jimv

Hi Folks...

I've been doing alot of experimenting with singlespeed coaster-brake hubs (sachs, bendix, etc) lately. My problem is that the axle slips forward in the track ends of my Steamroller when I hit the brakes hard (but not locked-up). The axles are 3/8 x 24tpi and not the hardest material. It's not too difficult to strip the threads by over-tightening.

Are there any axle lock type thing that would work with track ends to prevent this? I have tried serrated washers but it still happens.

Thanks...

jimv

OneTinSloth

chain tensioners...or "tugs" as some people refer to them. there's one on the pic. of my lotus in the other "this is for xcutterx" thread.

jimv

Thank you thank you .... I knew there was such a thing but google searches for 'chain tensioners' wasn't doing it......but 'chain tugs' yes. BTW, beautiful rides.

Thanks again...

jimv

OneTinSloth

hey, no problem! glad i could be of assistance.

familyman

Any good info about which hubs you prefer? I'm going to build up a coaster brake bike this summer and haven't decided whether to get a modern el-cheapo coaster hub or look for an older one.

jimv

Hi familyman....

The singlespeed coaster-brake hub (ss/cb) has been my latest area of bicycle-related fun (besides riding of course). I've collected a dozen or so and have been pulling them apart and noting the differences. I'm putting together a web page on the subject but I can give you some things to consider now. I'm sure there are those on this list that could add alot more info as well.

All NEWER ss/cb hubs (I've seen) seem to be constructed using a cylindrical hub body with 'pressed-on' flanges rather than a machined single piece body. Under spoke tension, this may be suitably strong but to me it seems overly flimsy. Mexican made Bendix and all of the commodity (OEM-type) hubs including Joytech, Shimano, KT, etc seem to made this way.

If you're going to build a bike for Sunday neighborhood rides then any hub should work, but if you live in hilly terrain or are building a bike for everyday use then I recommend finding an older US made Bendix or better yet, a German made Sachs. Both of these are made using machined hub bodies.

Once you look inside, the differences become obvious. The brake shoe area of a Sach as compared to a Shimano Type-D is dramatic. Not to mention the general 'beefiness' of all the parts.

Things to note:

1. ss/cb hubs are heavy. A good one will weigh 4 -5 times more than fixie hub.

2. ss/cb hubs have much higher internal drag. The Sachs has a brake-shoe return spring clip that greatly reduces this but the drag is still higher.

3. Coaster brakes can generate very high heat in the hub which can burn away the grease followed by hub failure (could be catastrophic). So I would always recommend using a front brake too unless your local riding terrain is very flat.

4. The axles are what they are, and that's usually 3/8" x 24tpi. Not the strongest setup. These hubs are best suited for narrowly-spaced dropouts like 120mm. If you're big (like me) you may bend an axle....though I haven't ... yet.

I have a Surly Steamroller set up as SS and wanted a rear brake while keeping the bike as clean as possible. I started with a Bendix (Mexico) and now have an old Sachs (actually the best parts from 3 old Sachs). This is turning out to be sweet setup. As a point of reference, My 59cm Steamroller (with the Sachs hub) weighs about 20 to 21 lbs.

I've made some drawings illustrating the basic double clutch action (drive-coast-brake) of these hubs and can post them to the list if folks are interested.

I've yet to dig into a Morrow brake (probably the best of the lot but complicated and hard to find) and a New Departure (I have one, just haven't ripped it apart yet). The New Departure is interesting in that it used a series of discs (a multi-plate clutch) to perform the braking action. I don't know much about them yet but from a physics standpoint (heat dissipation and braking moment arm) they seem less than ideal but that's just a gut feeling at this point.

I hope this info helps and apologize if this post was too long.

Take Care...

jimv

familyman

Lots of good info. Definately gives me something to chew on while shopping. Looking forward to the web page as well.

streetdog

A word of caution about coaster-brakes. If your chain brakes or jumps the ring (a distinct possibility if your axle is slipping) you are brakeless. You could drag your feet on the ground or use the side of your shoe on your tire to stop.
Have fun.

jimv

So very true. That's why I use a front brake as well....especially living here in Seattle. I checked with one of the many excellent LBS's here and am going to snag a set of 'tugs' to solve the slipping problem too.

Take Care...

jimv

streetdog

Very prudent. Your coaster-brake bikes make me nostalgic for my Schwinn Typhoon, I could lay down a great skid on that bike.

Jonny B

jimv, I'm sure you're aware of it, but just in case I'll tell you anyway. There's a great place to find old bike bits called Recycled Cycles, it's in the U District (Boat Street I think, right on the waterfront). Just take a 73 bus and get off at the first stop after you get off the bridge. They have loads of old coaster brakes, along with countless other bits and bobs; the perfect shop for those hard-to-find but essential parts and all those things you didn't even know you needed

schwinnbikelove

Yay! Another coaster brake fan! I'll take any opportunity to show off, so, here's my Super LeTour with a 1995 Schwinn anniversary chrome coaster hub. I think it's probably just an el-cheapo Shimano??? Do you know anything, jimv? Do you have a pic of your Steamroller?

I've only had a problem with mine once, on horizontal dropouts, and the nuts weren't tightened enough. Slammed the wheel forward and snapped the part that holds the brake arm to the frame (words eluding me...)

Good luck!

legalize_it

do you have any experience with the sachs torpedo coaster hub? it is an automatic 2 spd coaster hub. i desperately want one of these!!!! if not one of those, ill take the bendix 2spd kick-back. the kick-back 2 spd is cool, but not nearly as cool as the 2spd auto!!!

jimv

Hi Johnny B, schwinnbikelove, legalize_it....

Thanks for the responses. I'll comment in the order you folks posted.

