A while ago I bought some bar end lights for my Mrs road bike off th’ebay. When I came to fit them I discovered that no matter how tight I screwed them in, the expanding rubber bit wouldn’t expand enough to actually grip inside the bar. I ended up wrapping some bar tape round the rubber first and this gave enough for it to work.
I put this down to them being cheapo jobs from China and not made very well. However, recently I remembered that I’d won some Hope ones and I needed to replace the ones on my cross bike that it shed in last year’s Three Peaks. I imagine my surprise when the same thing happened. Am I doing something stupid here or are they made for a different internal dimension than the seemingly standard bars I am trying to use them for?? Gis a clue somebody, please!

I may be wrong but mtb bars are a smaller diameter than road bars. I had the same issue as you with the light up bar ends on a road bike but was fine om my mtb.

Don’t the Hope ones come with 2 different sets of rubber expander, 1 for road bars, 1 for MTB. I’m pretty sure mine did at least.

Ah, that’d explain it. Cheers Lunge.
It’s a bit poor with the light ones though – they’d be bloody useless for mtb as would point sideways rather than back!

Time for some inner tube shimming

But but bar eng plugs on a road bike are for holding the end of the tape , there should be an overlap inside the bar…..

On further inspection I was already using the largest inserts and they ain’t big enough. I have now used a bit of innertube before reading the above. Trailrat – there is some tape overlapping inside the bars but not far enough to reach the expander unfortunately. Hopefully I’m sorted now. Cheers all.