Originally Posted by
Princess_Allez
I was thinking that there must be some logic behind the design/placement of the Seasucker cups. I assume it's for redundancy and overkill. It's more reassuring having 3 cups vs just 1 and it helps justify the price.
Originally Posted by
trekmogul
Here is the top end SEASUCKER BIKE RACK and you can see how off set these cups can be adjusted to..One heck of a sweet rack..
I think this sums it up - there is engineering in how the whole thing is configured. With suction cups, I can very much see how having them offset so that no two cups ever see the same shear forces at the same time and having extra cups is definitely an advantage.
With the RockBros Rack, all the cups are in a line so they all experience the same forces at the same time especially in the fore/aft direction. So that is a major issue in my opinion since that’s the direction that you’re going to see issues from braking, acceleration and in the even of the most common fender bender style of accidents.
This sort of rack does require more attention than a bolt on rack. Anytime there is a change in altitude (air pressure change) or temperature change, it’s a good idea to check it. The SeaSucker rack has a red line on the vacuum pump that if it shows means it’s losing suction.
Like I said, we use ours for use on rental cars when we travel with our bikes. For that it works great and in several trips with maybe more than a thousand miles of driving with the bikes on the rack, we’ve never had a problem. So for that application, it’s without peer, I think and we’d recommend it.
The biggest aggravation with it is that I feel I need to remove it from the car before we ride away from the trailhead. There is a window and locking cable that can be attached and I may look into that. Either way, you can have the rack off the car in under 30seconds if you know what you’re doing.