Maintenance Tips Nimbus Unicycles and Unicycle.com unicycles and components will last for many years if maintained properly. Here are some tips to help keep your unicycle running smoothly.
Before the First Ride After initial assembly, check to insure all bolts are tight. Especially check the end bolts on the axle holding the cranks, the bolts holding the seat post to the saddle, and the pedals.
After the First 1 - 2 Rides Following the first couple of rides, check that your rim is true and that the spokes are tight. Obtain a spoke wrench and learn how to true (straighten) your wheel, or bring your wheel into a bike shop for regular maintenance. This will significantly improve the life of your wheel. After the initial adjustment and after any significant impact, check your wheel to make sure it stays true.
During Every Ride Be aware of any creaking noises or “loose“ parts on your unicycle. If you find any, check the following:
Pedals: If your pedals are loose, check that the wheel is installed the right way around in the frame (e.g. check Left/Right letter on the cranks). Riding with the wheel backwards will cause the pedals to loosen which is not covered by warranty.
Axle end-bolts: Loose axle end-bolts can lead to small amounts of play in the hub/crank assembly.
Bearing Housings: Overly loose bearing housings will result in frame movement on the bearings. Overly tight bearing housings will cause creaking and premature wear on the bearings and possibly crack the bearing race.
Saddle: Bolts holding the seat post to the saddle are subject to bedding in over time. You will need to tighten the bolts to prevent unwanted movement.
After Every Ride Keep your unicycle clean. Mud, salt and water are bad for bearings and can cause bolts to seize.
After Every 30 – 40 Rides Every 30-40 rides remove the cranks, clean and re-grease the axle. Rotate the wheel by ¼ turn before reinstalling the cranks to change the force directed to the spokes and increase the life of your wheel. Clean and re-grease all bolts, and rotate your tire by ¼ turn to prevent wear on one part of the tire. Check that the wheel is true and there are no loose spokes.
Warranty: Nimbus Unicycles and Unicycle.com products are warranted to the original owner against manufacturing defects for one (1) year following the original purchase date. For more details visit https://www.unicycle.com. Unicycling can be hazardous and can result in injuries. Use common sense, ride with your abilities, and wear safety gear. Disk brake rotors become very hot with use - avoid contact! Tuck in laces and avoid wearing loose clothing that could catch in brakes, pedals or other moving parts of the unicycle. Unicycle.com cannot accept responsibility for any personal injury that you might sustain or that you might cause to another person as a result of the use, breakage or improper assembly of Unicycle.com equipment.
Basic Unicycle Maintenance
Unicycles are not complicated but they do take a little bit of maintaining. Here are some of the key points:
Creaking Cranks: Stop riding immediately and tighten! If these are left ignored they will destroy the cranks and or hub. The creak comes with downward pressure of the pedal and is often confused with loose spokes. For Cotterless cranks: remove the caps from the end of the cranks and tighten with a 14mm socket wrench (or 8mm allen key). For ISIS Cranks: tighten bolt with 8mm Allen Key
Creaking Spokes: After some time spokes stretch and slacken, this is not normally detrimental for the wheel but does weaken it if not addressed. Tightening a wheel is a job that is normally considered to be a job for an expert like a local bike shop, but if approached carefully, it is not difficult for anyone to learn how to do it (there are plenty of how to videos out there). If the wheel is just loose, but centered on the frame, tighten each spoke using a spoke wrench by a quarter turn, being careful not to miss any, repeat until spokes are tight.
Loose and Stripped Pedals: Stop immediately! This issue is not considered a warranty for any brand! Check that you have the seat facing forward (a good indicator is a relief that is cut into the frame under the seat clamp should be facing the back of the unicycle) and you have the right pedal on the right-hand side. If your pedals come loose it is almost certain that you have the right-hand pedal on the left side and vice-versa. If this is left for any length of time then the crank and pedal will be destroyed. Tighten with a bicycle type 15mm wrench. If you have damaged your pedals and cranks we do sell replacements. To remove the cranks you will need a special tool called the crank extractor.
Loose Seat Bolts: When learning to ride, the constant dropping of the unicycle can cause the bolts that hold the seat to its post to come loose (this is considered normal). Check and tighten these regularly. To do this you will need a 4 or 5mm allen or a 10 or 11mm socket wrench to tighten.
Loose Frame Bolts: If you feel the frame clicking or moving then stop and check the bolts, if left loose the frame can develop cracks and will be destroyed. Use a 5mm allen or 10mm socket to tighten the wheelset tight enough that it won't rattle but not tight enough to restrict wheel movement, keep in mind that its a bearing adjustment as well as holding your wheel on the frame.
