Forum menu
Looking at potentially mulleting a new bike (if we get it) as my wife prefers a smaller rear wheel. Is there a rough way to figure out how much the BB will drop and head and seat angles will slacken? Obviously it will vary between bikes (and frame sizes) but is there a rough rule of thumb as my brain is struggling between night shifts?
https://www.bike-stats.de/en/geometrie_rechner - The bike may well be on there. If not select something else 29, hit 'Im changing a wheel size', select rear 27.5 and see what the differences are. All bikes will have roughly the same amount of change give or take.
No. Personally though I would invest in some offset bushes which will correct some of the change. Depends on your shock, if you can run one thats about 35% of the change, 2 is about 70% (off the top of my head). Im fairly sure you can run a pair of offsets on the AM9 - just check you have 2.5mm or so clearance behind the linkage first.
the old adage for fork length was 20mm == 1 deg of head angle, so the same would exist at the rear end (I think) - 1 deg slacker (which can easily be compensated with saddle sliding if you're not right at the front, but then your reach is effectively shorter, etc etc)
bb is approx 2/3 to the rear of the bike, so for a ballpark I would take 12mm off the bb height.
Personally though I would invest in some offset bushes which will correct some of the change.
I thought I should follow up on my earlier post and point out that if you don't get offset bushes that are sized really well for your shock, you'll end up with them running the wrong way round (as thats how they'll settle if bush friction gets a hold of them) and not only wasting money but actually making it worse. I have endless shocks and bushes to play with in order to get a perfect combo, I appreciate that makes it much easier! Ultimately shorter cranks will also deal with most of the problem. Try it and if you like it invest in some shorter cranks I guess!
Awesome, thanks guys.