# Pure skill nets magic gear



## OldZaskar (Jul 1, 2009)

Make that pure luck. 

When I bought my new geared road bike this fall, I rebuilt the 1996 Klein as a single speed. It doesn't have track/BMX type drops so it's all or nothing on the chain length... well, without filing I guess.

I played with the gear calculator and Eric House's magic gear site to find that perfect match that requires no chain tensioner. Didn't work. 

I ended up running a 42/16 - about 71 gear inches - with a tensioner. This was pretty good for the part of Atlanta I ride - lots of hills. But on the long flats and slight decents (where you still pedal), I was spinning out - couldn't match the speeds of my group. So, it was time to up the gear inches. I settled on 52/18 - about 78 gear inches. Couple reasons for that particular chainring/cog combo: It's about the percentage jump I was looking for and... I had the parts laying around. I also bought a new chain. This alone could've made the difference from what I've read - a stretched chain can throw off the calcs. 

So, the moment of truth... swapped gears, dropped chain on - pulled tight - the ends met on the big ring perfectly! Right down to the in/out links - no need for a half link. Just popped on the Sram PowerLink and that was it. The tension seems dead on. 

I rode the bike - so far so good. Then hit the HUGE hill in front of my house... Stood and hammered it - silent and smooth. 

How's that for pure luck!


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## Dave Hickey (Jan 27, 2002)

Sweet.....I've only been lucky once.....very good job


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## Dr. Placebo (May 8, 2007)

are there any downsides you can detect from doing a conversion? Also does your drop out go backwards instead of down? I can't figure it out from that pic. I wanted to build up a bike and potentially tear down my current one and convert it. Consider your rig my inspiration bike. And you ride candys to boot!


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## OldZaskar (Jul 1, 2009)

No downside that I've come across. That Klein came with Shimano RSX groupo - that's a level down from 105. But that frame - that frame! The welds, the paint... I just couldn't ditch the bike because of old mediocre parts. So, a conversion was right for this bike. 

You're not seeing things - the dropouts are different... Potentially better for SS conversions - I could (gulp) file into the frame a bit to allow a bit more adjustment. 









I initially used the Forte (Performance Bike) conversion kit - $25. It's a great kit for the money - comes with 3 cogs, the tensioner and several spacers. Once you select your chainring/cog, you eyeball the alignment - moving the cog in and out with spacers. This takes a bit of trial and error but is easier than changing a tube. 

The kit is a great place to start - ride for a while, change ratios, etc. Then, once you've narrowed in on the right ratio or gear inches, you can (if you care) worry about setting it up without the tensioner. 

For the most part, the tensioner is fine. I've had a couple occasions on my mtb. where the chain guide on the tension has come loose and bound up - more of a maintenance issue. 

I use one on my old mountain bike - hundreds of miles on VERY steep trails and no issues beyond the occasional guide thing...


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## Dr. Placebo (May 8, 2007)

Sweet MTB! You have filled this thread with awesome. :thumbsup:


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## oldfixguy (Nov 15, 2009)

Very nice bikes, I'm not usually one for brightly colored frames but I'll be darned if that Klein doesn't pull it off with style. Hey, lets get some end caps on that MTB bar.


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## OldZaskar (Jul 1, 2009)

Hey thanks guys. 

Oh, the mtb has end caps... that pic was shot just before the build was complete...


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## f3rg (May 11, 2008)

Luck, pure skill, whatever it was, congrats! :thumbsup:


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## serious (May 2, 2006)

OldZaskar: *You're not seeing things - the dropouts are different... Potentially better for SS conversions *

How do you remove that rear wheel? I guess you have to force the chain off?


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## OldZaskar (Jul 1, 2009)

serious said:


> OldZaskar: *You're not seeing things - the dropouts are different... Potentially better for SS conversions *
> 
> How do you remove that rear wheel? I guess you have to force the chain off?


Uhm... I really didn't think that far forward - seriously. Kind of funny huh. I'll have to get back to you on that. I will definitely go through the motions of dropping/reseating the chain before the next ride - would really suck to be 10 miles out, flat... and not be able to pull the rear wheel huh.


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## Fixed (May 12, 2005)

*flats?*

How do you derail the chain to get the wheel off to change a flat? Also, what happens when the chain starts to stretch?

