Same motor, different bike

jasonh

New Member
Jun 23, 2008
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Well, I decided to swap all my stuff over to my 99 Nishiki Bravo mountain bike. it's got an all-steel frame, better brakes, and is just more sturdy than my old Schwinn Moab. It is a little bit bigger though. Same length, but a couple inches higher. I kind of prefer the shortness of the Moab, but I think this will be just fine. Rode to work this morning, and it's nice and stable and all that jazz.



Here's the overall bike. You can see that I extended the muffler all the way back. I was going to extend the muffler on the other bike anyway, plus the stocker wouldn't fit this bike.

Unfortunately I really lack the tools to get that job done properly. I used some 3/4" conduit I found in my backyard. I didn't have a bender, so I had to use my foot and muscle strength, and then for the smaller bends a hammer and the sidewalk. So unfortunately that means it's all beat to heck.

Connecting it to the stock pieces was a nightmare. originally I was going to use some silicone hose pieces to connect them. Well, none of the parts places had any, so I just grabbed a freebie piece of normal heater hose and hoped for the best. Then I realized I didn't have enough hose clamps. So I started slotting the conduit and trying to cram the stock pieces inside it. Worked on the muffler side, but not the motor side. After breaking a few hose clamps and going and getting more, I have the heater hose connecting off the motor, and the muffler is clamped in fairly well just by slotting the conduit and cramming the muffler in there and clamping it down. I was looking for heavy duty clamps, but couldn't find any big enough.

The heater hose works ok. It only starts smoking and stinking when I stop for a bit :) I'm going to run to Napa today and see if they have some silicone hose. Checker/Advance/Autozone all had no idea what I was talking about haha. The guy at checker was trying to tell me that their heater hose was made by Goodyear and could withstand higher temps than silicone. Riiiiight. Luckily he gave me a scrap 1' piece for free.

Oh, more funny exhaust things...so the first time I rode it I had a crappy mount made, and the hose clamp was only connected to the motor side of the exhaust. it seemed like it was snug enough to stay together. Well, about 1/4 mi from home the whole exhaust fell off, lol. So I had to remove a sock from my foot, and pedal home holding the exhaust. Talk about failure haha.

Also, I had a heck of a time cutting the conduit. Was using my jigsaw with a metal blade, but the blade is really dull. The dremel with a cutoff wheel made quick work of it, but then my last cutoff wheel broke. The dull hacksaw just wasn't cutting it. What a pain :rolleyes:

So here is a photo of my mount to keep the muffler steady. My CDI wouldn't fit on my bottom tube with the stock clamping system, so I had to use zipties instead. So I took the metal clamp thing from my good and bad CDI's and made this little mount, and hold it to the muffler with a hose clamp. Seems to work well.



You can see the "convincing" I had to do on the exhaust pipe.

Overall it probably took me a good 6-7 hours or so to get everything put together. I didn't have to put the sprocket on the wheel, since I just used the wheels off of the old bike. I was going to use the original wheels on this bike because it has a solid axle, not a quick release, but When I pulled the wheel off I saw that the axle was bent. Not only that but the bearings looked terrible. I'll have to rebuild those wheels one of these days.

Made new gaskets from the gasket material stuff (the cardboard-ish stuff)...blew the exhaust gasket on my way to work today. The bike is pretty obnoxiously loud with a blown gasket, lol.

Ok, sorry for the book, I think I'll stop now.
 

Bikeguy Joe

Godfather of Motorized Bicycles
Jan 8, 2008
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You can find the silicone tubing you need at any model airplane oriented (R/C) hobby shop.

How does it run with that pipe? Any difference in where/how the power is? I know these china fire bicycle motors have waaaay to short a pipe stock.
 

jasonh

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Jun 23, 2008
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I don't think it really made any difference in power, honestly. If anything I have a little less power on my top end. It does get the exhaust out from under me though, so that is definitely a plus.

It's a little raspy/crackly now. I have some fiberglass cloth laying around, I was thinking I might loosely wrap it around that center part inside the muffler a couple times to smooth it out a bit - think that would work?

So yesterday was interesting. I was on my way home from work and was just pulling away from a red light, when the chain slipped off the back sprocket and bunched up at the motor. Turns out that this frame is just different enough that the quick release rear axle didn't work quite right...came loose and got all wobbly, making the chain fall off. After tightening and locking the release, it still didn't make good contact with the frame for some reason. Once I got it home (thanks to my lovely wife) I took a washer, bored out the hole a bit, slipped it over the axle, then the quick release. Seems to hold just fine now.

I really need to get that other back wheel rebuilt so I can have a solid rear axle. Who needs a quick release rear anyway?

So I also made a new gasket for the exhaust. This time I smeared it on both sides with some orange RTV. Says it's good to 650 or 690 degrees, can't remember. We'll see how it holds up.

I thought the gasket blew again this morning on my way to work, but it turns out that I blew a hole in the radiator hose. Figures. I have a spare piece with me, so I can replace it before I go home.

RC Hobby shop, huh? Never would have thought about that. So they should have 3/4" hose? Might have to check them out.
 

jasonh

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Jun 23, 2008
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Yeah, I thought about getting it online, but I only need 3" of the stuff. Just doesn't seem worth it.

I'll have to get some one of these days, since the heater hose only lasted 2 days before it let go.

here is a pic of the front motor mount, and you can also see my crappy pipe-bending job and the big hole in the heater hose under the top clamp. And you can kinda tell where the exhaust gasket blew yesterday :)

 

jasonh

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Jun 23, 2008
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I hate hose clamps. With a passion. One of them just broke while fixing the tube. Talk about lame-o. I've gone through probably 5 or 6 clamps in the last couple days because they keep breaking. I'm not evening tightening them THAT much. And I can't find any heavy duty hose clamps anywhere local either.
 

