i use a regular salsa style chain guard on the outside and a third eye style guard on the inside, no complaints yet.
with an xt rear derailleur, you might be able to accomodate a larger range cassette if you wanted, just make sure your chain is long enough.
this past sunday mine wasn't. in the middle of a race i was shifting down out of my big cog and the combination of bumps, torque and a short chain caused the chain to get caught. sent my derailleur into the spokes, and when i had untangled everything i discovered the chain itself had broken. it was a long run to the pit.
the common practice is to run the chain around the largest ring and the biggest cog and then add a full link. mine was a little shorter than that, but you might want to add two.
Originally Posted by Sheldon Brown
Because when fashion conflicts with function, I vote for function.
So I am building up the latest winter beater bike / cyclocross project.
I picked up one of the Scattante frame/forks for $225. The bike is being built with stuff I had laying around the garage.
Open pros with ultegra, XT rear deraileur, generic bar/stem/seat/seatpost, DA bar ends, 1st gen. XTR cranks...etc.
Anyway, I am going to run a single 46t front with a 12-32 rear.
Tell me what the cool setup is for ensuring that the chain stays on...-Z
I've got 2 commuters rigged this way. One's a rb and the other's an mtb. I got Rocket Rings for both. The mtb has 46t single w/a 26x12 7sp cassette, stock Alivio shifter/brake combo. The rb has the Sugino 103mm track bb w/172.5 Sugino cranks. I swapped out the stock 48t chainwheel for a Rocket Ring 48t because the chain kept popping off. I think the Rocket Rings are just ramped a little longer which is is enough to prevent the chain from dropping off. Also, the rb has bar-end shifting w/stock brake levers. It's got a 28x12 8 sp cassette. One can go Vuelta or FSA for alot more money, but for a winter beater RRs are only 15-20.00. I've yet to have the chain drop off either bike w/t Rocket Rings. Harriscyclery has guards for about 35.00 per or you can use and old chainring and grind the teeth off them if you're going off-road. Both my bikes are set up for street use. Your needs may be different. Either way good luck on your build.
Go with the ground down chainring (cheaper). Also, may I suggest the double chain guide? I had the same set up of outer guide & inner chain watcher. On occasion the jolt was just enough to drop the chain to the inside and even though I had the watcher in the correct position, the chain went under the watcher! Next to impossible to get it back without tweaking somthing. I also rigged/attached to the watcher a plastic guard over the chain, it still dropped! I've since gone to the sandwich chain guides and I'm hoping to now eliminate the problem altogether. I've seen a current pro with the same set up and they can't afford a dropped chain. Hope your bike turns out the way you want.
OK, I am going to order up one of the N-Gear today.
I am going to try using a standard take off 46T ring and see how it goes. I would like to use a 44T, but since my intention is to use this on fast road training rides, I am not sure it will be enough even with an 11.
We'll see how the chain stays on with this setup and if the gear ratio is enough.
I like the rocket ring concept and they are cheap enough to try out. I will also try to find a beat up chainring that is big enough so I can grind it off to use as a guard. Will a 2T increase be enough. For example, if I run a 46T, will a 48T ring ground off provide enough height to hold it on or do I need to find a 50T, which will be more scarce?
Thanks, I will report back with a pic of progress next week.
I would like to use a 44T, but since my intention is to use this on fast road training rides, I am not sure it will be enough even with an 11.
You should have written this in the OP. Since we live in the front derailleur era, it seems silly for you to use a single ring.
I use a single ring for cross racing because my compact road crankset (50/34) has too large a jump and has gears that I would never use in a race. But when I ride the bike on the road during off-season, I switch back to the double.
I was running the single ring with the NGear guide for a while. Worked well on the road, but I tossed the chain to the outside a couple times in the rough.
It is clear an inside/outside guard was needed.
I went to the local junk bicycle shop and picked up a used double front derailleur. $10. Small investment for an experiment.
I put in a longer lower limit screw so it would push the der. over further and locked it into position. The der. required a bit of cutting and bending to fit without rubbing, but went on without too much of a fight.
Anyway, initial impressions are positive. Looks like there is no way that it can drop to either side now. It isn't as clean looking as a naked front ring, but it is VERY functional.
Dino did you go with a 44t ring? Middle or outer position?
I got an FSA 44T ring today and it doesn't fit in the middle position because it hits my chainstay. So I'm forced to mount the ring on the outside position, which jacks up my chainline when in the big rear cog.
Next question, when my BBG ring guard comes in, should I attach that to the outside of the ring (which is already in the outside position) with a spacer? I have some 4mm spacers to use for this...
The evolution continues and I think I have settled on the good solution. I chucked the front derailleur as functional but too ugly. And went to the NGear guard with an outer ring.
On my frame, with my cheapie FSA Gossamer cranks I run the 44t in the inner position with the bash guard on the outer position. I get great chainline and have good clearance.
Not sure what kind of cranks you have, but I run Shimano on my MTB and the cranks came with spacers to put between the BB cups and the frame. I ended up swapping them around to get better chainline that what the manual called for. Not sure if this is appropriate for you, but I put it out there.
Let me know how you are doing on this. Sorry to hear about your poor experience with the bash guard so far. You will like it when it arrives. I can tell you very seriously if it has been 8 days that the thing is NOT coming. No shipping method takes 8 days from one end of town to the other.
You might want to call him, tell him that after 8 days, its not coming and would it be alright if you came and picked one up at his place. Tell him that if by some miracle the one he shipped arrives, you will return it. He is a real good guy and surely wants to keep his customers happy.
Here's my temporary setup until the ring guard arrives. My crank is a 130mm bcd Stronglight Pulsion. Currently, I have the 39T in the inner position with the 44T in the outer position since my ring guard hasn't arrived yet.
You can see in this photo that the 39T is already 3mm close to the chainstay. That leaves me enough latitude to accommodate maybe a 42T ring, but not my 44T ring.
Now, once my ring guard arrives, I might slap it on the outside of the 44T ring with a 3-4mm spacer. Follow me?
I am going to single a outer ring with the N-Gear chain stop you see on the seat tube.
I might pull the trigger and get a carbon ring guard in light of the delay in shipment.
It's a new crankset so I'm not going to get another BB with a longer spindle so I can fit the 44T in the middle position... gotta mind the sunk costs, you know?
Also note that I went to an XTR 11-34T in the rear in anticipation of going to a single up front.
44T by 11-34T is about 35 to 106 gear inches, or roughly the range of a 50/34T by 12-25T cassette. The only difference is that I have 9 steps between the extremes whereas a compact crankset would have 20 steps in between the extremes.