what did you do to your motorized bicycle today?

GoldenMotor.com

Skarrd

Member
Oct 13, 2010
501
2
18
34
Chandler, AZ
Re: what did you do to your motor bike today?

did some port work on the intake pipe. (mostly portmatching the flange to the pipe)

got a little more power but it still seems to bog a tiny bit if i floor it right away (especially in the higher gears)

rode it around alot until i realized my rear tire had gone flat, and had to push the bike about 4 miles home x_x
 

killercanuck

New Member
Dec 17, 2009
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Wallaceburg ON
Re: what did you do to your motor bike today?

d'oh, sucks pushing that far :eek:

Sorry I just thought of this, but I heard of a trick years ago for an emergency flat. What you do is get one tire bead off, and stuff it full of grass or leaves or whatever's handy. Stuff it enough so the beads will at least stay on long enough for you to limp home. Even slow pedaling is better than pushing, eh?


Been working on a unique fix for dual broken rear studs(came that way, bought it cheap), pics/thread soon.
 

scud

New Member
Dec 3, 2011
38
0
0
Fountain Valley
Re: what did you do to your motor bike today?

just posted some pics and a video in the motorized cruiser section of the work I've done. check it out!

[/IMG]
 
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5-7HEAVEN

Well-Known Member
Aug 2, 2008
2,661
240
63
Re: what did you do to your motor bike today?

I'm doing major preventive maintenance while on vacation.

New chains haven't arrived yet, so I scrounged up some 8mm pieces and assembled one. This will be my spare for now.

Gearbox is leakproof with no runout or wobbles. Seal is good. It's not as noisy as it was earlier this year. Clutch drum shows normal wear.

The 11t sprocket is showing normal wear; backlash between splines is increasing a smidge. They cost $8, so I'll order two more for spares.

The circlip that secures the 11t sprocket to the gearbox spline wore out and looks like a fishook! This is an engineering design defect; the sprocket diameter is too small. The 8mm chain passes so close to the snapring that it rubs against it at times, wearing one of the circlip's "eyes" to a sharp hook.. This is the SECOND time I'm replacing it in two years. A 14t sprocket would prolly have enough clearance between the snapring and the 8mm chain. However, if I did not install a larger engine chainring sprocket, it would drastically reduce my gear ratios from 46.36:1 to an ineffective 36.43:1. With a 14t, replacing the 72t with an expensive, hard-to-get 92t sprocket would change first gear back to 46.55:1. Their diameters would increase from 7.2" to 9.2", which MIGHT present clearance issues at the chainstay frame.

The expansion pipe's belly positions itself very close to the gearbox sprocket. If the snapring were to fail, the pipe would keep this sprocket and chain from falling off.

It's not worth paying $100 or more, replacing the 11t/72t sprockets to 14t/92t ones to cure this factory miscue. Besides the expansion pipe, a simple gear retainer could be fabbed to keep the sprocket from slipping off the gearshaft. A broken 9/16" circlip is only 40 cents, and is so easy to replace.

The Tanaka 3-piece expansion pipe needs to be better sealed at the slip-fit flanges. This is the reason why this exhaust is considered a loud pipe. With the correctly-sized sections of silicon hose, this engine-specific exhaust system should become more quiet. The pipe's belly is chafing on the 8mm chain 4" below the gearbox sprocket at times, so I'll need to correct that. The air cleaner is also chafing against the chrome resonator, so it'll need clearancing. This engine and pipe were engineered to fit on a gokart and a scooter, not a bicycle. Fitment is needed.

When I ran over an object on the wet road, it also damaged the chainring sprocket's freewheel. That caused even more sprocket wobble than normal. A used Chinese freewheel has been temporarily installed, while an SBP HD freewheel is having its 5-bolt pattern drilled to match the pocket bike sprocket's 4-bolt pattern.

Parts needed are three short pieces of exhaust hose, An 11t sprocket, one circlip and lube for the cables. I should also service my K&N air cleaner.

Preventive maintenance needs to be done on a regular basis, especially for a daily commuter.xct2
 
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scud

New Member
Dec 3, 2011
38
0
0
Fountain Valley
Re: what did you do to your motor bike today?

Looking great Scud! What kind of rims are those?
I got them online from Bicycle Wheel Warehouse

They are the Alienation PBR's in gold.

The warehouse will actually make rims to your specifications using their parts...rim color, spoke color, nipple color...type and color of hub. So if someone is willing to pay, they can get really creative!
 

DuctTapedGoat

Active Member
Dec 20, 2010
1,179
10
38
38
Nampa Idaho
Re: what did you do to your motor bike today?

