I got this Lotus Excelle.
The set of wheels is Weinmann and the rear hub is a Maillard Helicomatic hub.
I tune-up the bike, but on the second smaller gear the chain looks like is too wide and does not stay in the right position, comes out.
maybe the chain is too wide or what's wrong?
Thanks for any reply.

That's usually what I expect to to see if the chain is too wide. I've never run across this problem on a 6s freewheel, though, except for once with an old 5s chain on a Suntour Ultra-6 freewheel. What chain is it - 5s or 6/7/8s?

Is that a 6 or 7 cog rear hub (I can't tell from the photo)? As I recall there is a difference in the lockrings that hold them together - sort of a built on spacer on the lockring that varied between 6 and 7 speed hubs. Don't take my reply as gospel, because I really can't be sure I remember it accurately.

The "Helicomatic Museum" may be helpful:

https://www.borgercompagnie.com/helicomatic/index.html

Are you using that in Index mode? I don't think they were spaced correctly to work with shipmano indexing

Did you replace the chain?

Thanks for all your comments.
The chain was on the bike. I will try a replacement and if it doesn't work, I will use another set of wheels.

All 6-speed Helicomatic freewheels use narrow spacing, equivalent to Ultra-6 and to 7-speed freewheel spacing.

A Sedisport (narrow) chain is the best chain to use with these freewheels. I've also used modern 7-8s chain on the Helicomatic freewheels but the Sedisport seemed to work best by a small margin.

The standard-width old chain will be too wide for use on a 6s Helicomatic freewheel.

Huh, didn't know that. I have a helicomatic bike or two but I run modern 6/7/8s chains on nearly everything... which I guess is why I've never had any problems.

Unless you are running Index shifters, skipping on only 1 cog is usually a sign that it's worn out... It's frequently the result of running on that sprocket all of the time.

BITD we used to see a lot of Maillard 5 speed 14-28 FWs with a worn out 24T sprocket??? Why the 24T???

We bought those FWs in bulk from France in wooden crates of 50 or 100. They cost us ~$3.00 USD. Changing the chain and FW was almost a standard operation on French bike tuneups back then.

BTW, the Lotus probably would have come with different wheels, not a Maillard Helicomatic hub.

verktyg

That was my question, was the OP trying to run these in index mode.

I got a set of Helico wheels on my then-new 1984 Trek 610, and was always frustrated with the shifting. I never fully traced the problem, but the OEM chain was the Sedisport. I thought the chain was the problem. I switched to a Regina for 5-speed, and had more problems. Ultimately I did very little riding on that bike with those wheels, due to the shifting problems. In Denver I also needed lower gears, and could not resolve that until I got a used set of wheels for conventional freewheels.

Just want to mention, I have worked on a few Helicomatic freewheels with success and have the needed specialized tools to do so. I even took an old Helicomatic hub shell and modified it to work as my "vise" tool for removing sprockets for cleaning and inspection.

I agree with verktyg it does also sound as if that one sprocket is worn badly. It can be difficult to detect this while the sprocket is mounted because the wear occurs worse on the back side.

BTW, I recently serviced a 5 speed Regina Corse Oro sent to me and IIRC it was 13-23. The 18T center sprocket was one of the most worn sprockets I've ever seen on a freewheel. Reminded me of some "shark fin" teeth I've seen on really worn out chainrings. The interesting thing was the other sprockets showed little to no wear and when I polished them they were close to NOS.


Front side of a severely worn Regina Oro sprocket

Back side of a severely worn Regina Oro sprocket

Wow, that asymmetric cog wear really highlights how so many vintage bikes had too long of a bottom bracket spindle for best chainline.

I reason that, since it was so common for newbies in those days to either lose tension on a friction lever's screw or to just leave the bike with both shifters fully forward, using a longer bb spindle reduced the issues faced by those riders. It was the cheaper bikes that typically had the most overly-long spindles.

One of the first things that I do on cheaper vintage bikes that I take on is to install a shorter bb/spindle (or one with no offset). The sporting character of the bike really comes out when I'm having an "on" day and the entire range of the freewheel can be accessed without dropping to the small chainring. Rolling hills, bring 'em on!
Using modern chain similarly reduces the friction, wear and "rumbling feel" from crossing the chain from big to big.

pastorbobnlnh

I've seen several reports over the years of folks grinding the "hooks" off of worn out sprockets. Have you ever seen that in practice?

We wondered about the worn 24T sprockets on the 14-28T Maillard FWs but never gave it much thought. We just replaced the chains and FWs. Most of them had never been lubed after they left the bike shop where they were purchased. Running dry in the desert southwest allowed lots of dust and grit to do it's job.

Thinking back, most of those bikes had Simplex derailleurs and they may have had the travel limit stops mis-adjusted and or a bent claw hanger??? Anyway, we fixed the problems and tried to educate the owners a little on shifting and maintenance.

verktyg

Forgot to attach this picture... DOH!

verktyg

I don't remeber my 6 speed Helis in the 80's running narrow chains..... IIRC, they had standard width Sedisport chains.

Sedisport chain was one of the first narrow (~7.2mm) chains, and the first to use no discreet through-bushings.

Shimano's first narrow chain was their ~1977 "UG-Narrow" chain, what I consider to be the very first entirely modern bushingless narrow chain, copied by everybody and still sold to this day (in re-named and HG-reinforced form) having identical design and dimensions as the original.

