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btw....... how many inches from the bottom of the pipes to the ground with the bike stood up straight?

on a rigid with minimal front suspension travel

I find that less than 4.5" results in the bottom of the bike not getting along much with the real world and I am quite sure several of these guys that beat the snot out of there bikes can tell you how much clearance they have without bashing the bottom

high centering a bike can really be a rough proposition
 

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My old meg was almost exactly in the same place, but slightly smaller diameter. It dragged pretty bad at two points on the track with the shocks at full preload. One turn is an uphill transition right-hander (T3 at NHMS)and the other is a downhill bumpy transition right-hander. Street lean angles probably won't cause it, but just be aware. Maybe make a little feeler gauge for it the first few times out? My new setup uses a mid-pipe after the collector to move the meg back and up so that the outlet is just behind the rear axle. It would be an easy fix if you find that you have issues.
 

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My old meg was almost exactly in the same place, but slightly smaller diameter. It dragged pretty bad at two points on the track with the shocks at full preload. One turn is an uphill transition right-hander (T3 at NHMS)and the other is a downhill bumpy transition right-hander. Street lean angles probably won't cause it, but just be aware. Maybe make a little feeler gauge for it the first few times out? My new setup uses a mid-pipe after the collector to move the meg back and up so that the outlet is just behind the rear axle. It would be an easy fix if you find that you have issues.
 

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how much ground clearance do you have at the lowest point under your bike, how much suspension travel, and what is the max lean angle with suspension fully compressed?

there have been times I've been about convinced a street bike needs even more clearance, under and to the sides, than a race bike that is only ridden on relatively smooth pavement pretty much devoid of road hazards, huge pot holes, speed bumps and such as that
 

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how much ground clearance do you have at the lowest point under your bike, how much suspension travel, and what is the max lean angle with suspension fully compressed?

there have been times I've been about convinced a street bike needs even more clearance, under and to the sides, than a race bike that is only ridden on relatively smooth pavement pretty much devoid of road hazards, huge pot holes, speed bumps and such as that
 

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thats why you dont need to tie the header into the head completely tight either. rigid mounting the entire thing is a bad idea. i isolate my pipes now. no more cracking brackets. the race pipes are completely loose fitting with isolators at the rear. not doing it will almost always break something. so i gotta disagree. and no i didnt make that up. take a walk around any paddock and move the pipes with your hand. the constant frequency of those bikes will cause shit to just come apart. if i could list the pile of shit ive replace on a 350 from racing it. and thats only 8 laps a race, on a 2 mile track. maybe 30-40 laps a weekend. 6 weekends a year max. fenders have cracked. battery boxes. tach mounting plates. exhausts. frames. so, i cant see isolating the exhaust on a street bike is such a bad idea. just try it. also, if you isolate it, you can probably keep the little bracket and not use some huge thing.


if you toss that thing into a corner, the compressed suspension will cause it to hit. youll hit it for sure. fuck, we drag pegs mounted in the same spot on the racebikes. and thats with the rear raised an inch. that pipe looks to be about 6" below that. i'll post a pic of the 2-1 that bj just got rid of. he drug a hole in it big enough to have the baffle fall out. it looks to be about the same size, and its mounted higher up. i still dig it though. be a shame to toss it in one day and thrash the side of that nice looking pipe.
 

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thats why you dont need to tie the header into the head completely tight either. rigid mounting the entire thing is a bad idea. i isolate my pipes now. no more cracking brackets. the race pipes are completely loose fitting with isolators at the rear. not doing it will almost always break something. so i gotta disagree. and no i didnt make that up. take a walk around any paddock and move the pipes with your hand. the constant frequency of those bikes will cause shit to just come apart. if i could list the pile of shit ive replace on a 350 from racing it. and thats only 8 laps a race, on a 2 mile track. maybe 30-40 laps a weekend. 6 weekends a year max. fenders have cracked. battery boxes. tach mounting plates. exhausts. frames. so, i cant see isolating the exhaust on a street bike is such a bad idea. just try it. also, if you isolate it, you can probably keep the little bracket and not use some huge thing.


if you toss that thing into a corner, the compressed suspension will cause it to hit. youll hit it for sure. fuck, we drag pegs mounted in the same spot on the racebikes. and thats with the rear raised an inch. that pipe looks to be about 6" below that. i'll post a pic of the 2-1 that bj just got rid of. he drug a hole in it big enough to have the baffle fall out. it looks to be about the same size, and its mounted higher up. i still dig it though. be a shame to toss it in one day and thrash the side of that nice looking pipe.
 

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I know you're a perfectionist but why the worry about slag inside the megaphone from the last weld that you forgot to backpurge? Do you think it'll have that big of an effect on your lap times? I can see if that pipe fed a turbocharger or something but anything inside the pipe that breaks off will just get blown out the rear. Sure does look purdy.
 

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I know you're a perfectionist but why the worry about slag inside the megaphone from the last weld that you forgot to backpurge? Do you think it'll have that big of an effect on your lap times? I can see if that pipe fed a turbocharger or something but anything inside the pipe that breaks off will just get blown out the rear. Sure does look purdy.
 

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actually, with the slip fit, you should be able to mount the meg on an isolator. the slip fit will allow it to move enough. the slag isn't to be worried about from a performance standpoint really.
 

