Project Blue Bike (lowracer commuter bike)
 

I am building a recumbent lowracer bicycle for commuting and general transportation around the Detroit suburbs. My current commuter bicycle goes around 10mph average on a good day including stop lights, and I'd like to double that.

A friend and I collaborated on the design; he wanted to tinker with geometry and I wanted a fast bike without the uncomfortable seating position and inferior aerodynamics of an upright road bike. After a trip to an HPVA race in Ohio last year, we started in earnest.

We settled on a front wheel drive, moving bottom bracket (MBB) design built around a Sturmey Archer X-RD8(W) eight speed internal gear hub with integrated 70mm drum brake and 20 tooth cog. This hub was built into a 16" (305mm) steel rim (from Calhoun Cycle, MN) with a 1.95" Maxxis Hookworm BMX tire.

I am a short guy at 5'-2", so this configuration means that I can not only reach the pedals but run less of a chance of skinning my leg on the turned tire. It also allows the bike to be lower with a higher efficiency drivetrain than if we'd have gone RWD. All this essentially means that my entire drivetrain will be mounted to the front fork.

The Shimano rear hub is equipped with a Tektro 160mm disc brake, laced to a 20" (406mm) steel rim. My friend and I built both two-cross wheels in my living room; getting the spokes up and around each other on such big hubs and small rims was quite a challenge.

This bike will be equipped with chain guard, fenders and a rack to make it usable every day. I do not plan on racing it. It will feature remote under seat steering for comfort and control vs. a tiller. There will be a tall 'conning tower' of reflective tape and/or blinky lights to alert motorists of my presence, should I choose to ride on the roads; sidewalks can get bumpy or nonexistent around here and 20mph will be too fast to be passing pedestrians glued to their phones.

Bicycles are not legally considered vehicles in the state of Michigan and they are allowed on roads of 35mph or below. I'm not sure how this will all shake out in regards to practical riding, but seeing as this bike could be dangerous to pedestrians, I may have to bend some rules.

Below is the general blueprint of the bike with correct geometry.

http://ecomodder.com/forum/member-sv...ture6355-1.jpg

It's borrowing a front fork and headset from a $25 Huffy step through I rode daily last winter, with a 65 tooth chainring sourced from a $10, 1970's-era Schwinn Exerciser on a ~$5 Stingray one-piece crank.

The 'bent's 65 tooth chainring with tiny cranks sitting next to the stock 46 tooth from my 1963 Schwinn American. The 65 tooth will run to a 20 tooth cog and gearing is estimated to allow 30+mph speeds if my legs can take it.

http://ecomodder.com/forum/member-sv...-192501789.jpg

The donor-

http://ecomodder.com/forum/member-sv...900363-hdr.jpg

The wheels-

http://ecomodder.com/forum/member-sv...ture6364-3.jpg

Right now I am in the process of drawing plans for the front fork and whatnot. Here is the dropout blueprint. Next is working out measurements for the BB stays.

http://ecomodder.com/forum/member-sv...ture6353-2.jpg

Issues I am expecting to run into are:

- The 65t ring is too big to fit around the donor's chainstay, so the stay will have to be notched or zee'd.
- I have no idea how the chainline will look.
- Clipless pedals do not thread into old-style Schwinn cranks, so I will need to run adapters first and hopefully later get new pedal spindles machined to thread into the crank.
- I have still to work out the under seat steering mount, but am planning on using a severely shortened headset in line with the frame. Possibly with gussets (pictured in blueprint) to strengthen.

Also, I would like to build this in a way conducive to disassembly for transport. I could very well want to take this on a plane or train where carrying an assembled bicycle would be expensive or prohibited, respectively. I am planning on doing this by incorporating a large 6-bolt flange somewhere in the frame. I would then unhook the (likely) rear brake, remove the seat and stack the frame parts in a suitcase.

Last, I am trying to keep an eye on everything I spend on this project, so once I find and count all my current receipts I will try to keep a running tab in this thread. I'm trying my best, but the bike isn't going to be cheap.

