HSC Ceramics DUB Bottom Bracket
Review by Dave Peart
Initial review of the bottom bracket and the installation process
This review compares and contrasts the HSC Ceramics bottom bracket and its installation process with the stock SRAM DUB bottom bracket that was originally fitted to my Santa Cruz mountain bike.
This bottom bracket is for frames with an English/BSA thread (i.e. 1.37” x 24TPI, the left bearing has a right-hand thread and the right bearing has a left-hand thread). It is to be used with a SRAM DUB chainset that has a 28.99mm axle.
Bottom brackets from other manufacturers for this frame/chainset configuration include:
- SRAM’s DUB BSA Bottom Bracket (£30) – as originally fitted to my bike, but has failed after 1000kms – possibly resulting from excessive power-washing, as it was an ex-demo bike;
- Nukeproof’s Horizon DUB BSA (£60) – ABEC 5 certified with stainless steel balls and titanium coated bearings;
- CeramicSpeed’s BSA SRAM DUB (£189), with a choice of coated or uncoated ceramic bearings;
- Chris King – you would need to use the Threadfit 30 (£170 – steel bearings) together with DUB adapter kit (£20), the bottom bracket is available with steel or ceramic bearings.
What’s in the box:
- Right-hand bearing
- Left-hand bearing
- 2x 2.5mm (35mm ID) frame-spacers (for 68mm frames with 73mm chainsets)
- 1x 3.4mm axle spacer (30mm ID)
- 1x 1.7mm axle spacer (30mm ID)
- 1x 0.6mm wave washer (30mm ID)
Note that the HSC Ceramics DUB BB does not have a sealing tube between the bearings to prevent contamination from within the frame reaching the crank axle and bearings – but I’ve fitted it to a Santa Cruz Bronson, which doesn’t have any holes between the BB tube and the rest of the frame, so this doesn’t present an issue.
The first thing to note was the amount of effort required to loosen the DUB crank bolt – I had to resort to a 3’ tube over the end of a socket wrench, wedged against the ground whilst I pulled/pushed against both pedals with considerable effort! The rest of the disassembly process presented no further issues (see further down regarding tools required).
Note that there is likely to be a spacer between the bearing and one or both of the crank arms – you will need to measure the total width of the bearings and spacers to determine which spacers to use with the new bottom bracket.
For the assembly, as my frame’s BB width is 73mm, I did not need to use the 2.5mm spacers between the bearings and the frame. For a complete guide on the mapping of cranks, frames and spacers, please refer to this link.
I fitted the wave washer on the non-drive side – such that I could observe it flattening whilst setting the pre-load adjuster. I then fitted both the 3.7mm and 1.7mm spacers to the drive side before fitting the crank arm. No issues were encountered during this process and the pre-load adjustment was straightforward to set.
On the Bike
With the new bottom bracket installed, the cranks now spin freely and feel very smooth to pedal with no creaks and free-play. It is a notable improvement over the outgoing (worn) SRAM BB. At the time of writing, I’ve covered around 100km of arduous off-road riding in a variety of conditions with no detrimental impact to the bottom bracket. The wave washer has remained in the same state of pre-load and the cranks still spin as freely as they did when newly installed.
Note on Bottom Bracket Tools
The subject of BB tools is almost as complex as that of all the different BB standards. For threaded BBs, depending on your start point you will need one or more of the following:
- SRAM GXP, older Shimano (HT2), Campagnolo 16 notch, 44mm tool
(adapters also available for Shimano TL-FC24 and TL-FC25)
- Shimano SM-BBR60 (TL-FC25 / TL-FC37) 16 notch, 41mm tool/insert
- Shimano SM-BB9000, SM-BB93 (TL-FC24 / TL-FC34) 16 notch, 39mm tool/insert
- SRAM DUB 12 notch, 46mm tool
- HSC BB (see photo above) 10 notch, 47mm tool
Take a look at our review of the HSC BB86 bottom bracket here.