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Only One Way
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Discussion Starter · #1 ·
I was at the shop the other day and a guy working there had a cool Primo wheel set up.. it was a hub with a special cassette allowing an 8 tooth rear with a primo crank that ran a 23 up front. The clearance was amazing and the GR where not that bad…

Front Rear Tire Inch Gear
23 8 26 74.8
23 9 26 66.4
23 10 26 59.8
23 11 26 54.4

32 11 26 75.6
32 12 26 69.3
32 15 26 55.5
32 16 26 52.0
32 18 26 46.2

So I was wondering has anyone done this? I was thinking for my Urban / DJ build and to run the 23 / 10. the hub is a bolt on and 36 holes so I should be able to build it up no problem.. any comments?? BTW it uses a special chain but the guy at the shop said it was bomb proof (and he is crazy)

http://www.primo-usa.com/index.html
 

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1. What is the axle spacing? BMX is usually narrower than MTB.

2. Fewer teeth on the chainring/cog = faster wear and increased chance of the chain slipping. May be OK for urban/DJ
 

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I'm running bmx parts on my DK Xenia, its a 26" DJ/Urban, Park Bike, I'm running one of there hubs with a disc brake adapter in the rear with 33/15 gearing. One if the guys us about to try a 25t chain wheel on his 26" eastern, I think he is going to run 8 or 9 freewheel.

MT Road said:
I was at the shop the other day and a guy working there had a cool Primo wheel set up.. it was a hub with a special cassette allowing an 8 tooth rear with a primo crank that ran a 23 up front. The clearance was amazing and the GR where not that bad…

Front Rear Tire Inch Gear
23 8 26 74.8
23 9 26 66.4
23 10 26 59.8
23 11 26 54.4

32 11 26 75.6
32 12 26 69.3
32 15 26 55.5
32 16 26 52.0
32 18 26 46.2

So I was wondering has anyone done this? I was thinking for my Urban / DJ build and to run the 23 / 10. the hub is a bolt on and 36 holes so I should be able to build it up no problem.. any comments?? BTW it uses a special chain but the guy at the shop said it was bomb proof (and he is crazy)

http://www.primo-usa.com/index.html
 

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25-8 is a big gear isn't it...


I ran a 44-16 on my 20"...
 

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MT Road said:
I was at the shop the other day and a guy working there had a cool Primo wheel set up.. it was a hub with a special cassette allowing an 8 tooth rear with a primo crank that ran a 23 up front. The clearance was amazing and the GR where not that bad…

Front Rear Tire Inch Gear
23 8 26 74.8
23 9 26 66.4
23 10 26 59.8
23 11 26 54.4

32 11 26 75.6
32 12 26 69.3
32 15 26 55.5
32 16 26 52.0
32 18 26 46.2

So I was wondering has anyone done this? I was thinking for my Urban / DJ build and to run the 23 / 10. the hub is a bolt on and 36 holes so I should be able to build it up no problem.. any comments?? BTW it uses a special chain but the guy at the shop said it was bomb proof (and he is crazy)

http://www.primo-usa.com/index.html
You want a DeathMobile !
http://www.unrealcycles.com/item.php?view=194

What you are refering to is know as micro drive in the bmx world .
one problem you will run into is most MTB frames have a 135mm rear spacing with a 10mm axle .

BMX hubs have a 110mm rear spacing with a 14mm axle.

There have been a few MTB bikes that were build for 14mm rear hubs but had troble running true micro drive due to dropout clearence issues or rear end leangh .

Right now there arnt many true 26" urban and park bikes designed for 110mmx14mm micro drive .

We have one model in our frame line the DeathMobile that IS designed for this very set up , my personal bike has a 9t rear MacNeil LHD hub with a 23 Animal front sprocket .
I would post a pic but this bike is currently at a magazine for testing .

Here is a pic of the DeathMobile we displayed at Interbike with a 13T rear 27T front
gearing .
 

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OH,

and with a 110 rear hub is it disc compatiable, or atleast can you use a screw on disc brake adapter.

jherich said:
I think I like it, whats the steer tube angle, it looks really steep?
 

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I think I like it, whats the steer tube angle, it looks really steep?

Evil4bc said:
You want a DeathMobile !
http://www.unrealcycles.com/item.php?view=194

What you are refering to is know as micro drive in the bmx world .
one problem you will run into is most MTB frames have a 135mm rear spacing with a 10mm axle .

BMX hubs have a 110mm rear spacing with a 14mm axle.

There have been a few MTB bikes that were build for 14mm rear hubs but had troble running true micro drive due to dropout clearence issues or rear end leangh .

Right now there arnt many true 26" urban and park bikes designed for 110mmx14mm micro drive .