Cheers!

PS- It's Project Blue Bike as a pun on Project Blue Book. The bike will be powder coated the same bright blue as my 1974 Schwinn Varsity.

Sounds like a very fun project!

I might mention that this is a logical extension of my earlier dream to build a custom car that would best the Anal Probe in efficiency. As longtime followers of my build threads will know, I originally wanted to build a super-aero 250cc powered tadpole trike. That morphed into an electric tadpole. Then, realizing that my expected range had dropped to only 50 miles or so, I considered recumbent streamliner bicycles; due to my dislike of the high temperatures that would generate, as well as the decision to go with a MBB design, the fairing idea went out the window.

So, from aero modding a 20 year old car, I have taken the seemingly unlikely leap to selling my car and building a bicycle very similar to that which was banned from racing in 1934 for being too fast for the competition. ;)

Fun! Did you see my redneck recumbent?

I see people are bad at embedding links to previous project threads. :)

That is my snarky way of saying: subscribed!

I threw a link to this in my Ren thread for safe keeping, but have not seen the redneck recumbent...

Oh, yes. I've seen stuff like that. Personally though I don't want to ride a recumbent unless it has a significant aero advantage. I've already got enough bicycles to choose from, so the focus now goes on widening the capabilities of my stable!

(A 24" wheel fat bike is planned for this winter's commuting)

Ive been commuting on recumbents for 11 years now. Low racers do not make good commuter bikes. They are too low, you will be looking a cars wheels, drivers won't see you, not to mention semi trucks. Its scary! Too layed back, it's hard to balance, you will find yourself on the ground on the first sand patch. Too heavy, you are using solid steel parts. Ive only ridden a moving bottom bracket bike once, a cruze bike Vendetta. Very strange sensation steering and pedaling, they say you get use to it, but cadence has to be slow due to the dynamic imbalance on the fork, makes it wobble at high speed. Yes, I prefer long wheel base and web seats, though my current commuter is a Vision R40 swb with a tail box. It fits in the saturn. Good luck on your build.

Some links:
https://www.facebook.com/groups/1564...ocation=stream

https://www.facebook.com/groups/homebuiltbents/

The Recumbent Bicycle and Human Powered Vehicle Information Center


A few of my bikes:
bike -1
https://flic.kr/p/gfqV9s
bike -2
https://flic.kr/p/cxCBgf
bike -3 commuter
https://flic.kr/p/jufF6b
bike -4
https://flic.kr/p/6zk12j
bike-5
https://flic.kr/p/4Vv8AN
Bike -7 (carp)
https://flic.kr/p/4Vv48A
Bilke-8
http://www.wisil.recumbents.com/wisi...00/NB03047.jpg
Bike-9
http://www.wisil.recumbents.com/wisi...k2002-tony.jpg
Bike-10
http://www.wisil.recumbents.com/wisi...n2004_tony.jpg

I'm the 5th person to subscribe. I feel honoured. Thanks for sharing your experiences with the bike.

Someday I'm going to do similar, as there is no way in the next decade or two that I will be affording purchasing a recumbent bike, and it will be much more fun to cobble together a wreck than to purchase a good ride. By the time I build I should know what I want (or at least have a longer wish list :eek: ) so hopefully it will be better than a wreck AND have the designing and building fun too.

Thank you again for sharing your experiences,

Benphyr

Subscribed! Good luck Sven!

The input is much appreciated. I've heard about people getting spooked in traffic with low bikes, but I guess I just want to try it myself... my theory is that since I'm going slower than traffic, cars will be passing me and I shouldn't have too much of an issue with them seeing me. Especially with copious blinky lights. We don't really get semi trucks on the roads on which I ride- just Suburbans, Exploders, Acadias. Not small vehicles by a long shot, but much better than semis.