Frame Bolts: Its not very common to find these bolts coming loose. If they do then they should be tightened immediately. It is considerably more common to find them over tightened! If the wheel does not rotate freely then the bolts should be loosened by about a quarter or half turn. If the bearings are left over tightened for too long they will disinagrate and require replacing.
Under Inflated Tire: It is bad practice to ride a unicycle with a flat or an under-inflated tire, because all your weight is on a single tire, so you need to have the pressure higher depending on your riding style. An under-inflated tire can also cause the wheel to buckle under rapid turning or bouncing causing a pinch flat.
Worn Tires: When a unicycle has been ridden for a bit you will notice that there is one or possibly two areas of the tire that are getting considerably more wear than any other. This is due to idling and turning. This can be remedied by letting the air out of the tire and then rotating the tire 90 degrees, or you can remove your cranks and reinstall them in a different position on the axial.
Saddles When you are learning, you can destroy your saddle with the constant dropping. We sell a wide range of saddles from the top companies: Hoppley, Club, Trainer, Nimbus, Impact and Kris Holm. You can also change your saddle bumpers if there the only part of your saddle damaged. If your looking for a more comfortable saddle there are many options, a thing to remember is saddles are a personal preference. So trying out a saddle for the type of riding your looking to do can be a challenge but will be well worth it when you find one that works well for you.
Seatpost Have you outgrown your existing unicycle? Have you broke your seatpost? Do your want to adjust the tilt of your saddle more? We have seatpost to fix all those issues. Older seatposts tend to be 22.0mm, 22.2mm or 25.4mm. The current unicycles tend to be 25.4mm or 27.2mm.
Seatpost Clamps It can be very annoying to be constantly straightening your seat, so one of the most common upgrade is to add a double bolt or double quick release seat clamp to your frame. These clamp more area on the frame and help keep your seat in position you want even under the worst conditions. Beginners though are the other way round they need to be able to move their seat position regularly until they find the optimum height for their riding style, and to reposition your saddle if it moves.
Frames We carry frames for people that want to replace, update, upgrade and or custom build their unicycle. When you are looking to buy a new frame be sure to make note of your bearing size and hub width, this is important to make sure the new frame will fit your wheelset.
Brakes Brakes are a great addition to most unicycles. Brakes are a must for riding on roads when running 125mm cranks or shorter for control when going downhills to save your legs and stay on the unicycle. For mountain riding they are beneficial to have for technical terrain and downhills technical or not. When using the brake, you use it for drag only. Its not like using them on bikes. There are a couple options out there when considering what to ride with. The magura hydraulic rim brake is a classic that has been used for years on unicycles which require magura direct mounts welded to the frame. Disc brakes are also a great option that can be added to most unicycles with adaptors easily bolted on. If you choose to upgrade your frame the Nimbus Muni and Kris Holm frames will fit both style of brakes, the Nimbus Oracle and Oregon frames are disc only with using the Nimbus D-Brake mount.
Rims Rims are a worth while upgrade. Most times you may want to wait till the rim you have now gets damaged though. If your looking to just replace it then a good question to ask is, what would you like the new rim to do? The 2 most popular is to go to a lighter or a wider rim. There are great options available that work the best for unicycles on our site.
Tires One of the biggest, easiest and most noticeable upgrades you can do to your unicycle is replace the standard tire. On a unicycle all your weight is on one tire unlike a bicycle. For Muni the larger volume tire is preferred for suspension and control on unicycles. For Freestyle the non-marking Primo The Wall is one of the best tires of its type in the world. For Trials we sell the 19" Creepy Crawler & the NImbus Cyko lite. For road on a 29" the Schwalbe Big Apple 2.0 is one of the best. Tires are always getting better so as we find models that are good for unicycling, look to our site if your looking for something different to try.
Understanding the types of unicycle cranks
Cotterless (square) Cranks This is the standard crank that comes on most modern unicycles sub $200. The hub axle has tapered ends with a square cross-section and a bolt or nut to hold the cranks on. The cranks are forced onto the axle to create a press fit and locked in place with the bolt or nut. You should never ride with loose cotterless cranks as this will round the corners off the axle and distort the square hole in the crank, preventing them from fitting tightly ever again. This is why this style of crank never stays tight after it has been road loose just once.
ISIS cranks These are a type of splined crank but have tapered axles so it is still considered a press fit. To remove the crank it is similar to cotterless cranks BUT you must use a crank extractor with an ISIS head, otherwise it will damage the threads on the axle. Some extractors have a removable ISIS head so you can use them on cotterless and ISIS cranks. ISIS cranks will not fit Koxx axials, these cranks are not cross-compatible as are different spline formations.