I believe that Suntour's Ultra-6 chain preceded all other narrow chains for derailer bicycles, but these still had bushings connecting their inner plates, so less flexible and thus having more cross-chaining friction.

I thought, the first narrow chains that came from Sedis were the later Sedis/Sachs chains. Those are what I use on my narrow spaced 7 speed Maillard and Sachs cogsets. I use the older design Sedisports on my wider spaced, 6 speed Maillard cogsets. And they work well at both applications.

Sedisport was the #1 chain on the market, at least for all but low-level bikes, for many years. It worked with everything that was current at the time, including 5, 6, 7 and 8-speed applications.

Sedisport chain wears well, which further increased it's popularity with serious riders, and seemed to get along well with every style of cog teeth prior to HG.

Sedisport chain did not work properly on the new HG cassettes (that first appeared in 1989), and Sachs/Sedis' subsequent updated road and mtb chains seriously lagged Shimano's chain developments in performance for over a decade until Shimano's patents apparently expired in the early 90's (after which SRAM's 8 and 9sp chains started featuring bulged sideplates in the style of Shimano's).

I've been running my purple Rossin with Helicomatic 6-speed and Shimano 600 Tri-color in indexed mode for about five years now. And it's been wonderfully reliable. I'm pretty certain I'm using a 7-speed chain on the setup.

FWIW I had chain “skate” on Helicomatic fw. IIRC I tried a couple different modern (8,9 sp) chains to no avail. The teeth on my Heli’s cogs had a groove in them which I suspect contributed to picking up a modern “ramped” chain. If you really want to try to correct this I’d try a non-ramped, thin width chain (maybe 9 sp) or a similar vintage chain. But I wouldn’t get my hopes up too high.

Decided to disassemble my helicomatic 6 speed cluster yesterday. (I have the special tool to remove the inner lockring, but really this could be managed with some multigrips etc) I have had skipping issues with any chain other than the original sedis style, but recently was having problems shifting up from the 2nd smallest cog to the 3rd and from the 3rd to the 4th(17 and 20 T), the chain would tend to not move up easily and once enough force was applied on the shifter it would skip all the way from the 2nd smallest to the 2nd biggest cog.


So looking closely at cog 3 and 4, I could see there were quite worn/shiny on the leading face(these ones are all black) from when the chain gets pulled across them and there was a slight convexness to the face, possibly just the tiniest bit of ramping too..


Knowing that these cogs are reversible, I purchased myself a chain whip, you only need one if you do this on the bike and use the existing chain/crank to pull against(put the bike on the smallest chainring and biggest cog for max leverage), and removed the dual/one piece two end cogs that screw on and reversed the orientation of the four larger cogs. ( I also worked out you could do this off the bike without a 2nd chain whip , by putting two small posts into a vice, the biggest cog of the cluster has slots in it which can sit over the top of these to secure it to pull against) There are four loose spacers which have a gap in them, like a spring washer(didnt notice where the gap was when I removed them, and just placed them randomly when reassembling, I believe for the 7 speed the spacers are slightly smaller.


Result, problem of skipping over cogs 3 and 4 disappeared, fingers crossed this fix lasts a while.

I got an ultra-6 new-in-the-box when they came out, went touring with it. Was only a week but three of the bushings disintegrated; having a chain tool meant I could keep going; I lost the two bottom gears.

Then I got a Sedisport and that was *much* better.

Came across some info that says the 7 speed freewheel is actually a bit wider, the 5 and 6 speed are the same size with different size spacers. Dont know about the spacers on the 7 speed.
Supposedly the 6 and 7 speed fit on the same size spiralled spline.

Came across some info that says the 7 speed freewheel is actually a bit wider, the 5 and 6 speed are the same size with different size spacers. Dont know about the spacers on the 7 speed.
Supposedly the 6 and 7 speed fit on the same size spiralled spline.

...and problems after the fix i did with swapping the direction of the rear cogs. About two days later, and the morning after I had just rewaxed the chain, I was riding and some clunking started coming from the drivetrain, I stopped the bike and found that pedalling backwards wasnt possible and it appeared to be a link of the chain was seizing up, sometimes they are a bit stiff after a wax. But it kept going, knew it wasnt good, but needed to get to work on time! Closer inspection of what was going on(with my good glasses on) revealed that the freewheel lock ring had come adrift and it was possibly getting caught up in the chain as well as the free wheel floating outwards on the spline......Id tightend it with what was reaonsable force with the tiny bottle opener tool(and believed this things would get tighter as you pedal anyway-wrong)

Bottom line when at home and pulled it all apart, the lock ring was scratched up but still ok, but when putting the freewheel/cassette back on the hub, there was some noticeable play, indicating that the helical splines effectively got grinded out a bit when it was loose. It may have already worn to that stage(but in theory there shouldnt be any wear there if it is firmly attached) and I hadn't noticed it, but given I was expecting some consequences of it working loose it was identified in this case. So rather than put it back on and perhaps it wear more to become very loose I fitted a spare I had purchased for such an occasion. The NOS freewheel fitted snugly, indicating that the wear was limited to the grooves on the freewheel rather than the hub,
So do up that dinky lock ring tight