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BMX General => BMX Chat => Topic started by: monkeybat on November 23, 2011, 03:04 PM

Title: Gearing question ?
Post by: monkeybat on November 23, 2011, 03:04 PM
I have a lower mounted(chainwheel) ad990 brake, going to use an Odyssey evolver 2(lowest) and getting some 9 tooth wheels. What size sprocket should I get up the front so it misses the brake and is ok for gearing.
Cheers Steve.
Title: Re: Gearing question ?
Post by: theRuler on November 23, 2011, 03:05 PM
25T for ok gearing, fingers crossed for missing the brake!
Title: Re: Gearing question ?
Post by: Dannywhac on November 23, 2011, 03:09 PM
Get a 10t maybe (and save eating chains up with a 9t)?

Seen this done (but don't recommend it) - grind down the 990 lugs on the frame for a lower brake. Really again though, don't recommend it.....
Title: Re: Gearing question ?
Post by: Spen69 on November 23, 2011, 03:31 PM
Which ever way you go for gearing, ie 9/25 or 10/28 make sure you have a look on Porkchop's site for the retro snowflakes he's just done - they are mint and a change from the slightly soul-less ones out there at the moment :smitten:

Plenty of colours and plenty of sizes - here's the little 25T :daumenhoch:

http://www.porkchopbmx.com/Chop-Saw-SNOWFLAKE-19mm-spindle-chainwheel-25T-BLUE-CS-SNOWFLAKE-25T-BLUE.htm

Fingers crossed on the chain missing the brake lugs though, it's a bit of an issue if it doesn't :shocked:
Title: Re: Gearing question ?
Post by: pickle on November 23, 2011, 03:35 PM
So what rear hub are you using? Not that many cassette 10mm jobs  ???

I think you might struggle though on clearence
Title: Re: Gearing question ?
Post by: theRuler on November 23, 2011, 03:37 PM
What's the deal with 9t drivers eating chains?

I was just about to buy a 25T (now I want that snowflake!) for my old pk ripper, using a Nankai freehub with a 9t driver.
Title: Re: Gearing question ?
Post by: Spen69 on November 23, 2011, 03:44 PM
So what rear hub are you using? Not that many cassette 10mm jobs

Well Rob, you know me mate - I suspect some sort of cutting equipment will be involved and hopefully we can engineer a solution to the issue or resort to some kind of petrol-powered tool answer :shocked: :2funny:

Greame - I've just ordered that very snowflake and let's face it, they are fookin cool - he does them in all the sizes though, so what gearing are you currently running ???
Title: Re: Gearing question ?
Post by: theRuler on November 23, 2011, 03:49 PM
So what rear hub are you using? Not that many cassette 10mm jobs

Well Rob, you know me mate - I suspect some sort of cutting equipment will be involved and hopefully we can engineer a solution to the issue or resort to some kind of petrol-powered tool answer :shocked: :2funny:

Greame - I've just ordered that very snowflake and let's face it, they are fookin cool - he does them in all the sizes though, so what gearing are you currently running ???

Well I have the wheel I want to use on the bike - a 32 spoke KHE wheel with a 9t Nankai freehub.
So I guess it's gonna be 25T up front.
No brake issue for me, as it has a V brake on the seatstays.

Just wondered about 9t drivers eating up chains?
At this stage should I change the 9t driver for something bigger?
Title: Re: Gearing question ?
Post by: pickle on November 23, 2011, 03:58 PM
Never heard of it myself graham.......thought 9t was the standard nowadays?

By the way, I've got one of those snowflakes and they are sweet  :smitten:
Title: Re: Gearing question ?
Post by: TwoBobRob on November 23, 2011, 05:55 PM
Gra - you just need to get a current chain mate, you should be ok. Some chains early on fouled as they tried to get themselves around a 9t driver. The industry soon cottoned on though and chains (and drivers I suspect) evolved into things that once again work nicely together.

