Tiger Frame mods

Bodywork, Engine Mounting, Frames, Sub Frames, Forks, Suspension etc..

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coachgeo
I luv the smell of Diesel...
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Joined: Sun Feb 22, 2009 6:00 am
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Tiger Frame mods

Post by coachgeo »

Some of you may recall that Im eventually putting a 3cyl turbo diesel into a Steamer (mid 90's Triumph Tiger). Project is moving closer to starting though it could still well be a year away but..... its moving.

This has been done VERY successfully with a steamer a few times. Engine mounted simular to OEM but with ultima harley trany and belt drive. Search Heiko.

The Tiger frame is like a back bone that goes from front fork mounts under the tank and arcs downard to the rear of the engine. Swing arms for rear axle attach here. Above that is bolted a secondary frame that is the seat and rear fender location.

The cradle Frame to hold the engine below the back bone where the engine sits..... well the engine IS the frame. Engine bolts to the frame at its bottom rear edge where the swing arms for rear axle are. Engine then hangs there off of some minor arms that go up to the back bone above it and a few other places. Think of them like ribs that attach to the engine and back bone. These ribs dont encase the engine though. They just hang it out there. Hence this type of arrangement being called a "hanger" engine set up. For this to work good it is intended for this whole rib / engine network to act as a support in the whole frame complex (engine block is a main Stress Member in this complex).

Anyway....... as you know bikes in general rattle and vibrate.... but w/a diesel probably more. Have talked to one of the owners of a diesel tiger (Diesel Dave). His previous experience is with a diesel Royal Enfield so he was not able to judge much on vibration etc. compared to normal Tiger since his experience is on an Enfield which is a rattle box. He did say though On his diesel tiger the mirror immages are fuzzy from vibraton. This is the only imperical data he could give me.

Im wondering if I used engine mounts simular to concept and location as on the frame as OEM but set them up with rubber vibration isolaters if that would negate too much of the intent of steamers engine as a stress member. Could use isolaters where the hanger arms (ribs) connect to the back bone...... or instead put rubber at the engine where the hanger arms (ribs) attach to it... or both? Thought is with belt drive mounted solid and engine on rubber in one of the fasions just decribed; I could elemintate a lot of the vibes thru the bike that way.

So you bikers in here with engineering backgrounds... what do you think? Where best for Rubber isolators, at engine mountings or at end of support members (ribs) where they attach to frame, both or???.. or will doing any of this weaken the frame too much by reducing the engines ability to be a stress member?

I've thought about adding a craddle to be the stress member thus removeing that task from the engine. This way I could total mount engine to isolate its vibes from everything but I would hate to add more weight to a steamer. The diesel itself is already heavier as it is.

As Im sure you have already seen before... here is one of the other diesel tigers Hekio built. No rubber mounting at all anywhere as far as I know.

[youtube]http://www.youtube.com/watch?v=XRC7H8PMaGQ[/youtube]
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coachgeo
I luv the smell of Diesel...
Posts: 2002
Joined: Sun Feb 22, 2009 6:00 am
Location: USA Ohio, Above Cincinnati, Close to Dayton

Re: Tiger Frame mods

Post by coachgeo »

Here is what some folk with more direct Triumph Tiger experience have to say.

http://tigertriple.com/forum/viewtopic.php?t=6751
tappy
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Re: Tiger Frame mods

Post by tappy »

Very tricky to put stiffness and flexibility in the right places and aligned in the right directions to rubber mount an engine and still have meaningful stiffness from it.
Not sure you need to be so worried tho' - it's a triple so it'll be a LOT smoother than the singles and twins a lot of us are using. It'd be easier to direct mount the engine and rubber mount the footrests, bars etc.
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coachgeo
I luv the smell of Diesel...
Posts: 2002
Joined: Sun Feb 22, 2009 6:00 am
Location: USA Ohio, Above Cincinnati, Close to Dayton

Re: Tiger Frame mods

Post by coachgeo »

tappy wrote:...it's a triple so it'll be a LOT smoother than the singles and twins ... It'd be easier to direct mount the engine and rubber mount the footrests, bars etc.
While that crossed my mind, my concerns are not for "my comfort" but conerns with metal fatigue of engine mounts, tranny mounts, etc etrc over time due to vibration. Good point about less vibes with the tripple.
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