Cutting front bag cups- again - The 1947 - Present Chevrolet & GMC Truck Message Board Network

hotrodhomi · 03-15-2008, 01:34 AM

I know I've seen this question before, but the words are too short from the search function to work.
How much more drop will I get if I cut my cups down from 2 3/8" to 1 1/2"? I wouldn't think that it would be equal to the amount cut off. If I do this can I still use my stock shock mount? This is on a '72 with 73+ control arms.

shifty · 03-15-2008, 01:49 AM

In this thread, he cut the front cups down by 1.5".

The Fab Shack · 03-15-2008, 02:03 AM

the 'around about' on cutting cups and front suspensions is this.. if you cut the cup .500 inches, then you'll get around a 1" drop at the wheel.

gringoloco · 03-15-2008, 02:46 AM

My understanding is 2:1 ratio, cut vs. drop...

HotRodYJ · 03-15-2008, 03:56 PM

I cut mine to 1.5" total cup height. from what I could gather that's about as short as you can go safely. The bag may touch the arm at full drop, but wont rub when aired up so no harm done. 2:1 is a pretty good rule of thumb cut vr drop judging from how mine worked out.

68laydout · 03-16-2008, 12:03 AM

Curious as to what you guys are using to cut the cups?

HotRodYJ · 03-16-2008, 12:20 AM

Quote:

Originally Posted by 68laydout

Curious as to what you guys are using to cut the cups?

I measured the 1" I needed to cut off with 1" wide masking tape. Then use a 0.045" thick cutting disc in a 4 1/2" grinder to cut right along the edge of the tape. Really nice straight cut this way and doesn't take very long at all.

*Shane* · 03-16-2008, 12:21 AM

I plan on cutting a second pair i have on a lathe using a cut off tool.

shifty · 03-16-2008, 12:30 AM

I was thinking I was going to use a bandsaw. I wound up selling my cups within 2 weeks of buying em, though.

hotrodhomi · 03-16-2008, 06:02 AM

Quote:

Originally Posted by shifty

I was thinking I was going to use a bandsaw. I wound up selling my cups within 2 weeks of buying em, though.

Why did you sell. Are you using something different?

shifty · 03-16-2008, 10:06 AM

Yeah, when I realized I could get ART Strong Arms tubular arms for less than $700, I weighed the pros and cons, and decided this was the best deal for me. No BS worries with angle correction, bag mounts, bags rubbing, etc. So I ran with that and sold my cups.

Frizzle Fry · 03-17-2008, 12:10 AM

Quote:

Originally Posted by gringoloco

My understanding is 2:1 ratio, cut vs. drop...

The Fab Shack had it right. 1/2 = cut/drop

Frizzle Fry · 03-17-2008, 12:21 AM

Quote:

Originally Posted by hotrodhomi

This is on a '72 with 73+ control arms.

I think I've read that the 73+ arms have shallower spring pockets. This is how people can get away with cutting the cups down to 0.75"-1" with those arms. Again, I've only read this and have no first hand exp with the 73+ arms...

hotrodhomi · 03-17-2008, 05:31 AM

Quote:

Originally Posted by Frizzle Fry

I think I've read that the 73+ arms have shallower spring pockets. This is how people can get away with cutting the cups down to 0.75"-1" with those arms. Again, I've only read this and have no first hand exp with the 73+ arms...

I ended up cutting mine to 1 5/8" and I have only about 1/4" of clearance when fully slammed.

gringoloco · 03-17-2008, 06:50 AM

Quote:

Originally Posted by hotrodhomi

I ended up cutting mine to 1 5/8" and I have only about 1/4" of clearance when fully slammed.

Same here. 1" was too short...

jlaird · 03-18-2008, 05:16 AM

Quote:

Originally Posted by hotrodhomi

I ended up cutting mine to 1 5/8" and I have only about 1/4" of clearance when fully slammed.

hotrodhomi, gringo, 1/4" clearance from and to what? bag to arm? So with a 1 5/8 cup, the bag wont touch the arm when fully slammed?

