Monday, October 15, 2007

Ez3-usx trike users guide

The right place to install a motor on this USX trike. It would be much better to get a motor that has a gear reduction built right onto the motor, like for a hoist does. If the gear ratio is close enough to what is needed you will have all the hill climbing power needed.

See How much power do you really need?

EZ3-USX users guide: All the redundant detail.

The original ez3 is worthless junk; this one can be dealt with. The reason that some cycles are cheap is simply a matter of components that don’t last. I couldn’t find any info about this trike before I paid for it, so I want people to know what they are getting into.

There is no gyroscopic kinetics on the front wheel. So you have to hold the bars with your knees while putting your sun glasses on. At high speeds on a smooth road I can feel side-to-side vibration created by low-pressure tires. I can corner faster than a bike on a gravel surface. And I certainly don’t have to worry about wet streets. But you can’t ride on wet streets without fenders, unless you don’t mind being sprayed with road mud.

There is a considerable amount of side-to-side jostling on rough roads, and the need to lean to adjust for road camber is irritating, learn to roll with it.

The most irritating thing about this trike is that there is a problem with the nose sliding to the left climbing steep grades covered with gravel or on wet streets. However when I crank slow enough with an even cadence, it is less likely to slide over. A tadpole trike won’t have this problem. Elliptical chain rings could help with this, but they are not made any more because racers didn’t like them, and they control the market.

Riding on narrow roads can be dangerous and takes effort to keep cars from passing from both directions at once on any cycle. The 32” width of this trike helps.

Some drivers think they should slow down and pull over so the car behind me can pass one day someone came to a dead stop to let the car behind me pass, I had to yell at him that he was causing a traffic jam. Well that’s how I was hit several years ago (only my bike was hurt). The car coming towards me in the opposite lane didn’t have the room to move over and the driver behind thought he did. I always prevent this by moving out into the road so the car behind cannot pass until it is safe.

Not long ago my hand was hit by some ones mirror while walking my bike up a hill. After that I started using my vertical flag on the side. Some people are so near sited that they can’t see farther than 20ft in front of them. I think a flashing police light and a siren is what is needed. I use the wide Cateye 600 taillight visible in daylight while the batteries are new.


Mounting cargo on this trike takes a bit of planning.

The front wheel can’t handle more than 5lbs without effecting the steering and bags get in the way of the feet on a tight turn.

A “bikes at work” trailer can be attached to the center of the frame with a bit of work. A BOB trailer will attach to their special axle if mounted to the seat support tabs. (Not the strongest place).

A large aluminum box would be better than the plastic one I have, but it should rest on a support bolted onto the center of the frame. And not hanging from the seat, except as a balance hook.

THE SEAT. Some people worry about the low seating on recumbents because they are not used to watching the drivers that look only one direction when backing their cars. I sit in the most upright position to make eye contact then use an air horn.

The seats webbing won’t stay tight enough especially the lumbar support strap.

A headrest for steep hills would be useful; I could make one from PVC tubing. The seat slides with two quick releases. The seat back hinge is loose because the bolt is slightly smaller than the tube it goes through. I have seen two others that wobble; I think the aluminum seat frame may not.

At a year and a half the right side seat support arm broke at the tab, this is weldable.

Sun bicycles never did respond to my requests for a new seat, don’t expect any service that you don’t pay for. The Lycra seat cover will allow the foam seat to soak up rain. I intend to cover my seat with water-proofed leather by taking it under the wooden base.

it is essential to adjust the seat distance to the pedals correctly, but very easy.

BOLTS. All the bolts were left loose at the factory, including the axle end wheel bolts, the brake disk bolts, and the frame hinge bolt. Lock washers were applied where I could. All the bolts should be replaced with stainless steel if you don’t like rust.

BOTTLE RACKS. I put two bottle racks on the back of the seat with hose clamps, there are no braze-ons for bottles cages, wrap the hose clamps with vinyl tape or they will rip the seat webbing.

HEAD LIGHT MOUNTING. a handle bar stem with a short bar in the steering tube.

