Motorcycle Racing Forum

Racing Discussion => Racing Discussion => Topic started by: Nate R on September 01, 2003, 02:39:25 PM

Title: Interesting info
Post by: Nate R on September 01, 2003, 02:39:25 PM
OK, I have an 81 CB750K with 33K miles.

Just for fun, i did the front sag measurements today.

This bike i believe is listed to have about .52 springs stock, and weighs in at about 545 lbs with 1/2 a tank of fuel.

Travel: 153mm
Free sag: 46mm  :o
sag with rider: 69mm  :o

I think the proper sag with a rider should be about 50mm on this bike. Think I need stiffer springs?  ;) :D 8)  

Talk about a TANK. 545 lbs, soft front suspension, hardly any damping on both ends. Its a good streetbike, though.  ;D
Title: Re: Interesting info
Post by: Super Dave on September 01, 2003, 04:50:26 PM
Well, maybe 45mm at the most.  

What was the back like?
Title: Re: Interesting info
Post by: Nate R on September 01, 2003, 09:08:25 PM
Didn't get a chance to measure the back yet. Front is much easier, so I did that. When I do measure the back, I'll let you know. The item begging for my attention most right now is the clutch. Feels like the springs are bad, dunno about the plates yet. This thing is just a long haul of TLC.  8)
Title: Re: Interesting info
Post by: Super Dave on September 02, 2003, 05:08:29 AM
Was the thing sitting for a while?  If so, yeah, the springs might have a memory and the plates might be stuck together...they get dry and stuck together.  

I worked on a 1977 Honda MT125 GP bike in 1989.  It was last ridden in 1978, but never on a track.  Got it running, and when we tried to ride it around, the fiber exploded off the clutch plates;  they were just dried out.
Title: Re: Interesting info
Post by: tshort on September 02, 2003, 09:00:01 AM
QuoteI worked on a 1977 Honda MT125 GP bike in 1989.  It was last ridden in 1978, but never on a track.

You sure it was an MT125 GP bike?  MT's were enduro bikes - at least they were when I had a '74 MT125.  Basically a detuned CR125 Elsinore, with a headlight, taillight and turnsignals.
Title: Re: Interesting info
Post by: Super Dave on September 02, 2003, 04:44:21 PM
Ah, Grasshopper, yes, there was an MT125 Road Racer.  

It was related to the Elsinore's.

Here's the best pic I can come up with....

http://www.airtech-streamlining.com/hondaz/mt125.htm

There was big contingency offered to racers that rode it and a guy named Freddy Spencer did well on them when they were new.
Title: Re: Interesting info
Post by: tshort on September 03, 2003, 06:17:18 PM
Right you are -
http://www.ahrma.org/covers/covers06.htm

(https://www.ccsforum.com/proxy.php?request=http%3A%2F%2Fwww.ahrma.org%2Fcovers%2Fcovers06.htm&hash=0c17b8a8cb28e18d2d5cf99f1b00d1356ba3e622)

Guess you really *are* Super... :)
Title: Re: Interesting info
Post by: Super Dave on September 04, 2003, 08:08:56 PM
Oh, yeah, that's a nice one. 8)
Title: Re: Interesting info
Post by: the_weggie_man on September 04, 2003, 08:10:51 PM
Yep, I remember the MT125. Southeast Sales in Milwaukee had one on their floor for awhile when I worked there in '77-'78.  I thought about buying it but my lard butt was a bit to big for the little two smoker. It is a tiny bike.

My money went for a new '77 KZ650 street bike instead.
Title: Re: Interesting info
Post by: Super Dave on September 04, 2003, 08:17:58 PM
And would that have been the KZ650 superbike that Kurt Bieberstein let me ride a couple of years ago at Blackhawk.