E-bike brake pads for Aventon: when and how to replace them

An e-bike is heavy, and it's often carrying a kid, groceries or both. Brake pads wear faster than on a regular bike, and on most Aventons they are the one part you will replace every season. The good news: it is a job you can do at home with basic tools.

Doing both wheels? Our Aventon Brake Pad Refill Kit has the pads and cleanup supplies this guide uses, in one box. You supply the tools, and we carry the ones that make the job easier (listed under How to replace them).

Our take, Joe: On my Abound I take the front wheel off, because it is held on with a thru axle and comes out easily. For the rear I leave the wheel in and unbolt the caliper to get at the pads. You can also flip the bike upside down with stands under the handlebar. That has gotten easier now that I have done it several times.

Which brakes does your Aventon have?

Most current Aventons use the same Tektro 2-piston hydraulic brake, the HD-E3520. Aventon's own brake list puts it on:

• Abound, Abound SR and Abound LR
• Aventure 2 and 3
• Level 2, and Level 3 bikes with Tektro brakes (some Level 3s have Magura brakes instead)
• Pace 500 (all versions) and Pace 4

An original Aventure or Level may have a different brake, so check that your caliper says Tektro. Older and lower-priced models (Pace 350, Sinch, Soltera 2) use Tektro mechanical brakes with a different setup, and the Aventure M, Current and Ramblas use SRAM 4-piston brakes. Not sure which you have? Send us a photo of the brake caliper, the part that grips the rotor, and we'll tell you.

When to replace your pads

Look at the pads, not the calendar. Aventon's rule of thumb: the pad material should be at least 1 mm thick, about three business cards stacked. Tektro puts it as 2.2 mm for the pad and its metal backing plate together. Below that, replace them.

Other signs it's time:

• Grinding or scraping. That's the metal backing plate hitting the rotor. Stop riding and replace the pads before the rotor gets damaged.
• Squealing that doesn't go away, or a rotor with dark, oily-looking smears. The pads may be contaminated with oil. Tektro says to replace pads that have picked up oil. Aventon says contamination can sometimes be cleaned off the rotor and pads with rubbing alcohol, or by lightly sanding the surface of the pads. If that does not cure it, Aventon says to replace the pads and the rotor on that brake together.
• Longer stops than you're used to, especially with a passenger on the back.

Check the rotor too. Replace it if it is bent, deeply grooved, or worn below its minimum thickness. The minimum is usually stamped on the rotor; on Tektro rotors it is 1.5 mm. You need a caliper or micrometer to measure it.

Sacramento note: the first rain of the season brings a summer's worth of oil up off the road. If your brakes suddenly squeal after the first wet ride, that can be why.

Which pad to buy

This matters more than the brand name on the package.

Stay with the compound your bike came with. Aventon notes that pad materials are not universally compatible and says to check your rotor for a marking that names the pads it takes. The stock pad for the HD-E3520 is a resin (organic) pad. Resin pads are quiet and grab well in the dry.

• The stock resin pad for the HD-E3520 is the Tektro E10.11. We keep it on the shelf in Sacramento. For most Aventon owners this is the one to buy.
• Our Aventon Brake Pad Refill Kit is the easy way to do both wheels: two sets of E10.11 pads plus the alcohol prep pads, microfiber cloth and two pairs of nitrile gloves used in the steps below. Tools are not included.
• We also carry the Sumart DBP-23, a semi-metallic pad in the same shape. Semi-metallic pads last longer and handle wet and heat better, but they can be noisier, and they should not go on a rotor that has been running resin pads. Choose it only with a new rotor, or if your bike already runs semi-metallic pads. Not sure? Email us before you order.

Pads come one set per wheel, so doing both wheels takes two sets, or the kit. Shipping is $3.95, or free once your order reaches $49.

How to replace them

Before you start: your brakes are what stop you and anyone riding with you. This is how we do the job on our own bike. It is general information, not a substitute for the instructions from Aventon and Tektro or for a qualified bike mechanic, and you do the work at your own risk. If you are not confident at any step, or the brakes do not feel right when you finish, do not ride the bike. Take it to a shop.

This is how we do it on an Abound. Other Aventons with the same brake work the same way at the caliper, but check how your wheels come off before you start.

