I read that the new engine will have a toothed belt instead of the one currently used. I hope someone smarter than me can help.does the new design weigh less and cause less parasitic power loss? Or is the new belt quieter? Or is the new belt cheaper? And i sure hope the answer to this question is NO.Will the the toothed belt last longer and not need to be replaced. I have alot of miles on my 2015 RT and am hoping I never need to have it's timing chain replaced.I am positive someone out there will know the answers to my questions . Thanks in advance for your insight.
-
Welcome, Guest! We hope you enjoy the excellent technical knowledge, event information and discussions that the BMW MOA forum provides. Some forum content will be hidden from you if you remain logged out. If you want to view all content, please click the 'Log in' button above and enter your BMW MOA username and password. If you are not an MOA member, why not take the time to join the club, so you can enjoy posting on the forum, the BMW Owners News magazine, and all of the discounts and benefits the BMW MOA offers?
r1250 timing belt
- Thread starter jimbem
- Start date
Everything I see shows a chain to drive the cams.
1:33 into this video shows the cams with the chain.
https://www.youtube.com/watch?v=ivXBBa5XtKo
rguy
got, got, got no time...
I presume it is this type of chain
http://chain-guide.com/applications/1-6-3-inverted-tooth-chain.html
Vs the previous roller type chain.
https://goo.gl/images/5tPCX2
The toothed chain should be a lot quieter.
http://chain-guide.com/applications/1-6-3-inverted-tooth-chain.html
Vs the previous roller type chain.
https://goo.gl/images/5tPCX2
The toothed chain should be a lot quieter.
PGlaves
#13338
The video referenced in the above post #2 does indeed show an inverted tooth chain or whatever it is called. It is not a normal roller chain. And it is not a belt.
gloucesterman
New member
Hi
It's called a hi vo chain I believe.
Later,
Norm
It's called a hi vo chain I believe.
Later,
Norm
beemerphile
New member
Some good info on cam chain types...
https://www.hemmings.com/magazine/hcc/2005/09/Chain-Gang/1281485.html
https://www.hemmings.com/magazine/hcc/2005/09/Chain-Gang/1281485.html
Quieter
I'm not an expert, but I understand that the EU now has regulations limiting the operating sound levels of all motor vehicles (including motorcycles). This is not a "noisy exhaust" issue, they require the engine noise, tire noise, etc. to add up to no more than some set level of noise. Various motorcycle manufacturers are making changes to their engine designs, etc to meet the regulations. I believe KTM changed their valvetrain on some of their bikes to meet the regulation. I presume BMW has to do the same.
I expect that the new chain is more expensive, but quieter - I doubt if it is much different in expected lifetime, but maybe we'll be pleasantly surprised.
I'm not an expert, but I understand that the EU now has regulations limiting the operating sound levels of all motor vehicles (including motorcycles). This is not a "noisy exhaust" issue, they require the engine noise, tire noise, etc. to add up to no more than some set level of noise. Various motorcycle manufacturers are making changes to their engine designs, etc to meet the regulations. I believe KTM changed their valvetrain on some of their bikes to meet the regulation. I presume BMW has to do the same.
I expect that the new chain is more expensive, but quieter - I doubt if it is much different in expected lifetime, but maybe we'll be pleasantly surprised.
beemerphile
New member
Which puts all airheads in that category. I have historically gotten 80K miles from heads, but by 50K miles the timing chain is eating its tensioner pad and introducing spark scatter. I'd point out that I am not a "run to failure" type of person. Airhead heads often fail by popping the head off an exhaust valve (with the obvious internal consequences). Trying to time your repair one day ahead of that event is like counting on a deathbed conversion to keep you out of hell.
PGlaves
#13338
If a chain running in a well lubricated sealed chamber wears significantly then it is made of inferior materials. I took the oil/water pump and cam chain case off the front of my K75 to check for cam chain and tensioner wear twice. Once at about 60,000 miles and once at about 150,000 miles. Detecting no significant wear I ignored it until the bike was totalled at 370,000 miles. But classic K bikes are not Airheads.
kurt_wahtera
New member
timing chains
When I was a young auto mechanic in the 60's 70's, replacing a timing chain was a very common repair, often after jumping the sprockets.
When I was a young auto mechanic in the 60's 70's, replacing a timing chain was a very common repair, often after jumping the sprockets.
What I remember of timing chains "jumping", the cause was inferior materials in the cam sprocket. Often an aluminum sprocket with some sort of plastic over the teeth. The plastic would fail and the chain would jump. The chain itself would rarely fail, unless it had quite a few miles on the engine.
Also technology was gone leaps and bounds over the 60's and 70's, although sometimes when someone sees what some engineers come up with it makes you wonder!
beemerphile
New member
Honda many years ago pioneered the timing chain tensioner that disassembles itself causing the same outcome. Kawasaki got jealous and carried this design feature to the KLR650's balancer chain.
