 AM

Title: Theoben MK1 Gamo adjustment
Post by: Walk on May 10, 2026, 08:28:21 AM
Hi fellas my mates Mk1 is shooting very well now i fitted all new internals had to trim the new silent hammer pip in new hammer new valve and stem new O-rings new end cap i used same hammer spring after a little fettle its running as it should 11.4 lbs i have noticed that there is a long travel in the first stage how is this adjusted cheers Fellas ATB .
Title: Re: Theoben MK1 Gamo adjustment
Post by: Ca_Varminter on May 10, 2026, 03:40:42 PM
Sorry I don't do Gamo triggers....
It requires too much Voodoo and Witchcraft!!!
The only true upgrade to hel[p with adjustment is the
copy of the GRT trigger Dr Bob makes..
You can buy it off his Site...
https://www.drbobsgunbits.com/product-page/grt-111-trigger

Stuart
Title: Re: Theoben MK1 Gamo adjustment
Post by: Walk on May 10, 2026, 04:54:43 PM
Hi ok thanks ATB Phil. ;)
Title: Re: Theoben MK1 Gamo adjustment
Post by: Squinty on May 11, 2026, 05:32:38 AM
Quote from: Walk on May 10, 2026, 08:28:21 AMHi fellas my mates Mk1 is shooting very well now i fitted all new internals had to trim the new silent hammer pip in new hammer new valve and stem new O-rings new end cap i used same hammer spring after a little fettle its running as it should 11.4 lbs i have noticed that there is a long travel in the first stage how is this adjusted cheers Fellas ATB .


It can't be adjusted as such, it is a generic single stage trigger fitted to dozens of cheap springers.
There is no contact 'first stage' is simply the gap between 15L ' Fat trigger pull pin' and 15E bottom strut/sear being taken up against the return spring.

You can reduce the free travel by installing a bush  on 15L but it can be trial and error.

***** the safety catch should be tested to make sure that it still engages firmly ******

And be impact/drop tested with the safety off- ie at the very least a few good whacks on the butt pad with a rubber mallet. (scope off)

One common method is to use 8mm o/d x3mm W x 5mm i/d RC micro-bearing.
Or a piece of 5mm i/d tube- 0.75-1mm wall and as previously mentioned on another thread BigAl uses an o-ring.

All leave enough room for the trigger return spring leg to be reinstalled to the r/h side otherwise you can pull the trigger part way and it wont reset.

May need a longer adjustment grub screw but it won't need much adjustment as the micro-bearing mod can result in a very short pull - almost direct to the bottom lever /sear AND potentially a hair trigger.


https://www.youtube.com/watch?v=EsdP4yRVPnw

https://www.youtube.com/watch?v=iTmQJ-SaXmM
Title: Re: Theoben MK1 Gamo adjustment
Post by: Bigal. on May 11, 2026, 09:08:18 AM
Answers above from steve Phil.
First stage trigger pressure can be adjusted. Bending the spring eg wider gives stronger, in lighter, water oring etc less travel. ;) Al