What you need: a 6 mm hex key for the front thru axle, a 5 mm hex key for the rear caliper bolts (the Sumart sliding T-handle set has both), needle-nose pliers, a pad spreader or a plastic tire lever for pushing the pistons back, and a torque wrench. For cleanup: alcohol prep pads (or rubbing alcohol on a clean rag), a lint-free cloth to dry the rotors, and two pairs of nitrile gloves. The refill kit includes the cleanup supplies but not the tools. Wear gloves whenever you handle the pads or the rotor, and change to a fresh pair after the old pads come out: the oil on your skin is enough to contaminate them. Keep oil and lube well away from the pads and rotor, and don't squeeze a brake lever while its pads or wheel are out. It pushes the pistons out, and they have to be pressed back in before anything fits.

Tools from our shelf that fit this job:

• Sumart Sliding T-Handle Hex Tool Set: the 6 mm for the front thru axle and the 5 mm for the rear caliper bolts, with a T-handle that gives you better reach around the wheel guard.
• Sumart UBB-20: a piston spreader made for 2-piston calipers like this one. Safer on the pistons than improvising.
• Tektro TR-52 rotor, 180 mm: if your rotor is worn, grooved or bent.
• Handlebar Jack: stands for flipping the bike, if you take the rear wheel out.
• SILCA Ultimate Brake + Drivetrain Cleaner: for brakes that squeal but still have plenty of pad left. Try cleaning before you replace anything.

We do not carry needle-nose pliers or a torque wrench. Any hardware-store pliers will do. For the pad swap, a small torque wrench that covers 5 to 12 Nm handles every bolt. Only if you take the rear wheel out do you also need one that reaches 40 to 45 Nm for the axle nuts.

Front: take the wheel off

1. Remove the front wheel. On the Abound it is held by a thru axle. Undo it with a 6 mm hex key, slide it out and lower the wheel.
2. Remove the old pads. Straighten the bent end of the retaining pin with pliers, pull the pin, and slide the pads and spring out of the caliper.
3. Push the pistons back. Wipe the exposed pistons clean first, so you do not press grit into the caliper. New pads are thicker than worn ones, so the pistons have to go back into the caliper first or the new pads will not fit over the rotor. This is best done with a pad spreader, such as the Sumart UBB-20, or with a plastic tire lever. A tire lever is fine directly on the pistons as long as it is plastic. Press them back gently and evenly until they sit flat. Never use anything metal, such as a screwdriver. If the pistons will not go back with gentle pressure, stop and do not force them. Aventon's own method opens the bleed port at the brake lever, with a bleed cup attached, so the extra fluid has somewhere to go. Without a bleed kit, that is a job for a shop.
4. Fit the new pads, fresh gloves on and touching only the backing plates, with the spring between them, push the pin through and bend its end over so it cannot back out.
5. Wipe the rotor on both sides with a prep pad, dry it with the cloth and let it dry fully, then put the wheel back with the rotor between the pads and tighten the thru axle to the torque printed on it. Ours is marked 8 to 10 Nm.

Rear: leave the wheel in and take the caliper off

The rear wheel on a hub-motor bike is heavy and wired to the bike. Aventon's own instructions take the wheel out for a pad change. Leaving it in and unbolting the caliper is our shortcut on the Abound, and it ends with the caliper centered the same way Aventon does it: bolts loose, lever pumped, then tightened. If the rear rotor needs replacing too, do not use this method: take the rear wheel out instead (see “The other way” below) and do the pads and the rotor in one job.

1. Take the plastic wheel guard off first. On the Abound a black plastic guard sits between the rack and the rear wheel and covers most of the caliper. No bolts hold it on. Undo all of the Velcro straps that hold it in place, then lift the top of the guard up and over the bolts it sits behind and pull it away. With the guard in place you cannot get a hex key squarely onto the caliper bolts.
2. Unbolt the caliper. Undo the two bolts that hold it to the frame with a 5 mm hex key and lift it off the rotor. Support it in your hand or on the frame. Do not let it hang by the hose.
3. Swap the pads exactly as on the front: pin out, old pads and spring out, pistons pushed back with the spreader or tire lever, new pads and spring in, pin back and bent over.
4. Wipe the rotor on both sides with a prep pad, dry it with the cloth and let it dry fully.
5. Refit the caliper. Slide it back over the rotor and thread both bolts in loosely. Pump the rear brake lever several times until it firms up and the pads close on the rotor. Then squeeze the lever and hold it while you tighten the bolts evenly. That centers the caliper on the rotor. Aventon specs the Abound's caliper mounting bolts at 9 to 12 Nm.
6. Put the wheel guard back on. Slip its top back over the bolts and refasten every Velcro strap. It keeps feet, straps and bags out of the wheel.