Did you guys use the SD cups? I thought I remember reading they are slightly too wide for the cup to lay down on the bottom of the spring cup.

gringoloco · 03-18-2008, 09:15 AM

Quote:

Originally Posted by jlaird

hotrodhomi, gringo, 1/4" clearance from and to what? bag to arm? So with a 1 5/8 cup, the bag wont touch the arm when fully slammed?

Did you guys use the SD cups? I thought I remember reading they are slightly too wide for the cup to lay down on the bottom of the spring cup.

The bottom outside edge of the lower bellows rubbed the spring pocket at the inner edge(towards the cross-shaft) and where the pocket bulges to clear the shock mount bolt. At 1.5" total height using SD cups, I cleared the inner but had to massage the shock mount area.

1 5/8" should be perfect. These problems were all at ride height with the bag inflated to 6" tall. Deflated will touch, but it shouldn't matter...

hotrodhomi · 03-18-2008, 05:23 PM

I'm not sure where my cups are from, I bought them from a site member that wasn't going to use them.

chevydog66 · 04-09-2008, 06:44 AM

I cut 1" off my SD cups, on a lathe. I have a little bit of bag touch on the LCA when aired out, but no big deal.

gringoloco · 04-09-2008, 06:41 PM

Quote:

Originally Posted by gringoloco

My understanding is 2:1 ratio, cut vs. drop...

Quote:

Originally Posted by Frizzle Fry

The Fab Shack had it right. 1/2 = cut/drop

Just saw this- Damn you dyslexia!!!

jondancer · 07-11-2022, 08:32 PM

So 1.75” would be a good fit ?

03-15-2008, 01:34 AM	#1
hotrodhomi Registered User Join Date: Apr 2004 Location: Sacramento Posts: 3,737	Cutting front bag cups- again I know I've seen this question before, but the words are too short from the search function to work. How much more drop will I get if I cut my cups down from 2 3/8" to 1 1/2"? I wouldn't think that it would be equal to the amount cut off. If I do this can I still use my stock shock mount? This is on a '72 with 73+ control arms. __________________ '72 2wd blazer, bagged w/ watts link & EDC '72 C10 "Lowered Farm Truck" STOLEN 5-18-11 '66 impala ht

03-15-2008, 01:49 AM	#2
shifty Questionable Join Date: Mar 2005 Location: Atlanta Posts: 13,373	Re: Cuting front bag cups- again In this thread, he cut the front cups down by 1.5". __________________ If I've got anything up for grabs, it'll be here: 7-hole gauge cluster for a 67-72 p/u FREE (link) I can't check the forum daily. If I don't reply to you within 24 hours, drop me a PM! I'm (hopefully) still alive and will reply faster to a PM.

03-15-2008, 02:03 AM	#3
The Fab Shack Registered User Join Date: Jan 2008 Location: Lost in Central PA Posts: 7	Re: Cuting front bag cups- again the 'around about' on cutting cups and front suspensions is this.. if you cut the cup .500 inches, then you'll get around a 1" drop at the wheel.

03-15-2008, 02:46 AM	#4
gringoloco A guy with a truck Join Date: Sep 2005 Location: Germany, for now Posts: 5,921	Re: Cuting front bag cups- again My understanding is 2:1 ratio, cut vs. drop... __________________ -Chris Instagram _elgringoloco_ '70 Short-Wide How to: Ruin a perfectly good C10 ‘70 Blazer ConversionHow To: Ruin a Perfectly Good 4wd '72 Highlander How To: Ruin a Perfectly Good K/5 (SOLD) '72 Blazer 2WD How to: Ruin a perfectly good Blazer (SOLD) '05 Yukon Daily Driven (not so stock) Yukon (SOLD) ‘07 Yukon Denali (daily) Members met list: SCOTI, darkhorse970, 67cheby, 67cheby'sGirl, klmore, porterbuilt, n2billet, Fastrucken, classicchev, Col Clank, GSFMECH, HuggerCST, Spray-Bomb, BACKYARD88, 5150, fine69, fatbass, smbrouss70, 65StreetCruiser, GAc10boy