We have one model in our frame line the DeathMobile that IS designed for this very set up , my personal bike has a 9t rear MacNeil LHD hub with a 23 Animal front sprocket .
I would post a pic but this bike is currently at a magazine for testing .

Here is a pic of the DeathMobile we displayed at Interbike with a 13T rear 27T front
gearing .
 

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jherich said:
OH,

and with a 110 rear hub is it disc compatiable, or atleast can you use a screw on disc brake adapter.
Nope cant run a disk !
How would you mount the rotor to the hub ???

Plus the spacing is off in the rear , so the brake would never line up right !

I think Revel makes a 135mmX14mm disk compatible hub , but it comes with either a 16T or 18T driver so you would have to run normal MTB gearing.
The main problem with this setup is there arnt any real urban frames made to fit these hubs yet .

I think GeekHouse may have something availible in the future ......

If you want true micro drive though you will have to be happy with V brakes !
 

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Loves His Sunday
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Nemesis Projects are all sick. I haven't seen one I didn't love.
 

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Only One Way
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Discussion Starter · #13 ·
Thanks for the advice

Just back from a weekend Christmas trip and was catching up.. All are good points.. I really like the micro drive, and will take a look at the deathmobile...

Thanks C
 

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hands up who wants to die
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Eastern Bikes makes a frame that takes this hub sizing. I have a Hadley SS hub w/ 10mm->14mm axle adapters. I have a 14T cog, but could go to a smaller one if I wanted.

-r

Evil4bc said:
I think Revel makes a 135mmX14mm disk compatible hub , but it comes with either a 16T or 18T driver so you would have to run normal MTB gearing.
The main problem with this setup is there arnt any real urban frames made to fit these hubs yet .
 

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rpet said:
Eastern Bikes makes a frame that takes this hub sizing. I have a Hadley SS hub w/ 10mm->14mm axle adapters. I have a 14T cog, but could go to a smaller one if I wanted.

-r
Yea
The Eastern takes the same rear 135mmx14mm hub that the new GeekHouse frames come with , you run intot he same problem as a regular MTB hub like your hadley ( nothing against them they rock !!! ) is that the smallest cog you can run on the back is a 12T !

The orignal question here was that he wanted to run micro drive , IE: 8T ,9T and 10T
which they still dont make a driver that fits the 135mmx14mm MTB hubs .

Profile racing may be able to make a 135mmx14mm hub that fits one of their Ti driver's
in 9T or 10T that's kinda your only option at this point in time in todays market .
 

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The hubs on both my 26" wheel and my 24" wheel have threads on both sides. The rotor screws onto the non drive side. If you want I'll post photos when I get home tonight.

Evil4bc said:
Nope cant run a disk !
How would you mount the rotor to the hub ???

Plus the spacing is off in the rear , so the brake would never line up right !

I think Revel makes a 135mmX14mm disk compatible hub , but it comes with either a 16T or 18T driver so you would have to run normal MTB gearing.
The main problem with this setup is there arnt any real urban frames made to fit these hubs yet .

I think GeekHouse may have something availible in the future ......

If you want true micro drive though you will have to be happy with V brakes !
 

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jherich said:
The hubs on both my 26" wheel and my 24" wheel have threads on both sides. The rotor screws onto the non drive side. If you want I'll post photos when I get home tonight.
YES thoes are 135mm spaced MTB hubs !!
Read the orignal question at the top of the thread instread of just trying to prove someone else post in said thread wrong !

The orignal question in the thread was how to run BMX micro drive IE: 8t or 9T cogs on the single speed Mountian bike !

I'm pretty damm sure that NO BMX company makes a MICRO DRIVE CASSETTE BMX hub with a 110mm rear spacing with a 14MM axle set up to run disk brakes !
 

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hands up who wants to die
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I think 26 or 27T front / 12t rear would be a pretty nice set-up for a 26"-wheeled bike... small enough for good clearance, but high enough to get some speed.
Also you are a bit less apt to be pushing your bike home with a broken chain like the BMX kids like to do; this would be a bonus for me, since I pedal to my spots.

I'm sticking with 32t-14T for now... if I break my light mtb cranks, I may switch to a 12T-gear set-up with Profiles.

-r
 

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Only One Way
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Discussion Starter · #20 ·
Man I love that set up

sittingduck said:
I run 25/12, you can get a 12T cog for just about any cassette hub. You just cant run thick spacers.
I eventually want to get a woodman SS disc hub to replace the cheapo my stp came with.
Hey that set up on the STP is almost exactly what I want to build up.. What are the parts that you are using (Cranks, BB, ETC) and how well does it work for you?

Thanks Chris
 
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