Shifting problem

[KnottedYet]

Well thank goodness for Sheldon then.

Yeah! Can you put up the link? I gotta run catch my bus.

[OakLeaf]

Linky. You can plug in your gearing (stock cassette or custom) and wheel size and get gear ratios, gain ratios (if you put in your crankarm length), meters development or speed at a selection of cadences in mph or kph.

[Catrin]

The reason I've taken to using my big chain on flattish ground is that my chain doesn't make noise there and behaves itself. My rear cassette is 11-34, and some of the jumps between gears are pretty large.

In some cases I have a smaller range if I jump between the chains for some of the gear progression - someone checked out the gear ratio for my bike on Sheldon's site and suggested it. I've also found that I go a couple of mph faster if I am in the big chain on flattish ground (with the middle gear on the rear). My max speed so far that isn't downhill is 19.9 mph.

Oakleaf - it rubs on the same part of the FD cage regardless of what gear I am in.

As far as cadence is concerned, I try my best to keep it between 80-95 and as generally close to 85-89 as I can. Going uphill can generally keep it in the 70's - though when I am really struggling to get up that hill I don't think to look at my cadence but am focusing purely on perceived effort. On sprint intervals I am paying attention to my HRM (it is mounted on my bike) but can get cadence to 105 and this is typically on the big chain.

I understand about trying not to shift under load, so I try to anticipate when I will need to shift and to do it a little early, but not so early that I lose all of my speed too early. I am not successful with this much of the time but I seem to be improving.

I do try to "soft pedal" when I shift, and sometimes will even coast for the briefest of seconds while I shift and then start pedaling to complete the shift. This is a carry-over from when I first started to learn how to shift and at that time my coordination was worse and would go all over the road if I tried to shift and pedal at the same time I will pay attention to this in case I am not soft-pedaling as much as I think I am...

Thanks everyone, you have given me some things to think about and check out. Cleaning my drive train does seem a good idea, but there does seem to be more going on than that. At least my LBS will appreciate a clean bike later this week!

[OakLeaf]

Which part of the cage does the chain rub? That'll help isolate what needs adjustment.

[Catrin]

Which part of the cage does the chain rub? That'll help isolate what needs adjustment.

Standing at the rear of the bike looking at the FD, it is the upper right part of the cage. There is a part there that comes down, then goes over to the right - which is the perfect place for the chain to rub. And so it does.

Is that a good enough description? I can always take a pic tonight and post it...

[OakLeaf]

mmmkay. It sounds like your cable just needs a little tightening (just as I originally thought - after the shop repositioned the cable, everything will settle a little and need a tweak within a few rides). But two last questions to be sure.

Does it rub when you're in your very tallest gear (your 48x11)?

What about in your very shortest gear (your 26x34)?

[Catrin]

mmmkay. It sounds like your cable just needs a little tightening (just as I originally thought - after the shop repositioned the cable, everything will settle a little and need a tweak within a few rides). But two last questions to be sure.

Does it rub when you're in your very tallest gear (your 48x11)?

What about in your very shortest gear (your 26x34)?

It mainly only rubs in the middle chain - they originally had it adjusted so that I could use the tallest gear on the middle chain without rubbing, but now it always rubs once I get higher than the middle gear (if 1=lowest, it now rubs on gears 6-9 on the back;s sometimes even on 5). This doesn't leave many effective non-rubbing gears for me on the middle chain...

I do not recollect rubbing in the shortest gear when in the middle chain - but I am so rarely there. Typically by that point I probably have already headed down to the granny chain.

Very occasionally it will rub on the other two chains, but rarely. I try to be very conscious about cross-chaining - especially on the granny and big chains.

All of this is very helpful in understanding all of this. It is time for me to understand my drive-train, and once they show me how to adjust this I will be good to go