Right from the start, when I first got my Cervelo Aspero, I have been using the Trail Mixer in the rearward position. This increases the trail which enhances the stability of the bike.
While swapping around with different wheelsets, I encountered some problems with the alignment of the Trail Mixer. It is very difficult to get a good alignment, due to some part interference and hole misalignment issues. You can read all about the details in this blog post.
That was the reason why I did not switch the Trail Mixer to the forward position to try, as it was so difficult and time consuming to set the Trail Mixer properly, once it is loosened.
Recently, I managed to get a customized jig made, which will help with the alignment of the Trail Mixer. More details to be shared below.
Before that, let's check out the existing Trail Mixer position, which is in the rearward position.
Trail Mixer in rearward position. Note that a special brake adapter is needed to push out the brake caliper, to match the rearward axle position.
Another look at the Trail Mixer, and also the special brake adapter by Cervelo.
Some Aspero owners report that they do not have the special brake adapter, which means that they can only use the Trail Mixer in the forward position.
Now, I will be switching the Trail Mixer to the forward position, and see what is the difference in riding feeling compared to the rearward position.
If using the Trail Mixer in the forward position, the standard brake adapter that comes with the brake caliper will be used. Here is how it looks side by side.
The problem I faced with the Trail Mixer is that when I tighten the 2 small bolts at the side, it will cause the Trail Mixer to move during tightening, causing it to be misaligned. As the hole tolerances are tight, even a small misalignment will prevent the hub axle hole and Trail Mixer hole from lining up properly. The result is that the thru axle is unable to be inserted smoothly and fully.
I needed to be able to tighten the 2 small bolts, when the hub axle is aligned in the dropouts. However, the hub itself is big and will prevent the 2 small bolts from being tightened.
What I need is to be able to tighten the bolt, with the hub placed into the dropouts. This will ensure perfect alignment. However, there is no space to tighten the bolt in this condition.
The solution that I have is to use a dummy axle, which will simulate a hub axle in terms of dimensions but not the size. Then, I will be able to tighten the 2 small bolts with the dummy axle installed, ensuring perfect alignment.
Dummy axle with internal diameter of 12 mm and external diameter of 19 mm. Length is 100 mm.
Designed to fit the standard 12 mm thru axle with very small clearance.
Dummy axle placed into the dropouts, with the 2 small bolts of the Trail Mixer loosened.
Insert and tighten the 12 mm thru axle, so that it compresses the dummy axle. This ensures perfect alignment of all the holes. The Trail Mixer is free to move slightly for self-alignment, as the 2 small bolts are not tightened yet.
Then, tighten the 2 small bolts to lock in the position of the Trail Mixer.
This solution works really well! With the dummy axle ensuring perfect hole alignment during tightening of the 2 small bolts, there is no more issue with thru axle insertion. Finally I can say that I have solved the annoying Trail Mixer issue permanently.
Trail Mixer in the forward position for less trail, and standard brake adapter in use.
Bringing the bike out for test riding, with the Trail Mixer in the forward position.
Looking good on gravel!
I did some test riding on both the road wheelset and gravel wheelset, and compared the riding feeling. It is hard to quantify the differences between forward and rearward Trail Mixer position, but it is clear enough that the difference can be felt.
Rearward: Stable at high speed, able to ride without hands. Slightly sluggish in turning.
Forward: Tends to be more twitchy, but highly maneuverable. Behaves like a normal road bike.
Trail Mixer position with Gravel Wheelset
Rearward: Good stability when rolling down off-road slopes. However, difficult to execute sharper turns on tight switchbacks.
Forward: Needs more attention during high speed descents as it is less stable. However, great for making sharper slow speed turns over rough terrain.
As you can see, the differences are pretty much what I expected, from a difference in trail of about 5 mm. The difference is not day vs night, but it is enough to be felt. The side benefit is slightly more toe clearance due to the front wheel being located 5 mm further forward.
Note that both wheelsets are similar in size, especially since the 650B wheelset has 47 mm wide WTB tires. If a larger 700C x 40 mm wheelset is used, it will have a different feeling as well.
My preference is for the forward position of the Trail Mixer, as it gives the bike a more lively feeling. I like the ability to make sharper turns at low speed, making it good for more technical terrain. It also feels more like a road bike with the sharper handling.
If you have not compared the differences, I suggest you give it a try, and see which is better for you. It depends a lot on your riding style and riding terrain as well.
Thanks for the writeup... Did you notice any difference in riding position between the different Trail Mixer positions? For example, did one position feel more upright than the other in any noticeable way?
ReplyDeleteBoth feel the same in terms of riding posture. But the steering feeling is different as described above.
DeleteRear makes it 52 or 57 out of the offset numbers from the chart? I assume 52?
ReplyDelete