[Geeto67]

Hey Guys,

Saw this on craigslist: pretty rare bike. One of the few times when the factory built a cafe racer and got it right. plus it is a honda so you know it is reliable:

http://newyork.craigslist.org/lgi/mcy/114436137.html

The GB500 was built by honda in the late 1980s early 1990s to emulate the old british singles of the 1960s. Comes with all the right cafe bits from honda including a kickstart, low bars, rearsets and solo seat. they werent popular because they predated the nostalga cafe craze and everybody was into go fast sport bikes at the time. If honda was smart they would bring this bike back in a 1000cc parallel twin version to battle the triumph thruxton, and we could have an old fashoned factory backed rocker rumble. but honda is not smart....

 

[paced_haste]

I think it's a good looking bike. 500 seems small these days, might be a nice city bike. I think I agree with Honda about 'battling Triumph's Thruxton" though. Seems to me they have bigger fish to fry.

Z

 

[FR]

It is a cool bike. I'd still rather have an SRX. I bet that'd be a good match race if you built up the GB500. Or handicap the SRX.

Yamaha rules. (even though I have a bunch of Hondas in the stable right now.)

FR

 

[Geeto67]

the SRX, the only single with two exhaust pipes (it is a 4 valve head). Performance wise the srx is a faster bike but it also has 100cc's ont he honda. Looks wise the gb500 is really meant to be a cafer racer from honda factory. IT was more a riding expirence bike than a racer, the idea is that it would remind you of an old british single while actually starting on a regular basis. see one in person they are stunning.

 

[joe c]

not true, the nx's and xr's had 4 valve heads.

jc

 

[Geeto67]

I didn't say it was the only single with a four valve head, just the only single that I know of that had two exhaust pipes coming out of the head on a single cylinder. Admittedly I have never seen an nx in person.

 

[FR]

Geeto, I think all of the XRs and Xls with the 4 valve heads (RVPS or something like that) have a header for each valve. Mine does. I haven't seen a GB in quite some time, but I assumed they used the same engine from the XL, am I wrong? Can't tell from the pics in the add. Also can't remember what the Ascot had, I think that was also the XL engine...


FR

 

[Geeto67]

I don't think the ascott has one exhaust pipe per exhaust valve.

here is an FAQ about the gb500:

http://www.thumperpage.com/articles/gb-500faq.html

quote:
BHP 33.36 @ 7000 (on dyno)
Torque 26.34 @ 6000 (on dyno)
0-60 5.1
1/4 14.13 @ 89.7
Weight 390.5, wet
front wheel 2.15 x 18
tyre 90/90-18
rear wheel 2.50 x 18
tyre 110/90-18

The GB is a sleeved down XL600 engine displacing 498cc.. This means that it has the same stroke as the XL600 i.e 75mm. Its also running 8.9:1 compression so kickstarts are easy. Here's some stats for you on bores/strokes:

Model bore stroke
XR600 98mm 80mm (long stroke motor)
GB500 92mm 75mm (short stroke engine)
XL600 100mm 75mm (NZ, Australian model)
XR650L (NX650) 100mm 82mm (longer stroke again) (NX650 also called Dominator)
GB400 84mm 72mm (Japan model, imported in NZ, shares very few parts with the GB500, engine wise anyway)

The engine has a gear driven balance shaft that is positioned at the front of the engine. This certainly helps keep it tame all the way to its 7800 red line. The single overhead cam is driven by chain that is on the right hand side of the engine. The Honda RFVC (Radial Four Valve Cam?) valve gear is accessed through the four separate covers.

I road race a 618cc version of this 75mm stoke motor in England. You should be careful if you overbore to 101mm (mine is 102.4mm) using a Wiseco piston. I have destroyed two cylinder barrels by overboring to 101mm. The problem is that the thinner liner weakens the overall integrity of the barrel and a crack develops at the front of the cam chain tunnel. I would recommend using a barrel from an XL600 - 83-87 (75mm stroke), I've had no failures with a 102.4mm Wiseco since I started using this barrel . I would also recommend talking to Omega pistons in England 0044? 0121-559-6778. Omega make a very light 100mm & 102mm piston for the XR motors - around 100gm lighter than the Wiseco. Its a proper forged slipper piston with a 22mm pin so you'll need to sleeve the small end. Its worth trying to get if you're into tuning it, as another major problem I've had is a snapped crankpin at 8500 RPM in top gear !!! using a Wiseco. In standard trim its as bullet proof as they come. I get 62BHP @ 8300 RPM at the back wheel on a Dynojet with a bit more to come. Its cost a bit to get. If anyone wants a wicked XBR/GB/XR talk to me. Mine drives out of corners harder than a CBR600.

Edit, I didn't realize it before but the GB500 also has the twin exahust for the single cylinder. you can see a teally good pic of the systemr here:

http://www.champsclock.com/gb500hu.htm

I apologize, I was wrong about the exhaust pipe thing, but then again I don't spend much time around singles.

Edited by - Geeto67 on Dec 04 2005 10:04:09 AM

 

[Geeto67]

what a good looking bike, honda had an optional fariring for them, std on the gb400 in NZ and Japan. Looks really killer.

 

[jbranson]

I freakin love the GB's....I never talk about them...I keep hoping interest in them goes away so the prices will come down and I can add one to the collection.
JohnnyB

 

[Geeto67]

quote:
I freakin love the GB's....I never talk about them...I keep hoping interest in them goes away so the prices will come down and I can add one to the collection.
JohnnyB

I saw there was a guy in san fran selling one for $1650, the cheapest I have ever seen a gb500 go for. if you look they are out there. $3200 is a pretty good price for the NY one.

 

[FR]

Yeah, that's a purdy bike. I guess I could make space for it, next to the SRX, if I had an SRX. And by the way Geet, no need to apologize for being wrong, you'll set a precedent for manners that I for one, can't always live up to.

Alrighty then, moving on....

FR