Does anyone know the weight of the Altimax tire and the stock Kenda rear tire. If there is a significant difference in the weight that may have something to do with the vibrations.
While I can recall that it's not very much at all, there is something of a weight difference between the two - I used to know what it was, but I'm sorry, it's been a while and I'm not at home to look it up.
Mind you, many of those suffering from these 'vibration issues' still have the OEM Kendas &/or their clones fitted, so I'm not sure that it comes down to the different weight of the tires per se... However, in the case of those still running the Kendas, it could easily be the built in imbalance in the tire's construction - many Kendas/clones are fitted to Spyders despite being 'out of round' &/or with exceedingly heavy/light imbalance areas in the tire, and some rims aren't all that well 'balanced' similarly either, or they're just out of round/don't run true (we've even had reports of some hub seats not being 'square' to the axles!)

To get an idea of how bad any imbalance might be, just take a look at the number of weights that have been used during any balancing that's been done &/or that you can see fitted on many wheels, especially those still fitted with Kendas/clones in an effort to make them run smoothly!!
That does raise a thoughty tho??? Has anyone with these vibration issues had their
RIMS balanced/checked for round/running true
BEFORE fitting (and balancing??) and the tire going onto the rim?? Some relatively minor rim/tire imbalances/out of round/trueness can be compensated for by balancing, adding weights, or maybe even machining the rim &/or shaving the tires, but I've had about half dozen Spyder rims and a heap of OEM tires/clones go thru here that've come off various machines which have been so 'unbalanced &/or out of round/true' that I thought they were dangerous to even
try to use, and every owner of the Spyders they came off complained about vibrations before they swapped rims/tires... I don't see many Altimax tires here in Oz, but maybe some of those over there have come out of different manufacturing plants/another country and don't have quite the same level of quality control??
