Triumph 500 unit gearbox redneck repair

[Guest]

That's a good thing to catch

[datadavid]

Yes indeed, first it was just the one spoke that let go of the threads when i checked tension. Then i looked closer and the rim is rotated in relation to the hub so all spokes are cut and wrong lengths. Will be nice to have a solid rebuilt rear tire now that i can actually cruise at highway speeds.

[datadavid]

Been riding this for a few hundred miles now and third feels really solid, no amount of thrashing pops it out. Only negative thing is its almost overgeared with a 21 front sprocket, cruising at 100km/h in third, changing up to 4th at 120 otherwise revs are too low! Could use a fairing to reach top speed.. i can feel the engine not making enough hp to push through the air at that gearing
Ordered a 20t sprocket way back but hasnt arrived, would probably suit this bike better since im not trying for 140mph with it anyway!

[datadavid]

Somehow it managed to completely empty the gearbox of oil in a few hundred miles.. makes me wonder if i even filled it after the rebuild!😁 no trace of gearbox oil in the tranny.. no leaks anywhere. A Turner mystery i guess. Topped it up, now just gotta get some miles on it.
100% certain the bush isnt installed the wrong way around.

[datadavid]

Cold ass 300km ride, metal festival this weekend.. https://www.instagram.com/p/BU1hWpOl_p6/

[Guest]

Lookin good. I need to get on mine, buried workin on a shovel. Aimin to make a trip out your way next year.

[datadavid]

You coming to sweden/scandinavia? Cool, not too bad here in the summer. Last night was 200 kms, half in pouring rain. Bike did excellent; im fucked! ��

[Guest]

Nice, I'll have to try to keep the revs down on mine when I get around to putting it back together. I had a catastrophic failure every 100 miles or so. Made a 150 mile round trip once.

Yeah just gettin started on the plans, want to check out Gothenburg. Was aimin for right about this time of year, sounds like the weather might not be so good yet.

[datadavid]

Nice, I'll have to try to keep the revs down on mine when I get around to putting it back together. I had a catastrophic failure every 100 miles or so. Made a 150 mile round trip once.

Yeah just gettin started on the plans, want to check out Gothenburg. Was aimin for right about this time of year, sounds like the weather might not be so good yet.

Thats exactly how mine was when i bought it over ten years ago, i just had to break and strengthen and improve until stuff holds up, i just converted to miles, it did 300 miles last weekend.
Really hard to start today so i guess valves need checked.. 😃
Last time i did even half that distance the crank bush was shot!
Yea weather is really unstable all summer and every few years we get a full blast 30'celsius heat streak for a month or so.
Gothenburg is cool, big bike scene. Will definitely hook you up on all the local bike meets and you get to ride this ratty chop here as well if you come over. Got a thruxton and xs750 as well👍
Two guys in my shop build harleys as well and a third guy on his way back from stockholm right now but very mixed bike wise as you will see.

[datadavid]

So, the 20t front sprocket that was on back order a few months ago was lost in the mail, just got a word from the supplier that he sent a new one. Wont change it until this winter when the tranny comes apart for inspection. Will be cool to see how everything has held up in there.

[datadavid]

So, ive started taking it to higher revs in third before changing to 4th, and i need to change at 120kph for it to rev enough to have the power to pull through the air.. that gearing might be a bit tall for road use.. with a fairing and forks that actually work, not just flexing in the legs acting as suspension, 200kph is achievable.. not going for that in a chopper, but damn it was fast when i revved it. Now gotta get the jetting right, it turned very rich when i sealed the choke slide holes in the throttle a few weeks ago.

[Guest]

Yeah it's a lot of gear to use. With my 17/46 I'm not sure I had torque, definitely not room to run out fourth. hard to keep the rpms comfortable when they really don't start making power until about 4k.

I feel like I need to put a big front end on mine to try to slow me down, but it's real slow now, keep bringing home new projects...

[Dougtheinternetannoyance123]

maybe start looking at what cams and tuning you have. Theres a trick to it but possible to swap cams without splitting cases on a
(F*ck! Ads block half the text)
so, you can swap cams without splitting cases on a 500, NOT on a 650-750.
But 500 twins are all about the torque, talking bout torque (No treble) so if you gotta wrap them out past 4k somethings wrong
Not saying they dont sing out there,, but their sweet spots are generally idle to 4-5k
plus, worth mentioning again,,, Triumph factory engineers figured the stock alloy rods in a 500 twin race bike were only good for
ONE 500 mile race.
Asking sustained high RPMS in a time change item-service life alloy rod 50 years on is pretty amazing when you think
about it,, These Triumphs were pretty good little motors that they still tolerate this stuff, but
not to instill paranoia,,but either redial your setup to a more practical package -OR- Have a BIG pile of cases, rods and cranks

