Fat Granny Gears- Mtbr.com
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  1. #1
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    Fat Granny Gears

    Hi guys, I am excited to have launched my Fat Granny Gears project - larger gears for single speed mountain bikes. Please check it out and share, it can be found here via Kickstarter: https://www.kickstarter.com/projects...t-granny-gears

    or here on Facebook: https://www.facebook.com/fatgrannygears

    Thanks for any support!

    Fat Granny Gears-gears-stacked.jpg
    Last edited by iTodd; 11-14-2015 at 06:36 PM.

  2. #2
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    Reputation: Stevob's Avatar
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    I see hills.

    I want to climb them.

  3. #3
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    Thanks Stevob!

  4. #4
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    Welcome. And liked on FB too. Good luck with the fundraiser. There's a market for these, but not sure how big it is.
    I see hills.

    I want to climb them.

  5. #5
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    Thanks, I appreciate the support, with every 'like' and 'share' I hope I'm one person closer to finding that market.

  6. #6
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    Without knowing any details I'd venture to guess you're going after a very narrow market.

    The design looks great. Have you thought about starting with more mainstream sizes like 18T then building up to other sizes? The market is much larger and it might give you an idea of how big the larger size market is from customer requests. In the meantime you can start getting your name and product out there while building a revenue stream to expand your product line into other sizes.


    Sent from my iPad using Tapatalk

  7. #7
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    Good luck OP. Remember to have an open mind regarding your choice of products to make/sell. It is very easy to put the blinders on and narrow your focus to a few select items, when the reality is that you could find more success if you opened your mind to different/new/expended products.

    Remember that good marketing/customer service goes a lonnggggg way.

  8. #8
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    Very cool way to get folks into SS that would otherwise be unable to on smaller gearing.

  9. #9
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    They look great. Just out of curiosity, where would you use something like this? I'm assuming SSing up in the mountains?

  10. #10
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    Apparently these larger cogs would have been welcome at the SSWC in Japan this year.
    I see hills.

    I want to climb them.

  11. #11
    is buachail foighneach me
    Reputation: sean salach's Avatar
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    I really hope these get produced. I pledged on your kickstarter. I would get a 24t to start and possibly a 26t for slow speed fat bike crawling on sand and softer snow.

  12. #12
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    how thick is the splined base of those cogs? looks thin enough that it will gouge most freehubs. consider beefing them up at that point or you will disappoint a lot of customers.

  13. #13
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    Would consider some big old cogs for my Pugsley. 26 would be great

  14. #14
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    I could see this being good for dinglespeeds.

  15. #15
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    Hi guys, thanks a lot for all the great feedback, I really appreciate the support.
    So one concern that I've been getting from a lot of people is how narrow a market this is going after. I absolutely agree and it is something that has bothered me from the beginning.
    I have had to give it a lot of thought, and there are a few reasons why I went ahead with the project in spite of this. For one, it's the old saying, 'go with what you know'. While the market is very small, I didn't design these with a market in mind. These were a 'necessity is the mother of invention' project - I needed a larger gear with deeper teeth and no one made them. That is the primary reason that I'm in an echo chamber trying to sell gears to myself. :-) Another reason is time and financial constraints. Each gear takes many hours to design and prototyping small batches has been relatively expensive. My hope was that this project would succeed and help fund further bicycle parts design. I may have put the cart before the horse, but I'm still holding out hope.
    The truth is, I really believe there are not enough people having fun on bikes. And I'm old fashioned with my belief that while current mtb engineering is truly awesome, I was still able to have a lot of fun back in 1988 with my fully rigid Bridgestone MB-5 with rim brakes. I suspect the current market theme that you need suspension and 1x11 or 3x10 gears to enter mountain biking is not sustainable. I also suspect that because of this belief, most entry level mountain bikers spend way too much on bikes that allow them to outpace their skills level. If you haven't mastered basic mountain bike skills, a rigid single speed is a perfect way to spend your first few months or years on a bike. You'll have a lot more fun when you do upgrade and be a much stronger rider with better skills. So I believe the market exists but you won't read about it other than here - there is no money in convincing people they need to spend less.
    Another valid concern is the width of the gear where it contacts the hub. This was definitely one of my primary concerns with this thinner gear design, but after many miles of testing, I can tell where on the freehub that the gear rides but any deformation or gouging is minimal. So as a disclaimer, I would say that it is normal to expect minimal galling but not enough to prematurely end service life. For reference, I am 6’3” 250lbs geared up, so the gears were in no way babied.
    An unfortunate reality is that every part of the bike’s drivetrain is a wear item and gears, chains, and freehubs on a single speed are subject to stress. I ultimately decided that the thinner design in 304 stainless was the best compromise between price, strength, and longevity. Cromoly does not offer the corrosion resistance I was looking for in Pacific Northwest riding conditions and the manufacturing processes for aluminum are prohibitive, particularly in smaller batches, due to the fact that they need to be machined and then anodized.
    Here is a picture of the worst spot I could find on the freehub. You can see the shiny areas where the gear has ridden - there are 2 spots because I had my spacers backwards for a while. While technically I would consider this galling or gouging, I would also consider it negligible.
    Fat Granny Gears-freehub-marks.jpg

    Thanks again for the comments and support, if you have the chance please check out my page and throw it a 'Like' or a 'Share'.

    https://www.facebook.com/fatgrannyge...homepage_panel

    Fat Granny Gears-tshirt-pic-updated.jpg

  16. #16
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    That's a steel free hub body. Even the cheap stamped steel cogs will leave those hubs largely undamaged. That is not the case for aluminum free hubs. What is the spline width? 2mm? 5mm? something else?

