Riser modification, shims for TS370, reduce bowstring to rail pressure

44815 Views 292 Replies 35 Participants Last post by TomOnTheRun, Apr 8, 2022

TomOnTheRun

Discussion Starter · Dec 6, 2019

After reading bunny rabbits riser modification specific to the bow string pressure on the shooting rail I did start the process at 3/16 depth for the riser spacer. No go on brand new TS370. There is at least 1/8" gap between the string and the riser. It's a good start and bunnyrabbit thanks for starting this approach.

I did purchase key stock at 3/16 x 1/4 x 12". I'll go to Lowes to purchase something in the 1/8" thickness material and try that to see my results.

I'll purchase the gorilla glue (blue) per bunny rabbits suggestion. He has shot around 800 times with his shims and seems to be holding in place.

This fix does work at reducing the bow string pressure. Plus, I'm a rope cocker so I'm no so worried about serving wear issues from Barnett's CCD.

To be continued and I"ll post my finding when I'm finished.

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TomOnTheRun

Discussion Starter · #2 · Dec 6, 2019

The shim for the 370 needs to be fixed to the riser. I think different then BR’s Ghost as a FYI.

TomOnTheRun

Discussion Starter · #3 · Dec 6, 2019

Just returned from Lowes and found some flat aluminum that 1/8" and 1/16" thick. Will be cutting these to size for my TS370 to see how that works on my shooting rail bowstring pressure. Stay tuned. FYI: By doing this there is risk and want to advise others to note that. I'm doing this on why own as a possible OEM build fix.

Bowstring pressure is a common issue on many OEM Xbows. This is not exclusive to Barnett.

Also, the design difference between my TS370 and Bunnyrabbit might related to STR vs traditional foot stirrup riser designs regarding where to place the shims on the crossbow. This is initial observation. I'll try to post pics.

Reactions: 2

bunnyrabbit

· #4 · Dec 6, 2019

3

TomOnTheRun said:
The shim for the 370 needs to be fixed to the riser. I think different then BR’s Ghost as a FYI.

Here are pictures of the Barnett TS370, the Barnett TS390 and the Barnett Ghost 410. The TS390 has a similar built in stirrup as my Barnett Ghost 410. The shims can be fastened to the front of the rail-stock on both the TS370 and TS390 as the riser bolts to the rail-stock the same way as my Ghost 410.

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All the best.

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TomOnTheRun

Discussion Starter · #5 · Dec 6, 2019 (Edited)

5

Here is what I did to my new TS370 using bunnryrabbit's riser adjustment fix. However, for me to level the bows string on the TS-370 I had to use a 1/8" shims. I think the only thing I did differently was securing the shims to the riser with a bit of gorilla glue/blue instead of the rail-stock. The string barely is touching the shoot rail. Note: Bunnyrabbit, the pic of my TS370 is not the Xbow in your post. The TS370 I'm using has a traditional stirrup (no STR)

BowString:
Now, I can push the string downward to the rail. It's level.

If there is a gap between the string and the rail it is so minimal you can't see it. Zero downward pressure on the rail now.

The Crossbow comes basically assembled. All you have to do is install the riser to the the gun stock and you are set to go. I did gorilla glue my rubber stops to align to the center of the bow string. Total weight with scope is 7.84 lbs, not including the quiver. I don't hunt with quivers attached to my Xbow. Just my personal preference.

After owning two previous non-Barnett's Xbows recently I will tell you the TS370 build is quite impressive regarding the fit and finish. I personally think it's better. Now the bow string hump does require a fix. Thanks BR!

It is now fully assembled ready to be tested tomorrow. I will sight in at 20 yards and put it on the chrono.

Technology Electronic device Measuring instrument Pedometer Light meter

1/8" shims attached to the riser and rail-stock.

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Shims attached to the Riser.

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Assembled and now level bowstring.

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TomOnTheRun

Discussion Starter · #6 · Dec 6, 2019

Everyone: if you are new to crossbow do not forget this important detail before using this Xbow. Actually, any Xbow. Make sure you liberally apply string wax to the cable string intersections before installing the riser to your rail-stock. Also the same for the actually strings. FYI: I do not wax the serving materials on the strings.

Note: The assembly date when I opened the box was June 20, 2018. Yikes!

This is one impressive Xbow from Barnett. Out of all the Xbows I've owned since I started hunting the TS-370 is my favorite Xbow. If need be I can speed it up and it will shoot in the mid 370's to 380's if I want and that is using a 403 grain arrow. That's way above Barnett 380 grain arrows speeds.

Hope these comments and details are helpful.

Reactions: 5

Tnmtns

· #7 · Dec 6, 2019

TomOnTheRun said:
Here is what I did to my new TS370 using bunnryrabbit's riser adjustment fix. However, for me to level the bows string on the TS-370 I had to use a 1/8" shims. I think the only thing I did differently was securing the shims to the riser with a bit of gorilla glue/blue instead of the rail-stock. The string barely is touching the shoot rail. Note: Bunnyrabbit, the pic of my TS370 is not the Xbow in your post. The TS370 I'm using has a traditional stirrup (no STR)

BowString:
Now, I can push the string downward to the rail. It's level. If there is a gap between the string and the rail it is so minimal you can't see it. Zero downward pressure on the rail now.

The Crossbow comes basically assembled. All you have to do is install the riser to the the gun stock and you are set to go. I did gorilla glue my rubber stops to align to the center of the bow string. Total weight with scope is 7.84 lbs, not including the quiver. I don't hunt with quivers attached to my Xbow. Just my personal preference.

