- Joined
- Nov 17, 2010
- Messages
- 604
The RGM ones seem too hard also. I thought someone on here did a comparison a while ago by measuring the hardness somehow. The conclusion was the AN ones were softest and closest to the originals.
In the link below I reported Shore A durometer of new AN vernier isos back in 2014 and they agree with some of the numbers above, i.e., 45-50 Shore A range. All the values I recorded (many measurements taken around circumference of inner and outer front rubbers) fell in the stated range and no outliers were recorded.A little while back I bought a cheap durometer to check the hardness of the tyres on my old bikes. If truth be told, I don’t ride enough and most of my tyres harden with age before they wear out. The durometer has done its job well identifying some old tyres with a hardness of 80 that were starting to be skittish.
I am presently rebuilding a 1972 Commando and I thought that it would be interesting to compare the hardness of modern isolastics against the originals. My Commando was laid up in 1977, so I am reasonably confident that the isolastic rubbers I have taken out are original.
My durometer is not calibrated, but it measured a hardness of 58 on a new tyre that I recently fitted that has a specified hardness of 60. So I have a reasonable confidence in this instruments measurements. The durometer measures type A Shore hardness.
So, I measured the dimensions and hardness of my original Isolastics and mark 3 vernier type isolastics from AN and RGM. In each case I took 3 Durometer readings and took the average.
I know that this does not match up to Dyno Dave’s work, but I wanted to know how current products matched up to the originals.
Results
1. Hardness
Isolastic rubber Original AN RGM
Front Outer 48 44 57
Front Inner 80 44 57
Rear Outer 49 65
Rear Inner 70 65
Why did that one get locked? Looks like all the kids were playing nice...?In the link below I reported Shore A durometer of new AN vernier isos back in 2014 and they agree with some of the numbers above, i.e., 45-50 Shore A range. All the values I recorded (many measurements taken around circumference of inner and outer front rubbers) fell in the stated range and no outliers were recorded.
Shore hardness
I notice a few members having trouble with things cracking/breaking as late...Now i now Norvil produce EXTRA soft isos.."for added comfort" But as the engine now shakes more ...stuff hanging off the motor is more prone to fracture...When the commando was designed this vibration and rubber...www.accessnorton.com
Why did that one get locked? Looks like all the kids were playing nice...?
(US Mom's stearn directive to "PLAY NICE!")
Thanks.Time expired I'd guess...... It was around nine years since the last post???
Why did that one get locked? Looks like all the kids were playing nice...?
(US Mom's stearn directive to "PLAY NICE!")
No problem.Threads over approximately* 2 years old (or 2 years from the last post) are locked.
*(Locked in batches so not necessarily '2 years to the day')
I forget.
What was/is the rationale for locking stale threads? Seems if they found again one day, and people want to make responses, they would now have to start a new thread, re-hashing much of what has been covered previously.It wasn't officially announced back in August '22 when the locking of older threads began so it's possible you just hadn't noticed.
What was/is the rationale for locking stale threads?
Seems if they found again one day, and people want to make responses, they would now have to start a new thread, re-hashing much of what has been covered previously.
re-hashing much of what has been covered previously.