Staff

Nachum Wasosky

Nachum Wasosky is the Founder of Geerz. He has been working with youth and their families for the past twenty years.

Nachum is an avid mountain biker. In 2012 many of the local youth that he was working with expressed an interest to ride with him. As the interest grew stronger he fundraised for a few bikes to be used by these kids. Weekly rides began and Nachum was astonished by the positive effects mountain biking was having in changing the lives of the teens and their families. Unifying his two loves; working with youth and their families and mountain biking is what sparked the idea for Geerz.

Chaim Wizman

Chaim Wizman has been the director of the Get into Geerz charity ride since 2020. Chaim is an avid cyclist and marathon runner. A lawyer by training, Chaim made Aliya in 1996 and is married to Sarah. Together, they are the proud parents of six children and five grandchildren. Chaim is also the founder and owner of EliteMed Specialists, a medical clinic in Modi'in.

Rhea Glassman Plosker

Rhea has been with Geerz since 2019 and brings over 25 years of non-profit leadership experience, partnering with lay leaders to develop initiatives and strengthen organizations in Israel. She is passionate about helping participants of all ages build confidence, resilience, and life skills through Geerz’s work. Rhea holds an MA in Organizational Psychology and mediation certification from Columbia University, and dual BAs in Psychology and Talmud from Barnard College and the Jewish Theological Seminary. Originally from Scranton, Pennsylvania, Rhea moved to Israel in high school (1989), served in the IDF, and now lives in Modi’in with her husband and two sons.

In her role, Rhea oversees Human Resources and Geerz’s backend operations.

Amir White

Shana Wasosky, M.Ed.

With a master’s degree in education and over 25 years of classroom experience, Shana specializes in alternative education, guided by the belief that it is incumbent upon us to teach each child according to their own way. Shana has played a central role in developing and refining the organization’s curriculum and remains deeply involved in its day‑to‑day operations. A biker trained by her husband, Shana has led groups and trained instructors. She continues to build a therapeutic, nontraditional program that can touch so many. Her current work includes advancing curriculum designed specifically for IDF veterans.

Gavri Ostermann

גבריאל מביא עמו ניסיון של כ-15 שנים כמדריך וכרוכב, מתוך אמונה עמוקה בכוח הטרנספורמטיבי של רכיבת שטח. הוא מחבר בין עולם האופניים לבין עולמם הרגשי של בני הנוער.
כיום, כרכז בעמותת גירז, גבריאל אמון על יצירת מרחב בטוח ומעצים עבור חניכים במסגרות שונות. תפקידו כולל ליווי מקצועי של המדריכים והצוותים החינוכיים בכפרי הנוער ובקהילות, לצד ניהול הלוגיסטיקה והתכנים של קבוצות הרכיבה.
גבריאל רואה בעבודתו שליחות: לזהות את החוזקות של כל נער ונערה דרך הדיווש. הוא מאמין שהאתגרים הפיזיים בשטח הופכים לכלים של חוסן נפשי וביטחון עצמי. עבורו, התפקיד הוא קודם כל לראות את הילדים, להקשיב להם, ולהעניק להם את הרוח הגבית הדרושה כדי לכבוש כל פסגה – על המסלול ובחיים עצמם.

Rivka Aminoff

Rivka grew up in Australia and made aliyah to Israel to pursue her lifelong dream of teaching. She studied Jewish Studies with Jewish Education at the University of London, completed a Master’s degree in Jewish Education at the Hebrew University, and received her teudat hora’ah from Herzog College.
With over twenty years of experience teaching in schools in London, Beit Shemesh, and Jerusalem, Rivka brings a deep passion for education, curriculum development, and youth mentorship to her work. At Geerz, she focuses on curriculum development and instructor support, helping shape programs that integrate mountain biking with social and emotional learning and values-based education.

Sender Gross

Nechama Kolom

Nechama grew up in Chicago and completed her early years of school there. After spending a year in Israel learning at Sh'alavim for Women, she studied biology in Stern College and moved to Israel in 2022. Today, she lives in Ramat Bet Shemesh with her family. Nechama first learned about Geerz in Camp Moshava where Nachum and Shana were running a Geerz summer program. Seeing the gaping need for effective informal education, she was motivated to join an organization that is at the cutting edge of therapeutic programming for kids in Israel. Nechama enjoys using her creativity and formidable organizational skills to ensure the program at Geerz runs smoothly.

Tal Rozow

Tal’s journey with mountain biking began in 2004, leading him to become a certified instructor by 2011. He has since coached over 2,000 riders in Israel and earned the rare distinction of being a BICP Level 3 Advanced Skills Instructor—one of only 18 worldwide. A dedicated advocate for MTB safety and culture, Tal has shaped the local scene through content creation and trail work. Today, he brings this expertise to Geerz, leading the veterans' program to harness mountain biking as a powerful tool for healing and empowerment.

Miriam Zlotnick

Miriam joined Geerz last year with little prior experience in mountain biking and only a basic understanding of the depth of the Geerz program. It didn’t take long — and one memorable ride with Shana — for her to see firsthand the powerful impact Geerz has on youth across the country.
Miriam brings many years’ experience in educational and nonprofit settings and is known for her strong organizational skills, attention to detail, and ability to ensure programs run smoothly behind the scenes.
She looks forward to continuing to support the Geerz mission and make a difference in the lives of youth, both on and off the trails.

Emuna Wasosky

Emuna grew up closely connected to Geerz and therapeutic mountain biking, first as a participant and later as an assistant instructor. Being part of the program as a child showed her how time in nature, physical challenge, and peer support can be incredibly calming, empowering, and grounding for kids. During her national service, Emuna worked at a school for children with special needs, where she saw firsthand how creative and activity-based therapies help children regulate, gain confidence, and experience joy. These experiences deepened her passion for working with kids and belief in the meaningful impact Geerz has on their lives.

Tova Kaufman

Tova Kaufman brings a strong background in organizational operations and program coordination to the Geerz team. She holds a Master’s degree in Education and a Bachelor’s degree in Psychology, and has extensive experience working within complex educational and mission-driven systems.
As Executive Assistant to the CEO, Tova supports daily operations, strategic initiatives, and cross-team coordination, helping ensure that Geerz’s work runs smoothly and effectively.

Udi Hammerman

Dr. Oded Hammerman (PhD) is a medical psychologist specializing in mind-body therapy, CBT, mindfulness, and trauma-informed care. He holds degrees from the Hebrew University of Jerusalem, Tel Aviv-Yaffo Academic College, and Ben-Gurion University, where his doctoral research focused on psychological interventions for chronic pain.
Dr. Hammerman has extensive clinical experience in hospital, community, and private practice settings, including work at Hadassah and Shaarei Tzedek Medical Center. At Geerz, he supervises the therapeutic aspects of programs for reservists returning from active duty, integrating clinical practice with nature and physical activity.
An active IDF reservist since 1999, Dr. Hammerman has served extensively since October 2023. His broader interests include the intersection of psychology and spirituality, long-distance running, and hiking.

Avi Staiman

Avi Staiman is an entrepreneur, business owner, and proud Geerz volunteer who co-founded the Geerz for IDF Combat Veterans program. Avi worked with the Geerz leadership team to build out the veterans curriculum, staff the program, find and train madrichim, market and fundraise, recruit participants, and ride with different groups across the country on a weekly basis.