Mountain Bike Reviews Forum banner
1 - 20 of 52 Posts

·
Registered
Joined
·
829 Posts
Discussion Starter · #3 ·
FrozenK:

I get customers and friends who want to try the fixed gear thing. Some will spring for the best of the best while others want the easy way out. Mostly lower end mt bikes, not Wally mart crap, just the 3 to 4 hundred dollar basic mt bikes. I'm trying to arrive a some kind of kit I can assemble to make this work as simple as possible for their use. I know I will have to tweek stuff here and there. I'm not afrid of swapping out some parts to make the customer happy. After all it's about fun at this level for them.

Too bad someone doesn't make a Shimano freehub that is locked! I could pop that on and be on my way to Fixed Gear. I should just weld a bunch!

Now I'm really thinking crazy!
See what you did!

Thanks for the madness!
 

·
The devil is an angel too
Joined
·
7,330 Posts
Like I said: it depends. If the bike has horizontal drop outs or track fork ends, all you need is to work with the wheels. If they have vertical drop outs, you need an Eno hub. Or some welding equipment. If they have a means to keep the chain tight (hor drops, EBB...) and a disc wheel a four bucks singlespeed cog a drill and spacers will do the trick. If they have a wheel that takes a freewheel and not a freehub...

Oh, what you are thinking of doing sounds a hell of a lot like the Surly Fixxer.
 

·
Registered
Joined
·
172 Posts
If you have a disc hub (this is my post copied from the other fixie topic today):

I used a cheap pressed steel cog that came with a SS converter kit. These are quite easy to drill. Mine is an 18 tooth. You need a standard 6 bolt dics to mark it up - lay the disc on top of the cog and center it up - make sure of this - eye up the centre edges of the cog against the centre circle of the disc and measure the distance in three places to check it is in the middle. Hold tight and draw the 6 round circles where the bolts go. Centre punch these and then using good quality HSS bits drill the holes. 2mm first all the way through and then a 5.5mm to finish. De-burr with a 7mm or similar and that's it. Mine ended up spot on - just take some time and care - worth a try for a few £'s (or $'s!). Especially if it is not for you. The washers are just to perfect the chainline.

 

·
Registered
Joined
·
673 Posts
Surly Fixxer. About $60 I think. It replaces the freehub assembly with a fixed gear assembly. Possibly your best option as far as having a "kit" that you can use on any bike with chain tensioning ability (track ends, sliders, EBB), without having to go ghetto-tech. And they're solid so you won't have to worry about rather or not your rigged-kit would fail.
 

·
Registered
Joined
·
161 Posts
There is no works-all-the-time-plus-some-tweaking way to do it. The fixxer works on a lot of cassette hubs but not all. Even if it does work it is not cheap or super quick to install. Most MTBs have vertical drops and so you'd have to dork around and figure what gear works best which takes time. I figure the cheapest you could do it, installed, by the book, with no complications would be $100.

Whatever you do, don't ghetto fix it with a freewheel hub and a BB lockring. Someone will get hurt. And obviously, don't use a tensioner. Personally, I'd stock-up on inexpensive fixie hubs and build some cheap wheels. If you shop around for close-outs and have your employees build wheels during winter downtime you could probably work it out to $100 with a real fixie hub. You'd have to respace the axles but that's no harder than installing a fixxer.

Just my 2 cents.
 

·
75% Mountain cycle
Joined
·
331 Posts
weld-it

I had my buddy weld up my freehub. Take off the back seals and hose it out with WD-40 first to get as much grease out as you can. It tends to boil with the welding and spatter - the grease may contaminate the welds. I took mine apart and cleaned all the grease out but it was probably not needed.

Only negative is the cog shifts ever so slightly when you try backpedal to slow down. I jammed home made shims in to try tighten it up - it worked. You feel it a little. I use a cheap shimano BMX cog so maybe the high end cogs don't do that.
 

Attachments

·
Registered
Joined
·
55 Posts
doable with only one........

