V7 tyre fitting, part 2 – 16 Nov 2017.

And so to the front wheel. I repositioned the support and tie-downs which always takes me a bit of time. I’ve seen photos of bikes which have taken a tumble from benches like mine.

Once I was happy, I removed part of the bench wheel clamp, jacked up the front end and set about removing the wheel.

It’s easy enough. I have to remove the mount I made for the push bike speedo sensor first. Then disconnect the brake cable and start by removing it from the handlebar lever first. The other end can then be removed from the lever on the hub. The spindle/axle nut is undone and the clamp bolts at the bottom of the forks are slackened off. The big old screwdriver is then employed to wiggle the wheel spindle out. Usually the hub cover plate drops out with a clang at this point as I forget it’ll do this. I had to raise the front of the bike a bit further before the wheel would drop out because there wasn’t quite enough room for the brake plate to clear its locating plate on the fork leg.

Once it was out I went through the same performance as I did the other day to change the tyre. The old tyre was difficult. The new tyre was easy. Here is the newly mounted tyre next to the old ‘un.

The size difference is quite noticeable even though the widths are much the same. The 90% aspect ratio of the old tyre means its diameter is actually 20mm less than the new one.

I balanced the wheel which only needed 10g. I reused a real lead weight using some good double-sided tape. I would like to use spoke weights rather than these stick-on ones. I’ve seen some for sale but want to get proper lead ones if I can.

As they say in the manuals, “refitting is the reverse sequence to removal” (but you might swear in different places). Here’s the new tyre fitted.

I fitted the wheel clamp back to the bench

then turned my attention to another little job. Back in the summer, the loop securing the front brake cable to the mudguard broke and I just taped the loose bit up and out of the way. I needed to fabricate a new one which was surprisingly difficult. It will do until I can find something better. You can see in this photo where the cable has rubbed the paint of the edge of the mudguard.

There was now the thorny issue of tyre pressures. Originally Moto Guzzi specified 21psi in the front and 25 psi at the back for solo use with the rear to be increased to 28psi when carrying a pillion. The handbook also says to add about 3psi to the pressures if doing constant high speeds.

I was running the previous tyres at higher pressures (32/36psi). I’d been told this was necessary with more modern tyres. In fact, some said this was still on the low side. The issue I now have is that the maximum pressure for the new Mitas tyres is 33psi. The old Michelin rear tyre had the same load rating but carried it at 41psi.

Even so, the original “book” pressures still seem very low to me so, in the absence of anything else, I’ve gone with 24/28psi as a starting point – the “book” high speed/motorway pressures. I’ll see how it goes and might contact Mitas UK to see if they have any thoughts.

Here’s the fire bike ready for a run to scrub the tyres a bit. It was dry if a little cold.

It was only a dry test but, so far so good. I can notice a slight change in that the steering seems heavier at very low speeds, say under 10mph. Once rolling traction and grip seem more than adequate and the handling just as it was before. I doubt I’ll have to wait long for the chance to test wet weather performance!

Oh, one thing. The increase in front tyre size has made all the difference when putting the bike on the centre stand. I’d been finding this hard going to the extent that I avoided it. Now I think about it, the side stand didn’t ground when I took the bike off the bench like it had when I rolled it up there.

The annoying squeak from the front suspension is back but I know what the cause is. It’s the front brake cable rubbing as it passes through the support loop and grommet!

Once back in the garage there was one last thing. I recalibrated the push-bike speedo for the new tyre size and fitted a new magnet. I’d knocked the old one off during the tyre change. It got a bit messy as I had to cut the tube of Stixall open to find the last useable drop!

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