IMS Big Bang vs IMS Competition Baskets: Hole Patterns Compared
A research-based comparison built from IMS Filtri product pages and the IMS filter code guide. We did not bench-test these baskets.
Quick Answer
IMS Big Bang and IMS Competition baskets share 0.30 mm holes and recalibrated perforation, but they differ in hole layout. The IMS Big Bang (BB) pattern widens hole spacing from 1.5 mm at the center toward the edge, with up to 585 holes. IMS Competition baskets use an even grid: the E pattern at 1.73 mm hexagonal spacing (up to 715 holes) or the M pattern at 1.50 mm rectangular spacing (641 holes). Choose the IMS Big Bang if edge channeling is your recurring problem; choose an IMS Competition basket if you want an even, conventional precision grid.
This page compares two IMS basket families only. For full IMS Big Bang sizing and dose tables, read the IMS Big Bang basket review. For a cross-brand choice, see IMS vs VST vs Pullman precision baskets.
How IMS Names Its Basket Hole Patterns
Every IMS basket code ends with a hole pattern suffix. The IMS filter code guide reads a code such as B70 2T C H26 E as border, dose, shape, height, and hole pattern, and lists these IMS hole patterns:
- E pattern: hexagonal layout, 1.73 mm between holes, up to 715 holes in a 49 mm area.
- M pattern: rectangular layout, 1.50 mm between holes, 641 holes in a 44 mm area.
- N pattern: rectangular layout, 2.00 mm between holes, up to 481 holes in a 49 mm area.
- BB (Big Bang): incremental spacing starting at 1.5 mm in the center and widening toward the edge, 585 holes maximum.
The IMS Competition baskets compared on this page carry the E or M suffix, while IMS Big Bang baskets carry the BB suffix. The IMS shape letter also matters: IMS uses "C" for a convex bottom and "F" for a flat bottom.
IMS Big Bang vs IMS Competition: Spec Comparison
The table below sets published specs side by side for 58mm (B70) and 54mm (B62.5) IMS Big Bang and IMS Competition baskets, taken from the IMS pages for the B702TFH27.5BB, B702TH24.5M, B702TCH28.5E, and B62.52TH26E, plus the IMS Big Bang line page.
| Spec | Big Bang B70 (BB) | Competition B70 (M) | Competition B70 convex (E) | Competition B62.5 (E) |
|---|---|---|---|---|
| Hole layout | Incremental from 1.5 mm | Rectangular, 1.50 mm | Hexagonal, 1.73 mm | E pattern |
| Holes | 585 | 641 | 715 | 583 |
| Perforated area | 49 mm | M pattern in 44 mm | 49 mm | 44 mm |
| Hole diameter | 0.30 mm | 0.30 mm | 0.30 mm | 0.30 mm |
| Bottom | Flat | Rounded internal corner | Convex | Narrowing at base |
| Tamper | 58/58.4 mm | 58/58.4 mm | 58/58.4 mm | 53/53.4 mm |
| Heights listed | 21.5 / 23.5 / 25.5 / 27.5 mm | 22.5 / 24.5 / 26.5 / 28.5 mm | 28.5 mm | 26 mm |
IMS lists the B70 Big Bang, B702TCH28.5E, and B62.52TH26E as ridgeless; the B702TH24.5M page lists a 60.5 mm external ridge.
IMS Big Bang vs IMS Competition Dose Ranges at Similar Heights
IMS publishes dose ranges by roast for each basket height, so an IMS Big Bang and an IMS Competition basket of similar height can be matched to the same dose. The figures below come from the IMS product pages linked above and the IMS B62.5 Big Bang listings.
| IMS basket | Dark | Medium | Light |
|---|---|---|---|
| Big Bang B70, 23.5 mm | 17–19 g | 18–20 g | 19–21 g |
| Competition B70 M, 24.5 mm | 16–18 g | 17–19 g | 20–22.5 g |
| Big Bang B62.5, 25.5 mm | 17–19.5 g | 18–21 g | 18–20.5 g |
| Competition B62.5 E, 26 mm | 17–19.5 g | 18–21 g | 18–20.5 g |
| Competition B70 convex E, 28.5 mm | 19–22 g | 22–25 g | 23–27 g |
For an 18 g dose, the 23.5 mm IMS Big Bang B70 and the 24.5 mm IMS Competition B70 M both cover the dose, so the two IMS baskets can be compared without changing recipes. In a 54mm Breville portafilter, the 25.5 mm IMS Big Bang and the 26 mm IMS Competition B62.5 share identical published dose ranges.
