BO15 Cyrus the Virus

[OddJob]

CtV got its first shakedown run. I put it together and when I sat on it, I realized I was in 7th gear. What the heck, lets see how high 7th is. Nowhere near as bad as I thought it would be. First gear is ridiculously easy. I do have a problem, the cranks are too long with a 20" front wheel. I slapped a 24 on there and took off up and down the street. It's a little twitchy, but rides way better than I expected. It was a very quiet ride, no squeaks or clunks.

I would like to try a larger chainring, and am undecided if I should go with a 24" front wheel, or shorter cranks and the 20. Appearance wise, I like the 20" front wheel much better. But then again I was looking at a mountain bike tire on it which was too wide/tall and way too much of a knobby tread.

First is supposed to be 'ridiculously easy'. So once you hit an actual incline of any substance, you can 'squirrel cage' your way up the hill. Spin to win, brother.
The 24 would give it a little 'drift trike' look , which might be cool. A Maxxix Holy Roller would look good with those rear tires.

Or for more of a 'slick look' , this Odessey Path Pro ....

And both pretty reasonably priced, available through your LBS via JBI.bike.

 

[Psychographic]

With the rider position, and those heavy back tires, I really expected this to be a bear to pedal. I though for sure I would need that low 1st gear, but it is surprisingly easy to pedal.

The more I look at the 24" front wheel, the uglier it gets. I absolutely hate it! At first, it was a possible compromise, but now it's just hideous to me.

The cranks just kissed the pavement with a 1 3/8" tire on a 406 rim. I'll need a new rim no matter what, so I'm thinking a 451 front rim, and if needed go to 165mm, or 160mm crankset.

 

[Psychographic]

I measured the cranks on the Trek I stole the derailleur and shifter from, they are 152mm. The ones that I had on it for the test ride were 170. I put them on the bike with the 406 rim and I have plenty of clearance. I haven't ridden it yet, but sitting on the trike and backpedaling, it's much more comfortable. The reach with the 170s was a bit too much.

Now to give it another ride and see how it works. The Trek has 3 chainrings, so it might help dial in what size I will need. I thought the 39t was a bit too low.

 

[OddJob]

152 mm? That must have been a kids bike? I don't know of an adult Trek that comes with any shorter than 165 mm crank arms. Oh well. Glad it might work out for you. Save a bunch of running around, and hunting up a new wheel.

 

[Psychographic]

Armed with the shorter cranks and the 20" front wheel, I went for a ride around the block. The crankset has 3 chainrings, I started with the biggest which would be 21st gear. On flat ground it still pedals easy, so I stopped and dropped the chain to 7th gear and went up hill and around the block. By no means a steep hill ,but I wouldn't use high gear on my Varsity up it. It did wear me down a bit, but didn't kill me.

I got even more brave going downhill and took the turn pretty fast (no brakes), you really have to lean into the turn. It's amazingly stable, steers very well and is comfortable!!! The shorter cranks are perfect, not stretching to reach the end or too close at the other end of the stroke. I'm really loving this thing.

Next time out, I'll have to see if one of the neighbors will take a video for me. Here's how CtV looks right now.

 

[Psychographic]

I don't know about you but I need about 30" from the center of my crank to the seat top. I'm guessing the seat won't sit quite that low.

GC.

The seat IS that low!

 

[metalchewy]

The seat IS that low!

Awesomely Low. Great stance.

Building.... ....Riding

 

[kingfish254]

Great news on the gearing and cranks.
I bet you can't help but smile while riding this beastie too.

 

[restodave]

View attachment 124826

It looks great but it's begging for some height at the rear: either a sissy bar or that C-Cab you were mulling over.

 

[HuffnPuff]

I got even more brave going downhill and took the turn pretty fast (no brakes), you really have to lean into the turn. It's amazingly stable, steers very well and is comfortable!!!

Careful, next thing you’ll be wrapping the back tyres in pvc pipe and taking it drifting.

 

[GuitarlCarl]

The seat IS that low!

and the distance between center of the crank to the seat top?
I've got a couple that pedal out in front like that. A bit of a seat back to push your back against is nice, even just a bit at the base of your spine. That curve in the banana might be enough for a comfy ride. Do you like the riding position?

GC.

 

[horsefarmer]

and the distance between center of the crank to the seat top?
I've got a couple that pedal out in front like that. A bit of a seat back to push your back against is nice, even just a bit at the base of your spine. That curve in the banana might be enough for a comfy ride. Do you like the riding position?

GC.

