2004 Rocky Mountain Switch 2kW

Picked up this 2004 Rocky Mountain Switch for $350 complete without a chain. Needed new main pivot bearings, new bottom bracket, and a very thorough cleaning. Going for a “naked e-MTB” look.

Fork got an oil change to Valvoline Maxlife full-synth ATF (~9wt.). Very dirty. Made a seal-mate tool out of a plastic cup and cleaned out the dirt behind the seals as the fork was leaking slightly. Leak has stopped and the Marzocchi Super T Pro is buttery.

Running a vintage Shimano thumb shifter in friction mode with a XT RDM-786 clutched 10-speed derailleur on a six speed Hyperglide freewheel. Picked up a SRAM PC-971 9-speed chain which works great with both the 10 speed derailleur and the 6 speed freewheel (and the RaceFace narrowide chainring that came on the bike). Yup, 1x6. Just enough to have fun pedalling and shifting with the range for low speed maneuvering to cruising.

Bled the Hayes HFX-9 with fresh DOT4 with a homemade bleed kit. Not bad at all for 20-year old hydraulic brakes. Came with gold aftermarket Dangerboy CNC levers.

Put a 765mm wide 120mm (~5”) riser bar from Aliexpress made from steel and meant for a motorcycle on. It was 35$. 22.2mm diameter at the stem like BMX but the fork has a proprietary stem clamp so I had to use shims. Works great and gives me a more comfortable riding position and more space for the display and switchgear.

Replaced the bearings in the front 20x110mm hub.

Swapped the Maxxis front tire for a Schwalbe 26x2.4” Super Moto-X. Have the same tire ready to go on the rear as well.

The kit: 1500W CSC 26” from Aliexpress (actually 2kW, basically the leafbike motor with a 35mm steel stator, 0.35mm laminations, 4T I believe). Same motor as my first kit from Pasion Ebike also off Aliexpress. Both highly recommended. Comes with ultra-strong SunRingle MTX39 rim.

Came with KT 48V 18 MOSFET 45A dual-mode controller (square wave but can run sensorless as an option or fail safe). Other bike is the sine wave version. Square wave is a bit noisier at low speeds but has it’s own unique character. Very smooth still but different than the sine wave. Thumb throttle to try something new (other bike is half-twist) and so I can use a full-size grip on both sides. Display is the LCD8H which is the P revision with updated graphics/color scheme compared to the earlier version and comes with a USB charge port by default now.

Battery: 13S4P 3000mAh cells mounted on the top tube using the bag that was meant for the controller. I bought 2x13S4P batteries in a crazy deal last year (to eventually run in parallel for effective 13S8P). I’ve ran dual 13S3P on my other bike under heavy use at the 2kW level for the last two years without a hitch. You leave the batteries connected in parallel on the bike and simply connect the charger to whatever is more convenient to access. Still experimenting with the location of the second battery. Going to make a backpack harness and a downtube case and see. Had the single battery under the handlebars for a bit but it ruins the bicycle feel. Bike is set to 50% current in the C5 parameter setting and draws maximum of 1200W. No shutdowns with one battery so far. Made a parallel wiring harness 2-into-1 with 12G silicone wire and XT90S spark arrestor female as main connector. Left XT60 on controller for now. It’s a bit sleeker/smaller and lets me move the bulkier XT90 connectors further away. I standardized on XT90 for all my batteries across both bikes. I made a short jumper with 12G wire and XT60 —> XT90 connectors. Might just eventually put an XT90 on the controller pigtail to eliminate the extra connectors. Second XT90 for second battery is ready to go and tucked away for now.

Dropouts: reinforced the factory aluminum dropouts with 1/4” steel plates/torque arms that I made using a grinder and a file. Drilled a 9mm hole, cut the slot to it with the grinder, filed out to a very precise 10mm fit on the axle. Secured on the left side with a longer bolt through the brake caliper bracket and in the right by a bolt head wedged into a hole in the center of the factory dropout. Seems very tight and strong.

Probably put about 100km on it so far. Full suspension is nice. Linkage driven single pivot rear with a Fox Vanilla R Propedal. Set the rebound to max to stabilize the 15lbs of extra unsprung weight in the motorized real wheel. Same front triangle as the RM7 Downhill but burlier and simpler rear end for the freeride/DH oriented Switch. Love the bike and was lucky to stumble upon it earlier this year. Nostalgic era of bikes for me.

Holy Moly mate, that's some nice custom work alright!
What does Sylvester the cat think about all this? He/she seems rather nonchalant about the whole operation...but I guess that's to be expected...after all, cats don't ride bicycles very often
Love ya work mate, awesome build

Hey mate, did you purchase the 13s4p batteries from Ali Express also?

From what you have said, you have had no problems with purchasing kits etc from Ali Express. Personally, I have so far only purchased small items...like sunglasses etc...and have never had a problem.

Could you please recommend a seller that in your opinion is trustworthy?

Thanks very much :thumb:

Timmy@Ozz said:

Hey mate, did you purchase the 13s4p batteries from Ali Express also?

From what you have said, you have had no problems with purchasing kits etc from Ali Express. Personally, I have so far only purchased small items...like sunglasses etc...and have never had a problem.

Could you please recommend a seller that in your opinion is trustworthy?

Thanks very much :thumb:

Click to expand...

The cat is a big lovey cat that literally drools with affection when you pick him up and get him purring. What a way to live and they are definitely above it all. Free to come and go as they please (I don’t believe in having “indoor cats” personally, think it’s cruel), someone to scratch their ass and feed them, not too bad lol.

Have bought four batteries off Aliexpress and no problems. Two 13S3P with 2600mAh cells bought in 2019 and two 13S4P with 3000 mAh cells bought last year but just started to use now. I always assumed they were generic Chinese cells and have no reason to believe otherwise. My 13S3P batteries have held up to way more than I ever thought they would be capable of and I’ve got more than my money’s worth of use so far. Zero problems with the batteries. 48V 13S3P is a generic Chinese scooter pack size so they are cheap and available in many stores. At the time, anything larger had expensive shipping. The two 13S3P packs came in padded and cardboard reinforced envelopes in regular parcel mail so I guess it was the largest thing they could shove in the regular mail and get away with. Free shipping though and I got 13S6P = 78 cells and two batteries and a charger for ~200$. Cheapest way to get a lot of battery.

Pasion ebike and CSC are both great. Both sell similar kits. CSC can’t be beat for pricing and they have a wide selection. The seller is good too and will work with you and give discounts if you don’t need the cheap freewheel or brake rotor etc. Came with a nice controller case. Pasion ebike kit that I got in 2019 had free shipping at the time so it wasn’t much more then, but is a lot more now. They included genuine Shimano freewheel and Shimano brake rotor, and they also put XT90 as standard on their controllers’ battery connector (and supply a XT90S spark arrestor pigtail) and XT150 for the phase wires.

In my opinion you can’t go wrong with either.

Ordered tons of stuff from Aliexpress over the years and never had a problem. For the most part the stuff on eBay and Amazon is the same stuff with another middleman and more markup. Usually the sellers on Aliexpress for something like ebike parts are affiliated directly with the factory.

Hehe...yep...my whole childhood, growing up on the farm...we always had at least 2 cats. They were never allowed in the house, same as the dogs, and they had lovely sleeping quarters on the verandah...but they were awesome pets....always out catching parrots and rabbits during the night, they are smart little buggers.

Thanks for the info on Ali Express sellers, is good to know you've used them a lot and not had any problems.
Ali Express doesn't seem to have taken off in my neck of the woods, I often talk to people who have never heard of it.
I'll have to start using them more, thanks again.