[Guest]

maybe start looking at what cams and tuning you have. Theres a trick to it but possible to swap cams without splitting cases on a
(F*ck! Ads block half the text)
so, you can swap cams without splitting cases on a 500, NOT on a 650-750.
But 500 twins are all about the torque, talking bout torque (No treble) so if you gotta wrap them out past 4k somethings wrong
Not saying they dont sing out there,, but their sweet spots are generally idle to 4-5k
plus, worth mentioning again,,, Triumph factory engineers figured the stock alloy rods in a 500 twin race bike were only good for
ONE 500 mile race.
Asking sustained high RPMS in a time change item-service life alloy rod 50 years on is pretty amazing when you think
about it,, These Triumphs were pretty good little motors that they still tolerate this stuff, but
not to instill paranoia,,but either redial your setup to a more practical package -OR- Have a BIG pile of cases, rods and cranks

I'm gonna whole heartedly disagree. Peak power is advertised at 7200, so running best idle to 4-5k, no way. You're the first I've ever heard suggest such, I spent a lot of time reading up on every word of healys and the other builders over at britbike, and picking the brains of many others.

Running an early distributor model, I have two choices in cams unless I go custom grind. I run the hotter one, while not the best cam overlap and specs are decent enough that I opted out. Headwork is gonna produce power easier than chasing it on custom cams. Maybe the plethora of power robbing shovelhead cams has left a bad taste in my mouth though.....

Never was able to get the amals very happy, I'll throw in the towel and probably put keihins on it when it goes back together(could have saved an easy grand if I would have taken that advice initially) Never got it breathing well either, went 1/2" into the cases, tried rockers, tried this, tried that.

I'll keep breaking shit, if I didn't like it I'd own more hondas.

[Dougtheinternetannoyance123]

I would think Healy would have set you straight, I know John and when I ran my shop was a dealer for Coventry Spares (as well as JRC). Johns forgotten more than most mortals will ever know.

Feel free to do as you please, I am not knocking anyones path or ideas, just offering my advice after 35 years of wrenching, and many years of building. (12 years as a shop) Lots of real knowledge over on Brit bike as well.. But simply metallurgy is a proven science and always keep in mind that Physics,, not just a good idea, its the LAW!

I am a licensed A&P by the FAA as well as certified inspector as well as instructor. Well proven concept of time change items in industry,. transportation and motorsports where calculations are made for service life. a 100% duty cycle has a pretty short time frame but a unstressed component at a 30% duty cycle can live long and prosper. Care to guess where your game plan fits in on a duty cycle with a 50 year old engine?

7200 RPM? Holy crap!,, Yep, a local racer tried that for a while in conjunction with a local cam grinder. Called his bikes "Steel breeze" and engineered a 500 twin race bike to run full tilt like that. That thing went KABLOOIE and oiled the track down pretty good. He got a lot of grief from a lot of the locals for trying to defy the laws of physics as well as common sense. Some joked they should rename it steel shavings. I did give them much respect for effort and a good try.

Heres a few points to consider. Again, do what ever floats your boat, but Ill just point this out. Knowledgeable racers will all point out that for a race bike, the motors to have are post 68-69 500 twins because prior to that they run a bushing on the timing side. The bush is fine for low RPM motors and lightly stressed but there is compelling reasons why Triumph upgraded the platform to a Ball bearing on timing side and Roller on drive side. Also some upgrades to other parts of the motors. The later cams are better too. Lots of details on the motors improvements if you like a list its out there. Plenty of ink in the TIOC newsletter in tech articles as published by the editor is..................you guessed it,, John Healy.

Okay, fly in the ointment #2. Distributor model... holy crap on a twinkie! Talk about a glutton for punishment!
HELLO slop and backlash! Damn hard to get those dialed in, timing flops all over the place and a stroboscope tells the tale.
Ever consider WHY Triumph stopped using a Dizzy on them? That stopped around 63 or so... Theres service bulletins from the factory on this as well if you care to look. None actually say.....HEY! Dont do that! but its pretty clear if you read between the lines.
Now you CAN upgrade your early motor to a later style setup and wont cost too much. Then you have your choices of EI of whatever brand you prefer. Plus you can run a proper coil with things like saturation time and really good secondary windings to really light your fire.

I was not exactly suggesting custom cams. There IS proven combos that work and work well. Heck just a R radius lifter, Late Daytona cams, and a good ignition will get your butt moving down the road just fine. I have a number of friends who have done quite respectable in AHRMA racing, and run very affordably.

While some noted race engine builders really like the later bottom end (Daytona T100R) some prefer the early hemi heads, but hard to find pistons for those.. but a late 60s or even better a 1970-1973 Daytona head will flat out outperform a early head by 30-40% on average.

Talk to Marino or some of the wrenchs at MAP cycle on some of this,..See if they will send you the Triumph stage tuning articles they used to publish. See if Bob Raber will talk to you and set you straight. (or ask for Richard at the front counter) Those guys turn out a lot of bikes down there in San Jose..
(Rabers parts mart, San Jose KALIFORNIA)

Have you looked at Stan Shentons Triumph speed tuning book?

But on the other hand, maybe just keep doing what makes you happy. Any advice you get on a free internet forum tends to be worth about 1/2 of what you paid for it.