Doing a little surgery:

[speeder]

So to make a long story short, I bought a 1970 Triumph Bonneville last summer. Bought it online, site unseen, paid a lot but not quite top dollar. This is a bike I've owned at least 3 times previously, going back 40+ years. It's beautiful but was billed as ready to ride and while technically correct, everything mechanical is worn out. Low compression, front forks/tires/chain+sprocket, you name it.

I wish that I had done more due diligence but here we are. So, in for a penny, in for a pound, I'm making it right. I will be in it for a lot more than planned but have no intention of selling it, so I'm ok. Chalk it up to an impulsive pandemic purchase while sitting in a cabin with an internet connection.

I've already addressed most of the other issues and now I'm tearing into the engine for a top-flight rebuild. Haven't decided yet whether to install a 750 kit or keep it a 650 but since increased CR isn't really an option w today's gas, I'm leaning towards it.

I'll try to update this thread w the engine work. As I bought it:



And as of yesterday:

[speeder]

Got some new Dunlops fitted and balanced plus new sprocket and chain. I've already had to replace the clutch drum and basket+primary chain. Just had forks rebuilt by a really good shop. As pretty as it is, it needed everything.


Check out the dome on the pistons:

[Scott Douglas]

At least you won't have to spend more money making it pretty. Never would have guessed a bike that nice looking would have been totally worn out.
I grew up next door to a guy who had multiple Triumphs over his life time. I've always wanted one but now I think about how much they vibrate and the urge passes.
I wish I could have kept my V45 Sabre.

[speeder]

You are right that the cosmetic restoration had been done by one of the best around 20 years ago and it hasn’t really been ridden since. It’s as though it was done for a museum, not to be used. I want a rider.

As for vibration, it’s funny but a lot of modern bikes buzz my hands numb in 15 minutes but not an old Triumph, at least not one running right. It’s a twin and not the smoothest but Triumph cranks back in the day were balanced for higher rpm smoothness at the expense of idle smoothness. The slight jiggle of the front wheel at idle is normal and goes away the instant you touch the throttle. My engine will be balanced and blueprinted, hopefully putting out between 15-20% more HP than stock.

[LWJ]

Industrial art. Triumph is a favorite.

[speeder]

[Baz]

Nice project! I love classic motorcycles!

[Chocaholic]

Any idea how many miles are on that engine?

[speeder]

No idea.

[Evans, Marv]

Great project. I love the bikes from that time. At least you'll know what you have when you get finished.

[911boost]

Awesome, great project Denis.

I cannot wait to get one of our more famous Pelicans old Ducati back on the roads once the snow is gone. It is now a 944 versus a 900, so my thoughts are add the cc’s

[1990C4S]

It looks like a pretty straightforward project, no?

Valves and cam can be re-used? Can't you just re-ring it?

[gizmofixer]

Looking good!! I've restored quite a few 70's and still have one as a DD.
If you need any advice or odd questions answered, just give a call.
And yes, do the 750, it's a good mod. Also, invest in the newer upgraded Amals.
--paul

[944 S2]

Interesting the pistons are in phase with each other?

[speeder]

Originally Posted by 944 S2

Interesting the pistons are in phase with each other?

Yes, they go up and down together and fire 180 deg. apart. Strangely enough, my other MC does exactly the same, (BMW R100RS), but they move sideways, hence the name "boxer."

[speeder]

Originally Posted by gizmofixer

Looking good!! I've restored quite a few 70's and still have one as a DD.
If you need any advice or odd questions answered, just give a call.
And yes, do the 750, it's a good mod. Also, invest in the newer upgraded Amals.
--paul

Thanks a lot! I will be reaching out.

[speeder]

Originally Posted by 1990C4S

It looks like a pretty straightforward project, no?

Valves and cam can be re-used? Can't you just re-ring it?

It is very straightforward. As to whether various parts can be re-used, I won't know until I do some measuring and inspecting. As mentioned previously, I may choose to install 750 P/Cs and possibly different cams even if my existing ones are re-useable.

[astrochex]

Sweet machine, sure is purty.

Good luck on the mechanical resto.

[Superman]

Very worthy project.

[Baz]

Like the kickstand used to hold her up with wheels removed.....very handy!