SRAM DUB is a crank spindle standard. When a sheet says "SRAM DUB (28.99 mm)", it is telling you the diameter of the axle that runs through the frame from one crank arm to the other. That is all it tells you. It says nothing about whether the part will go into your frame — that answer lives at the other end of the same bottom bracket, in the shell.
This is the confusion we untangle most often at the counter. A rider reads DUB on a crankset box, reads DUB on a bottom bracket box, and reasonably concludes the two are a matched set. They are. But the bottom bracket has two faces, and only one of them is DUB.
What the standard actually does
A bottom bracket is a translator. On the inside it must match the hole in your frame — the shell: its bore, its width, whether it is threaded or pressed. On the inside of that, the bearings must match the crank axle that passes through them. DUB is the second half of that sentence. It fixes the spindle diameter so that one family of cranks can be carried across a shelf of very different frames.
So the useful way to shop is backwards. Start with the shell in your frame. Pick the bottom bracket that fits it. Then check that the bottom bracket provides the spindle standard your crank needs. If your crank is DUB, every one of the four bottom brackets below will accept it — and only one of them, at most, will accept your frame.
DUB tells you what the crank needs. The shell tells you what you can buy.
The parts in our archive that carry DUB
Four bottom brackets on file provide the same spindle. Read the two rows for each one as a pair: what it demands of the frame, and what it offers the crank.
| Brand | SRAM |
|---|---|
| Manufacturer part number | BB-DUB-BB30-A1 |
| Requires — Bottom bracket shell | BB30 (42 mm bore, 68 mm) or BB30, 73 mm or BBright (Cervélo, 46 mm bore, 79 mm) |
| Provides — Crank spindle | SRAM DUB (28.99 mm) |
| Brand | SRAM |
|---|---|
| Manufacturer part number | BB-DUB-BSA-A1 68/73 |
| Requires — Bottom bracket shell | BSA / English threaded, 68 mm or BSA / English threaded, 73 mm |
| Provides — Crank spindle | SRAM DUB (28.99 mm) |
SRAM DUB BSA bottom bracket, 68/73 mm
| Brand | SRAM |
|---|---|
| Manufacturer part number | BB-DUB-BSA-A1 83 |
| Requires — Bottom bracket shell | BSA / English threaded, 83 mm |
| Provides — Crank spindle | SRAM DUB (28.99 mm) |
SRAM DUB BSA bottom bracket, 83 mm (DH)
| Brand | SRAM |
|---|---|
| Manufacturer part number | BB-DUB-PF30-A1 |
| Requires — Bottom bracket shell | Press-fit PF30 (46 mm bore, 68 mm) or Press-fit PF30, 73 mm or BB386EVO (46 mm bore, 86.5 mm) or BBright (Cervélo, 46 mm bore, 79 mm) |
| Provides — Crank spindle | SRAM DUB (28.99 mm) |
SRAM DUB PressFit30 bottom bracket
Four part numbers, one spindle value in every "provides" row. That repetition is the whole point of the standard, and it is also why the spindle number is useless as a shopping filter on its own.
A worked example from the fleet
| Bottom bracket shell | Press-fit BB86 (41 mm bore, 86.5 mm) |
|---|---|
| Crank spindle | Shimano Hollowtech II, 24 mm |
The frame is press-fit, so instinct says the press-fit bottom bracket is the answer. It is not. The SRAM DUB PressFit30 bottom bracket does not fit the Canyon Grail CF SL 7 (2025): the shell on file does not match any shell in that part's requirement row. The bore is the sticking point, not the width.
The other three land the same way, for the same reason. The SRAM DUB BB30 bottom bracket does not fit the Canyon Grail CF SL 7 (2025). The SRAM DUB BSA bottom bracket, 68/73 mm does not fit the Canyon Grail CF SL 7 (2025), because that frame has no threads to take it. The SRAM DUB BSA bottom bracket, 83 mm (DH) does not fit the Canyon Grail CF SL 7 (2025) either. Each verdict is derived — read from one published sheet, not yet confirmed by a second independent publisher. No bike in our fleet is fully verified yet, and we would rather say that than pretend otherwise.
Notice also that the bike's own crank spindle row is Shimano Hollowtech II, not DUB. So on this frame the spindle standard and the shell standard both point away from these parts. That is a tidy no, and a tidy no saves a return.
- Does DUB mean the bottom bracket will fit my frame?
- No. DUB describes the crank spindle the bottom bracket accepts. The frame side is a separate specification — the shell — and it is the one that decides whether the part goes in.
- Why do four different bottom brackets all say SRAM DUB (28.99 mm)?
- Because they are four frame-side translators for one crank-side interface. BB30, threaded BSA in two widths, and PressFit30 all end up presenting the same spindle bore to the crank.
- Can I use an adapter to put a DUB bottom bracket into any shell?
- Not a question we will answer in general terms. We only publish a fit when the specific part and the specific bike are both on file. For the pairs in this article the verdict is does not fit, and no adapter path is on record.
- What if my bike's bottom bracket shell is not listed anywhere?
- Then the verdict is unknown, and unknown is a real answer, not a soft yes. Bottom bracket fit touches the drivetrain and your cranks; we would rather leave the blank visible than fill it with a guess.
What to carry away
- SRAM DUB is a crank spindle standard, stated as 28.99 mm. It is the crank side of a bottom bracket, never the frame side.
- Four bottom brackets in the archive provide it: the BB30, the threaded 68/73 mm and 83 mm BSA versions, and the PressFit30.
- Shop shell first. The requirement row on the part must name the shell on your frame's sheet.
- All four are recorded as does not fit for the Canyon Grail CF SL 7 (2025), on a derived shell mismatch.
- Missing shell data means unknown, and the shop does not sell a part into an unknown.
Filed in the archives in 2026. If a second independent sheet turns up for any of these frames, the confidence on these verdicts moves from derived to verified, and we will say so here.