luns

A 7 speed freewheel has 7 sprockets, each about 2mm thick, with 3mm spacers in between. So, the overall width of a 7 speed freewheel's sprockets is about 2mm + 6*5mm = 32mm. A 6 speed freewheel has 3.5mm spacers, so its overall width is 2+5*5.5mm = 29.5mm. This is only 2.5mm less than the 7 speed freewheel. The body of the freewheel will also add a little to both width numbers.

It's not that increasing the spacing is necessary, rather it went the other way around, reducing spacing to fit in an extra sprocket when 7 speed freewheels were introduced. These are just the dimensions that were historically used. Before we had 7 speed freewheels, Suntour did sell 6 speed freewheels with narrow-spaced (roughly 5mm) sprockets which they called ultra-6, but they're no longer made and I wouldn't suggest trying to find one to use.

I may have also partly misspoke on the 5 speed freewheels being another 5.5mm narrower. While this was definitely true of certain freewheels (5-speed and 6-speed Shimano 600EX share sprocket and spacer part numbers), looking at the exploded diagram of a Shimano MF-Z015 5-speed freewheel suggests it might not be 5.5mm spacing.

https://si.shimano.com/pdfs/ev/EV-MF-Z015-1949.pdf

Note that the plastic spacers are 4.3mm and 4.1mm. They don't list sprocket thickness, but for 2mm sprockets, this would mean they're spaced at over 6mm, and might not work well with 6-speed shifters after all. So I'm not certain that currently available 5-speed freewheels are spaced appropriately for indexing.


Actually, I think this entire discussion may be moot. Is this your bike?

https://www.norco.com/bikes/2021/cit...lle/yorkville/

The specs on there are that the rear dropout spacing is 135mm. Even if your model isn't exactly the same, I would guess the dimensions still are. I'd be surprised if your hub motor were wider than this, and it sounds like it actually fits aside from the 7-speed freewheel being to wide to go on it. I'm now mostly puzzled why a 7-speed freewheel doesn't work for you, since it doesn't appear that axle shortening is necessary for fitting your frame. I don't know what hub you're using, but the first thing I would do is check what the hub's manufacturer recommends for a freewheel.

Hmm.. the page for the yorkville lists a sunrace MFM2A freewheel. There is a 5-speed version of this, MFM2A-5DS which is listed as being Fluid-Drive which presumably is index compatible. The odd thing is that they list the 6-speed version as being compatible with 7.3-7.8mm width chains, while the 5-speed version is only listed for 7.8mm, which suggests the sprocket spacing might be different?

https://www.sunrace.com/files/catalo...eels%20MTB.pdf


As for the original question of what derailleur would work, I think your bike's original derailleur would be just fine.

Iride01 

All Shimano products are "quality" products. They are made with the precision and accuracy to do the purposes Shimano describes for each of them.

I know English isn't your first language and maybe that's part of the issue, but you need to quit dwelling on "Quality". It can and does mean too many different things to everyone of us here. Don't dwell on "Durability" either. It's another broad term. Shimano, SRAM, Campagnolo and many others all make quality parts. Buy from reputable vendors so you can be assured that Shimano, SRAM or Campagnolo sticker is on an authentic part made by or under the license of that manufacturer.

Just figure out what the model and part numbers are for the stuff you need to make your bike work. Then go look for them and buy then. If you have a choice between two parts, then read all the info you can find about both. Make a decision and do something. Even if you make a mistake, you'll learn from that..... or at least you should if you aren't totally depending on strangers from the internet to make decisions for you.

alcjphil

If the original derailleur is still in good condition it doesn't have to be changed. Rather, you will need a new shift lever to change from 7 to 5 or 6 speeds

Iride01 

You bring up a good point, with all the different threads for this user, I've long forgotten what their goal is.

The OP probably needs to remind us all what they are doing and what they want the outcome to be.

sloppy12

you can sometimes just add a spacer to hub motor to get the clearance you need for freewheel.

is this bike aluminum? do you have pretty beefy torque arms for both sides of bike? honestly if its a aluminum bike you should probably just quit and get another bike.

first trip

hi i did all this reasearch of course before buying the motor. it is supposed to fit

first trip

ho it has long been replaced and i do need atm to buy another Rder so that is kind of why im here , i what to buy one that will do well on a megarange 6 or 5 speed (since the 7speed is a bit too large. So i want to choose a Rder that would manage weel 5 or 6 speed to avoid having to buy another one if my first buy is not the right one.
someone wrote that having a OS pulley jockey helps megarange so i might look for this caracteristic even if atm i dont know that is cosidered normal or OS . im Learning

mine is a step true. its 135 too the motor is xiongda double speed and supposed to accept freewheel.