The other way: take the rear wheel out. For pads alone it is more work. But if the rear needs a rotor swap, you might as well take the wheel out: you can get at both the pads and the rotor in the same job. Aventon publishes a rear wheel procedure for the Abound, and the steps below follow its order. You will also need an 18 mm socket (a deep socket is ideal, but a standard one should work), wire cutters and two new zip ties.

1. Turn the bike off and flip it upside down, with a stand under each side of the handlebar so the display and controls stay off the ground. Two paint cans of the same height work, as in our photos. We also carry the Handlebar Jack, a pair of stands that strap to the bar and add 3.7 in of clearance.
2. Shift the chain onto the smallest cog.
3. Deal with the footboards before you touch the axle nuts. Aventon has you remove both: 6 mm hex bolts on the underside, 5 mm hex bolts on the side of the frame. We took ours off the first time. Since then our wheel has come out with the footboards still fully fastened (see the grease tip below).
4. Free the motor cable. Cut the two zip ties on the brake side and loosen the Velcro. Wiggle the connector gently and pull it apart by its body, never by the wires.
5. Undo both axle nuts with the 18 mm socket. Take off the nuts and washers and note which way each washer faces.
6. Hold the derailleur back with one hand and lift the wheel out with the other.
7. Swap the pads as in the front steps. If you are changing the rotor (we stock the Tektro TR-52 in 180 mm), Aventon specs the rotor bolts at 5 to 7 Nm, and the arrow on the rotor points the way the wheel turns.
8. Going back in: chain onto the smallest cog, rotor guided into the caliper. Watch the rotor as the wheel drops in so it does not scrape the frame. Paint scraped onto the rotor can hurt braking and make the brake noisy; if it touches, clean the rotor with rubbing alcohol before you ride. Seat the torque washers in line with the dropouts, then put a washer and a nut on each side. Tighten the axle nuts evenly to 40 to 45 Nm.
9. Reconnect the motor cable by lining up the two arrows and pressing it together firmly. Zip-tie the cable back to the frame, refit the footboards, then power the bike on and check that it runs normally.

The rear axle can fight you the first time. If the wheel has never been out, the axle can be very tough to get out of the dropouts. Take the footboards off first, as Aventon says. If it still will not move, two things help.

• A penetrant such as WD-40, used with great care. Anything oily that reaches the rotor or the pads will ruin your braking, and contaminated pads have to be replaced. Never spray it at the bike. Spray it onto a rag, well away from the wheel, then wipe it onto the axle where it sits in the dropouts. Keep that rag away from the rotor, the pads and the caliper, and wipe the rotor with rubbing alcohol before the wheel goes back in.
• A piece of wood and a rubber mallet. You may need to get crafty. Hold a piece of wood against the end of the axle and tap the wood with a rubber mallet to knock the axle free. The wood keeps the mallet off the axle threads. Damaged threads mean the axle nuts will not go back on.

What made it easy for us after that: a light film of grease on the dropouts and on the axle where it sits in them, put on as the wheel went back in. Since then our rear wheel comes right out, with the footboards still fully fastened. Keep the grease well away from the rotor and the pads, and clean your hands before you touch either.

If you flip the bike, expect squishy brakes at first. Turning a hydraulic bike upside down can let air pockets move in the brake lines, and the levers may feel soft when it is back on its wheels. Ours did. With the bike upright, hold each lever level with the ground, press it gently several times and give the bubbles a moment to work back up to the reservoir. That is the advice Shimano gives for its own hydraulic brakes. Keep pumping until both levers firm up, and check at walking pace that both brakes stop the bike before you ride anywhere. Ours took about a mile of easy city riding to feel normal again. Take that first mile slowly and without a passenger.

Before you ride

1. Pump each lever a few times until it firms up, then spin the wheels to check nothing rubs. If a rotor rubs, recenter that caliper the way the rear steps describe: bolts loose, lever pumped and held, bolts tightened to 9 to 12 Nm.
2. Bed in the pads. Tektro says new pads need 20 to 30 full stops to reach full power. Aventon gives its own method, ten repeats of this: get up to 15 to 20 mph, brake evenly without skidding until you are down to walking pace, and release while you are still moving. Either way, do it on a quiet street before your first school run.

If a lever pulls all the way to the grip, or it is still soft after pumping and that first easy mile, don't keep riding it. That's a bleed, not a pad problem, and it's a job for a shop.

Questions?

Email support@breaktimebicycle.com with your model and a photo of your brakes. We answer within one business day, and we'd rather help you pick the right pad than process a return.

Ride on,
Break Time Bicycle Co.