The defendant has appealed from his conviction after a jury-waived trial in a District Court on a complaint charging possession with intent to distribute a Class C controlled substance (phencyclidine; commonly known as TCP or angel dust) and has assigned as error the denial of his motion to suppress, the denial of his motion for a required finding of not guilty, and the imposition of a sentence greater than that imposed in his initial District Court trial. There was evidence before the judge from which it could have been found that at about 10:10 p.m. on August 31, 1979, two police cruisers were travelling outbound on Center Street in Jamaica Plain. The lead cruiser was marked, but the one following it, operated by Boston police Detective Ulrich, was not. As the cruiser proceeded along Center Street, Detective Ulrich observed the defendant operating a ten-speed bicycle at a rate of speed of 15-20 miles per hour in the middle of Center Street, heading in the same direction as the police cars were. Detective Ulrich testified to what he observed: “As the marked vehicle pulled along side of him, he [the defendant] made a turn to his right and then just a quick left and went into the traffic and stuff. It was just unusual movement. And I pulled in right behind him and chased him down St. John Street.”
The detective described that chase in these words: “As I pulled in beside him, or behind him, it’s a one-way street with cars parked on both sides, pulled behind him, he’d slow down and then he’d taken . . . off, and he’d slow down and take off, preventing us from going around him. I sounded the siren several times, almost the length of St. John Street [about 200 - 250 yards] and then when there was an opening with parked cars, I pulled alongside of him and just grabbed him off the bike.” Detective Ulrich then forced the defendant against the hood of the police car so that the defendant was facing him, and while doing so saw three small brown manilla envelopes “sticking out of one pocket” of the defendant’s vest. The detective seized them and also six other similar envelopes from other pockets in the vest. Each envelope contained a “greenish substance” *679which the officer believed was marihuana but which on analysis proved to contain PCP.1
Detective Ulrich was an experienced police officer and had been a member of the police department for ten years and had served five years “in narcotics.” During those five years he had made over 1,000 arrests for violations of the laws controlling narcotics. He testified that bicycles are a common form of transportation for drug peddlers in the area of the arrest, and that he had made “several dozen” arrests involving such use of bicycles. This use of bicycles was in the mind of the detective when he gave chase. Envelopes of the type seized from the defendant are commonly used in the packaging of marihuana and PCP.
1. A majority of the panel are of the opinion that the officer’s experience and knowledge in the drug enforcement field and his observation of the unusual actions of the defendant in turning his bicycle into the face of oncoming traffic and proceeding down St. John Street when a marked police cruiser came alongside of him gave rise to a reasonable suspicion in the mind of the officer that the defendant was engaged in some sort of drug trafficking. We are of the opinion that at that point the officer had the right at least to stop and inquire of the defendant as to his business in the area. See and compare Brown v. Texas, 443 U.S. 47, 50-52 (1979). The officer’s suspicion was bolstered by the defendant’s refusal to stop despite the officer’s repeated use of the siren to signal the defendant to do so. We are of the opinion that the facts observed by the detective and assessed by him in the light of his experience warranted his actions at each point in this situation. It was this type of reasonable police conduct that was approved in Terry v. Ohio, 392 U.S. 1, 20-27 (1968), and its progeny. See United States v. Cortez, 449 U.S. 411, 417-422 (1981). Compare and contrast Commonwealth v. Bacon, 381 Mass. 642, 643-644 (1980).
*680While the facts in Commonwealth v. Blatz, 9 Mass. App. Ct. 603 (1980), are somewhat more compelling than those in the present case, they are not so different in kind as to distinguish that case from the present. We regard it as authority for the position which we take.
We hold that the stop of the defendant and the seizure of the drugs did not violate the defendant’s Fourth Amendment rights and that the motion to suppress was properly denied.
2. While the record does not disclose evidence of the quantity of the substance in each of the envelopes, it was reasonable to infer that there was at least one dose in each and that the nine envelopes of the material would be a commercial quantity which the defendant was intending to sell rather than use. Further support for this inference is afforded by the defendant’s flight from the police officer and his obvious attempt to avoid arrest. This action could be reasonably inferred as consciousness of guilt as a dope peddler rather than merely as a user. There is also additional support for that conclusion in the testimony of Detective Ulrich that bicycles were commonly used by drug peddlers in plying their trade.
3. The defendant had appealed from his conviction by a District Court judge who had imposed a sentence of straight probation. On his present conviction he was sentenced to one year in a house of correction, six months of which were to be served and with probation for the remaining six months. The judge made clear in the course of his discussion with counsel concerning the sentence to be imposed that the sentence which was given in the first trial was too light considering the seriousness of the offense. The judge stated that he could not understand why the judge in the first trial “just gave him probation.” There is no indication whatever that the judge was imposing any extra punishment in retaliation for the defendant’s having appealed. Thus the bases for the sentencing strictures called for in North Carolina v. Pearce, 395 U.S. 711 (1969), and Blackledge v. Perry, 417 U.S. 21 (1974), are not present in this *681case, and the strictures in those cases accordingly do not apply. The principles and rationale of Colten v. Kentucky, 407 U.S. 104, 112-120 (1972), are applicable here. There was no violation of the defendant’s due process rights by reason of the sentence imposed by the judge.
Judgment affirmed.
It appears that the green substance was parsley which had been laced” with PCP in its liquid form.