i looked at the MFM2A-5DS and it tops at 28 teeth ... i really want 34 teeth.. i never use the high speed , i would even like to have larger megarange for more slow easy...
WOuld you happen to know a megarange 5 speed with less with than the 7 speed mega?

tx again

first trip

hi my research on endlesssphere led me to beleive that torque arm are needed for front only

i dont understand how adding a spacer can free space for the freewheel, is this what you say?

first trip

hi one is about quality , one about hierarchy . those are different from this one where i ask for help to choose a good rdre for a megarange 6 or 5 speed wich is the solution i thought about to solve the larger problem that the 7 speed is too wide when place with the hub.

does that help. the goals is to have a 34 megarange that allow the chain to do its work. idont care for if it is a 18 15 or event 12(well maybe a bit) speed but i need megarange.

first trip

HI if anyone can answer these question it would greatly help me

first trip

Just for the knowledge while staying in low money what material would you suggest for future choices ? steel? chromoly?

first trip

i dont know much about the spec but would this 6 speed mega freewheel be less wide than a mega shimano?
https://www.sheldonbrown.com/harris/freewheels.html

shelbyfv

I'm guessing you've run out your string here....

Iride01 

Well as I understand it Megarange is just a model name for a line of 7 speed Shimano freewheels that have a large 34 tooth cog and a differing range of cogs below that. I'd never have any reason to believe that any is less "quality" than another they put the name Megarange on. Nor will I believe that any other model of Shimano freewheel has any more or less "quality" than another that is significant for anything.

I'd use whatever Shimano freewheel I could find that has the gearing on it that I want and fits on my bicycle. Why do you have to have that 34 tooth cog? I thought you talked about only having a 6 speed shifter. Insisting on a 7 speed freewheel makes no sense for that shifter.

I will suppose that you might put a spacer on your axle if you already have the 7 speed FW and just need a wider O.L.D. spacing. (Over Locknut Dimension, AKA, dropout or through axle spacing) ..... But what about that 6 speed shifter? And possibly rear derailleur that might not handle the chain slack or range? or is this IGH and then what are you doing with a 7 speed FW on an IGH?

As far as hierarchy, what is your concern there? If you are going with a seven speed group, then you are in the 7 speed hierarchy or tier. Same for 5, 6, 8, 9, 10, 11 and 12 speed hierarchy groups. I think we can narrow it down to you are in either the 6 or 7 speed hierarchy. Pick one. You already said, I think that the 7 speed Megarange didn't fit without an issue.

Every 7 speed Shimano freewheel you get will have virtually the same total width as another 7 speed Shimano freewheel. Pretty much the same for other brands of freewheels.

And you are also in the lower end of the Shimano groups that might be disappearing soon entirely. These offerings where old back before the turn of the century. Though the names of the group may have changed for marketing purposes.

first trip

hi do you mean there is a limit no of question i can ask non written rule cause i searched and fond. this meaning aking all possible time available to obtain an outcome. It applies where there is a notion of a fixed or set amount of time to do what you can. Does anyone know the background of this e

first trip

hi
the quality question is another topic. i try to get away from7 speed not insisting on it
Every 7 speed Shimano freewheel you get will have virtually the same total width as another 7 speed Shimano freewheel. Pretty much the same for other brands of freewheels. seems to have some mm difference

Interesting this And you are also in the lower end of the Shimano groups that might be disappearing soon entirely. These offerings where old back before the turn of the century. Though the names of the group may have changed for marketing purposes
so by choosing a freewheel it is not futur proof. what is the new thing called that allow 34 and MORE teeth? i like easier slopes.

first trip

FOR MEGARANGE 34,:
HI so i receive this comment about pulley... how many teeth is an OSized pulley?
at the store, instead they talk to me about the importance of having a long arm....?
where is the truth? thx

Iride01 

This is getting old. Megarange is just a particular model line in Shimano. Nothing special about it in terms of quality. It does appear be coined as a marketing name for a few freewheels that include large 34 tooth or so cogs. But Shimano has other stuff that have 34 tooth cogs and larger. Not all of their stuff is compatible with the shifters, derailleurs and other components in different model lines of Shimano. Or any other brand for that matter.

As for over sized pulley..... you need to forget such stuff and just look at components that from the manufacturer are said to be compatible. If that component happens to have an oversized pulley wheel, then that's fine. You really don't just go out and buy an oversized pulley wheel to put on a DR that isn't made for an oversize pulley.

luns

I wouldn't worry too much about the OS pulley. There are derailleurs with and without that were sold for use with 34t freewheels.

The Tourney RD-TY500 (which appears to have been original for your bike) is current and is sold as a 6/7-speed Megarange derailleur. It would be a safe bet if you could get another one.