I am used to riding bikes heavily laden with groceries, packages and even other bikes (they have to get to the shop somehow), so I don't think the weight will be a problem unless I just can't get it up to speed. :confused:

We looked at doing LWB but the front wheel had to be pushed so far forward to avoid crank overlap that we didn't think it would be practical. I've only ridden one lowracer in my life (video below, pardon the language) and it was a SWB RWD custom job. It was too big for me but after just a few minutes of riding I felt quite comfortable on it. I'm hoping that my enthusiasm there will carry over onto Project Blue Bike.

https://www.youtube.com/watch?v=JU5SML8A3jE&index=18

LWB RWD proposal made in Autodesk Alias. I was trying to visualize stuff early on, and although I like the aesthetic, it would have been long.

http://ecomodder.com/forum/member-sv...type-model.jpg

Do you know if there's anything I can do to reduce fork flex on this thing? I drew up another blueprint last night and the dropouts are moving quite far outboard on the 110m fork, which will have to be trimmed as well to fit the 135mm hub. Maybe some strengtheners should be welded to the fork.

One last question, if you know. It looks as if you're using stock cranks, but would you have an idea how others re-tap shortened crank arms? I have been thinking I should make an account on recumbents.com... a lot of the inspiration for this bike came from their projects section.

:)

http://ecomodder.com/forum/member-sv...ture6365-5.jpg

A glimpse

3 piece crank conversion:

Old School BMX 3 Piece Crank Conversion Kit By Old School BMX

Maybe a cartrige BB and 3pc crank on version 2... I'll be able to fab up a new drivetrain while still riding the bike!

Subscribed. Great planning. BTW, hadn't noticed thjs thread until I saw the link in your ren thread.

Check the one piece cranks on bikes for small children for shorter arm length. The aero drag on an non faired recumbent may be the same as that of a racing tuck upright. I just received my 13T/16T gears cut to mount on a S-A 3spd hub in a 26" wheel; with a 40/50T chain ring the bike is capable of 35 mph at 90 ppm.

This guy invented MBB:

Aluminum Monocoque-Frame Recumbents

Nice project! I would like to try out a recumbent or trike someday.

Are you sure you'll be able to double your average speed? Even on my ebike with a 28MPH top speed, I only average about 21 or 22MPH with stops included.

The stops are killer. It is difficult to average out 0 MPH, plus the need to stop and accelerate.

Nice project.

What stopped me from further investigation on DIY recumbent is the suspension.
Where I drive, I need to go up and down passageways like 3 inches high and the position provided by a recumbent won't allow driver's easing it out ...

Wouldn't you have the same issue ?

Can you ride at 45mph with one hand? I hit 48 mph yesterday just before the bridge. This flick is a few years old:
https://www.youtube.com/watch?v=F1nP8LSvymQ

Just wondering-from the schematics above it looks like this is going to be a FWD recumbent-and most recumbents with mismatched wheels usually have RWD ging to the large wheel for better top-end speed.

Given the FWD nature of the plan above, why not use a larger fork-wheel diameter and a smaller rear wheel, or two even wheels for a slight rise in height (less Aero, but better traffic visability and balance overall)? any changes to the geometry resulting can always readjusted back with a few small frame bends to correct...

Yes, and who would want to go to work in a racing tuck every day?

I don't know. I assume you're riding on the road? There are only three stop lights and three stop signs on my way to work (and I usually hit one on the walk sign), so even if I'm on the street it shouldn't be bad...

Thanks! I don't know what you mean by passageways. We do have some sizeable bumps here though, and that's why I chose wide steel rims with fat (for lowracer standards) tires and hub brakes.

No, because I don't have a recumbent yet...

If the front wheel were bigger I would have trouble getting my short legs around it. Trust me, i wanted to do a 406/406 or even 406/559 but it just wasn't going to work. The rear wheel can't be too tall either because I want to be able to carry a small bag on top of the cargo rack without it poking too far above my head into the windstream. Hopefully most things will fit in slim panniers in the seat's slipstream.