Nagaredama said:
I've seen someone zip tie a cassette to the spokes. Getting rid of the freewheel in the hub.

seen a guy set it up with one 12" ziptie just thread it back and forth threw the cassette and spokes.............



cnb
 

·
Registered
Joined
·
1,835 Posts
UMMADUMMA said:
seen a guy set it up with one 12" ziptie just thread it back and forth threw the cassette and spokes.............



cnb
Brilliant way to tear up your spokes.
 

·
Down South Yooper
Joined
·
1,010 Posts
Yep

That's a Boone. Don't know if it's a standard item, or if Boone is making enough of anything to have 'standard' items. I've been seeing more and more stuff, so here's hoping that he's producing all that he can, and selling every bit of it.

I'm on the fixie track too, thinking of either the fixxie or a cheap fixed hub and new wheel. I build my own, so shopping for the parts and putting it together over the winter should net a wheel for around $100. I've been watching surly flip/flop fixed/free hubs, and would rather have another wheel, and probably a stronger one than by current XT rear. It will at least have wider flanges, which are better for singles and (I would think) fixies, where it may get run into more things than a geared setup, where you can plan and position your rear wheel a little better.

I don't know how the chainline works with a cog bolted to the disc mount, it seems like it might be a little inboard, but not having done it, I can't say. Anybody out there that can vouch for chainline with a disc side mounted cog?

Plum
 

·
drev-il, not Dr. Evil!
Joined
·
3,910 Posts
Plum said:
I don't know how the chainline works with a cog bolted to the disc mount, it seems like it might be a little inboard, but not having done it, I can't say. Anybody out there that can vouch for chainline with a disc side mounted cog?

Plum
I use an 8-speed chain, and it works ok. Older thread with a pic in it.
 

·
Sofa King We Todd Did
Joined
·
2,262 Posts
felixdale said:
If you have a disc hub (this is my post copied from the other fixie topic today):

I used a cheap pressed steel cog that came with a SS converter kit. These are quite easy to drill. Mine is an 18 tooth. You need a standard 6 bolt dics to mark it up - lay the disc on top of the cog and center it up - make sure of this - eye up the centre edges of the cog against the centre circle of the disc and measure the distance in three places to check it is in the middle. Hold tight and draw the 6 round circles where the bolts go. Centre punch these and then using good quality HSS bits drill the holes. 2mm first all the way through and then a 5.5mm to finish. De-burr with a 7mm or similar and that's it. Mine ended up spot on - just take some time and care - worth a try for a few £'s (or $'s!). Especially if it is not for you. The washers are just to perfect the chainline.
This technique's been shared here before and while I feel like it's a brilliantly simple means ride fixed, I worry that it looks easier on paper than it will in practice. I just know that there's no way I'm going to be able to 'eye up' the six holes and drill them so that they're perfectly centered. Is there some foolproof math help to get this done?

Does anyone sell these aside from Boone (a titanium version seems a bit rich for 'experimentation' purposes)? Endless Bikes show one on their site, but don't have a working link to it. Anywhere I can buy a 20T version of such a cog?
 

·
Registered
Joined
·
172 Posts
Honestly, honestly it is so easy - just measure carefully and take time, anyone can do it. As I say a pressed steel cog is easy to drill and at around £3 each if you screw it up it doesn't matter - try another. The cog I drilled sits more central than the Surly cog on my cassette hub.

Regarding chainline, the disc mount position is obviously fixed in the ISO dimension. It can be spaced out a little simply by fitting washers between the cog and hub. If mounted directly to the hub the chainline in mm will be around 52/53mm IIRC. This is easy to check on your bike if you have a disc hub - measure from the inside face of the drop-out to the centre of the mounted disc. Subtract this figure from 67.5mm and that is your rear chainline. Check this with your current front chainline and you can see where you stand (measure from the centre of the seat tube to the centre of the teeth). You can fine tune the front chainline by varying the BB/spindle length/chainring position etc.

 
1 - 20 of 52 Posts
Top