Life with the Avanti Inc 3
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Life with the Avanti Inc 3

Two years ago I invested in a belt drive bike for commuting to work. I had spent the previous ten years commuting on a Diamondback mountain bike with high pressure tires. The avanti is a complete change for me. It has a Shimano S700 hub with 11 gears, and a gates belt drive. My main reason for changing technology was maintenance. I had been changing chains every 2 to 3 thousand km on the mountain bike, and I was lucky to get 5000km out of a dérailleur hanger. Broken driveline components were a pain. I spent long nights working on my vehicle just so I could go to work.

I ride about 90km a week at the moment. My commute takes about half an hour. Traffic is lighter in the morning and the route is generally down hill so the morning commute is slightly shorter. The route is over undulating terrain. The lowest gear on this bike allows me to climb at about 13 km/h. I rarely use this gear. Speed in top gear is about 55km/h. I use it at one or two points on my ride.

I have been commuting on this bike since 2014-10-04 and my odomoter is currently 16050km.

This is my maintenance log

Using the S700 hub with clip in pedals

This shimano hub is an eleven speed gear box, and in the normal situation, a gear box would come with a clutch so you can isolate it from your engine while shifting gear. Bike riders with chain drives are accustomed to shifting under load, but this gear box won't allow that.

Instead of this it has a clutch which stores one shift until torque on the hub drops, then it shifts. If you click a second time before the shift, it will shift under load, making nasty noises and probably damaging the hub to a small degree.

For users of open (non-clip-in pedals) this is fine because their pedaling stroke includes time of low torque. This is the application which this hub is designed for. Users of clip in pedals have a problem because they ideally apply constant torque to the drive line.

The solution is to reduce the torque applied to the pedals while shifting. After about 1000 km of experimentation I found that it is possible to shift safely by making the slightest hesitation as I click the shifter. It takes a lot of practice, and I do get it wrong sometimes but it does make use of this hub bearable.

You need a longer hesitation when shifting to easier gears. You really have to stop pedaling for half a pedal stroke. But shifting to harder gears is a lot faster.

The gear shifter

The shifter failed at about 8000 km, with a broken return spring, and I had to get the shop to swap it over under warranty. Its pretty poor that a vital component like this can fail so soon, and that the shop didn't have one they could just give me. The new shifter has been fine so far.

The shifter clicks both up and down two gears at a time, with an extra deep press. Shifting this way to easier gears is good to have for coming to a halt. I occasionally use the double up shift when taking off from red lights.

On flat ground, with no wind I typically start in second gear. I rarely use third gear to start out. There are two places on my commute where I start in first.

Removing the back wheel

This bit is a pain and you really want to have a good tire on the back so you can leave that wheel alone. The wheel is secured by heavy bolts. There is no place for a quick release with this hub. So I have to travel with a heavy 16mm ring spanner. A shorter spanner might not be able to apply enough torque.

If you have to fix a tube out on the road, consider deflating the tire and fixing the tube with the wheel still attached to the bike. If you have to remove the wheel from the dropouts, then you have two options.

The gear cable is attached to the hub via an assembly which is rotated to clip it in to the wheel. I recommend you never remove this assembly. I have only re-attached it once and once had to take it back to the shop to ask them to do it. The cable itself drops into a slot in this assembly and follows this slot around the hub. By clicking into the highest gear you can create some slack in the cable and remote it from the clip which secures it to the hub. This is the correct way to go.

Changing brake pads

The shimano disc brakes on this bike have a ratchet mechanism which adapts to pad wear automatically. Because of this the calipers will be too close together for the new pads when you install them. I have cut a short length of yellow tongue from fiberboard flooring. This material is soft enough to not damage the caliper, stiff enough that you can use it to lever the calipers back, and very cheap to get hold of.

Adjusting belt tension

I can't get this to work. The rear wheel is fixed inside the dropouts so it doesn't move in relation to the bottom bracket. The belt has a constant path. There is no tensioner. The bottom bracket is offset, inside a cylindrical housing, which jams itself in place inside the frame. This housing is secured by a single bolt.

The idea is to loosen this bolt off, rotate the housing so that belt tension increases, then tighten the bolt again. The problem is that the housing is jammed in place and I haven't been able to convince it to move.

So thats it. The belt is much looser than it was two years ago when I bought the bike. It works fine but I can't increase the tension.

Frame size

Its too small. I have the extra large frame with a 57cm top tube, but its 1cm shorter than the same tube on the diamondback, which was barely large enough for me.

So I have put the seat almost all the way up, and I slid the seat all the way back. At its first service the avanti mechanic slid the seat forwards and said its because the seat might break. If the bike doesn't fit, I can't ride it, so whats the point of moving the seat? Just say don't ride the bike which we sold you.

I bought a 130 cm stem from another shop and this has helped a lot. It does make the headset bearing creak though.

Frame sizes are constrained by tube sizes and they don't change. But people are getting taller all the time and industry has to catch up.

The seat

It came with his nifty looking thing with a hole in the middle. Horrible to sit on so I took the seat off the diamondback and put this one on my old road bike, which needed a seat at that point.

Oil changes

The S700 hub needs oil changes at 1000 km, then 5000 km intervals. My oil change kit came on eBay but it didn't arrive for six weeks so I eventually changed the oil at 1500 km. After that I changed the oil at 6500. Next change is due at 11500, which will be in early 2017.

I followed the procedure with the official tools and had no problems. It takes about an hour.

The first time I changed the oil I was only able to extract 3 milliliters of oil out of it. In later oil changes I have extracted the full 15 milliliters so it wasn't that the oil change kit wasn't working for me. I phoned the shop and complained. They said that some hubs do come from the factory with low oil. If I buy a new hub, I will definitively change the oil when it is new.

The procedure includes a step to flush the hub with fresh oil before loading it with the final 25 ml of oil. Instead, I flushed the hub with 20 ml, and finally loaded it with 30 ml of oil. I did this because I want more oil available for lubrication when cycling.

At the 11500 km oil change, I was only able to remove 15 ml of oil from the hub. Thats half the amount I put in the hub one year ago. I have a suspicion that the hub leaks some oil from the right side of the bike, around the linkage for shifting gears. When you think about it, if it was normal to ship car or motorbike engines and gear boxes with oil inside, the oil would leak out too.

So I try to keep my back wheel as upright as possible.

Belt installation

I haven't changed the belt yet, but its different from a chain drive. The belt or chain has to thread through the frame. Chains can be broken and joined for this purpose, but a belt is continuous. Because of this the frame has a gap in the right seat stay, which is normally closed by two small screws. These screws are too small to take a lot of torque and initially they came open every six weeks or so. I eventually bought new screws and put a lot of tension on them and they have been fine so far.

The new version of this bike has a more complicated arrangement which adjusts the position of the rear axle as well as allowing the belt to be installed and removed. It uses more bolts, and on both sides of the frame. I don't know how well that will work in the long run.

In conclusion

Maintenance is minimal on this bike. I true the wheels every weekend. I change the front brake pads three times per year. I change the occasional spoke. I tighten the headset from time to time. Once I year I change the gear cable and change the oil in the hub. Thats about it. On the diamondback, any maintenance work would leave my hands covered with grease. On this bike they might get a little bit dirty. Thats all.

I am not ever going back to chain drives and derailleurs. I love this drive line. If you are riding every day, and you need your bike to work with the minimum of fuss, this is definitely the way to go.

Last update: 2017-12-08.