Ah yes I know it well ( I visit a few times a week ). My usual circuit involves stopping and shooting the breeze at Bikesport, Freerange Cycles, Wright Bros, Speedy Reedy, Recycled Cycles, R+E, and Bikesmith. I feel fortunate to live in a city with so many great LBS's. Sadly, one of the finest: Bikesmith will no longer be with us at the end of the month. The owner, Val, informed me this evening. He was really into anything unusual bike-wise and did alot to help people with a variety handicaps to ride again (or for the first time). He will be missed. He's been a great help with my coaster brake efforts as well. People like that don't usually don't have '.com' stuck to the end of their names.

When were you at Recycled? They've recently rennovated and you probably wouldn't recognize the place....but thankfully they've retained their cool niche.

Yes the coaster brake is a blast! Sweet bike you have too. If you take a picture of the hub body I probably could tell you what it is. If the flanges a pressed on It's probably a Shimano or KT. If there are red stripes running around the body of the hub it's likely a Mexican Bendix. Being from 1995 though I'll bet you're right about it being a Shimano.

The coaster brake arm on my steamroller says "Schwinn Approved" and is actually a beautifully machined (inside and out) Sachs. Smooth like butta!

How often do you ride the bike and what type of terrain? Has the hub performed well for you??

As for my Steamroller, I'll try to post pictures in the next few days with some hub close-ups. As to whether I know anything??? Hmmm, I don't know ;-)

Sorry, I'm clueless beyond 1-speed. But I'll talk to Val, if there's anyone who would know where to find one It would be him. He has made a 2-speed fixed gear hub. I believe it's a modded Sturmey-Archer. If he still has one around would you be interested in that?

BTW, I hope you realize that all of this is your fault. I checked on a 3-speed hub for you at Recycled Cycles awhile back and in the same bin was a Joytech Singlespeed Coaster. I grabbed it, took it home and disssembled it, and thought...."I like this, I wonder if there are better ones out there". So thanks for launching me into a whole new area of bicycle fun.

Take care all...

jimv

schwinnbikelove

So, jimv, let me ask you this. Is your axel spaced to death and your wheel dished, or have you found a hub spaced to fit your frame, or what? Mine is spaced at 110mm, I believe, and obviously the frame isn't, it's either 120 or 126, I don't remember for sure, but probably 120, if not, then that's a whole lotta spacin' goin' on. My wheel is pretty dished. (LBS's idea, I wanted to just squeeze the frame together )

Well, definitley not a red line hub. I think you were referring to the Stingray hubs here? So you've swapped out the brake arm on yours?

I haven't had any problems with mine, (I actually haven't even had it apart, it's already greased good, so no point in risking anything with my unknowledgeable hands, coaster-hub wise) except for the one I described earlier. I've also noticed that the cones are finniky and hard to get adjusted perfectly if you screw around with it. It could be just me here.

I don't know if you noticed or not, but it's got 26" MTB rims, obviously on a 27" frame. It affected ground clearance ( I have scraped pedals before when not careful) and steering, at least until I got used to it. Not too bad, though. It has been a rain bike so far, as well as a curb-hopper and the likes. Also, I like it when I'm feeling simple and just want to ride. Assuming that the cones are properly adjusted and the axel nuts are actually tight, LOL, I don't have any noticable drag at all, and the braking happens after an eighth of a back pedal, much better than the older ones, with sometimes almost a half rotation back pedal.

Here's the best pics I got with being too lazy to dig it out of a better spot than the corner of my basement. Does your setup look as bad as mine does in the second?

jimv

The Steamroller is spaced 120mm at the trackends and the Sachs was spaced for 110mm. That only required 5mm on each side. I can see how yours was dished to achieve a good chainline. I built my wheel symmetrically. If I had to space mine like yours I'm convinced that I would have bent the shaft after a few days. I'm 245 lbs.

No that was the arm that came with it. I believe Schwinn was using these nice hubs at some point in the past.

As long as they're well greased, they're pretty happy. I'm glad it's working out well. Pulling it apart isn't too tricky. I mentioned that I'll be putting up a webpage devoted to singlespeed coaster brake hubs and it'll have lots of pictures of disassembled hubs.

No, the cones can be a real pain. Assembling them in an axle vise helps alot (unless you can sprout a third hand at will ;-) The mexican made Bendix hubs actually need some play or the bearings will eat themselves. The older Bendix and Sachs hubs don't.

I noticed the wide rims but the higher profile tires makes it look right for the bike. The Steamroller has a 70mm BB drop and I use 175mm cranks but I haven't scraped yet but I do have alittle toe overlap....but it never caused me a problem.

Wow, that's very little. Of all my hubs, the Joytech is the smallest rotation at about 70 degrees. The low drag sounds like there's a spring mechanism to retract the break shoes while coasting or pedalling. The only hubs that I know of to do that are the Morrows and the Sachs. It's definitely not a Morrow but who knows, Sachs may have made pressed on flange hubs in the 90's. I'll look into it. If you ever take yours apart please take pictures of the guts.

Given the frame spacing you have, I don't think it looks so bad, and if it's working out well then I say ride it and have fun.

I'll post pics as soon as I can...

Take care...

jimv

familyman

I've got a bendix 2 speed kickback on a tandem that I'm going to be re-working in the next little bit. It's really really weird to ride. You'd think you have some controll of when it 'shifts' but in large part it shifts to high gear whenever it wants, you might be going slow, maybe fast, and you can't kick it back down until you're going quite slow. It's a family heirloom bike though so it has to stay all together. My wife's parents had it when they were first married and it still carries the city bike registration tag from 1972. It's pretty cool and rides so smooth. Weight about 60 lbs though.