chain swingarm clearance

[Crazymanneil]

was looking at my tiger today and noticed the chain rubs on the swingarm. this is on the chain slipper plastic thing at the swingarm pivot with rear suspension extended and chain pulled tight. not sure if this is right or not? when suspension compresses it should clear the swingarm ok so maybe its like that.

hope everyones good out there

n

[Sphere]

So as long as you don't have any bumps in the road you should be OK!

[coachgeo]

That's a question for a Tiger Speific board. Or should I say that's a topic worth searching archives of a Tiger specific board or forum, then asking questions

Has been some discussion on chain rub blocks at TigerTripple

[Crazymanneil]

Cheers for the tip coach, some good pics on there.

I think I'm gonna shim up the gearbox. The bracket I made ended up a little lower than I wanted. I'd thought this would be ok but experimented today it makes all the difference. in doing this it will slightly alter the other brackets too. Ho hum, would rather have it right I guess.

N

[Diesel Dave]

Hi Neil,

There is the little slipper wear block on the steamer that keeps things quiet when the chain is rubbing, they wear out really fast too with the suspension in the factory setup.

I've spun the rear spindle to the upper part of the eccentric adjusters and forks through the trees so the effect is less pronounced, it's dodgy engineering at best to have a chain sliding over bits of plastic.

As an aside it's a fortunate coincidence that extreme downward angles on off road swing arms cause the wheel movement to be rearwards as well as upwards when encountering an obstruction, effectively they move away from the object! So the aim is to have the swing arm still pointing downwards to the axle end even when loaded and on the road to ensure that the movement is correct.

On the opposite end - leading links with pivot higher than the axle = bad idea 'cos the wheel needs to move into the obstruction, however trailing links work really well, ride a traditional Vespa and realise how good they are.

gettin closer eh!

All the best
Dave

[Crazymanneil]

thanks dave.

Yes I noticed the downward swingarm angle. Even with me loading it up (bouncing on rear footpegs!) it still has a downward angle. I remembered you'd spun your axle and can imagine how that would help chain clearance.

From my measurements the gearbox was a little lower than where I designed (hoped) it. I'd thought at the time this would not be a big problem (didn't want to start again on the bracket!) so forged ahead but the effect was the chain in contact with the chain slipper on top of swingarm. With bike sitting under its own weight you could see a dip in the top chain run when looking up the bike (must try to get a pic).

The chain would also have rubbed the frame under the swingarm too without being moved. The little rub block takes up a bit of the chain slack for the long travel suspension and also helps lift it away from the frame at this spot. On my bike and on the spare frame there are chain grooves worn into the frame here so even the standard setup is not perfect. All design is compromise! I had a TDM 850 before that did not have any rub blocks etc and manufacturer reccomended chain slack was 50mm as a result! My DR350 has a little roller bearing mounted rubber wheel that does the same job.

So the bike is in bits again at the moment while I make up a spacer plate to lift the box. Better to get it right at this stage though.

N