I have a KHE (I think) halflink chain and run 25/9 and my bike is of course silky smooth.

Much like myself.

Title: Re: Gearing question ?
Post by: theRuler on November 23, 2011, 06:07 PM
Much like myself.

:)

Thanks Rob. KHE halflink chain it is!

Hopefully this thread can squash the 9t drivers destroy chains theory.
Title: Re: Gearing question ?
Post by: Dannywhac on November 23, 2011, 06:28 PM
Don't get me wrong - wasn't saying you'll immediately destroy a chain by having a 9t driver, but if you ride a lot (in my experience) you'll get through chains more.

Rob's right that more recent chains cope with this a lot more, but is a fact that 9t goes through more chains than 10t - have a butchers here:

http://chain-guide.com/basics/2-2-1-chordal-action.html

Explains sort of why - also explains why there'll never be an 8t........
Title: Re: Gearing question ?
Post by: Betty on November 23, 2011, 06:58 PM
I have a lower mounted(chainwheel) ad990 brake, going to use an Odyssey evolver 2(lowest) and getting some 9 tooth wheels. What size sprocket should I get up the front so it misses the brake and is ok for gearing.
Cheers Steve.

What frame is it going on?
Title: Re: Gearing question ?
Post by: TwoBobRob on November 23, 2011, 07:03 PM
Danny..... isn't there an 8t out there?  Matched to a 23t chainring. I'm sure I've seen it....

Not that I would run one though. It' a lot of horsepower going through very few teeth.

Gra - check with Stodgy first mate. And be sure to put it on the right way round.....  ;)

Title: Re: Gearing question ?
Post by: theRuler on November 23, 2011, 07:19 PM
Don't get me wrong - wasn't saying you'll immediately destroy a chain by having a 9t driver, but if you ride a lot (in my experience) you'll get through chains more.

Rob's right that more recent chains cope with this a lot more, but is a fact that 9t goes through more chains than 10t - have a butchers here:

http://chain-guide.com/basics/2-2-1-chordal-action.html

Explains sort of why - also explains why there'll never be an 8t........

Ah right!  I don't ride enough I don't think, to get through chains.
Title: Re: Gearing question ?
Post by: Dannywhac on November 23, 2011, 07:52 PM
Danny..... isn't there an 8t out there?  Matched to a 23t chainring. I'm sure I've seen it....


Oh christ......

http://www.missionbmx.com/products/wheel-accessories/8t-driver

Maybe I should change 'also explains why there'll never be an 8t........' to 'also explains why there should never be an 8t........'  :shocked:
Title: Re: Gearing question ?
Post by: TwoBobRob on November 23, 2011, 10:04 PM
 :LolLolLolLol:
Title: Re: Gearing question ?
Post by: monkeybat on November 24, 2011, 09:40 PM
Hi Guys, well I have a Schwinn Hydramatic Jay Miron sig version. Its a mid school bike, yep heavy and was thinking of ways to make it more rideable. New school wheels 9 t cog small sprocket up front but the brake is situated down stairs. Was asking Sawzal about putting the lugs up top but to much effort for this project. So a Odyssey evo 2 brake a 9 t rear cog and a 30 or 36 cog up front.
Title: Re: Gearing question ?
Post by: Betty on November 24, 2011, 09:46 PM
With a 30 or 36 up front you won't want a 9t at the back

30/11

36/13

You might not have enough clearance to run 25/9 on that frame, more than likely the brake lugs will be too tall...  :-\

Title: Re: Gearing question ?
Post by: monkeybat on November 24, 2011, 10:53 PM
A 36 / 14 clears a old ad990 with space to boot and a Odyssey evo2 is even shorter in height so I have to test it out.
Title: Re: Gearing question ?
Post by: Spen69 on November 25, 2011, 12:44 AM
Get a 13T Oddysey freewheel on a flip-flop hub and run 36/13 like I do. Plenty of coping clearance for the average rider and should clear your brake.
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