UKH

I decided given the amount of stuff we’re going to need to take that panniers was the only practical way to go. I got a bontrager back rack for disc brakes, and have tried to fit it- but the back forks where the mounting sockets are seem too wide for the rack. I could force the arms of the rack apart to make it fit, but it would mean bending them apart by a good 4 cm. it doesn’t strike me as a particularly good idea to do this to metal I’m then going to load with several kilos of baggage. 

Am I right in my reaction that the rack just doesn’t fit, and I shouldn’t be trying to force it? If so, any suggestion as to a back rack that will fit a Trek marlin 7...? 

I imagine you have a rack to fit a road bike (130mm hub) not a mountain bike (135mm hub). 

Can you return it for the correct one?

Oh and I don't think bending the rack is the worst idea but it's not ideal. 

If it's 4cm each side then that seems excessive, 2cm each side is pretty normal and not a problem.

Otherwise Topeak do a disc specific rack which has wider arms to go over disc brakes. Worth a try.

Possibly- but I specified it was for a mountain bike; and it seems a lot more than 5mm wider than the rack....

I once specified I wanted a 29 tyre and got a 26 but yeah 5mm vs 40mm is a hefty difference. 

Do you mean 2cm wider each side ie 4cm total? Thats probably about what it is. And that’s ok? Was worried about loading ‘stressed’ metal 

Yes 2cm each side so 4cm in total is pretty standard so I'd not worry.   I must have fitted hundreds like that over the years and never had a problem.

I think they design them like that so they are easier to fit and you aren't trying to get the bolt in the hole whilst pushing in on the side arm.

Thanks- managed to fit it ok, and seems to be pretty solid- next up, getting bags to out on it...

In the end I went for altura panniers and an alpkit bar bag- and used them for a trip into Faindouran bothy a couple of weeks back. We took loading the bikes to the limit- the forecast suggested there was still a lot of snow around, so the axes and crampons went; and 15-20kg of coal between 5; and, or course, the equivalent of 9 bottles of wine in boxes, and a bottle of whisky (we were going to be there for 3 nights after all...). Those 17 miles from Tomintoul, into a stiff headwind, seemed never ending.

but what a place.... the best bothy I’ve ever stayed in, in the most awe inspiring location. Freed from the luggage, the bikes were put to use to get to the bridge at the Ponymans hut, and we did beinn a bhuird and Ben Avon round the rim of slochd mor- this has to be one of the best days hillwalking in Scotland. 

Also bynack mor and its neighbouring Corbett, dropping down to the fords of Avon, and back along the river- that stretch was the most empty and remote feeling place I’ve experienced in the U.K.

The journey back out was considerably easier minus the coal and wine, all in all the best 4 days in the Scottish hills I can remember- and the panniers/bar bags did the job without any problems. 

When you have to take the back wheel out, it will come out easily enough but you may find that you need to pull the rear triangles apart a touch to get it back in.  Not that this has happened to me before (or that it took me a long time to work out what the problem was), you understand.