Bike-in-a-box blog: Performance anxiety

To my mild chagrin, there's very little space left to actually bolt things on to the bike, and it still hasn't suffered a failure. So out of desperation, I've had to resort to performance tweaks.

First, I fitted a 17 tooth front sprocket in place of the 16 tooth that was already replacing the stock 15 tooth. Interestingly, the rear sprocket is already a relatively small 43 tooth, giving the bike a long gearing, longer than that recommended by Xian Racing. Still, it felt good with this ratio, keeping the revs nice and low at commuter speeds, and I can always drop down a gear if the bike struggles. Theoretically, it will make low speed manoeuvres a little trickier, but I haven't noticed any difference so far.

I only barely managed to fit the 17 tooth sprocket with the stock chain. You (well, I) wouldn't think that such a small difference in the sprocket would tighten the chain up by so much, but it does. Even with the axle fully forwards, I couldn't get the front sprocket on with the chain on it, or the chain over it while it was fitted. I had to take the chain off the back sprocket, fit the front sprocket and chain, engage the chain on to the top rear sprocket then turn the rear wheel to wrap it fully round. It was touch and go, but once it was all on, there seems to be enough slack in the chain. Weird.

Next up, an after-market coil and HT lead.

I'm buying the marketing here: I have no objective grounds for believing that this unit is superior to the stock coil and lead. However, there are two things to bear in mind:

It's very unlikely to be worse.
It's red and orange, so it must be inherently faster...

Subjectively, the bike did feel smoother on my commute this morning, although (especially with the 17 tooth sprocket) I wasn't reaching the revs where a stronger spark should make a difference.

I should give the coil a good exercise on its own, but this afternoon, a new CDI ("POSH" branded, as recommended by a few Chinese Bike Forum posters) turned up, and I couldn't resist plugging it in.

Purty! It comes with a 4+2 rounded GY6 plug socket, so I've also bought a converter to the square 4+2 STD plug on the HN125-8. It's much bigger than the standard CDI, so has to nestle down the side of the under-seat area. At the top right here (where the old CDI was) you can see the accursed side-stand switch. I'm retaining it just in case it gets added to the MOT regs. I was watching Long Way Down, and was amused to see Ewan McGregor's BMW pimpmobile immobilise itself due to a defective side stand switch. On the advice of BMW UK, he just chopped it off and twisted all the wires together. Proper job!

Wait, did I say "Huonaio"? I meant "Reliant", of course.