Low Trail (High Offset) fork converstion
 

Soma sells this fork which has a relatively high offset @ 65mm:

Champs Élysées Low Trail Touring Fork | SOMA Fabrications

It states "It can also be used to convert some frames depending on headtube angles to have a front load bias ".

Anybody have any idea on what a proper HT angle would be? Thinking of trying it on my Double Cross @ 72 deg. I notice the Rando frame they sell is @ 73 degrees, so would imagine the DC would come close to that 73 deg number after the conversion.

I've emailed Soma but haven't gotten a response.

Thanks

Trail = (R*cosH – F)/sinH

Where:

H is the head angle
F is fork offset
R is wheel radius
T is trail
If we are talking about 700c touring tires, here are a couple of representative examples:

Conti Sport Contact 700x37c 350mm radius
Vittoria Randonneur Hyper 700x38c 350mm radius

For a 73 degree head with the 65 mm offset with 350mm tire radius, equals a trail figure of 39mm which is a nice low trail figure. A 72 degree head yields 45.4mm which is about where I build my bikes. Works well with a heavy front end load, preferably balanced with a similar rear load.

You also have to take into account the crown to dropout length of the fork. If the Soma fork is longer than your stock fork, it raises the front-end of the bike and reduces the head tube angle and increases the trail. If the Soma is shorter, it lowers the front-end and decreases the trail. If the two forks are the same length then just use one of the online trail calculators to figure out where the fork will you.

ETA: I realized you mentioned what bike you already have so if you have the Soma Cyclocross fork, there is 4mm of difference in length between it and the low-trail fork. That's probably negligible and not worth considering. I think the general rule of thumb is 1cm difference in fork length changes the head angle 1/2 degree.

Thanks for the input, the both of you, I appreciate it.

Nick-

Wondering if you ended up putting the soma champs elysee fork on your double cross and if so how you liked it? I've been pondering doing the same thing--have a double cross, currently with a space horse fork, which has 52mm of offset as opposed to the 65 on the champs elysee. Don't have a good sense of whether the handling might be changed substantially by swapping the forks, or if the 13mm difference is likely to be negligible. Appreciate any insight you might have!