Same, handling and weight also changes depending on the sequence in which parts were attached, sometimes bike can't move at all.

Also total weight doesn't go up properly with the weight of parts attached, i.e. a 15 weight wheel adds from 45 to 60 weight when attached as front wheel while as rear wheel it adds 20 weight.
Weight of fully assembled (no bags) R80/7 Classic jumps between 288, 303 and 318 lol.

I wasn't able to make my bike to ride as it did before swapping parts even with original parts installed back to it, bike is just undrivable now no matter what I do.

Another weird thing is that on the back you have to first install breaks and only then suspension while it is opposite for the front side and then you can also just remove breaks all together while everything else is installed.

Workaround.
Until it is fixed by the creator here is a way to make your bike behave normal:
1. Remove both tires
2. Install rear tire*
3. Install front tire*
4. Park bike on the trailer
5. Remove bike from the trailer

*sometimes you might need to first install front tire and then rear tire, keep an eye on vehicle menu, the sequence which gives higher weight for the bike seem to be the right one lol

I just installed the mod and have the same issue on b42, didnt change any parts tho... Bike just stops after releasing gas buttom