TRAILERS. My B.O.B. trailer quick release went on the extra seat support arm tabs with a hollow axle, but each side of the trike has to be raised to fit the holding pins in. I recommend using a two wheeled trailer with modified hitch, or just hang a basket off the back of the seat, I use a trash hamper (metal bar bent round under the rim). Be sure to let the bottom of the hamper rest on the outer tabs so that the weight is distributed over all four tabs so that you don't over stress one of the tabs. I intend to build a cargo box that will fit under the back of the seat. All but the BOB trailer needs to be attached by a metal strap with nylon plastic liner wrapped around the rear most bar and bolted together onto a straight boom from the trailer.

I believe the rans front rack will fir this trike with a lotta work (hostel shoppe) but the bags are very expensive.

BASKETS. The only way to add a basket to the front wheel is to turn it long ways so it won't hit your foot. And then you still can't put more than 5 pounds in it or it will affect the steering too much.

FRAME. The frame hinge bolt kept working loose making a horrible creaking sound. I finally replaced the post bolt with a solid bolt and lock nuts; obviously it doesn’t look as good. New ‘lock tight’ may work, but this hinge moves a lot. Be careful not to separate the hinge when changing bolts, there are fiber washers that can't easily be put back in. The midsection suspension is mostly for looks and ease of folding the frame. Which is beefy enough to last for 20 years, even if it’s not made of aircraft grade chromium molybdenum alloy steel. However Sun Bicycles are not very clear about the limit on the ‘life time’ warranty. But they do hint at not warranting the steel if it looks like it’s been flexed too much; don’t bother asking for a new frame. I have added approximately 370lbs with no ill effects except that the tires look like they could use more air. If you have long legs there is a longer front section you can order.

After 10 months one of the seat support arm tabs ripped off the frame because I was letting too much weight be on it. I will have to reinforce all the tabs with tubing cut in half with slot to fit over the tabs and brazed on. Using a two wheeled trailer is the only way to get the weight off.

FRONT BRAKE. I had problems with the tension set screw not engaging the coil spring. I discovered that the Avid brakes are so much better made than what I was on the trike. But I ended up with an old Shimano STX-RC with long post extension pads for narrow rims. A feature not available on the new V brakes.

REAR BRAKES. The disc brakes are both on the same right hand lever. The bolts on these brakes are rusting, and should be replaced with stainless steel. These cheap ‘Aerozip’ brakes use Shimano pads. Bike Nashbar has affordable versions for half the price. A ‘T’ handled 5mm hex wrench is useful to adjust the disc brakes, but it’s easier than V brakes.

Adjusting Brakes Set the pull levers (pull the cable, tighten the bolt) then adjust the outside pads to .20 or .25mm with a feeler gauge from a car parts store.

it can be very difficult to balance the rear brakes. And if you add a new rotor or pads on one side only it gets much worse.

I think all trikes would benefit from self-equalizing hydraulic duel reservoir brakes on the same lever. The front V brake helps keep it centered while braking hard, but it won’t stop the trike.

CABLES. The cable to the front brake caught under the under-seat steering stem, the cable tubing should be long enough to go over the steering head set stem.

After several years I have decided to buy Avid disc brakes because they are very easy to adjust.

You should count them as part of the price, don't bother with the cheap brakes that come with this trike.

STEERING. The steering bars are adjustable for arm length and width. The first winter the handlebars rusted, but the 14ft-turning diameter feels good. Unlike over seat steerng, the underseat steering relieves all the pressure from my carpel tunnel syndrome.

GEAR SHIFTERS. In cold wet weather the grip shifters are difficult to operate. With gloves even worse. I used bar end thumb shifters. Then I had to use a side mount mirror, see

PEDALS. Cheap but not the worst. the ‘swipe threw pull back’ action works well without cleats or straps if you place the arch of your shoe on the pedal rather than the ball of your foot.

REAR SPROCKETS. There are no cogs on this machine (see your dictionary). The old fashioned free wheel is located on a machined plug set on the right side axle of this model. Kelvin at angle tech says that the freewheel assembly can be pried off the axle with a large screwdriver. I could not get it loose. This is what I did: remove the left side left side axle assembly and throw out the rusty bolts. Then use a 3” gear puller form a car parts store with a 6” diameter reach. To remove the assembly I had to put a nut on the point of the gear puller, grind it round to keep from damaging the end cap threads.