Dave31

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Staff member
Mar 1, 2008
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My memory tells me that I bought some flex exhaust tubing for something one time and I got it at Pep boys or Autozone. It was 1 1/2 or 2inch diameter.

When I got some time I'll see if I can find it.
 

jasonh

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Jun 23, 2008
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Yeah I've seen that stuff before..except it's 1 1/2" and the stock exhaust is 3/4"...dunno how that would work out.

I think I will check out Murdocks or NAPA tonight and see if I can find SOMETHING suitable. This exhaust thing is driving me batty, lol. I found compression fittings for conduit and home depot, but I'm not sure if it would hold onto the exhaust since it's a bit smaller than the conduit.

I just need some mini muffler clamps, lol.
 

Dave31

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Mar 1, 2008
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It seems like I have used something around 3/4 to use for the tube on a EGR valve. But I think I got that at Merels Automotive...A big automotive suppler.

I now they make exhaust tubing that small but cant think where you could get it in your home town. :(
 

jasonh

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Jun 23, 2008
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hmm, yeah idunno. I haven't tried Murdoch's yet (you'd be amazed at the stuff you can find there) or NAPA.

For now I just kind of ghetto-rigged it. I slipped the hose on and then connected the 2 pipes so one was inside the other (like initially I wanted) and then used a 2" muffler clamp I had, flipped the one piece around (so it would make a smaller opening) and tightened it down. it's big and ugly, and I scrape my leg on it occasionally, but it gets the job done - I hope. No leaks this morning, hopefully it stays that way. Tried to get a pic but the camera corrupted the pic. I'll try again later.

You wouldn't believe how embarassing it was yesterday to ride home with a huge hole in the pipe. That thing was SO loud. And most of my commute is residential :( I got a few dirty looks and I felt bad.

I've noticed something. I've found myself wanting to leave work early every day because I want to get back on the bike and ride, lol :)
 

deacon

minor bike philosopher
Jan 15, 2008
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muffler shops I think have what you need. My mother in law's car needed a piece of pipe for the cat converter but they used rubber heat resistant hose instead. Give someone around town a call and see if they dont have something.
 

jasonh

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Jun 23, 2008
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I still haven't been looking too hard for the stuff I need. I need to though, because the exhaust started leaking again this morning. Starting to get really annoying. If I had a flipping welder I'd be done with this by now.

I'm wondering how that epoxy tailpipe repair stuff would work. I've seen it both in a tube as a paste, and in a "tape" form where you wrap it around the pipe and run the motor to heat it up. I'm curious how well it would bond the pipes together. I thought I remembered someone here saying they used the paste stuff, but I have no idea where that thread is, or who it was, or what the bike looked like.

All I know is somehow I've broken like 6 hose clamps even though I don't tighten them THAT hard, and this heater hose ain't gonna cut it, and I'm tired of banging my leg on my ghetto muffler clamp that seems like it's not holding as well any more. Oi. I guess this is what happens when I fiddle with things.
 

datz510

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May 9, 2008
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www.nissan4wheelers.com
Ride the bike down to the local muffler shop and see if they'll weld the pipes for you. That'll be the best solution in the long run.

Or, if you have a friend with a welder, it'd be a 2 minute job to weld the pipes together.

I was gonna say if you were in the Phoenix, AZ area, I'd happily weld it up for you, but you are in Colorado.
 

jasonh

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Jun 23, 2008
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It'd be nice to have them welded, but I might want to hold off til I can get a new pipe bent that isn't crimped and dented from using a hammer to bend :) Though really it wouldn't be hard to cut off and reweld later on. I wonder how much they would charge. Might have to find out this week or weekend.

Nope, haven't been in Phoenix since end of Feb. Lived there for 24 years, but no longer :)
 

Bikeguy Joe

Godfather of Motorized Bicycles
Jan 8, 2008
11,843
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up north now
Couple of tips-

Silicone tubing is available at most hobby shops in lengths of 12" or less.

GOOD hose clamps won't break, and yes, there is a huge difference in quality in hose clamps. Most auto parts stores sell good clamps. Aircraft grade are the best and are indestructable.
 

jasonh

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Jun 23, 2008
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I was going to get some T-bolt clamps from Napa, but I would've had to order a box of 10 for $56. Yikes.

Last night I got 2 things at the auto store. One was that exhaust repair putty stuff, and the other was the metal strapping with the holes in it and a couple bolts.

So I made some clamps out of the strapping, and funny enough I still couldn't tighten it enough to really clamp the pipes together - that conduit is way tougher than I thought it was. So I got them together best I could, and used plenty of the exhaust goop. let it harden over night.

So far, it seems like it's going to work out.

As my wife and I were watching American Chopper last night, she suggested that we need to save up and get a welder and torch, cause we both want to be able to do some metal work. I whole-heartedly agreed (I've been saying I need a welder for quite some time). Maybe around Christmastime I'll be able to fab up a new exhaust for the bike (maybe even fab up a whole bike).

So, crossing my fingers that this stuff will work out ok.

Also, as I was messing with the exhaust, I found I had quite the buildup of black oily goop. Checked the plug and it wasn't black, but it was a darker brown. So I figured I'd adjust the E clip a bit. (I've been getting crappy mileage anyway) Unfortunately after my ride this morning, it seems like I have a lot less power. Probably will adjust it back tonight.
 
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