matrosov

Good Evening. I have a Trek 3700 and want to install topeak bag rack on it. But looking at the bike and topeak pictures I cannot see how it would mount since there is no mounting points on the frame or the disk brake caliper is covering them which again makes it a no mounting point. Did anyone install topeak rack on their 3700 and if so which model did you use? I'd really hate going buy, try, fail, return route. Thanks a lot for your help.

cobba

Upload some photos.

North Coast Joe

Here’s a photo of a 2011 3900 Disc with a Topeka Explorer and fenders mounted. The rack bolts to factory holes in both dropouts and the seat stay. The rear fender required an .extension mount from under the rack mount

matrosov

Thanks. The 3700 is slightly different, I have quick detach wheel on it and the current rack goes straight on wheel hub. I'm trying to post some pics but apparently I need ten posts to upload them. I'm going to see if I can contribute elsewhere and come back here .

cobba

You've uploaded photos: https://bikeforums.net/g/album/24752455

There is M5 mounting holes on both sides of the frame for attaching the rack.

bboy314

Make sure the rack you order is disc brake compatible, usually meaning it’s spaced out at the bottom to clear the brake caliper, like the rack you’re currently using.

matrosov

cobba thanks. Thanks This is weird since it would not display pics inline in the post and I get this 10 post spam protection message. The angle of that other M5 hole was off. That other hole on the caliper side is occupied by caliper mount screw by the looks of it. I uploaded better angle pictures to the album. I hope.

matrosov

Right so I thought but there is some weirdness going on with mounting holes on that 3700 it looks like they used one of the rack holes to mount a disc brake caliper.

cobba

The two bolt holes I circled are for attaching a rack or fender.

The middle hole doesn't need that bolt to hold the disc adapter onto the frame, the 2 larger bolts are enough to attach it.

If you don't want the rack attached to the axle, remove that middle bolt on the disc brake side and attach the rack to the rack/fender mounting holes.

matrosov

Thanks I'll give it a try that caliper assembly thru me for a loop. For conservativeness sake topeak does not make axle mounted racks right?

cobba

Not that I know of and there's none on their website.