I drilled recess hole for the setscrews into the plug that hold the free wheel, to keep the puller from pulling the disc off without the whole thing. Longer setscrews were needed.

After grinding flat for the vice to grip I placed it face up in the vice, used a Shimano freewheel removal tool with a large wrench and a breaker bar. Chain whips are for the new cassettes only.

To put the freewheel assembly back on the axle with an 11-34, I had to grind off some of the bolt plate, I’m not sure why it wouldn’t fit. Place the key bar in the slot and slip the plug on, then tap the whole thing into place with a hammer. Don’t forget to grease the threads.

I replaced the rear derailleur with a Shimano 105gs for triple cranks.

AXLES. Sun Bicycles ignored my attempts to get info about what kind of metal the axles are made of. Fearing the possibility of rust I tried to pull out the axles to lube them, and discovered that they are press fitted to the bearings. This will make it difficult to change the bearings. And there is already rust on the external part of the axle. But the folks at Angle lake cyclery say they will tap out. I cu the bottom tube to a 12” because the chain was having alignment problems. Feeding the chain threw the tubes on a cold day is a bugger; carry hand cleaner and a towel and rubber gloves. My mechanic says that Shimano Hyperglide chain is the best, not Sram.

CHAIN MANAGEMENT. The rear derailleur clears the road by only one inch in the lowest gear.

The ABS chain tube is starting to fray after only 6 months. The wire that holds the tubes broke and coat hanger wire was not a good replacement, but will work if the wire to the bottom tube is stretched to the rear.

BEARINGS. The 21mm rear axles (cambered as on the aluminum Ez3) are supported by cartridge bearings. A large square key bar is used to lock the hubs on the axles. There are no bearings in the rear hubs. This is good because I hate to throw out good wheels just because bearing races wear out. The front hub has shielded bearings. (rubber cap with metal shield inside)

The head set bearings must be the cheapest also, and will need replacing with a sealed cartridge unit rather than lubing.

The bottom bracket’s crank bearing assembly lock ring kept working loose. I replaced it with a new sealed bearing shimano “krank box” as someone would say. 68x127mm spindle.

Remember to grease your threads. The old loose balls went in the trash where they belong.

TIRES AND WHEELS. The 65psi tires that came with it are worthless. After I had blowouts on both rear tires just above the beads on the disc brake sides, where the lateral forces are the worst on a delta trike. I replaced the rear tires with 110psi 2.1” primo comet extra thick puncture resistant tires sold under the blurb of having Kevlar belts, but do not say Kevlar on the tire. I think they are the pre Kevlar models. [‘Hostel Shoppe’ has 2.5” Greenspeed mudguard fenders]. And a 1.5” primo comet Kevlar tire on the front, I hate getting flats, so I added thorn resistant tubes as well. Then the non-drive side wheel broke a spoke after having the wheels trued on the warranty. I believe it was mostly due to a spoke being left loose by the wheel-building machine. But there are strong lateral forces that loosen the spokes.

I had custom hand built wheels done for only $133@ on the cheap hubs with heavy-duty BMX box wall BFR rims, triple crossed 14 gauge spokes, (we couldn’t find swaged spokes to fit). They forgot to use washers in the spokes holes on the hubs so I’ve been getting some noise whenever I give them too much lateral stress. I fix the noise by removing the wheels and compressing the wheels by leaning on the tires. Tying and soldering didn't cure the noise completely.

I think it would have been better to use 12 gauge spokes with hex head nipples, and crossed only two. See "The art of wheels building by Gerd Shrainer.

I think regular duty wheels may be ok for light duty people, if you don’t carry groceries. I load them with a combined weight of 450lbs.


The best place to get your wheels done is a shop with a good spoke-making machine.

TRUING STAND. To mount the rear wheels on a truing stand you need 24mm x 9mm(8.97MM TO BE EXACT) sealed bearings mounted on a bicycle axle made for sealed cartridge hubs: with a 72.5mm shoulder width.

