Ever since buying my V7 700 I have been concerned about getting a puncture, particularly in the rear wheel. I’ve been carrying a spare tube but know it would be near impossible to replace it at the side of the road by myself. To do so the back of the bike needs to be raised a lot to allow the wheel to come out. Alternatively the tank and fairing have to come off and the bike leant on its side and the wheel removed that way. That’s all before fighting to get the tyre off and back on again. Since damaging my wrist I’ve not had any success with tyre changing at all.
I’ve had variable results with “Finilec” type foam in an aerosol as a get me home measure in the past but decided I would try a tyre sealant this time. I realise that these puncture sealants are less reliable when used in tubed tyres but, if it doesn’t seal the hole, it should at least slow down the leak. I have had a tyre go down very quickly when traveling at motorway speeds and it’s not an experience I want to repeat. I will still carry the tube so a garage can change it if the worst happens and I have to call on my breakdown/recovery insurance.
I bought enough Oko Puncture Free to do both my bikes. The instructions say that the wheels must be properly balanced before adding the sealant. This is not just because the goo in the tyres will prevent you from balancing the wheel after. If the tyre is out of balance the sealant will make this worse.
I have roughly balanced wheels before by clamping the wheel spindle and letting the wheel rotate on its bearings. This is not a good way of doing things as the drag of the grease in the bearings doesn’t let the wheel move freely enough. I looked around the internet at home made balancers and came up with this.
The two stands were made out of the wood I had in the workshop plus four skateboard bearings as recommended elsewhere on the web. I would have made the stand from metal but I had nothing suitable. I had to be accurate in getting the stands vertical and the two lots of bearings square to the stands and at the same height.
I’ve still got my friends bike lift in my workshop while he’s building his garage so I used this with my wooden adapter plate to get sufficient height to get the back wheel out. I’ll do the front first.
This is a remarkably steady arrangement and you’d have to be really clumsy to have the bike fall off sideways. I was more concerned that removing a wheel at one end could upset the balance forward or backwards. It turned out that I needn’t have worried but I stood my small lift under the back wheel when I worked at the front.
So, front wheel off first.
- Disconnect front brake cable at hub.
- I had to remove the sender for my additional push-bike speedometer.
- Remove large axle nut and loosen the clamp bolts at the bottom of each fork leg.
- Pull out the wheel spindle and lower the wheel and brake plate to the ground. It made me jump when the cover from the other side dropped on the floor with a clang. It always does that!
There is a washer on the spindle between the left hand fork leg and the brake hub.
Once the wheel was out I put it in my wheel balancer with its spindle.
I should have taken some pictures. The spindle turns very freely on the skateboard bearings. I spun the wheel a few times and it came to rest in a different place each time. It would also “stay put” in any position I put it. When the tyres were changed last year I was told the front had been balanced by removing half the weights that were originally on it. It seems that was true so the wheel was left as it was and refitted to the bike, retracing the steps taken to remove it.
Time to get the rear wheel off.
- I removed the left pannier from the rack for access although I probably could have managed without doing so.
- Remove nut and lock washer from brake torque rod at the brake hub and loosen the fixing at the swing arm end of the rod.
- Disconnect the brake pull rod from the lever on the hub. I like to tie it to the rear shock-absorber.
- Remove the big wheel spindle nut.
- Loosen the spindle clamp bolt in the swing arm.
- The torque rod can now be pulled off the brake hub.
- I use a big bolt through the hole in the wheel spindle to turn it forwards and back while pulling it out. At the same time I hold the brake hub and wheel in place on the rear drive bevel box.
Once again there is a washer on the left side of the spindle between the swing arm and the brake hub.
- Pull the wheel and brake hub together off the splines on the drive box and lower it to the floor.
The wheel was mounted in my wheel balancer which had now been modified by screwing the two halves to a large block of wood. It made things steadier and keeps the spindle in line better.
This wheel was not balanced and I could tell just by spinning it. I could feel the heavy part going round! The trouble was that the rim was too dirty to stick weights to and I would have to clean it first. Cleaning valanced Borrani rims has been one of my least favourite jobs. However, I think that may be a thing of the past! I used “Elbow Grease” and my “Sonic Scrubber” I bought from Aldi last year. The Elbow Grease is cheap and was recommended for the job by another owner of old Guzzis.
It got the rim clean and I could have gone on to polish it with Solvol or something but, not on this bike. The wheel was put back in the balancer and weights were added to the rim, temporarily with masking tape, opposite the heavy spot until I was happy. It took a lot of weights. I was using stick on weights and, due to the rim profile, only 5 gram ones will fit. I used 11½ (57.5g) of these and the wheel balanced perfectly. I cleaned the area with thinners then fitted the weights properly.
I could have used spoke weights but, these are expensive and I didn’t know what sizes to buy. I think I’ll get some of these next time.
The wheel was refitted after re-greasing the drive splines then the brakes were reconnected and adjusted. I left the pannier off for the moment.
The whole purpose of the exercise was to be able to add sealant to the bikes’ tyres. The Oko web site gives the amount to put in each tyre.
- Rear, 4.00×18 – 225ml.
- Front, 100/90×18 – 225ml.
The bottles hold 500ml and are not marked that accurately . I used a syringe and some tubing cut from the Oko bottle. Getting the sealant in was easy.
- Turn the wheel till the valve is at 4 o’clock and remove the valve core.
- Add the measured amount.
- Blow the valve clear with compressed air and refit the valve core.
- Inflate the tyre to the correct pressure.
I think I got the amounts right as I reckon there was 50ml left in the bottle.
The pannier was fitted to the bike which was then lowered to the floor.
I went for a short run on the bike. The instructions say to go gently for the first 4Km to distribute the sealant in the tyre. All felt good so I took the bike up to speed. The sealant had no adverse effect on the feel or handling of the bike that I could tell. However, I’m not a “riding god” and just ride what I’ve got!