I'm new to drop bar hose/cable routing (currently building my first gravel bike) and I seem to be seeing a huge amount of variation in hose length and routing.
I watched the Park Tools video and they seem to have a fairly minimalistic approach with short hose/cable fairly tight to the headtube.
(I appreciate that the above shows callipers/cable not hydraulic hose & is a road bike).
So I've gone reasonable short leaving enough spare to remove the stem over the top of the steerer, rotate the bars and turn the bars right back to the top tube. I'm wondering whether I've done them a little too short.
Some other gravel bikes I've seen (including some pre-built ones) have rather large loops of cable and hose that look like they could easily snag.
Equally routing varies too, some insisting that cables cross in front of the head and other routing everything down one side (I've routed the rear brake hose from the left shifter down the left side of the bike as it seems tidier).
Is there any consensus or is it just personal choice? I'm not particularly worried about it having to 'look right' as long as it works.
If you are going to run a bar bag the short is best as cables and hose won't interfere with how the bag sits under the stem. Sust run enough cable so you can turn the bars lock to lock unimpeded. It also looks way better then a huge amount of spaghetti hanging on the front too. Just be sure of what bar height and stem length suits you before cutting as adjustments will be difficult if you want to say add 10mm on the stem, flip it or add more steerer spacers.
Personally I'd leave some wiggle room until you've done a few rides and got your position sorted. It's easy to trim more off down the line than replace if you need more length
If you are going to run a bar bag the short is best as cables and hose won’t interfere with how the bag sits under the stem.
Generally, I'd agree with this but I've found that sometimes it's good to have a bit more slack - especially if fitting "bikepacking" bags, when having extra cable/hose often means you can route them without sharp bends. I don't think there's one answer and a bit of trial and error is almost inevitable.
So, this ...
Personally I’d leave some wiggle room until you’ve done a few rides and got your position sorted. It’s easy to trim more off down the line than replace if you need more length
I'd definitely leave some slack in a gravel bike. I switched to some big flared bars and my cables just made it!
Unlike MTBs where I often just ziptie the gear/brake/dropper together to tidy up overly long cables. Road bikes a few mm matters to how much it curves and whether it rubs or doesn't rub. You can't spin the bars in a crash so really they just need to be long enough to let the bars touch the top tube and no longer.
Depends somewhat on the location of the cable stops and what your preference is on how far you tape the bars.