Is it worth buying a lighter bike? If so what kind? I've started cycling recently and am clocking decent mileage now. The only problem is, the bike is very old and weighs just shy of 20 kg. It's a heavy one!  It also has Kenda Kinetics tyres, I think they are made mainly for off road so not the fastest.
My main goal with cycling is to cycle 40 miles to a target destination I have.  So far I have gotten to the point where doing 20-22 miles is pretty doable for me now.  My best is 33.5 miles, after doing that one I was really lacking energy towards the end.  I live in a place where &quot;High&quot; is in the name, it's full of hills and coming back to those hills after doing that kind of mileage is killer, especially on my 20 kg bike, towards the end I was feeling like the 40 mile is not possible, but I had the same feeling when first doing my 20 mile runs.
It sucks as I wanna keep training to get myself to the 40 mile mark and I think I can get there eventually, but probably not this summer.
However, what I want to understand is whether it's worth me buying a new bike or not.  Will I notice enough of a difference, given that I can now do 20 miles with ease on my heavy bike?  Or do you think I should just suck it up and try to reach my goal with my heavy bike.  Am I just being an unreasonable amateur blaming the heavy bike?
My route:
Generally, a lot of my route is on the road, but some parts of the route are off road for several miles, with lots of twigs, tree branches, stones, other tree crap all over the floor, you can hear them crunching as the tyres go over them and at points the rear tyre or front tyre slips sometimes, as there is so much crap on the floor that it's hard for them to grip.  I'm not sure whether it's worth getting another bike, as I would ideally get a road bike but I don't think it can handle the route, my downhill bike has good chunky tyres for it but the weight is killer.
EDIT Feb 2021: I ended up buying a new carbon fibre hard tail, that weighs under 13 KG, it is a world of difference.  I can't believe how heavy my old bike is in comparison, I didn't realise how heavy it was until I got this new bike.
For anyone with a heavy bike, upgrading to a lighter bike is definitely worth it, especially if you live in a hilly area like me!
IMHO, it's not the weight that is hurting you the most. While weight makes a difference and a lighter bike would be much better, it's too common in cycling world for people to use weight as a proxy quality and performance. Any twit with scales can measure it.  That said, there is no doubt more suitable bike would make longer trips faster, and a better quality bike even more so, but only you can decide if the cost is worth it.
Weight only affects hills and acceleration. For a long ride mostly on the road we can practically ignore the effects of acceleration.
On the hills, lets say you shaved 10kg off the bike, your total weight is now 75kg instead of 85kg. From this calculator, a 100M climb over 10km will take 38 minutes on the lighter bike vs 40 minutes on the heavier bike. Using these rough numbers, the calculator comes up with figures that are close enough to help you decide &quot;Is it worth it&quot;
However, resistance and power loss from a bike such as this are a big factor that cannot be ignored.  New tires that are a hybrid might be more suitable—a bit of lost time in the forest for faster riding on the rest of the trip might be a trade off. Something like Schwalbe Hurricane would be a goods starting point.  The shock and fork should be tightened as much as possible, since I doubt they have lockout.  Your position on the bike, getting more aerodynamic would make a big difference—bar ends could help with this.
While the perfect bike for you sounds like a gravel bike, there is no need to head down the path of very expensive to get a significant improvement in performance. A hard tail 29&quot; MTB running something like the Hurricanes would be ideal and handle the forest section with ease. A drop bar bike running 35mm tires would be good if you are a skilled rider and happy to take the wins on the road for some drawbacks in forest sections.
Before buying, ask around and see if someone you know has a bike they may be prepared to lend you for a couple of rides—you might be surprised who has an old bike in need of an outing...