Lewis LHP+ U4 Brakes: Introduction - by Deniz Merdano

Article From: https://nsmb.com/articles/lewis-lhp-u4-brakes-introduction/

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The world is a big and complicated machine, often with metric-pitched gears trying to mesh with imperial values. This massive blue-ball hurtling through time and space has also become so small that you can't fart without someone on the other side of the world sampling it into a tune. Guarding intellectual and physical properties is a gargantuan task that requires expensive lawyers. Small firms rarely have the scratch to finance litigation against companies who they feel may have stolen their work, particularly if this theft happens far from home.

That was a load of vague foreshadowing regarding the ethics behind the design of the product I am about to talk about, which happens to bear more than a passing resemblance to another brake which, unlike this one, is not made in China.

I've been wanting to try Lewis Brakes for a few years now. The time has come to start the process, and I've realized I'd like to divide the reviews into a couple of parts to give them an opportunity to fail and report back, when and if they do. I am also interested to see Lewis' responses and solutions to these problems, should they occur..

Initially, the waters were a little murky about the design inspiration for these Chinese-made brakes. More recently, Lewis has been more open about the similarities between their products and the well-received, very expensive, German-made, Trickstuff Brakes. Trickstuff hasn't provided any testing products to the NSMB crew, but Lewis was happy to get a set of their newest LHP+ U4 Brakes to me for a long term test. Before this interaction, Lewis was in touch with me about 3 years ago when they were just getting into the market. At that point they were probably less aware of how MTB media works and the importance of it and they failed to follow up and provide a set for review. They did however keep revising their story and their products until they believed they were fit to be digested by the western crowd.

Lewis's latest, aimed at Downhill and Enduro riders, has four 17mm Pistons and infinitely adjustable master cylinders and levers. Mineral oil flows through their veins. They don't specify what brand or type but the stock stuff is green. The lever and the caliper are machined, quite nicely I might add, from 7075 T6 Aluminum. Finish options are raw silver or the black anodized choice seen here. There is also an LHT Ultimate brake with some crazy colour options, titanium bolts for some extra bling and better markings for the leverage ratio adjustment feature. I'll talk about that more later on. The LHP+ calipers also have built-in floating cooling fins.

The cooling fins actually fit between the pistons and the brake pads independently. I first dismissed this interesting approach and as dumb. I have since discovered they work really well. I initially assumed these fins would fall out, rattle or be non functional. Lewis seems to have thought this through and the fins are captured by the caliper in the pad cavity. While they are free to move in and out as the pads wear, they are only removable by splitting the caliper body in half. They will not fall out of the caliper or rattle while riding thanks to strong pad springs.

Speaking of pads, the shape looked familiar and it turns out they are of Hope's standard, so you can use Hope V4 pads as replacements. These pads seemed a millimetre wider than the V4s from Hope, which means Hope pads may rattle when brakes are applied. I have not confirmed this but I will update when I do. Lewis brake pads are much cheaper than Hope pads however, so I would stock up on these instead. This kind of cross-compatibility is good for trips to Eupope where Hope pads are easy to source. In Canada, Hope availability is improving thanks to proper distribution by NRG.

While I was impressed with this pad architecture, I am baffled by the pin clip design. If you are going to borrow ideas, make sure they are good ones. I am not sure if the British have needle nose pliers for fingers or what, but this is just a silly, overly complex design. These are guaranteed to disappear on the trail or in your workshop when you are trying to reinstall them. You can do better Lewis. (and Hope - Ed.)

Installation

You will need a variety of tools for this job.

1.5mm Hex for the Leverage adjustment set screws

2mm Hex for the Pad pin and Pad contact adjustment

3mm Hex for the bar clamp

5mm Hex for the Caliper bolts

T30 Torx for Caliper assembly ( not required regularly)

T15 Torx for Lever assembly(not required regularly)

T10 Torx for bleed bolts

8mm Wrench for the compression nut on the hose

Needle Nose pliers for the pad pin

You will also need a generic mineral oil bleed kit. Mine is from the internet because the Shimano bleed cup did not fit the Lewis lever. I would recommend getting the kit Lewis sells. It costs 22 USD and seems pretty comprehensive.

