Front Chainring: Ramp or Not
I know given the choice that you should use non ramped chainrings for SS. But what happens if you used a ramped one? The way I see it, the only purpose of the ramps is to lift the chain off the smaller granny ring up onto the middle ring. The ramps don't have any effect on the ring that they are actually part of. Is this correct? So why does it matter to use SS specific rings? Dave
...are a reason to go to a SS specific chainring. I think Ramped/Pinned/Profiled often get mixed together. The ramps and pins don't present a problem, but the profiled teeth are potentially a way for the chain to slip off.
Am I getting too bulky?
It's not just ramps
have you taken a look at the profile of the teeth on a ramped ring? To help the chain derail, some of them are barely there. It's a lot easier to drop (derail) your chain with a ramped ring because of it. It doesn't drop on a geared bike because of the derailleur keeping the chain on track.
I gotta roll, can't stand still, got a flame in my heart, can't get my fill.
It can be done, but...
I ran a ramped/pinned race face ring on the front of my converted Kona for almost a year with little to no problems. I had a singleator to keep the tension right and I think I only lost my chain one or two times when I really bounced the back end off of something. However, as was mentioned above, some of those teeth arte barely there and do not have the same profile as a non-ramped ring. Consequently, when it begins to wear, the little teeth wear at an alarming rate. Tha ring right now is being used as a bashguard and several of the teeth look as if they had been filed off (before it became a bashguard).
Surprisingly, I haven't had problems using ramped rings
I've used them a few times now in SS mode, and so far I've never had the chain derail from the chainring end of the bike. Presumably because rings are larger, and engage so many teeth at once, that the occasional short tooth doesn't seem to lead to derailment very often.
Still, I wouldn't trust a ramped ring as much. I might use a ramped ring I already have on an SS bike I was building up, but if I were spending actual money on it I would never BUY a ramped ring for an SS bike.
ramps, pins and profiled teeth may be a problem in some situations
If you have one gear, no tensioner and a dead straight chain line you probably won't have a problem. If you are using a derailleur as a tensioner the cage has to be stretched out to provide enough tension to prevent the chain from "slapping" about , and the chain line has to be very good. SSing needs to take advantage of every efficiency you can intoduce, including chainrings without ramps etc.
When I ran a tensioner (singleator) the chain would jump off my old ramped chain ring from time to time, but it always seemed related to a jump or hard bump and I figure it was more due to no front derailleur than the CR. When I figured out I could use a half link with no singleator I discovered my chain line was off as the chain was derailling off the CR sporadically. Once I fixed the chainline the derailling problem went away.
Originally Posted by hu-man
One day in the fields of the holy, I used a ramped ring, and like the sun setting over distant mountains, I fell of my bike, out on some distant mountains. Then one day, the little caterpillar asked me: Ernesto from Wisconsin, why are there ramps?
And I said: little caterpillar, one must choose the path of righteousness over the path of mediocrity.
The path of mediocrity is the wrong path to the lake, because it will take you over the cottages and dwellings of gnomes and fŁkking fairies. Instead, little caterpillar, do me a favor and donís piss me off.
As the hot breath emanating from a horse in a cold stable, donít use ramped rings. I did slip my chain, and racked my balls on the stem. Itís not fun, just like WW2 wasnít.
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