Splined Cranks Splined cranks are similar to the ISIS but do not use a press fit onto the axial. Most use a retainer bolt on the crank to keep it from loosening with the exception of the Onza with the Kris Holm/Onza cranks, they use a series of concave washers and shims. The bolts will probably need to be tightened after a week of riding and checked regularly after that. For more information read our section on maintenance of splined cranks. Never ride with the cranks on the wrong side or you will destroy them where the pedal is threaded in.
Profile Splined Cranks Profile Racing developed a unicycle hub to fit their Bmx bicycle cranks. Profile uses a fine 48 spines on a 19mm spindle, this system works great for the demands it was designed for.
How to Change Your Unicycle Bearings
Bearings on unicycles generally last a long time. Even when you take your unicycle in a fountain, or the sea, or just splashing around in the mud. They do give up in the end though, normally at the worst moment possible (like a race) you will hear them grinding first, then when you turn the wheel slowly by hand you can feel the restriction in the movement and a slight detent. This is to give you a guide of what to do if you are brave enough to try and replace them yourself. Be warned this is not an easy task and requires special tools, most bike shops will be able to do this for you.
What you will require:
Replacement bearings - see our catalogue for quality replacement bearings.
Crank extractor - again we sell these.
Socket set - not really necessary, normal wrenches can do but makes it easier.
Rubber hammer/mallet - again not really necessary, a little imagination can find other things that will do.
Bearing puller - either as small 2 or 3 leg bearing puller - this is essential.
Scrap of wood or Block - not really necessary but it helps to prevent damage and get accurate fit.
To remove and fit bearings: 1. Remove the dust covers from the cranks if you have them. 2. Remove the nuts/bolts from the center of the cranks 3. Remove the cranks using a crank extractor (see instructions). Be sure to screw the extractor all the way fully before you start to extract the cranks. 4. Remove the wheel from the frame, in most cases this involves removing 4 bolts from the bracket that surrounds the bearing. In the case of the Lollipop bearings the screws are in the side of the fork legs and the bearing holder stays with the bearing. 5. Fit a 2 leg or 3 leg bearing puller over bearings and use a wrench to pull the bearing from the hub. Be sure to seat the legs of the bearing puller securely under the bearing so that it is not destroyed before it is removed from the hub. On a lollipop bearing you need to extract the whole bearing holder. Do not try to remove with a lever or screw driver behind the bearing, it will damage the hub. For ISIS hubs use the ISIS cap from the crank extractor or something similar to prevent the bearing puller damaging the threads in the hub. 6. Once the bearing has been removed, clean the hub shaft with steel wool and little oil to remove any rust or dirt. 7. Put the new bearings over the shaft (be sure to fit spacer on first if one was fitted) and gently push, ensuring that it is square with on the axial. When it can not be pushed any further by hand place the old bearing on top of the new one and slip a pipe or socket on top. Ensure that the pipe/socket is pressing on the center of the bearing race, not the outer ring or rubber seal. Place the wheel on a piece of scrap wood to protect the other side of the hub axial. Hit the pipe/socket with a hammer until bearing is seated. Remove the old bearing. 8. Clean the bearing holders to be sure that there is no dirt or rust. 9. Re-fit the wheel in the frame. Be sure not to over tighten the bearing cups as this will impede the performance of the bearing. 10. Re-fit the cranks on the hub. Be sure to check that the cranks/pedals are on the correct side. On the end of the pedals there is a letter L or R for left and right and a letter on the back or front of the cranks. 11. Place the unicycle on your scrap of wood and use a rubber mallet to hammer the cranks on setting the pressfit (for cotterless and ISIS cranks only). 12. Tighten the nuts/bolts in the end of the hubs, these must be secure. Tighten snug, but do not over tighten. 13. Replace the plastic dust caps if you have them.
How to remove and install your cranks
There are four types of cranks: cotterless (square taper), ISIS, splined and cottered (cotter-pinned).
Cotterless Cranks: This is the standard crank that comes on most modern unicycles. The hub axle has tapered ends with a square cross-section and a bolt or nut to hold the cranks on. The cranks are forced onto the axle to create a press fit and locked in place with the bolt or nut. You should never ride with loose cotterless cranks as this will round the corners off the axle and distort the square hole in the crank, preventing them from fitting tightly ever again. To remove cotterless cranks you will need a crank extractor. First remove dustcover (if fitted) then unscrew (counter-clockwise) nut/bolt with 14 socket wrench or 8mm allen key. Install the outside threaded portion of the tool to the inside of the crank (making sure the threads are fully engaged) before turning the handle on the tool. Next turn the handle to extract crank. Then unscrew the outer threaded section to separate it from the crank. To fit cotterless cranks; gently seat the crank on the axle and press it into position with a mallet (not metal), then tightly lock in place with the bolt/nut. Make sure the righthand crank is on the righthand side and the lefthand crank is on the lefthand side before riding otherwise you will wreck the cranks.
