Not bikes but my brother did similar, got a carpet he'd ordered delivered, unrolled it part way and carefully cut out the hearth shape and a diddly bit where the gas pipe goes, unrolled the carpet the whole way and, oh goddammit.
a similar carpet fitting twonk from my brother in law 10 years ago.
a few weeks before before the birth of their son my sister rang me & asked if I could help brian fit carpet to the nursery, only to happy to help I said yes & arranged to call passed the following day after work.
I arrived to help with the carpet, sister told me that although brian wanted the help, he also kinda liked the thought of doing it for himself which I could completely understand as it was their first child. she made a coffee for me & I joined brian in the back garden who was cutting the carpet to size before taking it to the room. I walked outside to find brian had unrolled the new carpet on the patio & had placed the old carpet on top of the new & was using it as a template to cut the new to the same shape that way we only needed to carry the new one inside set it down on the floor & trim to fit. I had used this method a few times to fit carpet myself & it worked well & I had given brian the idea a few weeks earlier when they called past my house & I was doing the same thing in the daughters nursery.
I did after about 30 seconds though point out that he had the old carpet upside down & the new carpet right way up & before he starts cutting we needed to turn it over so old & new carpet both faced up otherwise he would end up cutting the same shape but would be the wrong way round when he tried to put it in the room, "ah right" he said "I had put it that way so the dirt from underneath the old carpet didn't dirty the top of the new one".
then the colour started to drain from his face "I need to turn it before I cut it" he said, followed by, "ah f**k. ive just finished cutting it"
I started to snigger but did manage not to laugh as at this point he still hadn't fully grasped what I meant when I said both carpets need to face the same way, so I told him to help turn the old carpet the right way up. as soon as we did that he understood what I meant & as he stood there looking down at his handy work my sister brought the coffee out handed it to me & asked whats wrong I replied with theres been a cockup, she looked down saw that the cut outs for the door way & alcove where she had planned for the cot to go where on opposite sides on the carpet from were they needed to be, looked at brian & said "honestly brian how can somebody whos so smart be so stupid, you can be a right twat at times". at that point though I have admit that I did start laughing which kinda helped break the tension abit.
to be fair he is very,very smart but lacks common sense.