How important are chainring pins and ramps?
I recently ordered a Sugino XD600 crank for my Bleriot build, and I'm anticipating that i may want to replace the 46 tooth big ring with something bigger, say, a 50 tooth ring.
The problem is that most of the 50 tooth rings i've been able to locate, that don't cost an arm and a leg, are 'plain' chainrings... in other words, they don't have the fancy ramps and pins and sculpted teeth etc. that most stock chainrings have. Will this be a problem for shifting? The bike will have bar end shifters, which means that front shifting will be as primitive as it gets (ie. friction). I assume that it won't be a big issue, but just wanted to check... thanks |
It'll work, but the shifting will be A LOT smother and faster
with a pinned and ramped ring. I have one bike with and one bike without. Both with D.T.F. shifters. If it wasn't to keep it as original as possible, I would never buy a ring that wasn't pinned and ramped. There again. It's only a 50T...... |
sydney used say it was all hype. He would then proceed to give an example of bikes he rode that worked great without it. I tend to agree with him. Most of my old 7 sp rides didn't ramps or pins and shift great. You start to notice problems as the chain gets narrower. That's why ramps and pins were put there. If your Bleriot is going to be a 9 sp, then you will notice a small difference.
IMO, buy the XD-600 with a 48 tooth big ring. Ben's Bike has them. Good luck Tim |
To me the key is the shifters. With friction shifting I'd say that a plain chainring will serve you adequately because you can overshift a little and tune it back. If you were using STI's or some kind of index shifter, I'd recommend using a chainring with the shifting aids.
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On an occasion, I inadvertently ended up with a middle ring w/o pins and ramps. The shifting ended up being a mess, although I use gripshifts that principally allow you to overshift. After a couple of weeks I ordered a pinned ring and sold the other one to someone who did not care.
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Originally Posted by Retro Grouch
To me the key is the shifters. With friction shifting I'd say that a plain chainring will serve you adequately because you can overshift a little and tune it back. If you were using STI's or some kind of index shifter, I'd recommend using a chainring with the shifting aids.
STI changed this. You need ramps and pins to make STI function as it was designed. |
Originally Posted by Retro Grouch
To me the key is the shifters. With friction shifting I'd say that a plain chainring will serve you adequately because you can overshift a little and tune it back. If you were using STI's or some kind of index shifter, I'd recommend using a chainring with the shifting aids.
An illustration: I had an old Suguino crank with flat chainrings on my beater bike that has a barcon friction front shifter. It shifted ok but was sluggish and reluctant if I tried shift under any load. When I upgraded another bike, I transferred its 105 8-speed crank (with all the ring enhancements) to the beater using the same shifter. The difference is very obvious and the new crank shifts much better. So, no, you don't need modern chainrings but they are a major improvement even with friction shifting. |
Originally Posted by Retro Grouch
To me the key is the shifters. With friction shifting I'd say that a plain chainring will serve you adequately because you can overshift a little and tune it back. If you were using STI's or some kind of index shifter, I'd recommend using a chainring with the shifting aids.
If you've got a triple and rarely use the small chainring, you can get away with the middle ring without ramps and pins because the shifts are rare and you can put up with poorer shifting for a shift you rarely make. But I do agree with HillRider, that ramped/pinned rings get you better shifting in any setup. It's just that a friction setup has more leeway for use with non-ramped/pinned rings. |
Hmm.. thanks. I ordered the crank last week, so i can't go back and change it to the 48 tooth model, although i could buy a 48 tooth Sugino chainring separately.
As a related question, does it matter what brand of chainring i get, or is any 'pinned and ramped' chainring with the right BCD going to work? (i assume it's not as critical as a Hyperglide cassette where each cog has a special orientation w.r.t. the others). |
Oh, duh. I just realized that i just have to look for road compact chainrings, and there are plenty of reasonably priced pinned and ramped options at 50t and more.
Is there any reason a big ring designed for a road double won't work with a MTB triple, as long as the BCD is compatible? |
Originally Posted by robo
Is there any reason a big ring designed for a road double won't work with a MTB triple, as long as the BCD is compatible?
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Originally Posted by robo
Is there any reason a big ring designed for a road double won't work with a MTB triple, as long as the BCD is compatible? Top |
Not to hijack this thread but to the OP: Did you come across any 130bcd 42/44/46 chainrings nonramped while you were browsing?
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Originally Posted by operator
Not to hijack this thread but to the OP: Did you come across any 130bcd 42/44/46 chainrings nonramped while you were browsing?
Non-ramped big rings seem to be made by lots of mfg's... i guess they're popular for SS bikes now. |
Shimano usually says that the biggest chainring for their triple front derailleurs is 48t.
Also, there will be a big step between the 36t and 50t chainrings. It's not good for triples. Shifting definitely won't be smooth. What about a different cassette? There are some with the 11t smallest cog. |
Originally Posted by Barabaika
Shimano usually says that the biggest chainring for their triple front derailleurs is 48t.
Also, there will be a big step between the 36t and 50t chainrings. It's not good for triples. Shifting definitely won't be smooth. What about a different cassette? There are some with the 11t smallest cog. Well, first i just need to see how the bike feels with the current gearing... which won't be for a few weeks at the least. |
Originally Posted by robo
Are you sure about that? The Ultegra triple crank comes stock with a 52t big ring, IIRC...
It should work anyway, just not very smooth. Front index shifting is always very difficult to adjust. |
Originally Posted by robo
I recently ordered a Sugino XD600 crank for my Bleriot build, and I'm anticipating that i may want to replace the 46 tooth big ring with something bigger, say, a 50 tooth ring.
The problem is that most of the 50 tooth rings i've been able to locate, that don't cost an arm and a leg, are 'plain' chainrings... in other words, they don't have the fancy ramps and pins and sculpted teeth etc. that most stock chainrings have. Will this be a problem for shifting? The bike will have bar end shifters, which means that front shifting will be as primitive as it gets (ie. friction). Actually, I think the bigger issue is going to be the 26 -> 36 shift. When you install the 50 tooth chainring, you will need to raise the front derailer by approximately 0.3183099 (1/?) inches. This will move the inner plate higher up from the 36 tooth ring, causing deterioraion in the upshift from the granny. If you haven't already bought a front derailer, I suggest that you look for a "10-speed" 105 or Ultegra unit...those are designed for a 14 tooth difference betwixt the middle and large chainring. Sheldon "Don't Need No Steenkin' Rins Or Pamps" Brown |
Originally Posted by Barabaika
Also, there will be a big step between the 36t and 50t chainrings. It's not good for triples.
Shifting definitely won't be smooth. |
If you haven't already bought a front derailer, I suggest that you look for a "10-speed" 105 or Ultegra unit...those are designed for a 14 tooth difference betwixt the middle and large chainring. |
That front derailleur was indeed intended for the 14 tooth jump Sheldon mentioned.
39/53 chainrings have been standard for road doubles since before ten speed. |
I'm running 26/42/52 chainrings on several road triple cranks and they shift fine. The 26 to 42 shift is a bit sluggish but I'm usually not in a rush for that one. The 42 to 52 and 52 to 42 shifts are fine.
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Originally Posted by reve_etrange
That front derailleur was indeed intended for the 14 tooth jump Sheldon mentioned.
39/53 chainrings have been standard for road doubles since before ten speed. The problem shift is upshifting from the small ring to the 39; that's not an issue with a double. Sheldon "Doubles Are Easy" Brown |
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