cvbattum

I'm trying to fix up an old, used tour bike. The drivetrain was basically bust. The front gears are completely worn, the back ones are still usable but I'd rather replace them too. The entire groupset is a Shimano 400CX. The left shifter/brake combo has been replaced with some cheap plastic, the right one is still original but kinda falling apart. The rear cassette is a 12-21T 7-speed and the front features a 20-32-42T combo. Problem is, the small and middle gears have a BCD of 58mm and replacements for that simply don't exist anywhere. The large one has a BCD of 110mm so that one is still be replaceable.

I had several ideas on what to do with this bike. One is to replace the front crankset entirely with a new 22-32-42T or something like that. I'm not sure that will really work, it's not really necessary to have that many speeds on this bike (it's mostly gonna be used on flat terrain) and for sure a modern crankset will look bad on this old bike. So, another idea was to keep the current crankset, replace the large gear and simply remove the two smaller ones. Convert it to a 1x. But we might also be using the bike for some mild hills. The rear derailleur can hold a 11-28T cassette maximum which isn't that much. Someone already recommended to me to use an 11-28T (Shimano HG41 cassette) with a 38T gear up front. That sounds pretty reasonable, but I'm not sure that combo will have enough range.

So that brings me to my final idea. This is definitely the most expensive one. I'd read somewhere that it's possible to mount an 8 or 9 speed cassette on older 7 speed hubs, by getting a 9 or 10 speed and removing one gear. The thinner spacers of those would make it fit on the hub. Correct me if I read that wrong though, bike is not my first language (I'd link the site but the forum won't let me). I was thinking of getting an 11-34T 10-speed and ditching one gear, and getting a derailleur and shifter that work with a 10-speed. This would seriously improve the speed range of the bike and a 42T front gear would probably be fine then (again, correct me if I'm wrong on that).

Obviously the bike is already old and it might not be worth investing into more expensive and better stuff. For now we only plan to use it as a back-up bike in case any of our daily ones fail. But maybe if it's actually any good to ride on, we can also use it for some leisure riding in the hills. That's what I'm hoping for at least. I myself won't be the one really using this bike so I can't really decide what it's gonna be used for, but I like the challenge of fixing it up and making it rideable again, and preferably in better shape that it was. Any tips would be hugely appreciated!

Andrew R Stewart 

I generally don't suggest doing any significant changing to an old bike, making it work is fine but trying to turn it into something it wasn't meant to be often has costs (time, money and results) that are not fully acceptable but only found out after the cost is paid.

Replacing three rings will cost close to what an entire crankset will. Have you checked out the bike's bearings yet? What condition are the wheels? Do the current ders still preform their jobs, independent of the levers? What levers do you have now, perhaps if Shimano a part number can be found. What's the RH's issues?

Do your homework well before spending much $. Andy

dedhed

What is the "old used tour bike" exactly? Is it a frame worthy of dropping new parts on?

https://www.bikeforums.net/classic-v...ergos-313.html

cvbattum

The bike is in okay shape. I took apart the wheel bearings to regrease them and they were slightly worn, but they still have some miles on them for sure. Basically everything needs cleaning and regreasing but other than that everything is in working order. Like I mentioned, replacing the all three chainrings is not really an option because you just can't get the small ones anymore, but I might replace the outer ring only and practically convert it to a 1x. Seems to cost about the same, slightly less, than a full new crankset. (though I suspect the latter will be slightly worse quality)

The rear lever is the one that comes with the groupset, its specific part number is ST-C040. The problem is that the plastic housing is missing some parts and it's now entirely rusted on the inside. The front lever is a SunRace replacement in good condition, but it's clearly cheap quality. The derailleurs still shift fine but the chain slips all the time (not really surprising when you look at the wear on the gears). They're probably slightly worn but definitely still good enough to use.

The rest of the repairs include changing the brakes and brake cables, probably shifter cables too, and just generally cleaning all dirt from the past 30 years out of every crevace.

Good point about not spending too much money. To be honest I'm mostly doing this to learn more about bike repairs and how to pick replacement components and not really to get a great new bike out of it. I can spend some 50 to 75 euros on it to get it back on the road, but really it's mostly just for the fun of fixing up a bike.

cvbattum

It's a Wheeler Trekking 6300. Nothing very high-end but the frame is good. It's definitely still in working order aside from the wear on the components.

Thomas15

I have no advice but in my opinion fixing up is one thing, fixing up and upgrading at the same time is quite another.

dedhed

https://www.modernbike.com/58-chainrings

https://www.profileracing.com/product/mtb-chainrings/

https://www.vueltausa.com/components...mm-20-24t.html