View Full Version : Is this not a sweet bike?

2nd December 2004, 14:55
Is this not a sweet bike????

And I have a question, if 2-1 pipes make more HP why do racers and Track runners have 2-2? Just wondering

Moved On
2nd December 2004, 15:36
Disclaimer... I'm definately not an expert on this topic...

I think that the 2:1 pipes help in a particular region of the torque/HP curves, down around the low end. But it doesn't matter so much either way up at higher RPMs. So if your racing at high RPMs all the time 2:1 doesn't help a whole lot. Thats why the call the straight open pipes "Drag Pipes" cause they are only really good if you are drag racing, not so good when you are puttin around town.


2nd December 2004, 15:41
Looks alot like this bike from Japan: (of course, this is a much newer bike)


2nd December 2004, 16:06
Understand that. I just dont see a FOT throughout the entire race. Unless redlining into power slides around turns. I can see that NVM. Got it. I just think this is a kick ass bike.

2nd December 2004, 17:32
I agree, that XR is a very sweet bike, very clean. Man, what I wouldn't do to have one of those...

2nd December 2004, 17:48
And I have a question, if 2-1 pipes make more HP why do racers and Track runners have 2-2? Just wondering

Ask George Crim that question.

2nd December 2004, 21:10
skippy , those bikes were made in the early mid 70's and at that time not a lot was known about exaust tuning (compared to now) so pipes were pipes

almost bought one in the mid 80's for 1000 bucks (wish I would have) stone stock and it was a 1000cc not a 750 with thunderbolt heads killer performance back then . wish I could find a set now

2nd December 2004, 21:32
Would be nice to own thats for sure

2nd December 2004, 21:37
Have you seen the 05 accessory catalogue? They now list a new crated XR750 engine (around £10,000) according to my dealer.

2nd December 2004, 22:52
Different pipes have differing power characteristics the 2-2 's like on the flat trackers tend to give a wide flat torque curve...good for playin the throttle on a low traction surface...gives a predictable power output.

A 2-1 tends to dip around 2700 and come good 3500 and up

2-2 with cross-over usually will be good around the 2500 mark

Straight drag pipes don't work untill over 4500.

Most (read all I've seen) sporty racers over here use at locally made 2-1 of which I'm runnin on my sporty

Buells are a 2-1 ..................

2nd December 2004, 23:00
Not my style at all, but that is a very clean machine...

2nd December 2004, 23:49
Nope, don't care for it........

3rd December 2004, 00:25
Like the XR!!! Would love to have one!! :D

26th December 2007, 17:53
What bike? The only bike I see is the one in the avitar.

26th December 2007, 18:11
original post was in 2004, the pic he linked is probably gone by now

sorry but thats the internet for ya

26th December 2007, 23:32
holy necro posting batman..

11th January 2008, 16:26
2-1 pipes are more for looks on a bike. In order to work effectively, the header pipes must be very long so they can acomidate long strokes and uneven firing orders. The vast majority of XR750's used 2-2 pipes because their operating range starts at 6500RPM. I tried 2-1 on the dyno and they failed miserably past 6500RPM. As far as technology in the early 70's, motorcycle racers were the most advanced of all forms of motorsports. Most race bikes had a wide array of exhaust designs ranging from reverse cones, boom boxes, stepped pipes, megaphones, silencers, and the list goes on. Street bikes never seen these because quite frankly looks sells on Harleys. 2-1 works OK with low RPM engines.