Bottom Shape: Flat IMS Big Bang vs Shaped IMS Competition Baskets
IMS Big Bang baskets are flat-bottomed and cylindrical. IMS Competition baskets come in several bottom shapes: IMS describes the B702TCH28.5E as having a convex bottom that collects coffee toward the center for easier drying and puck expulsion, the B702TH24.5M as having a rounded internal corner, and the B62.52TH26E as a cylinder that narrows at the base.
Bottom shape changes how the puck sits against the perforated area, so an IMS Big Bang vs IMS Competition comparison involves two variables: hole layout and base geometry. Readers who want to isolate the hole pattern should compare IMS baskets with the most similar base shape available.
Which IMS Basket Suits Which Home Barista
- Choose the IMS Big Bang if espresso shots show fast flow or blonding near the basket wall. IMS designed the Big Bang spacing to counter side channeling; the espresso channeling guide explains how to read that symptom.
- Choose an IMS Competition E basket for the densest even grid IMS lists, up to 715 holes, and larger doses from the taller convex model.
- Choose an IMS Competition M basket for tight 1.50 mm even spacing concentrated in a 44 mm area.
- On a Breville or Sage machine, both IMS families come in B62.5 form; match the IMS basket to the dose using the table above and the espresso basket size guide.
How to Compare IMS Big Bang and IMS Competition Baskets With the Same Coffee
The most reliable way to choose between an IMS Big Bang and an IMS Competition basket is a side-by-side run on your own machine. A fair IMS basket comparison holds everything constant except the basket:
- Pick two IMS baskets whose published dose ranges both cover your dose, such as the 23.5 mm Big Bang B70 and the 24.5 mm Competition B70 M at 18 g.
- Use one bag of coffee, the same dose, the same yield ratio, and the same puck prep for both IMS baskets.
- Dial in the first IMS basket to your target shot time, then pull the second IMS basket at the same grind setting and record its time.
- Adjust grind on the second IMS basket until it reaches the same shot time, then taste both shots side by side, ideally blind.
- Inspect each spent puck for wet spots or pinholes near the wall; edge channeling in the Competition basket favors the Big Bang, while even pucks in both suggest the hole pattern matters little for your setup.
Light roasts tend to expose basket differences most; the light roast espresso dial-in guide covers grind and ratio adjustments.
IMS Big Bang vs IMS Competition FAQ
What is the difference between the IMS Big Bang and IMS Competition baskets?
The main difference between IMS Big Bang and IMS Competition baskets is the hole pattern. IMS Big Bang baskets space their 0.30 mm holes 1.5 mm apart at the center and progressively wider toward the edge, with up to 585 holes. IMS Competition baskets use a uniform pattern: the E pattern is hexagonal at 1.73 mm spacing with up to 715 holes, and the M pattern is rectangular at 1.50 mm spacing with 641 holes in a 44 mm area.
Which IMS basket has more holes, Big Bang or Competition?
The IMS Competition E-pattern basket has more holes. IMS lists up to 715 holes in a 49 mm area for the E pattern and 641 for the M pattern, against 585 holes for the 58mm IMS Big Bang B70 basket.
Is the IMS Big Bang better than the IMS Competition basket?
Neither IMS basket is better for every coffee. IMS designed the Big Bang pattern to push more flow toward the edge and counter side channeling, while IMS Competition baskets use an even hole grid across the perforated area. The better IMS basket is the one that gives the more balanced shot with your grinder, dose, and roast.
Do IMS Big Bang and IMS Competition baskets fit Breville machines?
Yes. IMS lists B62.5 versions of both the IMS Big Bang and IMS Competition baskets, with a 54 mm body and a 53/53.4 mm tamper, as compatible with Breville/Sage and Solis machines.
Are IMS Competition baskets ridgeless?
The IMS Competition B62.52TH26E and B702TCH28.5E baskets are listed as ridgeless. The IMS Competition B702TH24.5M page lists an external ridge of 60.5 mm, so check the IMS product page for the exact code before buying.