Tiny wee bolt that holds the thru-axel conversion on the drive side of my Trance is rounded off, and I can’t get any purchase to tighen it up. Bes way of removing this? Dremel a slot into it so I can use a small flat blade driver to remove? I’ve looked at my torx and star bits and none are small enough to fit in. It’s tiny bolt but needs to make the dropout adaptor flush and tight. Previous owner rounded it off tryin to tighten it up.

If it is an Allen bolt the best method is to get a slightly too big torx bit hammered into it. The Dremel method can work but it is really hard to not damage the surrounding area. In either case an impact driver is your friend even if you have to use several step down convertors to get a small enough bit in the impact driver.
Before you do anything get as much penetrating oil as you can on the bolt.
Good luck.

Reverse thread bolt removers if it’s not too small: http://www.screwfix.com/p/screw-extractor-5-piece-set/18643?kpid=18643&cm_mmc=Google-_-Product%20Listing%20Ads-_-Sales%20Tracking-_-sales%20tracking%20url&cm_mmc=Google-_-Shopping%20-%20Power%20Tool%20Accessories-_-Shopping%20-%20Power%20Tool%20Accessories&gclid=CJGphtqlv8oCFScFwwod8BIN7Q

Is there clearance for mole grips? Have you tried tightening slightly (very slightly) to “break” the threads? What about local application of heat e.g. soldering iron?

It’s hard to say without seeing it, as a last resort you may have have to drill it out, starting with as fine a bit as you have and get wider until it’s just like swarf, just be carful to keep central and to shouldn’t need to go too close to the threads.

from motorbike land (so probably bigger bits)

slot idea as mentioned

can you file flatten the sides and get mole/spanner/pliers on it

and I suspect it too small but I’ve seen people use the two part araldite to glue a smaller allen key in, wait 24hrs and turn

If you’ve got a toolstation or screwfix near you, get a set of these for £3-4.
http://www.toolstation.com/m/part.html?p=51010

Assuming these will fit your small bolt..
Drill a small hole into the bolt and then turn the extractor into the hole..
Hopefully you’ll then start to undo the bolt in the process

Edit same as trailrider

I’ve used a left had drill bit before on a tiny bolt.

Both time it worked its way out.

those ‘jewelers’ screwdriver sets are handy. tap one slightly larger than the allen key you were using in. the rotating top makes it easy to keep pressure on, and you can use small pipe grips or large pliers to turn the driver.
worth pouring a kettle of boiling water over everything before you start trying to turn the screw as well.
make sure you cut back the allen key you used, or you’ll just round out more screws with it.

No Screwfix near me…

I did think about araldite’ing the allen key in actually. There’s no way of using molgrips or the like as the bolt is probs only half a mm out and it’s a countersunk head and it’s the inside of the dropout, not the outside like the non-drive side is.

I need to get hold of a replacement before I start removing the one that’s in anyway. Appreciate the replies and info, much help, thanks.

Assuming it isn’t a blind hole, start drilling out from the rear – drill will create some heat and will be driving it out as you drill.