John 'Zac' Brennan
I am riding 500 miles for Kahleesi. Please sponsor me and support my challenge to fight kids' cancer and save little lives.
I've Ridden
533.9 mi
to fight kids' cancer
My Rankings
- National: 211th
- State: 6th in CO
I'm Riding For
Kahleesi
Kahleesi ride your cool bike! Have fun❤️
My Story
29 Sep 2025
This September 2025 I am taking part in the Great Cycle Challenge to fight kids' cancer!
Why? Because right now, cancer is the biggest killer of children from disease in the United States. Over 15,700 children are diagnosed every year, and sadly, 38 children die of cancer every week.
Kids should be living life, not fighting for it.
So I am raising funds through my challenge to help these kids and support Children's Cancer Research Fund to allow them to continue their work to develop lifesaving treatments and find a cure for childhood cancer.
Please support me by making a donation to give these kids the brighter futures they deserve. I'm also riding for myself. In Vietnam in the Army I was exposed to Agent Orange herbicide and now at 75, have Stage IV metastatic prostate cancer.
Your support will change little lives.....and mine too!
Thank you.
John Zac Brennan
My Legacy
Here's my personal impact over 6 years to fight kids' cancer and save little lives.
-
514 mi Ridden$2,077 Raised2020
-
465 mi Ridden$1,695 Raised2021
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519 mi Ridden$2,266 Raised2022
-
546 mi Ridden$6,000 Raised2023
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565 mi Ridden$4,500 Raised2024
-
534 mi Ridden$4,240 Raised2025
3,144 mi
Ridden
$20,778
Raised
My Challenge
-
40.6 mi ride - Rabbit Ears base to Service Creek to Home - Tuesday, September 30, 2025
Logged this ride 31 days ago -
29.8 mi ride - Rabbit Ears base to Rd22 to River Rd - Monday, September 29, 2025
Logged this ride 32 days ago -
37.6 mi ride - Whitewood - Sunday, September 28, 2025
Logged this ride 33 days ago -
38.3 mi ride - River Road to Service Creek - Saturday, September 27, 2025
Logged this ride 34 days ago -
41.4 mi ride - Rabbit Ears base to Service Creek to River Road - Friday, September 26, 2025
Logged this ride 35 days ago -
39.2 mi ride - Catamount Lake loop - Tuesday, September 23, 2025
Logged this ride 36 days ago -
39.6 mi ride - Camp to Tom’s to Clark Store around Steamboat Lake - Sunday, September 21, 2025
Logged this ride 40 days ago -
19.6 mi ride - Campsite to Columbine Fork - Friday, September 19, 2025
Logged this ride 42 days ago -
16.4 mi ride - Camp to Clark Store - Thursday, September 18, 2025
Logged this ride 43 days ago -
18.8 mi ride - Camp to Tanglewood - Wednesday, September 17, 2025
Logged this ride 44 days ago
My Sponsors
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Kick Cancer's Butt Day matched donation
“Here's your matched donation from a group of wonderful Children's Cancer Research Fund supporters. THANK YOU so much for your awesome efforts to kick cancer's butt!”
$1,051.34Received this donation 51 days ago
John
“Thank you anonymous donors!”
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Dennis and Kathy Dougherty
“" You the Man" May all your hills be "down-hill" XOXO”
$155.25Received this donation 76 days ago
John
“Thank you Dennis. The kids appreciate your support.☮️😎”
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Rob Wilmoth
“Zac, Thanks for all the voodoo that you do! The kids are certainly lucky to have you in their corner. Rob”
$155.25Received this donation 51 days ago
John
“Thank you Rob. It is getting harder each year but I still dig riding a bike for a great cause!☮️❤️”
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Anne Krallman
“Zac , I am so PROUD of you !!!”
$124.20Received this donation 79 days ago
John
“Thank you Anne for your generous support !”
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Joe Huselton
“Go Zach”
$124.20Received this donation 51 days ago
John
“Thank you Paula and Joe! You’re the best!”
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Michael/Esther Belz
“way to go “cuz”. good Luck”
$124.20Received this donation 51 days ago
John
“Thank you Cousins! We had a great Match Day. Over 1.8 million dollars came in. My donations were over $1,000. My current total is now $4,038 dollars.”
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Christopher Flanagan
$103.50Received this donation 51 days ago
John
“Thank you Chris and Vicki. We raised $1,850,000 yesterday. I raised $1,000 and received matching dollars, I’m up over $4,000 now. The heat is off, now I can breathe easier and enjoy my rides!”
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Dan O'Neill
“You've got this!”
$103.50Received this donation 52 days ago
John
“Thank you Dan, you’re the best!”
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Dan O'Neill
“You got this!”
$103.50Received this donation 51 days ago -
Anonymous
$103.50Received this donation 65 days ago
John
“Thank you very much for your support. The kids need all of us to pitch in. Zac”
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Mike Ruzicka
“Thanks for doing all you can to help in the battle. Hope to see you at next week’s meeting.”
$103.50Received this donation 78 days ago
John
“Thank you Mike for your help! Kids with cancer deserve healthy lives. They should be riding their own bikes!☮️”
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Patricia O’Leary
“Way to go, Little Dear! Another year riding for a great cause! ♥️”
$103.50Received this donation 91 days ago
John
“Thank you Little Dear❤️”
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timothy anderson
“Zak. The man, the myth, the legend. Keep on peddling my friend.”
$103.50Received this donation 56 days ago
John
“Thank you, Tim. As I have said in the past, you’re all right.”
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Wayne and Lisa Adamo
“Go Zac! So glad you're doing this! Wayne and Lisa”
$103.50Received this donation 51 days ago
John
“Thank you WALA! The researchers are pleased to be getting the help they need from all of us. Kids cancer sucks.”
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Mitch Godfrey
“Great to see a fellow Vietnam Veteran ride 200 miles!”
$100Received this donation 77 days ago
John
“Thank you Mitch! Welcome home!!”
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Rob Dilldine
$100Received this donation 69 days ago
John
“Thank you Rob for your generosity. The kids need all the research possible to develop cures for their terrible cancers. ☮️❤️”
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Ergo Construction Inc.
“Bless you Brother!”
$72.45Received this donation 51 days ago
John
“Thank you James and Kaela❤️”
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Greg Krallman
“Those who help others while facing their own challenges… now that’s LOVE Go gettem Zac”
$72.45Received this donation 91 days ago
John
“Thanks Greg! Are you home yet?”
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Jen Havely
“Happy to support this great cause! Wishing you all the best on your challenge!”
$72.45Received this donation 78 days ago
John
“Thank you, Jen for your support. The research needs to be done. It looks like it’s up to us to support the researchers. The government has backed out of it. Thank you again.”
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Mark Lobstein
“Thanks again Zac for the reminder. Keep doing that great work in bringing awareness for these precious souls. Love you brother!”
$72.45Received this donation 52 days ago
John
“Thank you Mark for your continued support for the kids. Washington cut research funding and that further complicates matters. We all need to step up. Be safe . I love you like Doug’s brother 😎☮️❤️”