So, I am going with the huge chainring to the smallest cog I could fit. If the chainring ends up being too small (and even if it doesn't), I may end up getting a new one machined out of plate aluminum with some old school cutouts like this.

Have you thought of an electric assist bike? I recently rode two different kits that were really inexpensive at only several hundred dollars. Both were in wheel motors and the improvement is massive. Just from two cordless drill batteries at 800 watts, i could fly up hills that would have me at a crawl without assist. Assisting at half the power you pedal will give a range of greater than 20 miles.

No, that would ruin the fun for me. ;) I like my bikes to be human powered only!

I have a ton of things to do but hopefully will get more of these blueprints worked out! Rebuilding my mountain bike now after a minor crash and taco'd rim, and doing a big drawing for my dad and selling my car and (breathe in, breathe out) yikes.

Sven, I use aero bars on my commuter and they are quite comfortable. But this is your thread. See the array of info at recumbents.com and The Bicycleman has reviews.

Sorry I mean sidewalks border or shoulder maybe ?

Because sometime it is required to leave the road for the sidewalk.

Basically a recumbent can't be soft wheelied over such a border, making for a less fluid ride (with my personnal ride in mind)

Grant- I have a front rack that prevents aero bars, and don't like my stomach to be folded in half in a tuck. My neck also starts to hurt after looking up for a while. And I kind of just want to build a weird bike.

Renault- Ah yes, we call it a curb. Usually here there is a short ramp from the sidewalk onto the road so it can be traversed somewhat smoothly. The alignment of concrete slabs varies, but if it's really bad I can just choose to ride on the road in most places. I've never ridden a recumbent on the sidewalk, so it will be a learning experience. I'm sure some technique adaptation will be necessary.

Over half my daily commute is on surface roads (riding an upright), so that won't be an area of concern. The other part (a mile) is a 40mph (65kph) four lane road, where I ride the sidewalk when possible since there is rarely foot traffic. Bikes are only technically allowed on 35mph or less in Michigan and I have gotten heckled for riding on these higher speed roads- even in the dead of winter when it just snowed and it's the only passable route.

Moral is, I'll ride wherever I need to ride, and motorists will be angry no matter what.

Every bike regardless of design is to be careful matched to the purpose desired and the comfort of the rider. My frame, seat, and handlebars are precisely sized to accommodate my ample girth.:) You will find the best position to fit you and your muscles will adapt with use. If a rear suspension is not feasible at least put some type of springing under your seat.

If the 65T chain ring is too big for the frame a smaller gear on the hub could let you use a smaller chain ring and get the same ratio. Either 42/13T or 52/16T will be the same ratio and should be readily available.

I am trying to just get this thing together and on the road right now. Hopefully I can get everything pretty well dialed in and tested, and rock some spray paint until it's finalized enough to go to the powder coater. If I find it really needs suspension, I'll work on that when the time comes. "Steel is real." Until then, KISS. :thumbup:

I can't go any smaller on the hub. It came stock with a 23T but I put a 20T on it. The chainring is probably 10mm larger in diameter than the hub part it mounts onto. Worst comes to worst, I may be able to build a roundabout chainstay to avoid the mess, or even heavily gusset the lower stay. There should be some way to get around it.

All in all, if this thing is some kind of unrideable or unbuildable disaster, I can always revise the plans, reuse the parts and build a LWB, RWD version.

PS- Wheel building tonight to get the mtb back on the trails. Then maybe some time to work on the bent? Hah. So many projects.

Cool !
Could we have pics ?

Edit: I read that wrong. The only pics I have are going in this thread. Not much work going on right now as I try to get my mountain bike back together.

Here is the gearing for the 'bent at 80rpm. Should be a little faster due to wide tires.
http://ecomodder.com/forum/member-sv...gearinches.jpg

I have a Bendix 16T gear that fits a Sturmey Archer 3 speed hub.
OD is 2.82", ID is 1.42" and is .108" thick (flat)
If you are interested I can send it to you.

