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Stealth P7 Gear Cassette Upgrade

Stealth P7 Gear Cassette Upgrade


The P7 with a simple change becomes a legitimate off-road option for Central Oregon Mountain Trails.

After riding many different electric bikes by becoming a Voltaire Franchise Electric Bike and Electric Mobility Dealer I was concerned after I took the P7R on a test run over a moderate hilled trail in which I had to walk the bike up hills that I typically ride up with and without power.  Bend Oregon is on the map to say the least regarding mountain biking.  As a brand new Stealth dealer I was concerned the P7 as is wasn’t going to stack up as a legitimate off road trail machine.

Below is a comparison of a 1 x 11 gear set on the left with the Stealth on the right utilizing a typical 9 speed gear set and free wheel.  The Stealth P7 with a 1x9 can’t do the common trail terrain inclines even with it’s phenomenal 1500 watt power plant.


In Central Oregon I characterize the majority of our hills as moderately steep. If you want steep you can find it, but on the whole the majority of inclines are very manageable.  Unless all you plan to ride are the flats of the high desert my opinion is the P7 as is is will get left out of some very fun trails.

Box 2 has a 11x50 t Cassette with derailleur that fits on a standard 9 speed free hub assembly. You will find there are disbelievers that say the steps in ratio between gears is too large to be a viable solution.  I went forth anyway. We have 1500 watts of assistance to bridge the gaps the Negative Nellies are talking about.  The installation is straight forward and with a modest bike back ground and hub cassette key the do it your self person can be back riding in an hour or two.  As your Stealth Dealer in Oregon serving the NW we can perform this install for you.


As you can see the 50 t chain ring is larger than the hub drive! This gearing dramatically changed the versatility of the P7.

The stealth P7R likes to run at 15mph plus. But, in a pinch it gives good assistance at 4mph with this new cassette (lowest gear). A fairly fast low gear compared to the 1x11 and 1x12 sets on mountain bikes.

The hub gave a a fair amount of assistance on the steep hills and many hills were attainable at 7mph in the second largest chain ring. I did a fairly long steep grind for at least 20 minutes.  I was worried the P7 hub and controller might over heat.  The Stealth hub and controller protection system never intervened.

The challenge ride I did is not a typical ride.  I road 44 off road miles, a lot of motorcycle single track with 3200 feet elevation gain taking 3 hours to complete.  At the end of the ride the stealth extended battery option was left with 14% battery. I am not unfamiliar to this particular route in which it takes me 6 plus hours unassisted. I’d be hard pressed to complete this route with the Rebel Lynx All Mountain with Yamaha drive by BH due to the battery capacity.  Under these conditions the Stealth has at least 20 plus miles range over the Yamaha drive.  However these bikes really shouldn’t be compared.  I can climb steeper grades on the Yamaha.  I estimate the change to the P7 has it climbing over 95% of the grades I routinely take the BH on. The P7 due to its awesome clearance has not hit a rock with the peddle even once in which I routinely hit a peddle with the BH over the rock gardens I often traverse. The P7 ate up moderate gravel grade hills easily while still conserving battery at 20 mph.   In contrast the BH and rider would be spent fairly rapidly trying to keep up. 

Another discussion is riding a mid drive compared to a hub drive.  I like them both. There are pros and cons to each. The P7R doesn’t disappoint with its trail nimbleness and amazing suspension. You and the P7R will easily maintain 25 mph on the flats and if you add your own extra assist 30mph plus is easily doable.  It’s a relatively light electric bike under 70lbs with its massive battery. At around $6500 with the box 2 conversion the P7R with extended battery is a tremendous value and choice in the electric mountain bike category. 


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