Upcycle Cruiser Racer

[ManaCycle]

This is my first ebike build and since this forum has been invaluable providing ideas and assistance, I decided to share my experience too.

The bike is an old Northrock cruiser I found at a bike rental place. Its aluminum and has 1 1/8” integrated head tube. I wanted to do a cafe racer / board tracker style build. Accessories include monarch dual springer fork, 160mm front disc brakes, S/A X-RD3 rear hub, custom gaspipe layback seatpost, inverted half moon handlebars and an old seventies Samsonite suitcase I’m going to turn into the “gas tank” battery housing.

I’m using a Luna Cycles bbshd and 52v Wolfpack. It was a bit of trouble getting everything out here to Hawaii but the people at Luna Cycles and Approved Freight Forwarders were awesome. After a little research and help from Tony at Luna, I received two kits and two batteries about two weeks after I ordered online. That’s pretty good for Hawaii, where everything comes on a slow boat ride from 2500 miles away.

My kits came in just one day before we were set to travel to LA. I took the opportunity to visit Luna Cycles in El Segundo. The shop staff and Kyle were great. He even opened up a little early for me. I was able to get a couple of longer control and throttle cables and a cool T shirt. He even traded me a water bottle and calendar for some Kona coffee we grew. All in all, great experience.

Back to the build... I stripped everything down and rattle canned the frame. Fork fit in with a little cajoling. I added some washers and spacers to tighten up the springs a little for the extra weight. I made the seatpost out of 3/4” and 1/2” gas pipe, a reducer and a 45 deg coupler. All locktite together. For the battery housing, I cut down an old Samsonite suitcase I found at a thrift store. It’s plastic or fiberglass, with a faux leather finish. I cut out the tank shape and used flexible rubber edge molding to finish. Put a hinge on the top and three bolts on the bottom to close. I also made a bottom for it out of a roll of black rubber. Brown seat and grips and some beautiful old school brown bow pedals from Tony’s Schwinn in East LA complete the look. I also would like to make leather chainstay and seat tube covers but haven’t got to it yet.

I will post more pics of the finish build when I’m done.

The second kit is going to go on my 1998 CWC Roadmaster Luxury Liner. It’s a really cool anniversary edition of the 1948 model. Found it in a garage collecting dust. It’s a real head turner just the way it is. I want to put S/A drum hubs front and back to keep the classic feel. More on that build in another post...

[paxtana]

That luxury liner looks gorgeous. The chainring is pure badass

[ManaCycle]

I don’t think I can adapt it for a mid drive though. Maybe have to go hub drive to keep the most vintage parts and look.

[ManaCycle]

I got my S/A x-rd3 hub in today. Took a little effort to squeeze the 118 mm overnut into the 110 mm dropouts. I really like the way it looks and it sounds amazing.

Spent a couple hours on final wiring. I used a 3/4” heat shrink and 1/2” casing tube to group all the wires together coming out of the motor. I doubled up the casing to get around everything and electrical taped it together then used heat shrink on the ends.

Now all wires are in one hose that goes up the back of the seat tube and into the battery housing. Wish I could have done the same routing for the shifter and brake cable but they only had enough length to go up the down tube. Still, pretty clean for my first time.

I bought a 24” controller extension cable from Luna while I was in LA. That got me to the head tube with the routing I wanted through the battery housing. I also got a throttle extension I didn’t end up using. I wish there was extension for the display controller to display wire. With the display in the middle it doesn’t quite reach as far as I’d like, but I didn’t want to splice it so am going to deal.

Got everthing squared away and took the bike down to the beach for a test ride. It’s got amazing torque with the 32t chainring. In first gear it will almost wheelie. Bike rode great. A little top heavy with the battery on the top tube but not ridiculous. Top speed in first was 17.4 mph; in second 22.2; in third 30 but it seems like it likes to cruise at 28-29. I could go a little faster with the 46t or 52t rings I’ve got but I like the pickup of the smaller ring and live in a pretty hilly area.

One thing I’ve got to address is the brakes. Not enough stopping power. I’ll have to play with adjusting the drum rear brake. I hammer it and it barely slows down. The front disc is a cheesy Ying Ping knock off. Also the brake mount on my springer fork is on the suspension arm not on the axle arm. This makes the front dive a little when applying. I ordered a S/A 90mm front drum hub to solve.

My only other issue is adjusting the shifter. I have to hold it down to stay in first gear and have to do this weird pause pedal pause motion to get it to set. I didn’t install the gear sensor yet, still have to Youtube it. Just been babying it and taking it out of PAS to shift.

Once everything is dialed in, this is going to be one sweet ride. Turned a lot of heads down at the beach. All my surf buddies want one. Thanks again to everyone here for the knowledge and inspiration.

[ManaCycle]

[ManaCycle]

I rode over to a friend’s house for dinner and bent the top bracket on my springer fork! The disc brakes apply a lot of pressure to the springs when stopping and eventually bent the bracket. Has anyone else experienced this?

Does anyone one have a springer fork with drum brake? Does applying brake cause the springs to compress? I ordered a new front wheel with 90 mm drum brake and am hoping this will solve problem.

Also, does anyone know where I can buy just the top bracket and not whole fork? It’s the Fenix Cuda 1 1/8” on Amazon. Dealer said they don’t have replacement parts. I’m thinking about trying to get two and weld together or just a replacement and weld some gussets for strength. If I can’t source, then I’ll try taking it down to a machine shop and have them custom make a stronger one but this will probably be pricey.

Any suggestions would be great. I really like the Indian style fork, https://www.ebay.com/itm/Replica-Ind...UAAOSwAThcDtoi It looks HD and like it doesn’t put as much pressure on the head tube bracket. I can’t find one in 1 1/8” threadless though.