The 'Enduro 609 RS' bearings are so small that I had to wrap them with tape to make them snug. The 709 bearings have an O ring but may fit too tightly. I got a 3/8th inch axle and it did not fit, so I got some 6901 bearings and set them on the 3/8th axle with vinyl tape to take up the slack. I recommend having a machine shop make an axle for the 609 bearings, out of mild steel or even aluminum.

It's hell trying to get parts for this trike. The only way to get hubs for the rear wheels is to buy one of their cheap wheels and scrap the rim and spokes.

The outside spokes tension on (the longer side) works them self's loose every few weeks so I was going to have the wheels made with symmetric tension and length, but the average high quality shop truing stand cannot fit an off center wheel. So I will have to use my cheap Manura stand that wobbles a bit, but is more flexible in the fitting. Actually a good ridged truing stand could be altered to hold the wheels. They will be strong like front wheels. It is a myth that the disc brake side of a wheel needs a steeper angle of spoke on trike. Hase delta trikes are made with rims centered between the flanges, and their trikes are virtually the same as this cheap nock-off.

The reason the wheels were made like bike wheels is simply that they were made on wheel building machines, and they couldn’t possibly afford to make a new machine to tension the spokes symmetrically.

WHEEL REMOVAL. At first it may not be apparent that you have to remove the brakes from the rotors. Just swing the bottom up and pull the wheels off.

GEARS. The gear ratio is too high for steep hills even with my large leg muscles 76 to 20.3 (80 to 21.4 w/2” tires) gear inches, 170mm pedal arms x 52/42/30-sprocket chain rings with a 13-28-7speed free wheel. If you use a 11-34 mega range freewheel on the rear the front sprockets could be changed to a 48/36/26 for a gear range of 87.2 to 15.2gi and they will fee higher still with short cranks. If using a 44/32/22 crankset your gi will be 80 to 12.9 and you can’t use a fourth chain ring.

The best way to get low enough gears for a really steep hill is to install a 4th chain ring on to the crank. I used a Mountain Tamer triple adapter (I had to use their special flat head 12mm bolts to make space for the chain, be careful not to strip the aluminum threads in the crank.) []  With an 18-sprocket chain ring for 12.8gi, which enables me to climb a 14% grade with almost 400lbs-combined weight. After I changed to shorter cranks I changed the free wheel to an 11-34 shimano ‘megarange’ that gave me a 17.6 inch gear and 10.5 with the 18-sprocket chain ring (on 2” tires).

A quad adaptor won’t fit this crank without grinding off the bosses accurately. To bring the crank back over enough to shift up to the largest chain ring, I had to grind about 1/32 inch off the tapered flats of the spindle.

To shift down to the 4th ring I must stop and move the chain by pushing the chain tube over while cranking backwards by hand. I moved the chain tube up a bit to keep the chain off the bottom of the derailleur cage.

PEDALS. I used BMX pedals for a long time but later discovered that with clipless pedals I can get a much faster start and climb hills easier...and I don't have to worry about getting out of the clips fast.

KNEE PAIN. I had some pain relief because my knees are not bent as much as when pushing through the dead zone that pushes up the kneecaps,130mm cranks creates a deficiency in the ‘swipe threw pull back’ factor. You could save a lot of money by drilling and tapping the cranks at 150mm.

I still hurt myself by pushing too hard. It’s a bit harder to climb hills with because there is less leverage and uses slightly different muscle sets. It’s like cranking in a higher gear, so you need lower gearing for hill climbing.

I am sure that elliptical chain rings can help also, as they help get your feet threw the dead zones. But I hear that Biopace should be rotated for them to work. The use of shorter cranks would be possible without the swipe threw pull back problem and may not need a lower gear to compensate for the lack of leverage, don’t count on it. Also climbing with a faster cadence is easier because it helps you threw the dead zone at the top of the crank circle.

to calculate for shorter cranks add the percentage of shortening to the gar inches: 146mm is 16.527% shorter than 175mm. So 10.5gi will feel like 12.2gi.