That's awesome, the color sets it off, but they really do look like they're decent quality. I'ma bookmark that site. :D
 

scud

New Member
Dec 3, 2011
38
0
0
Fountain Valley
Re: what did you do to your motor bike today?

That's awesome, the color sets it off, but they really do look like they're decent quality. I'ma bookmark that site. :D
yeah I'd say they're fairly high quality. if I haven't broken any spokes after a couple hundred miles then I'll consider it a success...because I would break spokes constantly with my stockers
 

5-7HEAVEN

Well-Known Member
Aug 2, 2008
2,661
240
63
Re: what did you do to your motor bike today?

I took the HD 5-bolt freewheel to the local machine shop to have them redrilled to match my 4-bolt chainring sprocket. I brought the 4-bolt freewheel with me as a reference. The machinist said he didn't have the jig to "index" the 4-bolt 'wheel to the 5-bolt. I told him I just brought the 4-bolt as a reference, so he could transfer specs. I figured he could just use his mike or a ruler. The guy was worried about exacting tolerances. I said it was for my daily-driven bicycle. He starts lecturing me about spending too much and I don't have a $5,000 carbon-fiber bike, yada yada. So the machinist refers me to a cheaper machine shop. That shop was closed for the holidays.

I'll go back to the first shop tomorrow. This time I'll make it easy on him and bring the sprocket that the freewheel will bolt onto.

It slipped my mind. I guess it woulda been simpler if I'd brought the sprocket and the new freewheel with me.

I also bought a $4 siphon pump, two 40-cent circlips for my gearbox and some aluminum channel to fab a chainguard from gearbox sprocket to chainring sprocket. The siphon pump is for my oild dispenser project.
 

Dan

Staff
May 25, 2008
12,765
115
48
58
Moosylvania
Re: what did you do to your motor bike today?

5-7, this is why I bought a mill/lathe. I am all but clueless on how to run the thing but got so sick of that response. I in no way mean any thing against machine shops. Is just they really don't make any $ off our one of a kind things. Had one shop that does work for NASA make a bushing. Cost 80 bucks and all it was, was a brass tube with varying diameters at each end. Very cool guys but when the guy handed me the part, it was not what I needed, cost $80 and the poor SOB (son of a biker) stopped work on a $30,000 part to knock my thing out just 'cause it was cool. He thought, past tense, MBs were.

Next, a plasma cutter!

Just ranting. Is just a bummer to get that look when ya came up with a really cool thunk and can't get it made.

I have been talking to some guys about opening a sort of co-op/communal shop. An electrical engineer, artist, welder and some other tradesman. If it works out, gonna call it the "Hack-Shack" Just a shared work space were ya can just ask the guy next to ya; "how would you do this?"
 

KDB

New Member
Jun 19, 2011
47
0
0
Maryland
Re: what did you do to your motor bike today?

The nylon liners, do you put it between the rim and the tube or the tire and tube?
between the tube and the tire.
If you are having trouble w/ spoke heads popping tires from the inside the guy at the bike shop tells me
1) make sure spokes are good and tight. My first, sloppy build tended to pull the wheel to one side tightening spokes on the pedal side and loosening the ones on the left side.
2) a few layers of duct tape between the rim and the inner tube.

As far as the nylon liners go they were $15 for a stupid sheet of nylon 2" x 70 or 80" but they do seem to work. note, they do not protect against punctures on the sides of the tiers.
 

Goat Herder

Gutter Rider
Apr 28, 2008
6,237
20
38
N.M.
Re: what did you do to your motor bike today?

Hack Shack sounds like a neat Idea! That broken stud fix Killer was a man with a plan lol! I have not seen anyone do that approach yet had not even thought of it. Oughta work. .;):D
 

rustycase

Gutter Rider
May 26, 2011
2,746
5
0
Left coast
Re: what did you do to your motor bike today?

Skarrd, got a question on your piston cutting...

Did you roll your engine over to TDC, scribe the piston through the open port, and trim a notch into it?

How are the results for you?
any difference in low/top end power?
Has it affected balance/vibration any?

...
Serious looking mab u got there Scud!
it occurred to me that if you took 1 link out of the chain and re-positioned your tensioner, the chain run would be straighter and actually put less force on the tensioner, giving less possible force that could pull it into the spokes.
...'tis what I did on my own mab...

What happens is instead of the roller mounted up high, and the bracket farther to the rear, is, the roller is bolted low as it can go, and mounted to the chain stay farther forward. IMO, btr.

Of course, a sprung tensioner might be best.

Best
rc
 

Skarrd

Member
Oct 13, 2010
501
2
18
34
Chandler, AZ
Re: what did you do to your motor bike today?

