BMW OEM Crossbar slot dimensions for Thule bike and ski carriers

[Jobu]

I was shopping for Thule roof rack accessories for my BMW OEM crossbars, but I quickly found out that a proper fit is not so easy to determine. No manufacturer seems to specify what will fit with BMW OEM crossbars.
I searched all over the internet and was unable to find the dimension of the "slot" in the crossbar system. So, I measured it myself and here is the photo, with annotated dimensions, so now we know! The width is actually 1/8" larger than 1" in the photo.

Many Thule carriers are made for the Thule Rapid Aero crossbars (discontinued). I have not been able to measure the Rapid Aero crossbar slot dimensions, which I believe to be shallower and narrower than the BMW bar.

Nevertheless, I have ordered a Thule 91725 Universal Flat Top, plus the Thule Ski Rack Flush Mount Kit, and a Thule 594XT SideArm bike rack. The adapters for the Flat Top are, I'm told, suitable for the BMW OEM bars, while the SideArm has hardware included for slot mounting. I will post some photos of how these work.

[Jobu]

Well, I report success!


It was much harder than I thought. The Sidearm had horrible instructions and it took much time-consuming trial and error to get it installed properly. The 91725 ski carrier was a always a DIY, so I wasnt surprised about it.

First the Ski carrier. I ordered it from orsracksdirect.com. They had a great sale on the carrier, less then half price. Their website defiled the retrofit process, so I was prepared. , still I have some tips. The project involves removing the clamps that attach to the crossbars and using bolts that slide into the crossbar slot.

1. Drilling out rivets to remove underside clamps. I had to peel back the rubber bumpers that hold the skis in the carrier in order to get clear access to the rivets. DONT PEEL BACK TOO MUCH of the rubber, as it is a bitch to get back in the slots which hold it in. I has to use a knife ans soapy water to carefully push the rubber flange into its slot. No photo here. orsracks.com has a decent video.

I used a 1/4" it to drill out the rivet from the "inside". It worked well. After a while the rivet will start to spin. Just angle the drill bait to stop this and a ring of remaining rivet head may pop out shortly.

2. Bolts. The Thule Ski Rack Flush Mount Kit bolts are the WRONG SIZE for the BMW OEM crossbars. the bolt heads are too small. I bought 4 galvanized washers to increase their size to fit. The washers are slightly bigger than 1" outside diameter. As you can see in the photo, the bolt+washer combination slide into the crossbar slot. With the washers the bolts fit nicely,though they don't quite hold their place when tightening the wingnuts.

[Jobu]

Next is the "Sidearm" bike carrier.

I won't go into a complete install discussion, but lets just say that Thule's instructions are weak. I had to do a lot of trial and error. To save time here are some lessons learned:

1. Use the long, 80mm bolts for everything except the 2 upward facing bolts, where medium bolts work, if I remember correctly. You can't go wrong using all long bolts. The reason for this is that the BMW OEM bar is so thick, it requires extra bolt length.

2. Depending on the distance between bars and the size of your bike, you may need to mount the wheel strap IN BETWEEN the crossbars, not outside of the crossbar, as instructed. I'm carrying 26" wheel kids bike so this arrangement works for me. for a larger bike, I might have to move the crossbars closer together so I can get the rear wheel nearer to the end of the wheel tray. (The wheel strap can be right on top of the crossbar as the crossbar mounting hardware prevents that)

3. Use the plastic "dowel" to attach the odd, trianular shaped cover to the sidearm hinge. This "dowel" is sized to take the place of the lock which isn't included. If you don't use this, the plastic cover will fly off.

4. Use you own 5mm allen wrench, preferably a socket, its much better than the poorly fitting allen wrench that comes with the sidearm.

Good luck not spending 4+ hours of your weekend on this!

[sapphireX5]

Originally Posted by Jobu

Next is the "Sidearm" bike carrier.

I won't go into a complete install discussion, but lets just say that Thule's instructions are weak. I had to do a lot of trial and error. To save time here are some lessons learned:

1. Use the long, 80mm bolts for everything except the 2 upward facing bolts, where medium bolts work, if I remember correctly. You can't go wrong using all long bolts. The reason for this is that the BMW OEM bar is so thick, it requires extra bolt length.

2. Depending on the distance between bars and the size of your bike, you may need to mount the wheel strap IN BETWEEN the crossbars, not outside of the crossbar, as instructed. I'm carrying 26" wheel kids bike so this arrangement works for me. for a larger bike, I might have to move the crossbars closer together so I can get the rear wheel nearer to the end of the wheel tray. (The wheel strap can be right on top of the crossbar as the crossbar mounting hardware prevents that)

3. Use the plastic "dowel" to attach the odd, trianular shaped cover to the sidearm hinge. This "dowel" is sized to take the place of the lock which isn't included. If you don't use this, the plastic cover will fly off.

4. Use you own 5mm allen wrench, preferably a socket, its much better than the poorly fitting allen wrench that comes with the sidearm.

Good luck not spending 4+ hours of your weekend on this!

Thanks for posting! Do you have any full body shots with the rack and bike mounted?

How do you get the bike up without dropping on the truck?

[Jobu]

I'll post a photo next time I mount a bike. I attached an image from the Thule website. It holds the bike rather well.

Its not that easy to get a bike all the way up there. I basically have to hold the bike above my head and then step up on the running board, balancing the thing as I step up! Good thing bikes are relatively light now.

J

[dkl]

Just curious as why you didn't get the BMW bike lift? Seems much easier to load the bike. I have the Thule crossbars and want to do the opposite...that is, to use the BMW bike lift with the Thule crossbars. But after some initial researching, I don't think I can do that

[Jobu]

I saw it but had no info on the system, so I went with the more proven Thule. I wasn't in the mood to experiment. Also it was abit more expensive at about $240 plus s&H from getbmwparts.com p/n 82119404098. But I agreed it looks very cool. I would be open to trying it for my second bike carrier...

[Riff]

I came here to write a thank you for the post - I was able to equip my old ride.
It's been to tahoe a few times and rides smooth 85+mph sometimes with no issues

[Jobu]

Hey Riff. I appreciate it! By the way, nice E46 330ci! Glad it works. So much better then the clamps. So clean looking. Hope you enjoy Tahoe. I used to live in SF and went there alot. I'll be at Steamboat next week, so I won't be jealous!

[Riff]

Thanks!

I really liked the snowboard rack i got, but it definitely didn't have that flat bottom, so i had to improvise and create a base.

I think next year i'll try to get out to Utah and Colorado. Snow's weak out here - again!