Lewiebike, So I've been measuring the space between the tubes on my two mtb and I found that my old early 2000s genesis 26 bike has more space than my new 29 tornado (both Steel, it looks to me the welding on my genesis is much better than my New 29er) .The genesis has 26 wheels, no disc brakes and no suspension. What are the downsides of having 32 rear wheel spokes? I'm 156 lbs btw
darwin, the HS 53cc I found costs around 200$ and more, is that normal? The mitsubishi would cost me 150$ brand new( I actually don't know where they are made, could be chinese too).
Some pictures from today(the measure is not perfectly aligned cause I had to take the pics) :
Plamb, the main advantage is that your older bike is it's frame is a lot more close to matching the "V" angle used in your engine's mounting seats, the areas contacting between the seat and down tube parts of your two bike frames.
What this means is when you bolt your engine up to the frame, you can use your stock bolt mounts on both the seat and down tube. When I bought my HT engine, I had a bike already chosen out, that I had a good idea that the seat tube and down tube would be within a degree or less of ideally matching the clamping area of the bike engine's frame mounts. More precise sitting and less chance the engine will creep out of alignment.
Here's my bike, which is a 1958 J.C. Higgins 3 speed frame built by Steyr in Austria..
Notice that I used some PVC black irrigation pipe to fill in the gap of the clamping part of the bike. When I first test fitted this engine into this frame it dropped right in without any misalignment, but the clamp diameter was a 1/8" or so too big.
Which isn't surprising as these engines were made to fit Chinese built, 28" wheel size, rod brake fitted Flying Pigeon single speeds, all based on the old Raleigh 28" Roadster. The engine clamp angle hasn't changed on any of these engines, ever since they were first made. Flying Pigeon has made a billion or more of these bikes. All based on the 1930's standard English designed Raleigh roadster.
So finding a bike frame that fits properly isn't easy, but most really old MTB from the 1980's and some 1990's bikes are going to be better fits than any cruiser or more modern MTB with more acute angles between the seat and down tube.
In an ideal world, you would buy a Flying Pigeon bike with all quality aluminum bits, indexed gears and decent wheels. But your 2000 Genesis is a good match. If the rear wheel is sound and in recent overhauled condition and has been recently looked over by a competent wheel builder/bike mechanic. The rest of the bike's condition matters also. Is the bike in recent overhauled condition, especially the brake pads new and the brake cables and cantilevers tuned up?