To shorten your crank arms drilling and taping is not as easy as it sounds, you have toget the right kind of taps from Park tools 9/16"-20. Then even harder is the right size drill bit, 33/64th inch. Actual a 1/2" should work.

GEAR INCH FORMULAS. Obviously everyone is different, even at different times. So you can use this only to for estimation with 170mm cranks. If an average healthy man can sustain a power output of about 0.33 hp, or 10890 ft-lbs per minute, up to 45 minutes. Or .2hp = 6600ft.-lbs/min. for 1.5 to 2 hours for climbing those long mountain roads. If you're trying to climb a 14% grade with a combined weight of 390 pounds with a power output of 10890 ft-lbs/min, divide by (.14 grade x 390 lbs) = 199.4505 feet per minute. Now, if your cadence is 80 rpm at the crank, and you're moving at 199.4505 ft/min x 12”= 2393.406 inches per minute, divide by (80rpm x pi)= 9.52gi. [70rpm= 10.88gi and 60rpm= 12.69gi]. It is best to calculate at 80rpm cadence to give yourself room for error in your strength level. If you’re forced to slow down to 60rpm you’re pushing too hard. Over 80rpm your wasting too much energy just heating your legs. An approximate 14% grade is the maximum that I can pedal aprox. 390lb at 12.5gi. (slower than 60rpm) resting my legs every 20ft or so. Don’t worry most hills are never more than 9%. To move a quarter ton up a 10% grade 10.4 gear inches would be needed.

The best way to measure the road grade is to hold a level, one end to the road surface and measure the other ends height when level. The grade is the vertical distance divided by the horizontal.

Gear inch: driving sprockets divided by driven gear sprockets, multiplied by measured diameter of drive wheel and tire. A set of gears equaling a 20” is like pedaling a 20” wheel without gears. See for more info.

POWER ASSISTANCE. The most efficient motor for an HPV is a hub motor. The only place to put one is at eh end of the left side axle, and you would need a new axle made at a machine shop. I don’t know if they make one that fits. It may be better to strap a motor on the side of the axle and connect it to a single freewheel with a BMX chain.

PURCHASE. Any bike shop can get these for $825 plus shipping, tax and fenders: $1125. I have about $1800 into it with upgrades. And could go over $2000 with a new seat.

MARKET. This usx trike was made to take a pleasure ride on a sunny Sunday after noon, oh glorious quality of value. However if you want to use this machine much you should hold out for a Light Foot under seat steer Greenway trike, or a Greenspeed UTE tadpole trike (my favorite) or wait for someone to start making a good cargo quadracycle in america. There are two in Europe. The ez3 tadpole trike maybe a better ride but it will still cost a minimum of $500 beyond the sticker price including shipping and tax. Organic Engines SUV is the most advanced design for a work trike and is under $2000.

VERDICT. This trike is OK for hauling groceries. Being the conundrum that it is if you up grade most of the components. I still use my cheap MTB after 10 years of hard use. A cycle is the sum of its components, held together by a frame. But if you start with a good machine you won’t have to pay as much, in psychotherapy.

CLANDESTINE CONSPIRACY. How many years has it been that you haven’t seen the word ‘sprocket’ used correctly? Some where along the line some one got tired of calling the geared discs of a free wheel ”sprocket wheels” and called them sprockets. This led to more illiterate confusion and people called them cogs. Cogs are the toothed gears that fit into other gears of the same configuration. Unfortunately people are not going to use it correctly until they see it in print, and the editors refuse to use it correctly because they are afraid that people won’t recognize it. Ubiquitous illiteracy propagates its self.

sprock·et P Pronunciation Key (spr k t) n. 1. Any of various tooth-like projections arranged on a wheel rim to engage the links of a chain. 2. A cylinder with a toothed rim that engages in the perforations of photographic or movie film to pull it through a camera or projector.

cog1 P Pronunciation Key (k g, kôg) n. 1. One of a series of teeth, as on the rim of a wheel or gear, whose engagement transmits successive motive force to a corresponding wheel or gear. 2. A cogwheel. 3. A subordinate member of an organization who performs necessary but usually minor or routine functions.

A fairing for this trike: