OTT chain tensioners

[dickie]

I've been seeing a lot of comments lately about OTT chain tensioner failures, particularly casa.

Both my motors have them and it's starting to concern me. So what's the solution? Regular checks? Change to a different manufacturer? Change gearing so that I can use a regular tensioner?

[gizmo]

I've seen this. Always thought they were the best thing since sliced bread.

[Tony Hart]

Evening Dickie. I’ve got them in two bikes. One has done about 10k miles without issue but the other lost one of the fixing allen screws during running in. Thankfully I ‘heard’ something amiss when I was pulling into my drive and found the screw on the magnetic drain plug straight away. Cleaned threads up and used locktite when refitting. Since then done about 5k miles this year without a problem. Would use again

[Norrie Bodge]

These work well for me !
Loctite the 2 Allen bolts mind

https://www.catalyst-findit.co.uk/index ... &pid=60981

[Fast n Furious]

These OTT tensioners can suffer if they've been subjected to harsh "down the box" gear changes or engine seizures. Personally, I'm not a fan of them.

[dickie]

I suppose the real question is whether they're any more or less failure prone than any other tensioner, but with such a limited uncontrolled market we're extremely unlikely to get any reliable data, so it becomes anecdotal.

However, one doubter is Chris Sturgess who I have a great deal of respect for. He's a highly skilled and experienced tuner as well as being a thoroughly decent chap.

So that alone is probably enough for me to be anxious about the casa ones, but are those from AF any better? Does anyone apart from Norrie Bodge have any knowledge of a significant number of failures? Either their own or friends?

[Fast n Furious]

I suspect that most of the failures seen with these OTT tensioners are a result of using them with overly stretched chains

[Toddy]

I run the Casa ones in a couple of my scooters for the last 6/7 years only one issue one of the early mark 1 type came loose on the euro in Spain which was a design error I’m told on the bolt length this was replaced with a mark 2 version which has been in since and I’ve done a few miles on them

[dickie]

I run the Casa ones in a couple of my scooters for the last 6/7 years only one issue one of the early mark 1 type came loose on the euro in Spain which was a design error I’m told on the bolt length this was replaced with a mark 2 version which has been in since and I’ve done a few miles on them

That's interesting. Do you use threadlock? And does your motor vibrate much?

[Toddy]

I run the Casa ones in a couple of my scooters for the last 6/7 years only one issue one of the early mark 1 type came loose on the euro in Spain which was a design error I’m told on the bolt length this was replaced with a mark 2 version which has been in since and I’ve done a few miles on them

That's interesting. Do you use threadlock? And does your motor vibrate much?

Yes always put a dab on and no more vibration than a normal lambretta

[bookertmgs1]

Have the casa tensioner fitted in two scooters & others in same group run them

No problems so far with any of them

Have done a decent amount of miles - However, I have used my own fasteners plus a dab of loctite. I also made sure they were "tight" tight

Clearly some concerns from other people which shouldnt be dismissed out of hand but theres very few parts that someone somewhere hasnt got a gripe about

[dickie]

Clearly some concerns from other people which shouldnt be dismissed out of hand but theres very few parts that someone somewhere hasnt got a gripe about

You're absolutely right there. I usually take very little notice but as some of it came from Chris Sturgess I was more interested than usual.

I always use a dab of loctite, so I'm more relaxed than I would be. Maybe all the failures are motors without loctite. Either way, winter is upn us. I've nearly finished my s2, so I'll take the side casing off my s3 and give it a once over.