Upgrade 5-speed to 10-speed?
 

Hi all,

I'm absolutely loving my 5-speed 1970's Puch mixte - I changed out the steel wheels for alloy, swapped out the non-functional Simplex RD for a Suntour Cyclone, and replaced the drop bars for northroads (much thanks to BF for assistance!). It is now the most comfortable bike I've ever ridden, and I'm absolutely in love with it. I bought it for my mother to pootle around on when she visits, but it has turned into very much MY bike. :love:

However, I live in Edinburgh, and the hills are kicking my butt. I would love to ride this thing all over, but it's been relegated to shopping trips and short jaunts to friends' houses on the weekends - my commute to work up the Royal Mile is out of the question (I can barely manage on my commuter bike!).

SooOoo, my question is - can I stick on a double crankset and a FD and call it a 10-speed? It's got a single clamp-on down-tube friction shifter - I assume swapping for a double wouldn't be a problem? Also it's a cottered crankset, and I've been thinking of taking it to my LBS to have the bottom bracket serviced (not sure what state it's in!). Would it be a relatively easy thing to do while it's being serviced?

And lastly, is this just stupid, and should I just shut up be happy with my lovely 5-speed and just ride it at the weekends?

Thanks!

ps, here's a reminder of the bike

and pps, I know it's from the wrong side - I'm still learning! ;)

http://photos-a.ak.fbcdn.net/hphotos..._7378981_n.jpg

To do the switch, you will need an entire new bottom bracket and a good crankset. No way you want to continue with a cottered crank if you go with a double. You might be able to find a replacement splindle to avoid a new bb, but I do not think that will be worth the effort. Down tube clamp on shifters are available around here used on ebay and other sources, as well as new at some on line shops. You will also need a clamp on cable guide of some kind to route the FD cable, and a FD of course.

What is the size of your current chain ring? I can't tell from this side. Newer double cranks are around 52/39, older ones were 52/42; compact doubles can take you down to a 48/34 chainring set. Use the Sheldon Brown calculator to see how much you will be gaining for this change. Unless you do it yourself with some found (cheaper) used parts, you will be spending quite a bit on this upgrade.

Depending on the size (# of teeth) on your current chainring, you might get almost as much benefit from changing the rear freewheel instead. Much less work, fewer parts, etc. What is the size (# of teeth) of your smallest sprocket, and your largest sprocket? Changing to a wider spaced freewheel (larger big sprocket) is the cheapest option. Run that through the Sheldon Brown gear calculator as well.

Thanks for the quick reply.

My current chainring is 46 teeth, and the freewheel is 14-28 teeth.

I'll have a closer look at Sheldon, thanks!

ps, are you near Asheville? My folks live there, and I love love love it.

You should "down grade" it to a three speed with a three sprocket freewheel. Now that would be really cool. I had a road bike with a four sprocket freewheel, so it's an eight speed. I got lots of looks, and cool comments all the time.

Right, I found this calculator, which I find a bit easier to understand than Sheldon (unless I'm looking at the wrong Sheldon page?)

If I'm making sense of this correctly, I would gain quite a bit of range with a compact double (1st gear at 33 gear inches vs 44 gear inches as it is now).

However, if I were to find a 5 speed freewheel with a bigger range (say up to 32T), I would see a significant improvement for less cash/bother (39 gear inches).

Does this sound about right? I have a hard time translating this into a real functional difference in my mind, although the cadance MPH calculator on that page helps a bit.

Now, I see that there's a freewheel that fits the bill on Harris Cyclery's site - is this thing worth the 50 bucks?

While I appreciate that this might be unique and cool to someone who knows what they're talking about (and I'm also trying to figure out if you're making fun of me in a round-about way that I'm not picking up on ;) ), I'm looking for more/wider spaced gears - not less!

First of all, that's a really sharp looking bike!

Gear ratios:

The problem I have with traditional 10-speeds is the redundant gearing. You really effectvely only have six different gear ratios to choose from. So it's really a 6-speed, IMO.

My 10-speed has gear ratios from 1:1.5 to 1:4. I could get that same range from a Nexus 8 speed hub and a single chainring, and have 8 distinct gear ratios.

Or, I could get an even wider spread with an 11-34 9-speed cassette & a single 50T chainring: 1:1.47 to 1:4.54.

I'm beginning to question the need for a FD at all.

I would not spend $50 on a freewheel. There are a couple of good looking ones on ebay right now for less than $10 (a 13/30 and a 14/32). I live west of Asheville in the mountains.

You could also look for a smaller front chainring. Perhaps pick up a double cottered crankset cheap (a lot of people toss them), and just use the small ring (depends on how the crankset is constructed, but this is what some of the FG folks are doing). Avoiding a FD keeps the cost down.

Thanks, Hambone

I do appreciate the simplicity of the single chainring, and the reduced maintenance involved and cleaner look.

I am hesitant to go for a freewheel with more sprockets - a bigger freewheel would require spreading the frame, wouldn't it?

Definitely go with the freewheel change first. Swap your 14-28 for a 14-32, 14-34, or even a 14-36. Now, going to that large a (diameter) low gear means you're going to need to go for a rear derailleur with a long arm (assuming you don't already have one), but that still less work and expense than swapping out the bottom bracket, cranks, etc. And if you're talking the same number of cogs on the freewheel, you don't have to worry about spreading the rear stays, longer rear axle length, etc. 14-32 and 14-34 freewheels were pretty common in the 70's and shouldn't be hard to find.

Re-glancing back at your picture, it appears that you may already have the long arm rear derailleur. What brand/model is it?

Thanks, guys. Will keep my eyes out for a suitable freewheel.

skyerocker, the photo shows a Shimano Tourney on the bike, but this has since been replaced with a Suntour Cyclone GT (quite a long cage - I imagine it could handle a bigger sprocket?)

The drawback of a wide-range freewheel is the large average percentage jump from gear to gear. If you can find an ultra-6 wide-range freewheel, you can keep your current ratio spacing and add that desired granny gear. You currently have 46 / 14-17-20-24-28, splitting the difference from the very popular 52-40 / 14-17-20-24-28 10-speed combination of the same vintage. (Note -- no redundant gears there, because the ratio change in front was 1.5X that in back.) If you can find something like a 14-17-20-24-28-34 ultra-6, you'll be in business.

I also like all the comments about derailleur/epicyclic "hybrid" gearing, having ridden a 14-16-18-20 cogset with a Sturmey Archer AW hub for several years.

The GT suffix denotes a long-cage Suntour rear derailleur, so you're OK there. You'll probably be OK for chain length too as this type of derailleur can take up a lot of movement (spreading the chain round a larger sprocket). I've got a Suntour V-GY on one of my Claud Butlers that handles a Suntour 38 tooth rear sprocket (very rare now) and a ten tooth dirrerence in my chainwheels. Having a single chain ring makes it so much easier.

Great - this has been an education, thanks. (GT = long cage, who knew?)

I think I'll try to do this myself, so I might be back for more help!

God bless the internet - I now have a Shimano freewheel remover tool and a Suntour Perfect 14 - 34 T 5-speed freewheel whizzing to my door as fast as the Royal Mail can go (which isn't too fast these days).

I'll be back if I run into trouble. Thanks again!

You can't do too much better than that. Keep it. You may have to spring for a new chain, to put something on longer. Time will tell, once you've got the rest of the setup installed.

Get a Brooks saddle :)

I haven't been able to justify the expense for a bike that I only ride at weekends, but I have already promised myself one (a black B67 perhaps?) if I get this thing set up so I'm able to ride it to work. I love the B17 on my commuter bike.