How do you ensure your stem is perfectly aligned with the wheel? I have tried the "close one eye and stand back" method and it all looks good in the garage but once out riding even the smallest fraction of a degree out is noticeable.
So, what have you clever chaps and chapesses come up with to help out with this task?
Line up the bars with the fork crowns by eye.
It doesn't matter what you do at home. You will always be doing a trail-side adjustment 5mins after setting off from home.
I just do it by eye, if its not right then it get adjusted somewhere mid ride.
Ben (kinetics) made a 3d printed stem mount that held a laser pointer so you could align in the middle of the front wheel, there's also an expensive tune version
Make sure your eye is in the vertical plane of the bike-centre by checking the front tyre and hub, then adjust the stem.
Place a ruler horizontally across the fork legs, look down at it from over the middle of the stem, adjust until both sides are the same.
grow one arm longer than the other. Thats what I ended up doing!
Usually take me two or three goes to get it right
Place a ruler horizontally across the fork legs, look down at it from over the middle of the stem, adjust until both sides are the same.
Some times the simplest solutions are the best. I like this.
Come on STW what else have you got?
Front wheel square on against a wall, measure wall to grip on both sides and adjust until they're the same distance?
Focus your eyes down to the front of the fork crown from the rear of the bars.. If the bars touch the crown at the same time.. It should be straight.. Or you need glasses
Interesting that my original question was regarding a road bike. Which has a nice long stem to line up with the tyre. I guess MTBS with short stems are harder to get right with this method, hence the lining up with fork crown.
Do it on a nicely tiled floor for grid lines.
Brush handle horizontal over the stanchions, line up bars off this by eye/measure bar end to brush handle if you really want to
"I guess MTBS with short stems are harder to get right with this method, hence the lining up with fork crown."
It's much easier to line up the bars with the fork crown than a stem with a tyre! You can get it really close to perfect.
It’s much easier to line up the bars with the fork crown than a stem with a tyre! You can get it really close to perfect.
Cheers, isn't that what I said?
"Cheers, isn’t that what I said?"
Yes and no. My point was that MTB's with suspension forks (and thus chunky precisely made crowns) are much easier to line up straight than any other sort of bicycle.
Just done the fork crown thing. A revelation was had...
I've never understood why steerers/stems don't have a small notch in them to aid this.
Just imagine your fork is slightly off to one side (but within tolerance) and your stem is also slightly off to that side (but within tolerance) - you'd have a perma-squint!
I’ve never understood why steerers/stems don’t have a small notch in them to aid this.
Because Steerer tubes are simply pressed into the fork crown. There is nopositional accuracy required other than making sure the thin end goes through first followed by the fat end.
A 'notched' steerer, or one with printed graphics for instances, would require a whole bunch more processes during manufacture to make sure that IT was line up with the fork crown itself!
Buy one of these. It has a LASER.
https://www.bike-discount.de/en/buy/tune-spurtreu-alignment-tool-for-handlebar-stem-412172
snotrag
A ‘notched’ steerer, or one with printed graphics for instances, would require a whole bunch more processes during manufacture to make sure that IT was line up with the fork crown itself!
Shouldn't be that difficult to clamp the fork at the axle and use that to align the notch on steerer.
Wheel on - plumb Bob
Wheel off - forks against wall (or some boards which are against the wall as spacers depending on HA and stem length or brifter size for drop bars) measure from wall to end of bars on each side. Assumes your bars are centred though.
I imagine it's more of a case of expense, rather than difficulty.
MTB - line up the the bars with the crown
Road - stand the bike up and look at it from the front from a few metres away and check the stem is in line with the wheel. Go for a ride and realise it isn't. fix it.