ISIS Cranks: These are a type of splined crank but have tapered axles so their removal is similar to cotterless cranks BUT you must use a crank extractor with an ISIS head otherwise it will damage the threads in the axle. Some extractors have a removable ISIS head so you can use them on cotterless and ISIS cranks.
Splined Cranks: Splined cranks are stronger than cotterless cranks due to the bigger diameter of the axial and therefore are more suitable for muni or trials unicycling. They do require slightly more maintenance. There are several different models out there: Kris Holm, Kris Holm/Onza, Onza, Profile, Qu-ax, Koxx and Torker. Please keep in mind these cranks are not cross-compatible with each other unless specified. The bolts will probably need to be tightened after a week of riding and checked regularly after that. Never ride with the cranks on the wrong side or you will destroy them.
Cottered (Cotter-pinned) Cranks: These do not come on any new unicycles. The crank is held in place by a tapered bolt, called a cotter-pin, which is at right-angles to both the axle and the crank. To remove the cotter-pin; unscrew the nut slightly then carefully hit with a hammer/mallet. Repeat this process until the pin is completely removed. Do not completely remove the nut and hit it with a hammer since this tends to bend the pin, making complete removal a little more difficult. When you change a cotter-pinned crank it is recommended that you also replace the cotter-pin. Before riding, make sure the righthand crank is on the righthand side and the lefthand crank is on the lefthand side before riding otherwise you will ruin the cranks.
Tuning new cranks on twin chain giraffe unicycles
If you ever have to replace the cranks on a twin chain giraffe unicycle you will need to “tune” the chain system so that the two chains work correctly together. You will know if you need to tune the chain system if one chain is tight at the front while the other chain is and visa-a-versa. Depending on how much adjustment is needed there are 3 processes than should be followed until you find the one that tunes the system for your giraffe.
Method 1. At the wheel you will see 2 plate sprockets. These are held on by 12 bolts (6 per side). Loosen these bolts by a single turn each while the chain is in place. If there is only a small amount of adjustment required the chains automatically centralise the sprockets in the correct place. If this is the case, tighten up the sprockets and the tuning is done. If this is not the case, go to method 2.
Method 2. Repeat method 1, but this time take all the bolts out of the sprocket that has 12 holes on it and allow it to it rotate until you can use the second set of holes. This should allow the sprocket to rotate further than the tolerance in the holes allowed in method 1. If this does not work – or makes it worse, go on to method 3.
Method 3. Remove the wheel from the frame and remove the 12 hole plate sprocket and flip it over. Now re-apply it (loosely to begin with). Re-mount the wheel and repeat firstly method 1 and should that not work then method 2 will work.
Good luck with your maintenance. Remember; to do regular checks on all bolts and lock-nuts on your giraffe to be sure that they are tight. Damage can occur (both to the giraffe or yourself ) if the giraffe is ridden when parts are loose.
What size seatpost clamp do I need?
Bikes have always specified the clamps by the frame size. Unicycles didn't start out that way and have been lucky in that they only needed 3 sizes for ages.
This list will help clear things up if your not sure:
The d'brake has been designed to have the disc running on the inside of the frame keeping it well out the way and allowing the rider to use their existing cranks. The d'brake uses the IS (International standard, Front) two bolt configuration for cycle disc brakes. This allows you to run any caliper/disc combination without having to modify the mount in any way. Instructions:
1. Take the wheel out of the frame. Remove the Left crank, spacers and Left bearing from the hub.
2. Place the disc on to the hub the correct way around. Note that the disc has a direction and an “outside” printed on it.
3. Install using the 6 bolts provided. Tighten these incrementally so that the disc it tightened up evenly. This helps keep the disc straight.
4. Refit the bearing, spacers and cranks to the hub.
5. Fit the IS mount (or caliper if your model has it built in) to the d’brake mount. Use the bolts provided and tighten up well.
6. Install the caliper on to the IS mount using the bolts provided. The brake should be fitted in the middle of the slots.
7. Mount the wheel in to the frame and loosely tighten the right bearing housing.
8. Slide the brake caliper over the disc and the d’brake over the bearing.
9. Tighten the bolt of the clamp nearest to the brake down hard.
10.Tighten other bearing housing bolts until secure, but do not over tighten.
11. Check that the wheel spins without the brake touching the disc, if it does adjust the bearing housing bolts in slots until it is clear.