If you want an upgrade from that, I expect that any more current Megarange 7/8 or 9 speed derailleur would also work. The currently available Altus RD-M390 derailleur is an 9 speed derailleur that people have reported as working for 7 speed, which is close enough to 6 I don't expect any problems.

If you want to go even higher yet, I've seen reports that the Deore RD-M592 (a 9 speed derailleur) also works for 7 speed, but this is probably straying a little far from what your bike started as. If it were me in your situation, I'd probably go for the M390.


Okay, this helps. The pictures I could find of that hub with a freewheel attached, all show it with a 6 speed freewheel. Did yours not come with a freewheel? The engineering drawings indicate a 37mm space from hub body to locknut, and it's conceivable that a 7-speed freewheel wouldn't quite fit, but a 6 speed freewheel does.

There's a very limited market for 5 speed freewheels nowadays, and I don't know of any with a 34 tooth low gear. But given that your hub seems to support 6 speed, I wouldn't bother trying to find a 5 speed freewheel to use. Shimano has a 6-speed Megarange freewheel, the MF-TZ30-6. With any luck, you'll be able to get one.

https://www.ols.ca/mystore/shimano-f...mftz30/dp/6468

For shifters, I think there are a few variant of 6-speed Tourney shifters available - twist shift and thumb levers. I don't think there was ever a 6-speed rapidfire shifter (up/down triggers). I expect that any of the Tourney 6-speed shifters would work fine with an Altus 7/8-speed derailleur.

https://www.sjscycles.co.uk/gear-shifters/shimano-tourney-sltx50-6-speed-sis-thumb-shifter-plus

first trip

hi could you link me to some example of larger freewheels plz

first trip

Hi yes i would like a 6 7 derailleur since i officially checked and i can fit a 6 speed but not a 7 with the motor hub. Is is possible that Tourney RD-TY500 has different version , the pictures on amazon are a bit different and one says long cage? long cage ? what does it mean
id yours not come with a freewheel? The engineering drawings indicate a 37mm space from hub body to locknut, and it's conceivable that a 7-speed freewheel wouldn't quite fit, but a 6 speed freewheel does. è=è
Mine came naked i found a 6 speed megarange yesterday for it yeahhhh. Could you show me a link to the ingenering drawings you found and spec? tx would be usefull

. I expect that any of the Tourney 6-speed shifters would work fine with an Altus 7/8-speed derailleur
is the altus you talk about indexed and is it rapid fire?
the links look good
they look different https://www.amazon.ca/Shimano-Tourne...7842678&sr=8-2

https://www.amazon.ca/Shimano-Tourne...7842678&sr=8-1

luns

Here's the drawing:


https://sc01.alicdn.com/kf/H24dad373...38178d64be.jpg

As I said, I don't think I've ever seen a 6 speed rapidfire shifter. Of what's reasonably available nowadays, there's only Tourney thumb shifters (SL-TX30, SL-TX50, SL-TZ500), and twist shifters (SL-RS35). Altus hasn't been 6-speed in years, and other groups in even longer, but if you track down any of the older shifters, they'll probably work too.

The two Tourney derailleurs you showed are different listings probably created by two different people, for what's possibly the same part. If you check Shimano's exploded view for the RD-TY500, the only variations are in how the derailleur mounts to your frame. The derailleur either bolts directly onto a frame, or has its own permanently attached tab. The two Amazon listings are ambiguous about which version they're for, and some of the reviews report being sent the wrong one, so that's the only thing to watch out for.

https://si.shimano.com/api/publish/s...Y500-3957A.pdf

Iride01 

I wasn't referring strictly to freewheels. You can get a cassette that needs a freehub. And Shimano makes those with over 50 tooth sprockets on them. But, they are 10, 11 and 12 speed cassettes.

I don't even know if Shimano makes a freewheel today. There are Shimano freewheels all over the internet for sale, but I think it's just remaining stocks that various vendors or their suppliers already had. If Shimano is still making them, then their selection choices probably are few if they even retail them. I haven't seen any listed on their site. And there are other freewheels for sale too.

If you specifically have to have a 6 speed or 7 speed freewheel, you don't have a lot of choice today. Get what you can find and hope for the best. Or get an entirely new bike....

Don't be stuck in discussion here for another month looking for your perfect and ultimate freewheel. It may not be out there.

first trip

I already have the freewheel

first trip

hi i have a hanger like this on my bike https://www.deporvillage.net/union-g...RoCUkQQAvD_BwE

what are the name of the shape and donut shape part of the derailleur i have to choose from and wich one do i need to buy?
do you happen to know a site that has like 15 days and less of delivery that ships to canada?
also i notices some have

SGS written in there name