My Experience rebuilding an entire Mountain Bike

Rebuilding my 2016 Orbea Occam to be more aggressive.

0
737
Orbea Occam Aggressive Short Travel Trail Bike
Aggressive Short Travel Trail Bike

It’s fitting that I took the bike photos at this location as both the bike and the bridge have been rebuilt to serve a new purpose.

My journey on this project started just at the beginning of the Covid-19 Pandemic. With everywhere in lockdown, I decided it was time to replace my drive train. However, since purchasing the bike in 2016 and logged over 3K+ miles, I decided it was time to refresh all the parts. Not to mention the frame had plenty nicks and scratches in the paint. So a fresh paint job could at least make the old bike look new again.

Original Orbea Occam TRM30Orbea Occam DC Edition
A Before and After Shot of my bike, in scenic Barbados. #weridewhereyouvacation

So with a plan hatched to replace everything but the frame, I started researching my parts list. My main goal was to install practical parts that would make the bike more aggressive at trail riding, lighter to maneuver, more confidence inspiring and lastly durable. I’m also a bit frugal so all parts had to be found at the most affordable price possible.

FRAME GEOMETRY

With the frame’s geometry a bit dated by current industry standards, how could I push the frames geo, knowing there were some fixed measurements such as the top tube length (599mm) and reach (431). Installing a pair of Offset Bushings was the best way to achieve this. The 3mm offset each bushing provided moved my HTA from 68 to 66.5 degrees and lowered my bottom bracket height by about 15mm. The drop in BB position was a concern as it could mean more pedal strikes but the way to mitigate this was to find shorter cranks 170-165mm options.

So what are the benefits of offset bushings? They provide the same function as a ‘flip chip’ in a frame – decreasing the length of the rear shock to lower and slacken the bike’s geometry. See the example below.


For the rear shock I went with a Fox FLOAT DPS Factory EVOL, taken off a Ibis Ripley. The shock tune was more inline with my style of riding as I found the original Fox DPS Performance’s tune to blow through travel too easy, even with a larger volume spacer.

Kashima DPS looks great but DPX2 is on the way.

FORK

The stock fork was a 120mm Fox 32 and my goal with switching this out was to improve stiffness and ride feel. I choose the 130mm RockShox Revelation because this fork gave me the ability to install some purposed upgrades and not to mention that the 35mm stanchions meant it’s plenty stiff. I installed a MRP Ramp Control Cartridge which now allows me to quickly change my ride feel between super plush or supportive on the trail via the turn of a 16 click progression knob. This translates into a supple ride feel over small bumps like roots and rocks when needed and maximum bottom out resistance in harsh drops when descending. I also swapped out the lackluster motion control damper to the updated Charger 2.1 (Select +) model. Which provides better traction as the fork cycles through it’s travel.

COCKPIT/CONTROLS

My original cockpit had a 50mm stem, 740mm flat bars and entry level Shimano Deore Brakes, which did serve me well but it was time to get Aggressive!!

Deal hunting, I scored a Bontrager Line 35 780mm bar with 27.5mm rise as a new takeoff on Pinkbike, at a fraction of MSRP. I purchased a FUNN Funduro 35mm stem to compliment my wider bars, as the closer stem allowed me to sit more upright and in a relaxed position when descending. I purchased a set of OE Shimano SLX BL-BR-M7100 levers, which were well reviewed for their performance and price point. I also loved the blue hue they came in.
Because I wanted to make this build extra unique, I made the choice to change all stock bolts to Gold Ti versions. Titanium bolts have the benefit of being lighter, stiffer and corrosion resistant. I capped off the cockpit with a set of DMR Brendog Death Grips in the Gum color which turned out to match the gold color scheme perfectly but also these grips feel awesome both with and without gloves.

DRIVETRAIN

Starting as a 2×10 and then a 1×10, the natural evolution was to go 1×12 but which route should I take was my question for this build.
Because I love the smooth shifting and ability to shift under load of Shimano’s technology, I choose to go with the Shimano’s XT 8100 12s shifter, derailleur and bottom bracket. To complete this setup, I went a bit unorthodox with the rest of drivetrain parts choosing them based on price/performance/durability.

