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TBT Short Stroke spring length

SiegeA

SiegeA

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Hi
Can anyone tell me the length of a standard TBT short stroke spring for the TX200 (mk3) please?

From reading around, 220-225mm is mentioned but I wondered if anyone knew for definite.
Thanks for looking.
 
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keep to standard length as you quoted because you may need the extra preload to retain power level, but you also then have the option if you want to trim down a coil if you want to reduce power
 
31 coil spring comes 235 mm in length. Pitch of spring is approx 8 mm which makes 219 mm and 251 mm respectively for 29 and 33 coil.
Choice of spring will also depend on calibre and desired muzzle energy.
 
TimD81 said:
keep to standard length as you quoted because you may need the extra preload to retain power level, but you also then have the option if you want to trim down a coil if you want to reduce power
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Cheers Tim
Long story short (no pun intended) I bought a nice US last week and it’s short stroked (TBT HW nose conversion) and the spring sits at 205mm, but it’s a little bit harsh for my liking. I’ve no idea what spring it is as the guides are not TBT so it’s not the whole kit as would be supplied. It’s a very decent job IMO, lock time is obviously improved and it’s really accurate but just considering having a tweek where I can.
 
shergar said:
31 coil spring comes 235 mm in length. Pitch of spring is approx 8 mm which makes 219 mm and 251 mm respectively for 29 and 33 coil.
Choice of spring will also depend on calibre and desired muzzle energy.
Click to expand...
👍🏼 29 coil is fairly standard for sub12 .177 isn’t it? Is that 219mm as supplied by TBT?
 
SiegeA said:
👍🏼 29 coil is fairly standard for sub12 .177 isn’t it? Is that 219mm as supplied by TBT?
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The length of spring is important as it determines preload. Number of coils only important in regard to length.
Problem with a Weihrauch spring, cut down to 205 mm is it becomes 10% stiffer than the same spring at 230 mm.
 
SiegeA said:
Cheers Tim
Long story short (no pun intended) I bought a nice US last week and it’s short stroked (TBT HW nose conversion) and the spring sits at 205mm, but it’s a little bit harsh for my liking. I’ve no idea what spring it is as the guides are not TBT so it’s not the whole kit as would be supplied. It’s a very decent job IMO, lock time is obviously improved and it’s really accurate but just considering having a tweek where I can.
Click to expand...
on standard tx's Iv cut springs at 205mm and they are too short, Im sure the magic number I found was 215-220mm, your shortstroke head probably reduces stroke by 10mm at a guess (Nick tbt can confirm that right or wrong) I think a oem mk3 spring is pretty soft, as its used with a mk2 piston for a softer cycle (shorter stroke)... you have a few options for a new spring oem mk3 dagda welsh willy, Nicks springs whatever they are or titan springs which some people say are harsh but Iv used plenty and they are fine.
 
TimD81 said:
on standard tx's Iv cut springs at 205mm and they are too short, Im sure the magic number I found was 215-220mm, your shortstroke head probably reduces stroke by 10mm at a guess (Nick tbt can confirm that right or wrong) I think a oem mk3 spring is pretty soft, as its used with a mk2 piston for a softer cycle (shorter stroke)... you have a few options for a new spring oem mk3 dagda welsh willy, Nicks springs whatever they are or titan springs which some people say are harsh but Iv used plenty and they are fine.
Click to expand...
I think the TBT ‘head’ reduces by 12-13mm Tim. I’ve an untouched TBT spring which I may ‘play’ with and get it in at say 220mm (like you suggest) and see how it feels.
The current set up has negligible recoil which is actually good, but as mentioned, the feel is harsh. I might be being a little unkind there but it’s a firm cocking (as you’d expect) and has that ‘harshness’

It really reminds me of my 97 and I want something a bit softer but with all the other benefits☺️ Sending out to someone springs to mind (Nick Simmons for a full glide and lightening?) but I’m not sure I’m there yet and want to see if I can improve on things myself.
 
Tinbum said:
We have been without electricity since 8pm last night, sorry for the delay.

The TX Maxi Pro comes with a 29 coil spring 🙂
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Ooh bu88er, glad that you’ve got sorted.
So how long in mm is that Nick please?
 
It'll be longer than you need, so you'll need to cut it down in small steps, and test, to get the right length for your rifle.
 
weepete said:
It'll be longer than you need, so you'll need to cut it down in small steps, and test, to get the right length for your rifle.
Click to expand...
👍🏼 I don’t have one, but looking to shorten a TBT spring that I have, to spec length as a starting point.
 
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