PS, sorry, I see this has already been asked.


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## OldZaskar (Jul 1, 2009)

Just derailed the chain using only a plastic tire iron - very simple; almost no strain on the chain or chainring. "Rerailing" the chain is as expected - seat the chain on the top of the chainring and pedal. There's a bit of tension but not bad. 

Regarding chain stretch... well, not sure on that. The chain seems to have more than enough tension right now - losing a small amount wouldn't negatively impact it. If it stretches to the point of skipping, I'll either attempt to scoot the wheel back a bit (not optimistic) or drop $29 on a new chain... depending on how long it takes to stretch that much.


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## Fixed (May 12, 2005)

*huh*



OldZaskar said:


> Just derailed the chain using only a plastic tire iron - very simple; almost no strain on the chain or chainring. "Rerailing" the chain is as expected - seat the chain on the top of the chainring and pedal. There's a bit of tension but not bad.


I once had a chain on a fixed gear that was barely long enough that appropriate tension was with the axle maybe 1/8" rearward of the front of the track ends, and even then, I found it impossible to remove the chain when I got a flat. I had to remove the chainring bolts to get it off. 

If the chain comes off that easily, should you be worried about accidental derailling?


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## OldZaskar (Jul 1, 2009)

Fixed said:


> I once had a chain on a fixed gear that was barely long enough that appropriate tension was with the axle maybe 1/8" rearward of the front of the track ends, and even then, I found it impossible to remove the chain when I got a flat. I had to remove the chainring bolts to get it off.
> 
> If the chain comes off that easily, should you be worried about accidental derailling?


Given my limited experience with fixed/ss, it's hard for me to say with authority that the tension is great and I have no worries of accidental derailment. But... if I think back to my years in BMX (way back - like 24 years back) and the desired tension, I've got at least that. Also, the cog and chainring on the Klien are pretty big (52/18), e.g. could be running a 42/14 for a similar ratio... which does help with accidental derailment.

I rode the bike today on my hill repeat loop - lots of steep hills. There were out-of-the-saddle efforts with nothing but smooth silence.


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## dhellis (Dec 16, 2009)

I live in Marietta, and I ride a Trek Soho that came with a 44t chainring and a 17t single speed and 16 t fixed gear flip flop hub. I have the same challenge as to the correct gear combination. Except for the last half of the block long steep hill leading from my culdesac and one other hill I have to stand up on to reach the top on my 9 - 23 mile circuit I normally ride, I often wish for more gear on flats and on most downhills. In fact, I coast down anything more than a slight decline because I have to spin so fast the bike becomes unstable. Then there are days and times I'm okay with the way it is.

I was thinking of going to a 46T or a 48T chainring, but being that this is currenly my only bike, I don't want to make it unuseable for all of my riding. Personally, I am not comfortable with the 16t fixed gear. I forget to keep spinning and practically lose it too often. One ten mile ride, and I haven't tried it again in the 21 months of owning the bike.

Any suggestions?

Really nice bikes, by the way.


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## OldZaskar (Jul 1, 2009)

dhellis... right now you're at 69.9 gear inches. Going to a 46 ring would net 73.1 and the 48 would net 76.2 gear inches... Fortunately, your frame allows infinite ratios - you can just move the axle around as you change ratios/chain lengths. The only gamble is in the money spent on swapping chain rings and/or cogs until you find the right ratio. 

It sounds like going to 73.1 or so would be a safe move - standing and hammering those few hills will only get easier 

Changing either the rear cog or front chain ring 1 tooth will move the axle 1/8". So if you go from a 44t to 46t, your axle would slide forward 1/4". Check and see where your axle is now - do you have room to go forward? The other option is to drop from a 16 to 15. This would net 75.6 gear inches and move the axle back 1/8".


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## roadfix (Jun 20, 2006)

dhellis said:


> Any suggestions?


With the right tools, it's cheaper, faster, and easier to replace the rear cog than to replace the chain ring.


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## dhellis (Dec 16, 2009)

I have the Park home tool kit and a complete set of Barnett's manuals from my mountain biking days several years ago. Though the tools and manuals were and still are over my head, if you will. 

You gave me an idea though of perhaps swapping the 16t fixed gear for the 17t single speed. How hard do you think that would be?