03-15-2008, 03:56 PM	#5
HotRodYJ Registered User Join Date: Jan 2008 Location: Johnson City, TN Posts: 264	Re: Cuting front bag cups- again I cut mine to 1.5" total cup height. from what I could gather that's about as short as you can go safely. The bag may touch the arm at full drop, but wont rub when aired up so no harm done. 2:1 is a pretty good rule of thumb cut vr drop judging from how mine worked out. __________________ 66 Chevy Stepside tandem project My junk: http://67-72chevytrucks.com/vboard/s...d.php?t=480902 Last edited by HotRodYJ; 03-15-2008 at 04:00 PM.

03-16-2008, 12:03 AM	#6
68laydout Junior Member Join Date: Jun 2006 Location: Frisco Tx Posts: 311	Re: Cuting front bag cups- again Curious as to what you guys are using to cut the cups?

03-16-2008, 12:21 AM	#8
Shane Account Suspended Join Date: Jun 2000 Location: over yonder Posts: 14,270	Re: Cuting front bag cups- again I plan on cutting a second pair i have on a lathe using a cut off tool.

03-16-2008, 12:30 AM	#9
shifty Questionable Join Date: Mar 2005 Location: Atlanta Posts: 13,373	Re: Cuting front bag cups- again I was thinking I was going to use a bandsaw. I wound up selling my cups within 2 weeks of buying em, though. __________________ If I've got anything up for grabs, it'll be here: 7-hole gauge cluster for a 67-72 p/u FREE (link) I can't check the forum daily. If I don't reply to you within 24 hours, drop me a PM! I'm (hopefully) still alive and will reply faster to a PM.

03-16-2008, 10:06 AM	#11
shifty Questionable Join Date: Mar 2005 Location: Atlanta Posts: 13,373	Re: Cuting front bag cups- again Yeah, when I realized I could get ART Strong Arms tubular arms for less than $700, I weighed the pros and cons, and decided this was the best deal for me. No BS worries with angle correction, bag mounts, bags rubbing, etc. So I ran with that and sold my cups. __________________ If I've got anything up for grabs, it'll be here: 7-hole gauge cluster for a 67-72 p/u FREE (link) I can't check the forum daily. If I don't reply to you within 24 hours, drop me a PM! I'm (hopefully) still alive and will reply faster to a PM.

03-18-2008, 05:23 PM	#18
hotrodhomi Registered User Join Date: Apr 2004 Location: Sacramento Posts: 3,737	Re: Cutting front bag cups- again I'm not sure where my cups are from, I bought them from a site member that wasn't going to use them. __________________ '72 2wd blazer, bagged w/ watts link & EDC '72 C10 "Lowered Farm Truck" STOLEN 5-18-11 '66 impala ht

04-09-2008, 06:44 AM	#19
chevydog66 GM ONLY BABY!!! Join Date: Oct 2003 Location: Fort Wayne, IN. Posts: 1,998	Re: Cutting front bag cups- again I cut 1" off my SD cups, on a lathe. I have a little bit of bag touch on the LCA when aired out, but no big deal. __________________ 2 wrongs don't make a right, but 3 lefts do. 66 Chevelle Malibu 406ci, 573hp, 10.99@121mph 96 Chevy Silverado Z71 72 GMC 1500 Super Custom LS 6.0/4L65 on airride http://www.cardomain.com/ride/707879...mc-c-k-pick-up

07-11-2022, 08:32 PM	#21
jondancer Registered User Join Date: Jul 2010 Location: central michigan Posts: 1,194	Re: Cutting front bag cups- again So 1.75” would be a good fit ?

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