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actually, with the slip fit, you should be able to mount the meg on an isolator. the slip fit will allow it to move enough. the slag isn't to be worried about from a performance standpoint really.
 

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Discussion Starter #32
I worry about the sugaring because I feel like I did a great job on the system, and I really should have done that right as well.

I hesitate to even disclose this, but i honestly rarely ride my bike. I prefer to build them. Once i have them finished, I get bored and want to build another. I'm supposed to be restoring an MG Midget for my wife, not screwing with bikes. I certainly never take the bikes to the track, though it would be fun.

In my experience, the exhaust do need a bit of flex in them. I've cracked 3 exhaust systems by over tightening them. So this system has a bit of flex in it to allow for the heat expansion and vibration.

Hack:

I feel you brother, but i want to put this project to rest for the summer. Maybe I'll get well inspired in the witer and either modify this system or completely redo it. I think I'll do 18ga 321 next time.

No worries on being overly critical. Ya gotta have thick skin around here.

I'm going to start travelling a bit for work. if I find myself in your area, I'll swing in a kick tires with ya. Or work for a day or two. I bet I'd learn a lot.

--Chris
 

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Discussion Starter #33
I worry about the sugaring because I feel like I did a great job on the system, and I really should have done that right as well.

I hesitate to even disclose this, but i honestly rarely ride my bike. I prefer to build them. Once i have them finished, I get bored and want to build another. I'm supposed to be restoring an MG Midget for my wife, not screwing with bikes. I certainly never take the bikes to the track, though it would be fun.

In my experience, the exhaust do need a bit of flex in them. I've cracked 3 exhaust systems by over tightening them. So this system has a bit of flex in it to allow for the heat expansion and vibration.

Hack:

I feel you brother, but i want to put this project to rest for the summer. Maybe I'll get well inspired in the witer and either modify this system or completely redo it. I think I'll do 18ga 321 next time.

No worries on being overly critical. Ya gotta have thick skin around here.

I'm going to start travelling a bit for work. if I find myself in your area, I'll swing in a kick tires with ya. Or work for a day or two. I bet I'd learn a lot.

--Chris
 

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heres a pic of that exhaust i mentioned. sorry for the crappy pic. thats a hole drug in the bottom of the pipe. not from crashing mind you. enough of a hole that the bolt ground through, the end cap loosened up, and the baffel came out. fortunately we had the end cap wired on so we didnt loose that. you can see its quite a bit higher than yours. this entire exhaust is rigid mounted. but the mounts did crack and break off when i first got it. then i made a new humungo bracket and its been fine since. the collector dosnt allow for any movement. so its all pretty tight.

anyone know what make this pipe is. i think its an older mac. but im not sure. we need a new baffle for it actually.
 

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heres another photo.

also, the headers for this pipe have these quite nice little aluminum flanges that hold the pipe to the head. pre drilled for wire. also, and im dont know if this was done by the builder, or form the factory, but the pipes have the moon crescent thingers welded on to the pipes.
 

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it's quite common for all but the best aftermarket exhaust systems to have thin and frail tabs and even to see them incorrectly joined to the tubing

so it doesn't surprise me that yours broke solidly mounted

MAC has made some good exhausts but some of the are not very robust in my opinion

if you really want to see some laughable attempts at mounting exhausts systems solidly

study any of the vintage brit bikes, the triples are generally ok but most everything else is silly frail and cheaply done

but, that doesn't mean that solidly mounted exhausts cannot be done right

the pipes on my red 45/750 are mounted solidly enough to hoist the bike by them and they only have a slide in slip fit into the ports

they are stainless and 5 years still going strong with no sign anywhere of problems

are not the stock systems on these bikes solidly mounted?

I am pretty sure they are and I'm equally sure I've seen more than I can count that sported original exhausts for 10,000 miles or more

did your failed MAC system have any mounts on it that remotely resembled this kinda stuff? that's just the rear one too



those pipes aren't going anywhere and I'd be shocked if any part of the exhaust system failed

reckon that's just fanatical overkill?

I'll go ahead and own the less than great beads on that stringer.... did that on a day those reversals had my hands nearly inoperative
 

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ive actually had and seen more race pipes fail. rarely on streetbikes. which is what i was initally saying. i attribute that to the fact they are mounted with some play for the most part. since ive left slop in mine, never a problem. my t12or never had a problem, well, unless you count the bolts rattling out. i chased a few sausages around broadway in southboston! but leaving play in the system cant hurt things. and that pipe on the racebike pictured is what i believe to be a street exhaust modified for a racebike. the bracket was very lightweight and skinny.

i included the pics so he could see where this pipe is located, and to show it hits the deck. and to havea relationship pic of where it is on our cb's. the yashima pipe on my 550 is awesome though. that thing is tight. and power baby.

and yeah, with the pieces on that exhaust, you could fucking build a bridge!
 

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Discussion Starter #38
I just took the bike around the neighbor for the first time with the new pipes. This has increadible power. It is insane. Well worth all the hard work. I just cannot believe how much better this works over the old system.

Fucking crazy.

--Chris
 

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Discussion Starter #39
I just took the bike around the neighbor for the first time with the new pipes. This has increadible power. It is insane. Well worth all the hard work. I just cannot believe how much better this works over the old system.

Fucking crazy.

--Chris
 

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cool, how did the aluminum stuff go? forgot to mention adjusting the frequency and intensity if you have those adjustments
 
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