Interpretation ID: aiam1754
Executive Director
New Jersey Turnpike Authority
New Brunswick
NJ 08903;
Dear Mr. Flanagan: This is in reply to your letter of December 3, 1974, requesting ou view whether the removal of portions of a tie bar in a truck tire, for the purpose of reducing tire noise, is subject to NHTSA's *Regrooved Tire* regulation (49 CFR Part 569). You state that the removal of the tie bar material does not require that the tread be cut to a depth equal to or deeper than the original groove depth.; We concur in your opinion that the partial removal of tire tie ba material is not subject to the *Regrooved Tire* regulations. This practice would not be considered the making of a 'regrooved tire' (49 CFR S 569.3(d)) as long as the removal of tie bar material did not extend to the original tread depth. Any removal or renewal of tread that did extend to at least the original tread depth, however, would be considered the making of a 'regrooved tire' and would be subject to the requirements set forth in S 569.7 of the regulation.; We are concerned, however, that this opinion may result in th indiscriminate removal of tire tie bar material from truck tires having varying tread designs. We believe it possible, notwithstanding the absence of regulations prohibiting such removal, that the removal of tie bar material could in some cases induce tread cracking, instability, and otherwise reduce the safe performance of truck tires. Consequently, we believe you should determine, through testing if necessary, that removal of tire tie bar material will not produce adverse results in tire performance before any large-scale project involving venting is implemented. Any such program should also take into account that effects of venting may differ among various tread designs. Finally, tread venting on new tires manufactured after March 1, 1975, could affect the conformity of those tires to Federal Motor Vehicle Safety Standard No. 119.; Yours truly, Richard B. Dyson, Acting Chief Counsel