Lewis LH4 Brake Review - Brad Kelly

Article From：Brad Kelly

First thing you'll notice is the cnc machining on these is damn nice, especially compared to cast aluminium or plastic construction.

Fitting and bleeding is similar to any other brake but probably the closest to a Shimano, except the lever diaphragm design enables you to use a syringe on the lever and you can be pretty forceful with removing bubbles without the risk or fear of the diaphragm bursting. The levers (and calipers) are also easily rebuildable with spare parts available.

They run on the mineral oil of your choice, which means the fluid is not corrosive and won't absorb moisture.

The orientation of the expanding/retracting channels in the lever diaphragm does mean some small bubbles can get caught up in them, but I've had no troubles removing them with pushing/pulling on the lever syringe and tilting lever to direct bubbles out of the bleed port.

The next and best part of these systems is the levers. The lever actuation/feel is light and ultra smooth, due to the sealed.

cartridge bearings not only at the blade pivot, but also on the push rod pivot, which means there is zero play both laterally and radially in the blade. The combination of leverage, blade length, 9mm lever piston, piston spring rate and low friction caliper seals (pistons can be pushed back by your fingers similar to Magura), which means no forcing or damaging pistons/calipers or the requirement of specific piston pressing tools.

I've also found the lever blade ergonomics and feel under my finger to be the most comfortable I've felt.

The bite point is solid (but as with any system, partially relies on caliper/post mount set up/alignment and pad compound) and with a great range of contact adjustment that doesn't alter/counter act the lever reach.

Even the lever reach adjuster has a friction adjuster to fine tune the resistance within the reach adjuster threads!

The weak point of the lever is the clamp which is nice, as it's the cheapest part to replace.

The fittings and pistons are all either stainless steel or titanium (depending on model) meaning no rust or corrosion and the hose banjo's aren't pressed on, which means you can shorten the hose at the caliper end or potentially use different manufacturers hoses without requiring the specific banjo.

They use Hope style/compatible pads, but I've found the stock Lewis pads to be great.

The power is the greatest I've experienced, but has unbelievably good modulation which means I haven't accidentally locked the brakes without meaning to.

The pad retraction is also great and I've had no problem keeping my brakes drag free, especially with 2.3mm rotors.

Note: the increased braking power and pad/rotor friction can increase pad/rotor wear.

These brakes aren't perfect, but they are by far the closest I've experienced, especially comparing to other manufacturers who have had the benefit of 20-30yrs to refine and improve their products.

I'm still absolutely loving these brakes after 3 months of hard and consistent use and have since purchased sets for all my bikes.