leswaller wrote:Roy,
If the gearbox final drive sprocket is in the same horizontal plane as the swinging arm pivot and they are very close to each other and the axle is fastened to the swinging arm then as the arm pivots it will perform an arc round the swinging arm pivot point and the nearby drive sprocket, and as the swinging arm is a fixed length the maximum difference in chain tension will be equivalent to half the distance between the pivot and the final drive sprocket centre
Janet wrote:Look up "motorcycle drive chain tensioner" or similar wording and you'll see various ones for sale although probably not for our style of bikes.
Just had a look Janet. The very first option showed pictures exactly like the push bike tensioners that also assist gear change. I was referring to, with a guess of what would make a tensioner. So many little bits to wear and fail, to add to the tool box with a spare split link. Any idea's how insurance and breakdown cover would react due to a claim of the declared mod. failing ?
That's a very good point about possibly invalidating insurance. I wonder how easy it would be to get a response from an insurance company about if they would be happy for such a modification before proceeding with it. Cheers. Bruce.
leswaller wrote:Roy,
If the gearbox final drive sprocket is in the same horizontal plane as the swinging arm pivot and they are very close to each other and the axle is fastened to the swinging arm then as the arm pivots it will perform an arc round the swinging arm pivot point and the nearby drive sprocket, and as the swinging arm is a fixed length the maximum difference in chain tension will be equivalent to half the distance between the pivot and the final drive sprocket centre
I do agree but far to technical for me if a spanner and hammer won't do it them I am buggered but don't tell G Ray.
Janet wrote:Look up "motorcycle drive chain tensioner" or similar wording and you'll see various ones for sale although probably not for our style of bikes.
Just had a look Janet. The very first option showed pictures exactly like the push bike tensioners that also assist gear change. I was referring to, with a guess of what would make a tensioner. So many little bits to wear and fail, to add to the tool box with a spare split link. Any idea's how insurance and breakdown cover would react due to a claim of the declared mod. failing ?
That's a very good point about possibly invalidating insurance. I wonder how easy it would be to get a response from an insurance company about if they would be happy for such a modification before proceeding with it. Cheers. Bruce.
That's why I mentioned it Bruce.
Quite a few mods are made to the old bikes, I am sure not all declared. The likes of oil line tap, electrical etc . May not cause an accident. A thrown drive chain could cause a very serious accident. Even fly off and injure a pedestrian. Way back in the 1950's I had an accident. When I went to get my bike back after £155 worth of repairs ( very close to being a write off ) The bike had no fairing, crash bars or panniers. I had declared these extra's . The insurance said there was no evidence left on the bike having to prove these extra's were fitted. They wanted a photo showing them all on the bike. I sent 2/3 photo's and got them fitted.
Rob, a bike is less likely to throw a chain and so cause an accident if the chain is correctly tensioned. Therefore a correctly fitted and appropriate chain tensioner will improve safety. There is no more chance of it coming off than one of your panniers coming off if they are both correctly fitted.
We didn't use to have seat belts in cars but I don't think an insurance company would penalise you for retro fitting them to an old classic car
Les
Rules are for the obedience of fools and the guidance of the wise
leswaller wrote:Rob, a bike is less likely to throw a chain and so cause an accident if the chain is correctly tensioned. Therefore a correctly fitted and appropriate chain tensioner will improve safety. There is no more chance of it coming off than one of your panniers coming off if they are both correctly fitted.
We didn't use to have seat belts in cars but I don't think an insurance company would penalise you for retro fitting them to an old classic car
But what if it falls off like a tool box lid ( Poland ) and caused a accident ?
leswaller wrote:Rob, a bike is less likely to throw a chain and so cause an accident if the chain is correctly tensioned. Therefore a correctly fitted and appropriate chain tensioner will improve safety. There is no more chance of it coming off than one of your panniers coming off if they are both correctly fitted.
We didn't use to have seat belts in cars but I don't think an insurance company would penalise you for retro fitting them to an old classic car
I agree with you Les, but I wouldn't want to rely on a wheedling insurance company accepting such a reasoned argument or a common sense explanation. Getting an MOT after fitting it might help, but I still wouldn't want to take the risk of my insurer declining to cover potentially bankrupting compensation awarded to an injured third party.
'There is a tide in the affairs of men
Which taken at the flood............'
leswaller wrote:Rob, a bike is less likely to throw a chain and so cause an accident if the chain is correctly tensioned. Therefore a correctly fitted and appropriate chain tensioner will improve safety. There is no more chance of it coming off than one of your panniers coming off if they are both correctly fitted.
We didn't use to have seat belts in cars but I don't think an insurance company would penalise you for retro fitting them to an old classic car
I agree with you Les, but I wouldn't want to rely on a wheedling insurance company accepting such a reasoned argument or a common sense explanation. Getting an MOT after fitting it might help, but I still wouldn't want to take the risk of my insurer declining to cover potentially bankrupting compensation awarded to an injured third party.
Having a similar chain tensioner on a Derailleur gear push bike is all I can relate to Neville. It was always throwing the chain. Probably because it was not tensioning the chain, leaving it slack to jump off the little cog. Riding along a bumpy riverside towpath the chain was forever coming off. So I would not fancy a similar tensioner on a motor bike. On which I can only recall throwing a chain a couple of times in 50 + years. Once in the 50's when I did not know better than riding a bike with worn out slack chains. Then again in the 80's when I thought I must not have fitted the split link firmly in place. Without any moods, it does not take much to keep the chain tension correct. I would consider it a gamble to trust a gadget to do the job. So its really up to the individual to make their own choice.
As an exracing cyclist I can say that a properly set up bicycle derailleur will work well with a freewheel. But I can't see a sprung tensioner working without a freewheel, as soon as you close the throttle the lower chain run becomes tensioned and the chain will go slack.
si is does non opportunus vos postulo a maior pango