Again, I am not crazy about riding fixed gear.

What is the biggest challenge with changing the chainring? Will I have to remove the crank and all from the BB or can I just unbolt the chainring bolts?

Thanks for your response.


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## dhellis (Dec 16, 2009)

Thanks for the input, Old Zaskar. I like the idea of going with the 46T chainring, but I just want to ensure I was clear that the rear sprocket on the freewheel side is 17t not 16t. The 16t is on the fixed gear side.

I was also wondering as I stated in my reply to Roadfix if I could easily sway the 16t for the 17t on the freewheel side of my flipflop hub.

How, if at all, would that affect your calculations.


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## roadfix (Jun 20, 2006)

dhellis said:


> You gave me an idea though of perhaps swapping the 16t fixed gear for the 17t single speed. How hard do you think that would be?
> 
> Again, I am not crazy about riding fixed gear.


You mentioned in your previous post that you already have a 17t freecog (singlespeed) installed.


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## dhellis (Dec 16, 2009)

Ignore my question above about swapping the 16T and 17T sprockets. I just walked out to the garage and saw that the 17T is integrated with the freewheel.

As to room to move the axle, there isn't any visible room to move it forward though I have up to .75 inch to move it backwards. I guess I would also have to replace or somehow extend my chain if I increase the chainring size.


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## dhellis (Dec 16, 2009)

That is correct. It is a flip flop hub with the 17t freecog on one side and a 16t fixed on the other. I was just wondering if I could swap the two around but after going out to look at it, I realized it wasn't that simple.


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## roadfix (Jun 20, 2006)

dhellis said:


> Ignore my question above about swapping the 16T and 17T sprockets. I just walked out to the garage and saw that the 17T is integrated with the freewheel.
> 
> As to room to move the axle, there isn't any visible room to move it forward though I have up to .75 inch to move it backwards. I guess I would also have to replace or somehow extend my chain if I increase the chainring size.


If you need more latitude you can either remove or add one single chain link.


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## roadfix (Jun 20, 2006)

dhellis said:


> That is correct. It is a flip flop hub with the 17t freecog on one side and a 16t fixed on the other. I was just wondering if I could swap the two around but after going out to look at it, I realized it wasn't that simple.


You mean as far as flipping the wheel around?


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## OldZaskar (Jul 1, 2009)

I agree with RoadFix - if you can get ahold of a 16t for the freewheel side, it'd be cheaper. Also, if you're axle is that close to the frame end of the drops, the wheel will move back (where there's room) as you lose a tooth 

You shouldn't have to shorten the chain if you swap the 17 for a 16 - as you said, you've got 3/4" of play and need only 1/8". 

Play around with this gear ratio calculator - assume 27" for wheel size... http://www.hostelshoppe.com/tech_gearcalc.php


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## dhellis (Dec 16, 2009)

Flipping the wheel around is easy...even for me. No, I was referring to actualy putting the 16T sprocket on the freewheel side in place of the 17T, but asked that before going outside and looking at it. The 17T sprocket is actually part of te freewheel.


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## roadfix (Jun 20, 2006)

With the right freewheel removal tool you can remove that freecog and install in its place a fixed cog. You'll end up with a fixed cog on both sides of the hub.


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## RFC (Mar 30, 2008)

Great use of a great older and still hot road bike.

Here is my version: A 1994 Performanced branded Ti road bike, beautiful old Dura Ace crank, 53x18 gearing, weighing in at about 15 lbs.

BTW, your tension is fine for a SS. Most error on the side of too tight with increased friction.


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## roadfix (Jun 20, 2006)

RFC said:


> Great use of a great older and still hot road bike.


I agree. Converting them makes a lot of sense instead of trying to sell them for almost nothing.
I converted my old 1993 Litespeed Classic w/ horizontal dropouts into a dedicated SS and kept the original Super Record crankset on it. I'm currently running a 44-17 on it. I think the heaviest component on the bike is the White Industries freewheel cog on it.


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## Torelli4 (Mar 1, 2005)

Help me out: what's the box hanging from your top tube?


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## OldZaskar (Jul 1, 2009)

Torelli4 said:


> Help me out: what's the box hanging from your top tube?


The battery for headlight


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