Now I know making these changes is frowned upon because you are changing the overall geometry in a way that was not intended. However, in my case I felt the pros outweighed the cons. I started by looking for a 120mm fork and quickly realized I first needed to understand the impact on the geometry of my bike. The best online tool I found for this was at https://bikegeo.muha.cc/ which appears to have been specifically designed for upgrading forks. While not all forks are available in the drop down there were enough across the popular brands (RockShox in my case) to do a decent comparison.
My existing build was with a Recon Silver TK (Solo Air) with 100mm of travel. This was the fork travel originally spec'd on the bike but with a Reba. So in playing I started by selecting the "Reba 100mm" option in the drop down. Then I updated all the other frame geometry values with those from Fuji's website. After playing with the numbers and being realistic with the options available on eBay I settled on a fork with 140mm of travel which resulted in a -2° adjustment in head angle (71° to 68.9°). With this still being well above modern day bikes but a huge improvement for my setup I then had to consider the other changes this would invoke on the frame's geometry. Most notably were the following items:
- Head Angle = -2°: This is the main goal to slacken the bike.
- Fork Length = +44mm: contributing to the slacker geometry.
- Reach = -20.7mm: This is probably good considering it is a 21" frame and I probably need a 20".
- Wheelbase = +15.1mm: A good thing IMHO overall tracking.
- BB Height = +15.5mm: Another good thing for clearance.
- Seat Angle = -2.09°: Maybe not optimal but I'll leave with it. I think the head angle is still steep enough that climbing is mildly affected.
Now for the fun part. I found and ordered a RockShox Sektor 140mm (Solo Air) in black that was a new bike takeoff. Catch was it required a 15mm thru-axle for the wheel and mine where quick release (QR) skewers. So I had search out a new wheel that not only had a 15mm thru-axle but also the Shimano center-lock for the 180mm disc brake. I could only find one wheel which was a Mach1 ETR with Shimano Deore hub with Center-Lock and 15mm thru-axle. Downside it was shipping from Bulgaria. Oh well seems to be the reality of trying to upgrade a 26" MTB.
Now the new wheel had a internal width of 23mm which larger than the previous and was begging for me to use a wider tire than my current 2.1" Maxxis. So of course I couldn't resist and purchased a 2.25" Maxxis Ardent DC/EXO/TR tire for the front. I kept the rear Maxxis 2.1" Advantage the same as this offset is pretty common for MTB applications.
In addition to these items I also purchased a new FSA headset and upgraded my handlebar from 720mm and 760mm. I did the bar upgrade before receving the other items and noticed a massive improvement in easy of steering (less user input needed). In the future I'm considering a forward offset seatpost to counter the loss in seat angle and move me from the rear axle to the BB. Previous upgrades not documented were: 34T Oval chainring, Stages 2 Power Meter (used).
Finally all parts arrived with the wheel being the last and despite the fact it was listed as "Easy Tubeless Ready" I still had to use rim tape and sealant before it would hold air for 24hrs. I've since ridden twice once on an easy hardpack trail and another time on rooty rough terrain with plenty of steep drops and punch climbs.
In summary I'm extremely pleased with the upgrade choices and result of the overall ride. I have more confidence in downhills and drops, steering is easier and climbing has remained as efficient as before. Guess I'll be selling the Recon Silver TK 100mm fork and wheel and they are no longer needed. Or maybe I'll save them for a build for my son?
Final results of the bike...
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