PigzMightFly wrote:The main priority is light weight, I have a budget of around £400 maybe a bit more if I get exactly what I want.
It's often thought that light weight is important but especially in your case it shouldn't be a high priority.
When riding on level ground at a steady speed the weight of a bicycle plays a very minor role in reducing effort. When you climb steep hills or accelerate the bike it can have an effect.
On level ground at the speeds a fairly fit non-athlete might ride at, roughly half the effort goes into overcoming air resistance and the other half into overcoming rolling resistance. You reduce air resistance by riding in a less than upright position and by wearing clothes that fit closely and don't flap about. If you want to be upright then you have to pay a penalty in terms of air resistance and you can't do much about it. You reduce rolling resistance by using tyres which roll well, pumped up to a suitable pressure, so you can do something about this though such tyres do cost a fair bit, perhaps £20+ each. In my view it's well worth it.
Going back to the weight issue, if you imagine you have a bike of 13 kg, which a hybrid bike might well weigh, and you yourself weigh say 70 kg then the total is 83 kg. If you reduce the weight of the bike by 2 kg which might actually cost quite a bit of money, then the total weight, which is what matters, goes down from 83 to 81 kg a percentage reduction of just 2.4%. This means that when climbing an extremely steep hill it will take you just 2.4% less time to climb the hill or conversely you'll do it with only 2.4% less effort! If the hill is only moderately steep then the difference will be even less since the saving will be masked by the air resistance effect which won't change.
Because of all this if you have a fairly limited budget then if I were you I'd put the money into comfort and reliability rather than low weight.
As an example of what I'm saying, I just switched the wheels and tyres on one of my bikes from summer to winter ones so that I could use it on a muddy slippery cycle track to go shopping each week. The difference in weight will be between 1 and 2 kg but although I can detect the difference when I try lifting the bike, when I ride it it's hard to detect any difference. at all.
. here's hoping someone can help.