Many of the great Acharonim discuss the issue of whether or not it is forbidden to ride a bicycle on Shabbat. Hagaon Harav Yosef Mesas zt”l (Chief Rabbi of Haifa) writes that riding a bicycle is forbidden on Shabbat, for we are concerned that the bicycle will break as one is riding it and the rider will then come to fix it on Shabbat. We must therefore enact a decree prohibiting riding bicycles on Shabbat just as our Sages prohibited playing musical instruments on Shabbat, lest one come to repair them on Shabbat.
It is correct that our Sages outlawed playing musical instruments on Shabbat because they were concerned that one would come to fix them on Shabbat as is actually the case where many musicians, even nowadays, tune the cords of their instruments anew every time they play, which indeed constitutes a Torah prohibition on Shabbat. Thus, our Sages decreed that one may not play musical instruments on Shabbat.
The same should seemingly apply to bicycles in that were our Sages to prohibit riding them on Shabbat lest they break down, we would surely comprehend the reason for their decree and we would absolutely prohibit riding bicycles for this reason. However, since bicycles did not exist in the days of the Sages of the Talmud and the Torah luminaries of our generation do not have the authority to make new decrees on the Jewish nation, this cannot be the premise for prohibiting bicycle-riding on Shabbat.
Rabbeinu Yosef Haim zt”l, author of Ben Ish Hai and Rav Pe’alim, writes likewise that since we do not have the authority to enact new decrees like the Sages in the time of the Talmud did, we cannot compare the decree prohibiting playing musical instruments on Shabbat to riding a bicycle on Shabbat. He therefore concludes that according to the letter of the law, one may ride a bicycle on Shabbat.
Hagaon Harav Azriel Hildsheimer zt”l writes that it is prohibited to ride a bicycle on Shabbat because the wheels of the bicycle make ditches in the ground and this constitutes the forbidden work of plowing on Shabbat. Maran Rabbeinu Ovadia Yosef zt”l rejects this view and writes that since the ditches in the ground are not being made by a plow, rather, they are being made indirectly by riding a bicycle, in addition to the fact that that the ditch is being made does not interest the rider, there is no need to be stringent on account of this claim.
Nevertheless, halachically speaking, Maran Rabbeinu Ovadia Yosef zt”l (in his Chazon Ovadia-Shabbat Part 4 page 43, as well as in his Responsa Yabia Omer Volume 10 in his comments on the Responsa Rav Pe’alim) agrees that riding a bicycle on Shabbat is prohibited based on what the Gemara in Masechet Shabbat (113a) writes, “’If you shall turn away your foot because of the Shabbat-by not making your ways,’ your mode of walking on Shabbat shall not be like your mode of walking during the weekdays.” The Poskim derive from this Gemara that one may not run on Shabbat, as we shall discuss in the following Halacha.
Thus, since bicycle-riding is meant for traveling long distances which is not the usual way of walking on Shabbat, it is forbidden to ride bicycles on Shabbat. He proceeds to bring many sources to defend his opinion, one of which is based on the Gemara in Masechet Beitzah (25b) which states that one may not go out in a chair on Shabbat. This refers to the custom of an important figure sitting in a chair and being carried around by people to his destination of choice (as is common in some lands in the Far East even today). Our Sages prohibited this practice on Shabbat, for this is not respectful to the Shabbat as this is considered a weekday mode of travel. Maran zt”l quotes other reasons to be stringent as well.
Thus, halachically speaking, one should not ride a bicycle on Shabbat; even if one is doing so for the purpose of performing a Mitzvah, one should still act stringently regarding this matter. We shall, G-d-willing, discuss the laws regarding bicycle-riding for children in a following Halacha.