[paxtana]

Yikes..never heard of that happening but it might explain part of why this design is less commonplace versus modern coil forks.

[AZguy]

All forks with angled travel will compress upon braking - the braking force pushes back and since pushing back at something with an angle some of the force goes up the angle. Fork dive is an inherent nature of the beast. You likely have fairly soft forks so see it more. The only way to get rid of it aside from fancy valves and controllers is to make a geometry where the front wheel travel is straight up and down (e.g. BMW telelever front suspension). I owned a couple of those and it's amazing how little dive they have and the ultra powerful brembo's on the front really stop these heavy beasts. It won't make any difference what type of brake with regards to brake dive. I'd stick with disk.

One issue with a single brake disk on the front is you get fork twist which you won't generally get with a drum. If you are getting fork twist something like a fork brace helps but I'd look for beefier forks if that's a problem since they are weak and still stick with disks.

[ManaCycle]

I made a fix for the suspension bracket. I took it off the bike, then heated it up with a hot air welder and hammered it back as straight as I could with a sledge. Then I installed a second bmx stem right over it (Without the top plate on it.) The stem is wide enough to spread the load across the whole top plate of the bracket, not just around the headset spacer. Then a 1/8” spacer over that and the handlebar stem and top cap. Works well so far but I will definitely be keeping an eye on it.

[Defjr333]

Sturmey's xl-fd (the 90mm drum brake hub) WILL bend front forks if you jam it hard and have light duty forks. That was one of my hardest parts to find, a heavy duty front fork. Which is why mine have no suspension to them. I am using the XL-FD (90mm) on my build. IdeaRat is using the X-FDD(70mm with Dynamo) on his I think , he is also using a springer type fork. He wanted the 90mm version but said it was too hard on the springr forks. Most Front Fork Downtubes I have seen measure aprox 1.5-1.8mm in thickness. I found a heavy duty set that measure 3.2mm in thickness. Both where made of steel. With the number of stories online of that hub(90mm) bending forks, I wanted to be sure it was over built.

[ManaCycle]

I put on the SA XLFD drum hub today. After reading defjr 333 comment, but having already acquired the hub, I bent down a handle bar shim I wasn’t using to wrap around the fork under where the brake arm bracket is. Hopefully this will distribute the load a bit. Thanks for the safety tip D.

It test rode great. I love the complete silence of the brakes. It really goes with the theme. The front drum actually stops the bike better than the disc brake did. I was getting a lot of load on the springs with the disc that caused the bike to stutter a lot and the front end to dive excessively. The wheel also had a tendency to pull to the side with the disc and the fork to want to twist. Also noisy as hell. I didn’t want to use. I went through a perfectly good pair of shoe soles stopping dirt track style.

None of these issues with the drum. I did notice that the suspension seems a little tighter. I don’t get as much play in the springs, but it still does the job of softening road bumps. I’ve gone full stop on a couple of really steep hills and so far I can feel the load on the fork arm but not enough to bend it I hope.

The drums don’t really come on as strong as discs do. I jam them and still gradually stop. I haven’t been able to lock up the rear and skid, even in gravel. No indo stops from the front either. Still, good even stopping power and completely silent. Now I drag my shoes just to let people know I’m there!

P. S.
Az guy, have you seen the Munroe e bike? Seems like a very similar suspension to the BMW on a really sexy ebike.

[AZguy]

I hadn't seen that Munro... wild looking bike... sort of steam punk meets the future


That twist comes from the torque the disk brake puts on the forks since they are mounted on one side/forkleg. Motos with dual front disks don't do this at all. I had a couple of motos with long travel weak forks and single disk brakes that twisted terribly under hard braking. It's sort of a bizarre sensation since what's noticed is that while hard straight line braking the handlebars turn to one side quite a bit.

On my motos that twisted like that a fork brace alleviated it considerably although not altogether - enough it wasn't an issue though. For a bike you'd likely need to have someone machine a brace but they work.

I'm not a fan of drums, particularly up front where all the braking power is - they are weak, heavy and fade quickly. Frankly after going hydraulic on my MTB's ~fifteen years ago I never want to go back...

[ManaCycle]

Here you can see the handlebar shim under the brake arm bracket. Helps to distribute torque load on fork arm. I can totally see how the fork would bend with just the bracket but this seems to be holding up.

Second picture is is final product for now. I had to ditch the retro headlight for something higher visibility in traffic and at night and reworked the chain guard bracket to fit it back on. I actually caught my pants twice without it and had to cut the cuff away to get them out since you can’t back the chain on the chainring!

[Defjr333]

Yeah, those clamps S/A provides are sketchy. when I saw the instructions I realized I would be making my own. They do not distribute the torque of braking across a wide enough area. I had a local machine shop fab me an adapter for the rear, and made 2 new clamps with a distribution plate for the front. Now, all that torque is applied across a section 15x greater. I also used heavier gauge downtubes to help with this. I just didnt trust those clamps. As far as brake power.....These have more power than ANY brake I have ever used, aside from hydraulic disc. They are totally silent, and cannot get gummed up with mud. The cleaner look is also a plus for me. If my brakes where any better, I would find myself sitting in the road a lot due to being bucked off like a rodeo.

[ManaCycle]

Defjr totally agree. The drum hubs are great. I was able to use the coaster brake arm mount for my rear and I can see how the front clamp would probably work fine on a regular fork. My fix for the front fork works great so far, after a lot of high speed miles and hard downhill braking everything is totally holding up.

Now I’ve put about 140 miles on the bike and established a feel for my riding habits. I’ve found that I like riding fast, all the time, on sketchy mountain roads. If any of you ride like me, my advice is to use quality components so you don’t compromise your safety. 20-30 mph is a really crappy speed to be going when things fail and the asphalt doesnt give second chances.