Cutting teeth from a standard sprocket into a skiptooth?

[slick]

O.K. Just let me know if i'm crazy or not. I can take it. I need everyones opinion here before I get hurt. I want to chop a standard rear wheel sprocket into a skiptooth. Simply die grind out every other tooth. Simply for the fact that I have lots of Kool skiptooth cranks and chains but no extra old sets of rims to run. Frankly, I can't see spending $100 or more for a set of old original rims that will have to be repainted, relaced, and the hubs rechromed to get the look I want so I had the idea of cutting out some teeth. What's the worse that can happen? Sprocket breaks, or chain? Thanks,Chris

 

[deorman]

Quite a few people here have done that, fit's not tight but it apparently works ok. Finding a chain that's not worn out, heavily rusted or somewhat pricey, however, is getting tougher with time, so consider yourself lucky on that count.

 

[Road Master]

I just recently did that on my RRBBO5 build. I was concerned before I did it because the 1/2" sprocket isn't as thick as the skip tooth but I've taken it out on a couple 6 mile runs and it seems to run fine. The sprocket that came on the wheel was a 19 tooth so I had to replace it with a 20 which worked out well because for the $2 I spent at the LBS I got a much heavier sprocket. If it's a fairly modern sprocket and easy to replace I'd say try it. By the way, I weigh 265. Good luck

 

[user 135]

Road Master, Thanks for the nice detail pictures. I added this to the How To Manual.

 

[B607]

Excellent job cutting the teeth out. The finished cog looks factory. Gary

 

[Road Master]

I just used a Dremel tool with a small diameter cutting wheel and cut through half way from each side and then trimmed up the flash with the same attachment. I bought a flex shaft attachment for my Dremel some 20 years ago and swear it's a good investment. It makes controlling your work much easier and less tiring than holding the tool itself.

 

[slick]

Road Master, That is awesome!! Exactly what I wanted to do. That sprocket looks factory. I'm going down to the local bike shop tomorrow and see if I can get a couple of those beefier sprockets. Thanks!

 

[Rat Rod]

I really need to invest in one of those Dremels...and the flex shaft too apparently. :wink:

 

[zoso]

Karfer did this (and was the one that told me about it) on a nexus 7 and I've done it on 2 bikes. I've ridden one of them on a few 5+ mile trips and it's been good, no problems.

 

[dogdart]

Perhaps I'm just fortunate to have some skiptooth sprockets , but I like to modify originals . The Bendix style hubs w/ the snap rig are only slightly larger . Grind out the center of the sprocket to fit & spot some welds where the notches are

 

[zoso]

I like that, but it seems like it would suck if you ever broke a spoke.

 

[deorman]

Hub still comes apart easily.

 

[dash]

so do you have to run a skip tooth chain or can you use a normal chain?

 

[c.p.odom]

I have run 1/2 inch chain on "fake" 1 pitch chainrings and cogs with little problem. But then all the components were new.

 

[aahallx]

When you do this does it change your gear ratio?
or does it stay the same and you just have less teeth because the diameter of the sprocket doesnt shrink at all?

but at the same time if you cut the amount of teeth in half wouldnt the load per tooth be doubled?

 

[twomorestrokes]

This is great information. Good topic.

 

[c.p.odom]

No this will not change the ratio.
Yes it will increase the load on both the chain, sprocket and cog.
This is why inch pitch chains are 3/16" wide instead of 1/8" or 3/32".
Have you noticed the hooked teeth on some old inch pitch rear cogs?

 

[deorman]

As long as the chain can't escape, a few teeth carry the load fine. Think of a derailleur bike on the smallest sprocket out back and it's largest front. It's the hardest gear to pull, but there's only 3 or 4 teeth touching the chain at the hub, and the chain has lots of play. It would increase wear, but probably imperceptibly. It takes a lot of hard riding with a stock chain or excessive tension to wear out a 1/8" single sprocket . The cheap stamped ones eat more chain than good ones, and chain "stretch" is the main cause of sprocket wear. :|
And no, it's not going to pop off if your sprockets are aligned and your chain is snug. :mrgreen:

 

[SCHWINNRAY69]

That came out great :shock:

I just recently did that on my RRBBO5 build. I was concerned before I did it because the 1/2" sprocket isn't as thick as the skip tooth but I've taken it out on a couple 6 mile runs and it seems to run fine. The sprocket that came on the wheel was a 19 tooth so I had to replace it with a 20 which worked out well because for the $2 I spent at the LBS I got a much heavier sprocket. If it's a fairly modern sprocket and easy to replace I'd say try it. By the way, I weigh 265. Good luck