  17. #17
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    Hi, thanks and I believe you are spot on. This is another case of engineering compromises. The only advantage aluminum freehubs offer is weight savings. And this advantage is at a significant loss of strength and durability. I realize many manufacturers offer aluminum chainrings and sprockets and freehubs but I don't know that I would recommend aluminum for any part of a single speed drivetrain. To reiterate, every component of a bicycle drivetrain is a wear item. To illustrate, here is a picture that bike picturer posted in a thread about aluminum freehub bodies:
    Name:  Aluminum hub with cassette markings.jpg
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    That is significant galling and gouging and that is with a splined cassette. I would hate to see what any width single speed gear would do to that freehub.

    The thread is here: http://forums.mtbr.com/wheels-tires/...et-901227.html

    There is no doubt that the Fat Granny gears are an engineering compromise, but they are designed to offer the best value in single speed gears in sizes that are not currently available. Laser cut from 14 gauge(.075" thick) 304 stainless steel and finished with a machined tooth bevel, these are beautiful, thoroughly tested, and well suited for single speed mountain biking.
    It is understandable if you want to wait for version 2.0 but in the meantime may I recommend a sweet tshirt?
    Fat Granny Gears-tshirt-pic-updated.jpg

    https://www.kickstarter.com/projects...t-granny-gears

  18. #18
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    Ok, so that's less than 2mm thick. Those will gouge an aluminum freehub body. You are wrong about any/all cogs gouging an aluminum freehub body though. Wide base cogs do not suffer from this malady, and I use them regularly with aluminum freehub bodies.

  19. #19
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    solo-x, I agree. These gears are not designed for use with aluminum freehub bodies. But my guess is that the stronger and more experienced rider that has upgraded to an aluminum freehub, has zero need for a larger singlespeed gear. Sheldon Brown did not like aluminum for freehub bodies:
    Fat Granny Gears-aluminum-free-hubs-sheldon-brown.jpg

  20. #20
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    Ok, one more try....

    If you make the base wider so it won't gouge an al freehub body, you'll increase your customer base. Telling people that their al freehub body is a poorly engineered part because of material selection is poor salemanship. You are engineering a new part that could be engineered to avoid the problem with hub material selection by using design freedoms readily available. E.g., making the spline base wider, to about 5-7mm width.

  21. #21
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    I appreciate your input but in my opinion I've made my case above. If you would like a custom aluminum cog with a wider base, please contact me and I'd be happy to discuss pricing. Thanks for your feedback and any support.

  22. #22
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    iTodd, I think you might have put your blinders on w/ regards to how your gears will be used. I understand that using aluminium for a free hub body prob isn't ideal, but I would "guess" that 95% of rear hubs (either high end or machine built) utilize a form of aluminium for the fh. If a potential customer has an aluminium fh body and wants to use your gears, how will you adivse? Would you suggest he/she upgrades to a steel unit (how many manufacturers evan have a steel fh option?), or will you state that they should simply live with the fact your product may severly gouge their fh?

    Have you tested your products on an aluminium fh with a 275lb rider? Can you provide photos of what that fh looked like after 500 miles? Any time you design items that "don't fit the norm", people are going to second guess your theory and designs, you just need to be ready to back up your design with facts, not opinions.

  23. #23
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    iTodd, I'd also encourage a wider base for the cog. Also, your responses to constructive feedback come across as defensive and unwelcoming. I hope your customer service is better!

  24. #24
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    Quote Originally Posted by Bhaalgorn View Post
    iTodd, I'd also encourage a wider base for the cog. Also, your responses to constructive feedback come across as defensive and unwelcoming. I hope your customer service is better!
    I think we are seeing his customer service. As they say on Shark Tank, "I'm Out!"

  25. #25
    is buachail foighneach me
    Reputation: sean salach's Avatar
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    I can't imagine needing customer service on a cog.......

    Anyway, I was sorry to see the project get shelved. I would have bought one or more for fat bike touring.

  26. #26
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    Quote Originally Posted by sean salach View Post
    I can't imagine needing customer service on a cog.......

    Anyway, I was sorry to see the project get shelved. I would have bought one or more for fat bike touring.
    Do some reading on here about HBC (who pretty much just sold cogs/chainrings) for a demonstration on why good customer service is important. Customer service encompasses the entire organization-consumer relationship, including order fulfillment.

  27. #27
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    Agreed that this is a good idea for dingle-speeders and those looking to keep their bikes (esp Fat bikes) SS or DS for the winter. Small group for sure, but could be a valuable product for them.
    My other bike is a /7.

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