C.P. 's Winter Project

[C.P.]

Well, this one's been under way for a few weekends, (*LOTS* of hand filed miters!)and it's already been on a test ride (with my son) - it's NOT a trail bike, but rather a biketrail/round neighborhood tandem bike.
It came to life using bike frames donated by splat (fork) and many other donated frames. I had this old set of 26"wheels with a NEXUS 7 speed hub/integrated brake laying around from a commuter bike project - and all the other parts were in my "junk" parts bin - (bad habit of saving everything). Some materials came from an aircraft supply house (steering linkage), but most was local steel supply house.
It ranks up there with strange bikes for sure, but it actually rides quite nice...
I built it after seeing a similar design in the Netherlands,
http://www.familietandem.nl/tandemtransporter.html
and never really liking the trail-a-bike designs because I couldn't see my son on those...
My design takes the netherland one I saw one step further - I have added a freewheel for my son's crank so he doesn't HAVE to pedal...when he get's older (he's just barely 2 now) he'll join me on rides on his own bike or the family tandem with a child stoker kit...but for now - he's on board with me. I also made the (front) bottom bracket adjustable (up/down) as well as the seat, so as he grows, I can keep him at a low center of gravityand the bike will "hopefully" still steer good.

Remaining things to do.

-Machine/Tap sons crank arms so they are shorter crankarm length.

-Add gussetts and such to the headtube - (it was just mitered/welded on the frame a second time - the first design had too steep a headtube and steering was too jittery)

-Get 22T freewheel for front crank so his pedals go the same speed as the captains (mine - using the small 22T chainring)

-get extra long brake cable for front V brake (to be added)

-get an Adams trail a bike seat back (seat belts for him)

-paint

This one ought to get some stares - at least I know the kids 'l be envious of this thing...my friend came by with his kids (3 and 4 1/2) and they were lining up for turns on it...

(sorry about the LARGE formated photos)

[C.P.]

I read somewhere that BB cups have the same thread as freewheels...I got an old set of steel square taper 135mm cranks arms from the bone yard, and machined & welded a BB cup to the driveside - then installed singlespeed freewheel...worked perfectly...and my welds won't get any awards for being as pretty as TIG as we've all become acustomed to...

[C.P.]

mother approved seat back w seat belt ;)

[splat]

Chris !

That is too cool !

are the cranks a little lonfor his legs ?

[C.P.]

Chris !

That is too cool !

are the cranks a little lonfor his legs ?


Thanks John, yep, they are too long, 'on the to do list to shorten them to 90 or 100 mm and add little toe clips/straps so his legs don't get smacked should he miss the pedals...

[splat]

Chris

Why did you make it so Long ? Couldn't you have just put head tube , right after your sons handle bars ?

[C.P.]

you know, I've thought about shortening it ever since I placed the cockpit for my son...I didn't measure for his cockpit correctly the first go around, and had to shorten it...ever since that change, I've wondered if I could shorten the whole thing...maybe I will...MAYBE...

I have noticed one thing, with it as long as it is, I can see the front tire over my sons head, if it were shorter, I couldn't - that would make some situations difficult...and not safe...

[If_Rider]

Pretty cool. When does production start?? ;D

If you can, post some ride pics.

[EVIL BOTA]

C.P. its a good thing you are a skilled rider.Not sure if I'd take my little guy on that there contraption..lol
No wheelies lol.. J/K

[CouchingTiger]

Nice! Looks awesome ;)

Are you planning to add another piece to the head tube/top tube junction? Looks like that could be a high stress area and definately NOT one you want it to fail at.

-Couch

[C.P.]

Nice! Looks awesome ;)

Are you planning to add another piece to the head tube/top tube junction? Looks like that could be a high stress area and definately NOT one you want it to fail at.

-Couch


Thanks Couch, always good to get positive feedback from the NEMBA resident fabricator extraordinaire...