These brakes show up pre-bled and ready to install. The hose fitting is reusable and can be removed and installed a few times without losing much, if any, fluid. You will need to cut the hose to remove the compression nut anyway; otherwise you won't be able to slide the hose through your frame. It would have been better if the system came filled with oil but with the hose unattached to the lever. The hose could be capped off to prevent leaking. This way the end user could route the hose through the frame and attach it to the lever.

If you are running external routing on your bikes, then chapeau, sir or madam.

When you order your brakes, MAKE SURE TO TELL THEM YOUR PREFERRED REAR HOSE LENGTH!

OK, I didn't mean to yell but my set came with just enough hose for a size medium Orbea Rallon. Either Lewis has all the stats on my bike and size or they just attached whatever hose they had sitting around for the media. If you need a certain length, put that in your order. Better safe than sorry.

The routing through the frame was uneventful. The Rallon is not tube-in-tube design so I routed the hose through a jagwire foam insulator to reduce rattles. It was relatively easy and the hardware pressed into the hose without a fuss. Make sure you don't forget the O-ring on the barb and tighten the 8mm nut gently. There are only 2 wrench flats on them and they are rather small. You will strip them if you are not careful. They look pretty but that design needs an update as well. Lewis, are you taking notes?

Attaching the Lever to the handlebars is unique to Lewis (and, coincidentally, Trickstuff). The two-piece clamp attaches to the lever and to the bars simultaneously. I personally prefer the Shimano system but despite my preference, the Lewis clamp works well.

Be aware that the 3mm hex head bolts have an order of priority. While you have to start threading them on at the same time, the order is that you gently snug the lever side bolt first, then tighten the bar side bolt second to 4Nm or so. This was enough clamping force to keep the lever from rotating on the Raceface ERA Carbon bars I run.

Once everything is secure and you place your lever approximately where you want, you can attach the calipers to your frame or fork. I found a couple of limitations here. My bike has 203mm Galfer Wave rotors front and rear. They work fine and didn't need replacing. Lewis calipers are compatible with 2.3mm rotors making them very responsive to lever adjustments. My 1.8mm rotors work fine, but once they wear out, I may switch to 2.3mm.

I wanted to reuse my Shimano +23mm brake adapters because they were compatible on paper. Unfortunately, no matter what I tried, I could not stop the calipers from shifting while tightening the bolts. Conical washers were not an option because there wasn't enough room due to the machining on the calipers. I bought some North Shore Billet adapters but I made a boo-boo and got +20mm instead, so in the photos you will notice 1.5mm washers. They have since been replaced with the proper +23mm adapters. I understand the functionality of the 4 bolt brake adapters for shorter, stronger bolts, better alignment and arguably better cooling with more material.

Bleeding

This was a dead simple process but, before you bleed, make sure your pad contact adjustment ( it sits inside the lever reach adjust knob) is all the way out and the lever reach too.

The Lewis method involves a gravity-fed bleed cup but I used two small syringes, one with a hose crimp at the caliper side, one without on the lever side. I filled the caliper syringe full and left the lever syringe mostly empty. Once I pushed the fluid from the caliper up to the lever, bubbles appeared in the upper syringe. At this point, I squeezed the lever a few times, repeating the process, and voila, bleed done. Next I dialled the pad contact in( 1.8mm rotors may requ all of this adjustment) and adjusted the lever to the distance I wanted from the bars. It all seemed easy.

I then took the master cylinder top plate off to see what was underneath, discovering a well-machined system with an expanding bladder. The bladder sits between the cap and the lever body without much of a groove to guide it. If you decide to take it off, make sure it is placed perfectly flat or you may end up with a leaky lever. I didn't mess this up, but I came pretty close and I won't be removing that cap unless I intend to remove all the oil from the caliper, and clean the surfaces with alcohol before reassembly.

Adjustments

The LHP+ Lever is an extremely adjustable piece of engineering.