Skarrd, got a question on your piston cutting...

Did you roll your engine over to TDC, scribe the piston through the open port, and trim a notch into it?

How are the results for you?
any difference in low/top end power?
Has it affected balance/vibration any?
pretty much, i couldn't find something to scribe it with this time. so i just eye balled it, then ground away, and kept checking it to see how much more i needed to take off.

it pretty much increased power overall, mostly bottom end and top end, mid was left about the same.

didn't notice any change in vibration at all.

i know i need to check the piston clearence on the top at tdc to see if i need to mill the top of the clyinder body at all for the new head i bought.

bike so far is topping out at 35mph-ish. needs some more tuning and adjusting before it'll get back to the 40mph range.
 

vincent713

New Member
Jun 2, 2010
287
0
0
Dallas
Re: what did you do to your motor bike today?

between the tube and the tire.
If you are having trouble w/ spoke heads popping tires from the inside the guy at the bike shop tells me
1) make sure spokes are good and tight. My first, sloppy build tended to pull the wheel to one side tightening spokes on the pedal side and loosening the ones on the left side.
2) a few layers of duct tape between the rim and the inner tube.

As far as the nylon liners go they were $15 for a stupid sheet of nylon 2" x 70 or 80" but they do seem to work. note, they do not protect against punctures on the sides of the tiers.
Thanks for the tip, I will definitely utilized this to prevent from frequent flats.
 

5-7HEAVEN

Well-Known Member
Aug 2, 2008
2,661
240
63
Re: what did you do to your motor bike today?

5-7, this is why I bought a mill/lathe. I am all but clueless on how to run the thing but got so sick of that response. I in no way mean any thing against machine shops. Is just they really don't make any $ off our one of a kind things. Had one shop that does work for NASA make a bushing. Cost 80 bucks and all it was, was a brass tube with varying diameters at each end. Very cool guys but when the guy handed me the part, it was not what I needed, cost $80 and the poor SOB (son of a biker) stopped work on a $30,000 part to knock my thing out just 'cause it was cool. He thought, past tense, MBs were.

Next, a plasma cutter!

Just ranting. Is just a bummer to get that look when ya came up with a really cool thunk and can't get it made.

I have been talking to some guys about opening a sort of co-op/communal shop. An electrical engineer, artist, welder and some other tradesman. If it works out, gonna call it the "Hack-Shack" Just a shared work space were ya can just ask the guy next to ya; "how would you do this?"
Yeah, today I'll go back to the machine shop with freewheel and sprocket.

If I had the workspace, I'd buy cool tools too.:-||
 

killercanuck

New Member
Dec 17, 2009
1,748
6
0
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Wallaceburg ON
Re: what did you do to your motor bike today?

Yea, cool tools are great to have, but if you'll only use them once in a blue moon... why drop a grand, eh? We need to re-read Norm's casting metals thread. He's built a machine shop out of scrap metal, basically :p

So my modded mount held up pretty good after "riding it like I stole" if for a good 1/2 hour for a good stress test. It screams too, I'd bet if I had a 36t it'd keep up with my 29er easily. I'm running no head gasket, after lapping head/jug from 220 down to 1500, trimmed skirt, cleaned transfer ports, port matched, mmmm... Or as Tim the Toolman would say, "Arrgh arrgh argh argh" :p
 

The_Aleman

Active Member
Jul 31, 2008
2,653
4
38
el People's Republik de Kalifornistan
Re: what did you do to your motor bike today?

I installed my "cargo assembly" the other day on my daily rider. Been testing out the side effects of having it.

It's between 12 and 15lbs. Consists of a Topeak Explorer rack with "tool channel" that has a Wald 962 folding basket hoseclamped to each side. A large 4xAA generic taillight is screwed to the reflector tab. The "tool channel" takes various Topeak-branded things like trunk bags with panniers, baskets, and even a child seat. I have a trunk+pannier set since 2007 that I occasionally use with the rack. The trunk slides into the channel and panniers fit over the baskets, whether folded or not, so serious cargo hauling is possible.

I also installed my 4G cover and a downtube fender about a month ago. So far it's been doing an awesome job. It's simply a short fender that mounts on downtube and protects the bottom bracket area and sprockets from getting sprayed by the front tire. That area can be tough to clean on MaBs, and this fender was $9 shipped from Amazon. I think it kinda looks cool, too. Lots of pieces of my bike are plastic or polycarbonate, and it pulls it off, I think.

I still need to regear/change my crank sprockets and install V-brakes and dual-pull Paul Component levers. Then it's on to upgrading the headlight system and reworking my old LED tailights for my current application.

Does it ever really end with these? :D
 

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