  • Absolute Black Oval 32t Chain Ring for improving traction and climbing while reducing stress on knees
  • Custom 170mm alloy hollowtech cranks that use SRAM direct mount but Shimano 24mm BB spindle
  • KMC X12 12 Speed Gold Ti MTB Chain
  • ZTTO 12 Speed Cassette 11-52T 413g HG
Controlling the budget with ZTTO Cassette and KMC Chain

WHEELS & TIRES

The hardest choice in the build was selecting my wheels. I didn’t want to over spend but still wanted to have a solid “bombproof” wheelset. Since I already purchased a HG cassette, my choices were a bit a limited. Luckily Chain Reaction Cycles had a sale on the Nukeproof Horizon V2 wheelset and the 102 points of engagement meant technical climbing would be improved and that buzzing sound would be quite pleasant. The bonus was that I got a pair of Advance Rim Defense (ARD) inserts that allow me to run lower tire pressures and mitigate rim strikes.

ARD Insert was a bit of a pain when installing the tyres.

I knew I wanted to have tan walls for my tire style but the choice were a nit slim. I actually ordered a set of 29r Maxxis DHF 2.5 and DHR 2.4 and on arrival I was disappointed to find they were 27.5 🙁
Diving deeper into the tan wall options I came across Teravail Kessel. These tires had an aggressive thread pattern, large side knobs and reportedly good sidewall protection. I ordered the 2.6 for the front and a 2.4 for the rear.
The color, fit and handling was quite impressive for a tire brand I’d never heard before. They offered gobs of traction and great cornering support.

Tan Wall Slippers to Match, lol

Dropper & Saddle

For the dropper I went with a Raceface Turbine R 150mm Travel. It has received good reviews and I liked the lever’s tactile feel and throw.
The saddle is an on going work in progress. I initially started with a custom carbon saddle that is super light (141g) and minimalist, with a thin padding. Even with it’s slim profile, the built in flex of carbon gave it a lot of compliance. However, to match the bike look, I wanted to have a tan/brown leather cover. This requirement placed me on a journey that lead to a leather craft shop, hand picking leather, endless videos on leather craft and saddle making.

Not wanting to spoil the carbon saddle, I choose to demo my craft skill on an old slight deformed but functional SDG saddle. The outcome for first attempt was pretty decent.

Frame Painting & Assembly

The final piece to this bike puzzle was paint selection.
I knew I wanted a unique color and having so many options to choose from made it difficult. Green, no green with a flip, no blue with a flip….I finally got inspiration while on a late night Instagram binge from a mustard colored Transition Sentinel.

The paint mix to have the silver and gold metallic flakes was suggested by Degory and I suggested a hint of black Onyx craft glitter to go on with one of the clear coats.

Finished Product & Ride Review

This journey was long but in the end, well worth it. With the knowledge I obtained on this project, I now have two other projects I am working on; a Tandem Bike and a Steel Framed Hard Tail.

The bike rides extremely well. The upgrades to the geometry, suspension, tire width and grip not to mention drivetrain and brakes, make for very capable short travel bike. I’ve managed to already set some PRs both going up and down. On the climbs, I find that the pairing of the Oval Ring and instant engagement of the rear hub offer me instant torque to get over any obstacle. While on the descents, the bike feels a lot more composed which translates to more confidence for me while piloting it through gnarly terrain.

Since taking the photos, I’ve changed my pedals from my old Shimano SPD Trail pedals to Crankbrothers Candy 1 pedal which saw a vast improvement in me clipping in and out. I also swapped out the FOX DPS for a DPX2 and instantly got improvement in small bump sensitivity and the rear wheel now tracks the ground so much better.

  • Orbea Occam Aggressive Short Travel Trail Bike

LEAVE A REPLY

Please enter your comment!
Please enter your name here