chain goes loose then tight

Hi everyone, I had this problem where my chain would be perfect tension then in halt a turn of the rear wheel it would go loose.... I was advised my chain an sprockets were goosed (9000 miles)so I bought renthal sprockets an a did vx chain(didn't skimp), I've found that it's still doin it....the rear sprocket is in line as I've held a pointer to it while spinning it and it's true.....I'm now wondering is it possible to bend the shaft that the front sprocket attaches too. I understand this mabey a bit far fetched but the bike has 9000 miles on it all done by me......mabey popped about 5-6 really poor wheelies in 2nd gear in the whole time I've owned it

[Seeker]

What kind of variation are you getting? If you set the tension to 25 mm at the tightest point, what is at the loosest? Mine varies a bit but I've never worried about it.

How old is the bike?

This guy suggests rotating the rear sprocket on the hub to different positions to find an optimal location:

https://www.youtube.com/watch?v=8rXQKVEn3mk

The variation he was getting was excessive. If that doesn't work the only other thing I could think of would be a problem with the cush drive rubbers.

I doubt whether you would have bent the gearbox output shaft - you would have damaged the bearing and seal before that (imho) and only then if you had run with an excessively tight chain.

[Bibio]

all chains have a tight spot even new ones. give it a few hundred miles and see what its like after that. your advisement was more than likely your sprockets were worn rather than the chain having a tight spot.

Yeah if I'm setting at 25 at the tightest...it goes to 35-40, the bike was new in September it's done 9230. And the new chains been on about 300 miles now!!
I'll check that vid out cheers

Originally Posted by Seeker

What kind of variation are you getting? If you set the tension to 25 mm at the tightest point, what is at the loosest? Mine varies a bit but I've never worried about it.

How old is the bike?

This guy suggests rotating the rear sprocket on the hub to different positions to find an optimal location:

https://www.youtube.com/watch?v=8rXQKVEn3mk

The variation he was getting was excessive. If that doesn't work the only other thing I could think of would be a problem with the cush drive rubbers.

I doubt whether you would have bent the gearbox output shaft - you would have damaged the bearing and seal before that (imho) and only then if you had run with an excessively tight chain.

Hahaha, so hang on just a God damn minute.....could it really be as simple as in that vid?????
Gotta be worth a try!!!
Cheers pal

[Seeker]

I don't think a 10-15 mm variation is excessive. My L7 was new last summer and has now done 8700 miles on the original chain/sprockets. I used to use WD40 brand chain lube every 300 miles with a paraffin clean every 600, if I let it go longer or there was salt on the roads I would get tight spots. I read the owners manual (what?) and it said that gear oil was ok, after giving it a good scrubbing with paraffin (every 500-600 miles) I wipe it down with an oily rag after each ride. I won't say that it's devoid of any tight spots but maybe 10 mm, nothing like the guy's chain in the video. The rear wheel spins freely with no undue noise.

Let us know if rotating the sprocket makes a difference. Good luck.

[Craig380]

As said above, pretty much all chains get tight and slack spots. The slack in mine varies by about half an inch / 15mm. Just set the slack so it's correct at the tightest point on the chain, and as long as it's not sagging like soggy spaghetti elsewhere, you'll be fine.

This is just my opinion, but when I look at the bikes I see parked up, many riders run their chains much too tight ... there's a guy with a Honda CBR who parks in my office car park, and his chain is like a guitar string. Too tight is bad for the chain and sprockets, cush drive and the gearbox output bearing, and it also absorbs power.

I'm not suggesting running it flapping loose either, just don't worry too much about having a little slack in it. When you sit on the bike and compress the suspension, it takes more slack out of the chain anyway.

After riding home last night the wheel felt terrible.. I think I had it too tight!!! (lot smother this morning after slackening it of a tad.

I just changed my sprockets and chain for the first time, but I only cleaned the last one once in 9 months an mabey lubed it once a month (bout 1200 miles lol) before anyone starts. . I know how bad that is...which is why am being a bit particular over the new set...this chain has a split link so I will be removing every weekend from now on and cleaning it before relubing, but I'm off to assen NL on Wednesday an just wanted it right before I go.....I'm stripping the back wheel down this weekend and checking everything twice.
I have had the sprocket mount out of the rim a few times in the past tho (as the best way to clean the wheel is to remove it on the back)
Mabey I haven't seated it properly or put it back in a different position... I'll let u guys know...cheers for the help so far tho guys

[Biker Biggles]

Split links are a weak point and have no place on a big bike other than as a temporary link while you ride it to a bike shop to get it riveted.You really dont want the chain to break in use as it tends to cause damage to the crankcases and can cause seriou injury to you.
As for cleaning I think we fret too much.Just keep it lubed little and often.My last sv did nearly 30000 miles on its original chain,and I never cleaned it once,only oiled it.

[R1ffR4ff]

Originally Posted by Biker Biggles

Split links are a weak point and have no place on a big bike other than as a temporary link while you ride it to a bike shop to get it riveted.You really dont want the chain to break in use as it tends to cause damage to the crankcases and can cause seriou injury to you.
As for cleaning I think we fret too much.Just keep it lubed little and often.My last sv did nearly 30000 miles on its original chain,and I never cleaned it once,only oiled it.

+10