After owning two previous non-Barnett's Xbows recently I will tell you the TS370 build is quite impressive regarding the fit and finish. I personally think it's better. Now the bow string hump does require a fix. Thanks BR!

It is now fully assembled ready to be tested tomorrow. I will sight in at 20 yards and put it on the chrono.

View attachment 160552
1/8" shims attached to the riser and rail-stock.
View attachment 160558
Shims attached to the Riser.
View attachment 160556
Assembled and now level bowstring.
View attachment 160554

Good job Tom! Have fun!!!

Reactions: 1

TomOnTheRun

Discussion Starter · #8 · Dec 6, 2019

Thank you! Thanks to BR I feel like I have this Xbow set to go out of the box. Curious to see how much longer these OEM strings will last. I will be counting shots to see how these strings last compare to custom strings I have used.

Reactions: 3

Huntersthompson

· #9 · Dec 6, 2019

Did you chrono before and after shims? How do you like that new target?

Reactions: 1

TomOnTheRun

Discussion Starter · #10 · Dec 6, 2019

Haven't shot yet. Will tomorrow. I doubt there will be a noticeable speed gain. I'll see how his Xbow shoots. First one I have owned in a while where I did not send out to be tuned. I think BR fix is quite helpful.

Reactions: 1

TomOnTheRun

Discussion Starter · #11 · Dec 9, 2019

2

First hunt today with this TS370.

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TomOnTheRun

Discussion Starter · #12 · Dec 9, 2019

The background hill is steep as one can ask for. The pic does not do it justice! I AM TIRED!

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TomOnTheRun

Discussion Starter · #13 · Dec 13, 2019

Okay, my hard rubber material came in today. 1/8" thick and quite rigid. Should be exactly what I'm looking for. Now I have to pry off those glued in metal shims. Yikes!

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primeduck

· #14 · Dec 14, 2019

TomOnTheRun said:
Here is what I did to my new TS370 using bunnryrabbit's riser adjustment fix. However, for me to level the bows string on the TS-370 I had to use a 1/8" shims. I think the only thing I did differently was securing the shims to the riser with a bit of gorilla glue/blue instead of the rail-stock. The string barely is touching the shoot rail. Note: Bunnyrabbit, the pic of my TS370 is not the Xbow in your post. The TS370 I'm using has a traditional stirrup (no STR)

BowString:
Now, I can push the string downward to the rail. It's level. If there is a gap between the string and the rail it is so minimal you can't see it. Zero downward pressure on the rail now.

The Crossbow comes basically assembled. All you have to do is install the riser to the the gun stock and you are set to go. I did gorilla glue my rubber stops to align to the center of the bow string. Total weight with scope is 7.84 lbs, not including the quiver. I don't hunt with quivers attached to my Xbow. Just my personal preference.

After owning two previous non-Barnett's Xbows recently I will tell you the TS370 build is quite impressive regarding the fit and finish. I personally think it's better. Now the bow string hump does require a fix. Thanks BR!

It is now fully assembled ready to be tested tomorrow. I will sight in at 20 yards and put it on the chrono.

View attachment 160552
1/8" shims attached to the riser and rail-stock.
View attachment 160558
Shims attached to the Riser.
View attachment 160556
Assembled and now level bowstring.
View attachment 160554

How does extending the riser forward reduce downward pressure from the string?

Reactions: 3

bunnyrabbit

· #15 · Dec 14, 2019

primeduck said:
How does extending the riser forward reduce downward pressure from the string?

Two shims are installed between the riser and the rail-stock at top section (one on each side of the arrow groove). This tilts the cam end of the riser limbs up a bit reducing the downward pressure on the bow string. Before I did my Ghost 410's, with the crossbow in the uncocked position, looking from on cam to the other along the bowstring, the bowstring humped up as it crossed the rail-stock. Making this modification, the bow string is level and basically illiminated serving wear.

The hump in the bow string was a manufacture fault where the riser was not set quite high enough where it met the rail-stock.

All the best.

Reactions: 5

primeduck

· #16 · Dec 14, 2019

Gotcha. May to check my Ghost 360. Thanks

Reactions: 1

TomOnTheRun

Discussion Starter · #17 · Dec 14, 2019

Be advise you have to use shim thickness trial by error. For STR setup BR used 3/16" thick shim. On my TS370 I used a 1/8" thick shim.

Good luck you decide to do this. All credit goes to bunnyrabbit. They guy is a true Xbow guru.

The string hump that BunnyRabbit references is common on many Xbows. However, he right to me why in the past I always sent my Xbows be tuned and inspected. This is one of many areas that can be improved on a out of the box Xbow and is common for all OEM's and brands.

Reactions: 2

TomOnTheRun

Discussion Starter · #18 · Dec 14, 2019

oops, not wearing glasses.... Yikes! I hate it when I dod that.

The string hump that BunnyRabbit references is common on many Xbows. That is why I sent "out of box" Xbows to be tuned and inspected. This is common for all OEM's, models and brands. At least many. The shim is a big deal when it comes to bowstring pressure. It's a big deal to me anyway. No no issues and only positives so far.

Gabowman

· #19 · Dec 14, 2019

Tom, why are you replacing the metal shims with rubber ones?

Reactions: 1

TomOnTheRun

Discussion Starter · #20 · Dec 14, 2019

My intentions are more for cosmetics. Kinda want all black look. Than I thought maybe the hard rubber would add a small element of vibration dampening. That is it. I guess what's not broken why fix it.

The metal shims I have now are working great.

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