HL500

[Oppet]

I wonder what kind of steering angle will you get with youre 17.5" shocks?  on real or gmc replica HL
I got app 29 degrees with husky 78 frame, rm 400 swingarm, yz forks and "350mm shocks"

[Marc.com]

I wonder what kind of steering angle will you get with youre 17.5" shocks?  on real or gmc replica HL
I got app 29 degrees with husky 78 frame, rm 400 swingarm, yz forks and "350mm shocks"

should be 28 degrees but we can ask GMC .... nothing like a direct link to the manufacturer

[Oppet]

If I would put shocks of 350mm and stroke of 110mm I would get 9.5" travel, I think that is the amount of real HL`s?
If so when did frame makers changed head angle for more travel/longer shocks?

[Marc.com]

If I would put shocks of 350mm and stroke of 110mm I would get 9.5" travel, I think that is the amount of real HL`s?
If so when did frame makers changed head angle for more travel/longer shocks?

From my understanding TT500 had 29 degrees and they sucked it back to 28 degrees on the HL. Geoff is ther expert on this subject.

The reason to reduce rake has nothing to do with shock length or travel but stability or in the TTs case getting it to turn faster.

[Oppet]

what similar has TT and HL? nothing except engine?

If you lift up youre rear you have to do something for the front end also

[Marc.com]

If you lift up youre rear you have to do something for the front end also

Yes you would have to have similar length of travel at the front, frame rake has not much to do with it.

[Oppet]

I have 38mm and 43mm kyb and they are both same lenght, different travel.
Still I think if you put longer shocks in rear you lift it so youre head angle changes as you have same lenght in front, thats why there have to be compensate for the angle. As I dont see too much difference in frame and how the shocks are connected to it

[Marc.com]

I have 38mm and 43mm kyb and they are both same lenght, different travel.
Still I think if you put longer shocks in rear you lift it so youre head angle changes as you have same lenght in front, thats why there have to be compensate for the angle. As I dont see too much difference in frame and how the shocks are connected to it

The PE swingarm has the shock mounting points closer to the frame than the HL so you may have an issue there. Regarding steering head angle it doesn't really change as such if you jack up the back, you are just changing the weight bias on to the steering head which exagerates the effect of the forks compressing and the consequent shortening of the wheel base.

So I would fit the 38mm Kayabas as if they are from F/G YZ or similar then they will be about the correct length. Then level the bike out and take a look at what fits, I think my bike ended up with 17" shocks which is about 431 mm, you have 350 mm or 13.7" shocks which sounds very short. Soo have a look at the position of lower shock mounts.

[brent j]

If I would put shocks of 350mm and stroke of 110mm I would get 9.5" travel, I think that is the amount of real HL`s?
If so when did frame makers changed head angle for more travel/longer shocks?

From my understanding TT500 had 29 degrees and they sucked it back to 28 degrees on the HL. Geoff is ther expert on this subject.

The reason to reduce rake has nothing to do with shock length or travel but stability or in the TTs case getting it to turn faster.

From the info I've found over time the HL had a steering head angle of 30 degrees with 130mm of trail. From memory a set of Yamaha YZ/IT forks and clamps have the 60mm of total offset to match these figures. I'm sure the rake and trail are the same as the Husky of the time which is what the HL frame was based on.
 
Apart from altering the head angle, if you go too long on the shocks you end up with a steep swingarm angle and a bike that slaps you in the backside every time you accelerate on a bumpy track as the swingarm tries to climb under the bike and stiffens the rear suspension.

[Oppet]

The PE swingarm has the shock mounting points closer to the frame than the HL so you may have an issue there. Regarding steering head angle it doesn't really change as such if you jack up the back, you are just changing the weight bias on to the steering head which exagerates the effect of the forks compressing and the consequent shortening of the wheel base.

So I would fit the 38mm Kayabas as if they are from F/G YZ or similar then they will be about the correct length. Then level the bike out and take a look at what fits, I think my bike ended up with 17" shocks which is about 431 mm, you have 350 mm or 13.7" shocks which sounds very short. Soo have a look at the position of lower shock mounts.