Thanks, but they are only a few dollars online and won't fit anyway. The 8-speed has larger splines. :rolleyes:

I am looking into an XL-RD5(W) (5-speed drum) for my commuter and I believe S-A uses the same cogs for that as they do for 3-speeds and kickbacks. Of course the only hub I'd like to have a small cog on, doesn't allow that!

Got my mountain bike together and initiated it on a 40 mile "triple trail challenge" that almost killed me lol. So work continues on my favorite money pit.

I finished my last fork blueprint last night (finally got to use my carbon paper again!) and also did some tabulation. I'm going to get some copies of the blueprint tonight and then line up a time to get the fork welded up.

My friend gave me a set of Shimano SPD clipless pedals he wasn't using, and with some measurements he concluded that they could probably be rethreaded to go into my Schwinn crank. We'll see. Again, last resort would be to get new spindles machined with the correct specs.

Here is a running list of expenses for the project, for the curious and for my own convenience. I will try to update this when I spend money on crap. I'm including some vendor names in case anyone is looking for similar items.

Wheels
Front hub (Sturmey Archer XRD-8(W)) and 20T cog-....$166, Bikeparts.com
Rear hub (Shimano Deore disc front)-........................$21, Universal Cycles (UC)
Chrome 36h rims.............................................. .....$40, Calhoun Cycles
Spokes, store bought + nipples.................................$40, UC
Custom-cut front spokes.........................................$36 , Brooklyn Bike Doctor
Tires (Maxxis Hookworm)......................................... $40, UC
Rim strips and tubes............................................. ..$12, UC

Brakes
Rear caliper (Hayes MX5 cable disc from a friend's bike)..$30
Rear rotor (Tektro 160mm)........................................$20, UC
Levers............................................ .......................$free/parts bin
Front brake is a drum, included in hub price

Donor Bikes
Huffy [Granite?] (former winter commuter)....................$25/parts bin
-BB and frame segments
-Threaded headset

70's Schwinn Exerciser......................................... ....$10/parts bin
-65T chainring
-Minty Schwinn oval head badge
-Assorted tubing
-Minty BB bearings

80s Free Spirit Dynasty 10spd...................................free
-headset for under seat steering
-(the rest of the bike will be donated to the LBS)

Other
Crank, one piece (Schwinn Stingray or similar).............$5, East Side Bike Shop
Pedals (Shimano SPD).............................................$ free from a friend

Welding
Front fork.............................................. ...............traded for snow tires

TOTAL
$447

Worked on the digital model a bit... it's pretty accurate. Good for keeping the morale up ;)

http://ecomodder.com/forum/member-sv...415-bike-3.jpg

I like the digital model you posted. I am eager to see how this works out. I have been considering building a front drive recumbent from some scrap bikes too. I may go with 700c front and rear wheels though.

May I suggest that you try a more conventional steering arrangement at least till you see how it goes? It would be easy to change later if you are set on understeer. If your model is accurate, it looks like you could drag a handlebar in a corner and set yourself up for a really bad crash.:(

Dropped my fork stuff off at my fab guy's house last night! He's doing the welding and whatnot in trade for my snow tires. :thumbup:

I encourage you to experiment! 700C is on the big side for me even on an upright, but some people can make it work on a bent, so more power to them.

As for the steering, in the model I made some criteria planes representing slightly more than a 30 degree lean angle before the handlebars touch the ground. In reality it will be all what feels right within those constraints, but I doubt I'll have the guts to be leaning that far in anyway- if I'm 30 degrees over I'm probably already crashing! Haha. I'll be cautious and see how it all goes together. Maybe I'll modify it a bit for better angles after it's together.

This guy has a lot higher handlebars than I'm planning for, so maybe it will be uncomfortable to have them so low?

Other resources
 

A couple other sites you (all) might check out for ideas etc are:
AtomicZombie - DIY Recumbent Bike, Trike, and Chopper Plans and recycledrecumbents.com