Done - did it last night...and had a MUCH easier time now that I finally got a drill press vice so I could cut the miter with a hole saw - the headtube junction is now real beefy.(and to think all I had to get was a drill press vice)...In hindsight, I'm glad I learned how to hand file Miters, but I will never hand file one again ;)

It must be nice to have a shop or space to work in. I'm just a frustrated artist, mind full of ideas and no resources to carry them out.

May i suggest a chain gaurd. Little fingers cut off easy and bike chains draw them like moths to a flame.

Yes, i have a scar to prove it.


bill

[C.P.]

It must be nice to have a shop or space to work in. I'm just a frustrated artist, mind full of ideas and no resources to carry them out.

May i suggest a chain gaurd. Little fingers cut off easy and bike chains draw them like moths to a flame.

Yes, i have a scar to prove it.


bill


Thanks Bill! I hadn't really thought that one out - but a chainguard will be added soon - what a great suggestion!

With that said, anyone have a chainguard for a little kids bike? I may have to make one myself - as the freewheel up front is smaller diameter then most chainguards I've ever seen.
Maybe I'll have to get one of those cheap "runt" mini bikes on ebay and steal the chainguard off it...
http://search.ebay.com/search/search.dll?query=runt+mini+bike&catref=C3&socolumn layout=3&lotr=3&from=R2&sacategory=7294&BasicSearc h=

[SloMoJo]

What in tarnation is that thing!? :o

I believe I saw one of those on the streets of Whoville. (Grinch)
In fact, I think CindyLuWho got one for Christmas. ;D

[turch]

Patience, slo. It will all come together and look just fine once he installs the electroseussioflute.

[radair]

Cool rig! I love the chain tensioner. Make sure the little guy keeps his fingers out of that!

[Baconman]

That's a great ride. I have a bike trailer (single wheel, bars, pedals, seat) that I took my 4 year old on some moderately technical singletrack. She couldn't keep her feet on the pedals because of the rocks but managed to stay on. Anyway she loves to ride and even pedals as hard as she can.

[pk]

Welcome, Baconman!

I presume you're not related to Hogboy? Haven't heard from him in a while.

pk

[C.P.]

That's a great ride. I have a bike trailer (single wheel, bars, pedals, seat) that I took my 4 year old on some moderately technical singletrack. She couldn't keep her feet on the pedals because of the rocks but managed to stay on. Anyway she loves to ride and even pedals as hard as she can.


Thanks, I've heard ( no firsthand experience ) that a good suggestion for the little ones (trailer bike or tandem with child stoker kit) is to put toe clips on their pedals, with the straps somewhat loose. It allows them to get in and out when needed, but aid in keeping their little feet on the pedals as they learn to pedal smooth circles...I will be putting a set of small ones on this one, I'll let you know how they work out...

More work tonight...headtube junction finished, and added one more vertical support under the captain steerer ass'y.

[Baconman]

I called my Mom. She swears I'm not related to any HogBoy.

[splat]

I have found toe clipping them in tight is better. once there feet are out of the clips , they can't get them back in.
also by having them cliped in tight , is a little more insurance that they will not fall off the bike.

[C.P.]

My son Aidan is very proud of this...as I am too...
It's Almost done:

Left to do:

-Toe clips on my sons pedals
-Chainguard to protect little digits and pant legs
-Install backrest with built in harness

We did a little ride around the driveway last night, and the little modified 90mm crank arms work perfectly.

Cant wait for the harness to come for a real ride, my son cant either...

[AA]

Wow that came out great, the paint job gives it a nice finished look (as compared to the in process pictures). You should patent that bad boy.

[C.P.]

My wife said the same thing - so I sent the provisional application for a "patent pending" last weekend.

looks great!

Go Sox!

[SloMoJo]

I'm quite impressed.

That little boy has a pretty cool dad. ;)

[C.P.]

Here's a recent ride pic with one of my favorite riding parteners. Lately, I'm getting more ride time on this than my other bikes.
We regularly do 10 mile rides (on / off road - NB for a two yr old)) and hit the fire roads in Borderland! - Lotsa fun! It's even hard to get him off, usually he's whining as we pull into the driveway - b/c he knows the ride is usually over..