I can +1 on that my semi - recumbent had a backrest and you needed it!

 

[Psychographic]

Great news on the gearing and cranks.
I bet you can't help but smile while riding this beastie too.

It's fun looking at the few peoples reactions that have seen it ride by.

It looks great but it's begging for some height at the rear: either a sissy bar or that C-Cab you were mulling over.

I agree with how it is in the pics, I have leaned the bars back and it helps a lot.

Careful, next thing you’ll be wrapping the back tyres in pvc pipe and taking it drifting.

Now that does sound like fun!

and the distance between center of the crank to the seat top?
I've got a couple that pedal out in front like that. A bit of a seat back to push your back against is nice, even just a bit at the base of your spine. That curve in the banana might be enough for a comfy ride. Do you like the riding position?

GC.

The seat is 5 1/2" higher than the crankset, if you draw a line straight from the center of the cranks to where my butt hits the seat, it's 27". With the shorter cranks, and the bars back further than the pic, it is very comfortable.

 

[SkyknightJohn]

Glad you got the pedals worked out to keep the 20” front, the stance is great! Lookin’good!

 

[OddJob]

Looks like you got the bugs worked out, Pysch. I am looking forward to seeing you on this thing. Hopefully a neighbor will comply to shoot some vid.
Where are you at with the braking process? Just hooking up cables between levers and calipers?

 

[Psychographic]

Looks like you got the bugs worked out, Pysch. I am looking forward to seeing you on this thing. Hopefully a neighbor will comply to shoot some vid.
Where are you at with the braking process? Just hooking up cables between levers and calipers?

The rear axle needs to go on a lathe to turn down what's left of the welds for the drive wheel bushing. I ground out the ends of the hole in the bushing so there was a place to weld, then get turned down even to the size of the axle without cutting through my weld. I cleaned it up close by having a friend crank the bike while I used a combination of a cut off wheel and grinding disc.

Once the lathe work is done I can cut another much thinner bushing I bought to make the 1/8" wide shims that space the hubs and align the brake rotors. If I mount the hubs without shims, the rotor bolts ride against the axle bearings. I will also need the non drive hub machined to get the flange bearing to sit flush with the hub.

Once the machine work is done, it will be just hooking up the cables for the rear brakes. As for the front, I have the rotor, caliper, and freewheel adapter. I just need to decide on a wheel and get a locking lever, which will be my parking brake. I'm very curious as to how well the brakes will work. This will be my first foray into disc brakes, so of course I chose the easy route!

I'll take some pics in the morning that will help explain my situation.

 

[OddJob]

You wouldn't necessarily need a front wheel with a 'freewheel' on it. You could set up a parking brake on the front wheel like what is used on a wheelchair or a push golf cart; if it's only used for parking, which should be sufficient.

Both just have a tab that sits up against the tire when the lever is in 'locked brake' mode. Regular bicycle brake cable and housing is used. Pivot point needed for the tab, and a cable stop at the tab and the lever.

Pull lever back to brake, push in the pin, stays locked in place.

 

[Psychographic]

I've got all the parts for a front disc brake except the lever and cable, plus the fork has the bracket and guide for the disc set up. It will look stupid to have the brackets with nothing on or through them, and I'm surely not ruining the chrome by cutting them off. I think a wheelchair style brake will not look right for my taste. It is a good alternative for a rat bike, but rats are not my style.


Right now I'm looking at a 144 spoke lowrider wheel. If I could get just one vendor to reply to my requests on the axle length of the wheel I want, I can decide on a front wheel. I'm amazed out of three vendors, not one has replied, or will answer a phone.

As promised, here are some pics

This is the freewheel side, I have a temporary PVC spacer in it for now. You can see without it, the bolts would ride on the bearing. What you can't see, is the flange on the bearing doesn't allow the rotor to fit flush against the hub. It uses the same bearing that is in the axle housing. I think this will weaken the rotor to hub attachment.

Here is the drive bushing, after cleaning up the weld a bit. It still needs to be cut down to the axle size so it will fit into the bearing on the axle housing side.

 

[Psychographic]

I guess the vendors that sell lowrider bike parts are too good to bother dealing with a low life like me. Not one of them got back to me with a simple question about the width of the axle to see if it will fit my fork, I was up to about 5 vendors I inquired with.

So China will get my money, I sent an offer on the wheel @kingfish254 posted earlier and it was accepted. It won't match my rear hubs, but I guess I'll live with it. What I can do is add black to the rear hubs to help it match the front wheel. Now I just hope it gets here in time and in good shape.

 

[sandman]