Adjustments include;

Lever Reach

Pad Contact

Lever Leverage

Lever reach is tool free. You can dial the round knob closest to the grips quite a few turns. I've set mine at 62mms from the tip of the lever blade to the grips. This feels good for my size large hands. I may never be a pianist but I finger-pick the guitar all day long. My settings are somewhere in the middle of the range.

Inside the lever reach knob, there is a 2mm hex that allows for pad contact adjustment. Lewis includes a tiny tool to access this without removing the lever from the bars. If you bring this tool on a ride, you will most certainly lose it. I discovered that winding this adjustment all the way in was the best setting anyway. We'll see if change my tune when I switch to 2.3mm thick rotors.

On the front-facing part of the lever, there is another flower-shaped knob that allows for lever leverage adjustment. Most people are really curious about this function and I definitely need more time to understand its full potential. You first have to loosen 2, 1.5mm grub screws to allow the adjuster to rotate freely. Failing to do so will damage the adjustment screws and, ultimately, your day.

The idea of this functionality is that you can set your lever feel to your preference. Since most people will be coming into the Lewis sphere from other brakes, they will be chasing a feel they have appreciated before. Shimano people like me will want a snappy feeling lever that has a distinct wall of resistance before the brake starts grabbing. Hayes people may want the same. If you want a more gradual and softer initial bite of the pads, set the leverage to reflect that. The infinitely rotating knob will spin an eccentric spacer that the lever blade attaches to. This will change the leverage point and thus, the effective feel of the brake. I also found it impacts stopping power. Unfortunately, there are not markings to tell you where you have it set. It is all by feel and most feels have shit for brains. I would like markers on the lever bearing or the lever blade to correspond to a setting. I think I have the front and the rear levers set identically, to the most responsive setting, but I can't verify this visually.

So what does this mean on the trail?

Lewis's LHP+ U4 brakes, with metallic pads and 203mm rotors, are the most powerful brakes I have experienced. While this is a tough one to quantify, I have easier access to more power than what I am used to with XTR and Code brakes. These brakes increased my confidence in situations where the lines of Power and Modulation intersect. I can relax my hands more and have access to immediate power when I need it. Am I riding faster than I was before? Probably not. That is on my ability to read the trail at speed and that is kind of shit, to be honest. I have maxed my processing speed and I don't think I can ride faster on the North Shore technical double blacks without skipping over a whole lot of information. But I do enjoy the usable power range so far. I think more adjustments and experiments on smaller rotors, and MTX pads are required to find the sweet spot for the riding I like to do.

I also noticed the pads do not require a warm up period before they deliver their stopping power. This means I can shuttle or climb up in cold temperatures and drop right into steep terrain without having to put some heat into the pads. This is not something I can say about XT or XTR brakes. Codes seem to respond more quickly but overall, they lack power for me. However, a recent go on CODE Ultimates with HS2 rotors has made me doubt that belief.

I attached a scale to the lever on freshly bled brakes of all three brands and applied 6kg of force to them. This is about as much force as I would put into the lever for maximum braking. At about 7kg, the lever pulls almost to the bar. So I believe on the trail, your fingers are not pulling the lever any more than 7kgs of force. I am really looking forward to testing this with some measuring equipment.

The usable power comes on a bit later than XTRs but sooner than the Code RSCs. It also builds up quicker than XTR and Codes after the initial bite. The curve feels more progressive than Shimano and Sram brakes and tapers off nicely as you reach peak power. I find the XTRs to be very manageable in rough, fast trails while these seem to have a little more power on tap and can cause over-braking. This is all by "feel" of course but feel is half the battle on the mountain bikes.

I am looking forward to putting more miles on this setup as the year progresses. I would like to try different pads and rotors to see the limits of the system. I would also like to see how Lewis deals with problems that may occur. So far the lever feels extremely solid without much flex. The brakes haven't faded, nor has the bite point wandered after bigger descents. The Galfer rotors make some squealing sounds when heated to the limits, so ultimately they may be on their way out the door for a more quiet riding experience.

Lewis seems to be looking for Canadian and North American distribution as I write this. While this would be good for them to establish consumer trust in the long run, the question remains; Will a Canadian company bite the bullet and take on a young brand like Lewis?

Stay around for Part 2 in the next few months.