[/quote]

Youre bike is much nicer than mine. But I think youres are closer to frame and more down.
Anyway as I have measured at my laboratory and I believe in numbers. I have measured 50mm difference in shock lenght affects in head angle almost 4 degrees, it surly is more than just weight

[Marc.com]

assuming you have almost equal suspension travel or suspension movement under load then head angle will be correct, try the 38mm forks and then work out your shock length with the bike height at the correct rake angle. If you use the 43mm YZ forks you may have to jack the back up higher than you would like. Depends on how tall you are and how you want it to look, also of course 43mm are not really class legal.

Then ideally you should have the shocks and forks so they have the same spring compression rate. Choose your forks then shocks last as they are easier to adjust for length and spring rate. My bike had a trip back to the Ohlins guy once it was assembled and we adjusted the length by 10mm and spring rate as part of the deal of buying new shocks off him.

I have shorter travel HL rep coming up using same frame as you, 38mm IT forks and White Bros swingarm, it will have that early laid down suspension thing going on.

[VMX247]

yep Its all in the angle of the dangle 
http://cgi.ebay.com/ebaymotors/VINTAGE-HL500-HL-500-/160630374666?pt=US_motorcycles&hash=item256651010a

[HL500]

I've used IT490 forks on my HL.  I didn't release they were different in length than the 38mm forks.  I owned a YZG and  YZH which had the 38mm and 43mm forks and the bikes sat the same.  Yamaha altered the steering head angle by half a degree on the YZH but that was it.
Using the 43mm forks on the HL, I opted for 420mm ohlins on the rear but the back was too high and didn't look right.
After setting the bike up I eventually reduced the shock travel to 400mm and now the bike seems to sit correctly and balanced with the front.

[Marc.com]

yep Its all in the angle of the dangle 
http://cgi.ebay.com/ebaymotors/VINTAGE-HL500-HL-500-/160630374666?pt=US_motorcycles&hash=item256651010a

keehrist were they building a chopper, good example of how not to do it, you can see from the lower frame rails the frame is not level. plus it is the earlier swingarm with shock position at the end of the swingarm .... so totally wierd looking cock up in combination with 43mm forks with longer travel shocks.

Shame with 38mm forks from YZ400F or similar could have been done as really nice example of early spec bike much loved by the 'which is the real HL?' crowd.

[Lennu Jr]

HL500 was Yamaha Europe's own project. The bikes ordered from NVT, UK. The order was 200 bikes in '78 with the option of another 200 for the next year. The option was used. 1978 the bikes were built in ex-Norton factory in Andover. 1979 the production had to be  transferred to ex-BSA factory in Shenstone, both locations in Hampshire, England. The total production was 200 + 164 = 364 bikes. 80 bikes remained in UK. The rest were shipped: 90 to Germany, 80 to Holland, 50 to Belgium, 40 to France, 20 to Sweden, 2 to Denmark and 2 to Switzerland. The bike was "Europe only". There were no earlier models than 1978, because the negotions between Yamaha Europe N.V. and NVT were officially started after 1977 World Championships season. The famous HL500 sales brochure (seen in this topic) is a bit funny one. The bike in the brochure is from 1979 model and the technical spesification as well. The visible identification is easy: in 1978 model, the exhaust pipe is on the left and 1979 on the right hand side of the bike. This can be easily checked from 1978 Spare Part catalogue.

HL500 was called (commercial reasons?) Aberg Replica. The Åberg's bike in 1977 was never called HL but the official name "Hallman & Eneqvist Yamaha 500 design Sten Lundin" was used. This bike was ProFab-framed with TT500 engine tuned by Nils Hedlund. This bike had 2 sisters used mainly in Sweden. The owners were Lundin's son Kenneth and Björn Casselberg. One of the three is still in Lundin's carage. One of the HL frames (all made by NVT) is now in Finland.

Sorry my Englis. B.R. Lennu Jr., Finland