Crescent wide jaw adjustible wrench.

[zerodish]

My tool kit has not changed much photo below. I lost my adjustable and had to buy a new one. I wanted the lightest wrench that would fit my headset which seems to be 34mm. I bought the extra wide which opens up to 1.5 inches. It says 39mm but mine is closer to 38.2mm. I wanted the Crescent locking adjustable but the 10 inch does not open up wide enough. Brookstone used to sell a simular wrench but there was a patent dispute. The Chinese wrenches will not be as strong and heavier that the American made which are no longer sold. I expect it will be strong enough and they did a good job reducing the weight. Also I like the new larger screw. I spent $10 extra for the black coated. This is bolted to the down tube with two hose clamps and a screw in the water bottle boss.  https://flickr.com/photos/63373992@N07/7122658997/in/photolist-bRpunt-AGna4m-oEQuyi-xzjuP1-MvVXCt-fraX88-2k4T9NY-mZvSwp-mZvh98

[ray b]

Man - does that bring back memories. My tool kit from the 70s was similar (though a Swiss Army knife took the place of the ingenious, drill chuck).

I suppose the cresent wrench can also serve as back-up for personal security in a pinch....

Before I moved on to more modern parts (i.e., more easily found on the road), I used to carry a lightweight set of headset wrenches that doubled for use on the old bottom brackets. The weight savings and specifity of use over my large Craftsman crescent wrench was sufficient to justify the substitution. Just a thought.

[canalligators]

I have a short 32/36mm wrench made by Topeak.  Something like that could save a LOT of weight and space.  Personally, I would not take a large adjustable wrench on tour. Headsets can be snugged up by hand until you can borrow a big adjustable.  I also don’t carry tools for low probability, low consequence problems. 

[BikeliciousBabe]

Personally, I would not take a large adjustable wrench on tour. Headsets can be snugged up by hand until you can borrow a big adjustable.  I also don’t carry tools for low probability, low consequence problems.

+1.

Wonder what the motorized drill bit head is for.

[Pat Lamb]

Headsets can be snugged up by hand until you can borrow a big adjustable.  I also don’t carry tools for low probability, low consequence problems.

If you pass an independent garage, knock on the door or give a holler and ask to borrow the big wrench.  You may also get a good conversation and some cold water out of the experience!

[BikeFreak]

1. Use locktite on the threads before leaving home. It's EXTREMELY unlikely that it will unwind itself and therefore you will not need the wrench.
2. Consider replacing your headset with an 1" Aheadset and you can make all your adjustments with an Allen key. However this also requires a new stem.