Topeak Disc Rack Mounted on CrossCurrent

EriderM

Member
I installed my Topeak Baby II Disc rack system on the Crosscurrent today. I like this rack because I can easily go between my MTX pannier bags, and the baby seat. The items I needed in addition to what came with the rack are:

1- 6 x 1.0 - 50 screw for the disc brake side
1 - 6 x 1.0 - 25 screw for the torque sensor side
2 - 1/2" spacers with 1/4" hole
Blue Loctite

I used the existing hole on top of the brake caliper, as well as the rearmost torque sensor hole. I did not need to bend the rack, but manipulated the rack to line up with the holes. The two spacers seen on the left side were used to level the rack. Instead of trying to bend the rack the spacing naturally leveled the rack. The rack is not "perfectly" level, but good enough that you don't notice it unless you stare.

I measured the screws listed above to ensure that they fit perfectly due to the brake disc having tight clearance with the caliper. These screws also prevented me from needing to drill or tap new holes, so I can restore the bike to its original state. I did need to slightly bore the holes on the rack get the screws to slide through, which can easily be done with a regular drill and 3/16" bit.
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Finally, I took it for a test ride with my daughter. She weighs about 40lbs. The interesting thing is that the bike didn't seem to struggle with the additional weight. It felt like it accelerated and maintained close to the same speed as it does without her. I apologize for the long write up, but hope this helps anyone that has been thinking about getting a rack and worried about the install.
 

jharlow77

Member
Glad to hear the extra weight didn't affect performance. I am eagerly awaiting my CrossCurrent Air mid August and will be installing a Thule bike seat for my daughter who weighs about 25lbs. I might have to cut off one of the water bottle mount nubs though as the Thule base clamps to the seat tube.
 

Spikeytree

New Member
Thanks for the write up! I have the step thru version of the bike and the same rack. With my current config I have to tilt the rack a couple of degrees off center in order for my rack pannier/bag to not interfere with my seat. So by going with your setup I will be able to lower the rack to create extra clearance for the pack. Thanks!
 

Spikeytree

New Member
After riding a few weeks with my rack mounted similar to the one mention above I started noticing some weird power issue. The only reason I can come up with is that the new mounting position is affecting the torque sensor readings. After relocating the rack or the factory mounting holes the power problem went away. I would suggest anyone using this mounting position to pay attention to the power output of the bike.
 

jharlow77

Member
The Air has mount holes on the bottom for a normal rear rack, right? Holes that are not ones used by the torque sensor? I'm still patiently awaiting my bike so I'm getting all my gear ready to put on it.
 

Spikeytree

New Member
The Air has mount holes on the bottom for a normal rear rack, right? Holes that are not ones used by the torque sensor? I'm still patiently awaiting my bike so I'm getting all my gear ready to put on it.
It does come with a set of holes for a regular rack (disk brake type rack needed) but it mounts the rack pretty high and forward that's why some owners wants an alternative mounting spot.
 

jharlow77

Member
It does come with a set of holes for a regular rack (disk brake type rack needed) but it mounts the rack pretty high and forward that's why some owners wants an alternative mounting spot.
Hm, I see. I can't wait to get mine to experiment. I have this "Universal" rack that I plan to use. If a rack compatible with 28" bike sits too high I wonder if one could use a rack for a 26" bike?
 

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Spikeytree

New Member
Hm, I see. I can't wait to get mine to experiment. I have this "Universal" rack that I plan to use. If a rack compatible with 28" bike sits too high I wonder if one could use a rack for a 26" bike?
It will be compatible but once you mount the rack on you will know why I feel that it mounts too high comparing to other bikes. I am excited for the 500w bikes to come out. I am wondering how much faster will they be.
 

jharlow77

Member
It will be compatible but once you mount the rack on you will know why I feel that it mounts too high comparing to other bikes. I am excited for the 500w bikes to come out. I am wondering how much faster will they be.
I will be mounting a thule kids seat that floats above the rear rack (base straddles the seat tube) so if the rack sits too high I might have to do some modifications as well.
 

EriderM

Member
After riding a few weeks with my rack mounted similar to the one mention above I started noticing some weird power issue. The only reason I can come up with is that the new mounting position is affecting the torque sensor readings. After relocating the rack or the factory mounting holes the power problem went away. I would suggest anyone using this mounting position to pay attention to the power output of the bike.

I didn't have any issues with it. Did you use a torque wrench on install? If the bolt is not torqued properly then it could miss read your pedal input.
 

Spikeytree

New Member
I didn't have any issues with it. Did you use a torque wrench on install? If the bolt is not torqued properly then it could miss read your pedal input.
I thought it was pretty odd as well i have torqued it down pretty good and there are two other bolts on the same bracket. Since i have noticed the problem since the first mile after the install i have just went back to the original mounting holes for the time being. :/