| i just bought a 70 something Schwinn Super Sport that has been fitted with what appears to be a Tokheim Speedisc 5 speed transmission with a grip shifter. It is marked Tokheim Patent Pending. I have only found a couple of references to the Tokheim transmission and just one not too clear drawing of it in Whitt’s Bicycling Science. Do you know of any source for information on this transmission? The bike looks like it has not been used a lot and may have sat in a garage for most of the past 30 years so I want to service it before trying it out. |
| Is this an internal gear?|
| The Tokheim was a five speed, expanding sprocket. In was introduced in 1974 and lasted until about 1980. It was found almost exclusively on entry level bicycles. I believe I have an old article on it, if I can find it. |
| I found passing references to it but nothing describing adjustment and operation. |
| according to the book "The New Complete book of bicycling" by Eugene A. Sloan,1974, and heavily edited by me...|
tokhiem gearmaker, tokhiem corportation, Fort Wayne Indiana
Maintanance of the gearmaker
to compensate or take up slack in streched cables, shift unit into fifth gear, adjust cable until an index hole in the bracket plate is lined up with and index hole in an "interposer assembly" and retighten cable locknut. in the picture I have the interposer assembley looks like some sort of guard that wraps around the front of the sprocket assembly.
according to the picture I have, this index hole is under a slot in the outer housing, the one that the cable mount is hooked to.
it takes a 1/8 inch chain.
you can't remove the rear wheel without breaking the chain, but the book claims that you should be able to remove one side of the tire and patch the tube without dismounting the wheel. yay.
the book says that the gearmaker takes a wider than normal spacing between stays, and takes its own hub.
the point of the thing is apparently to keep the chainline strait in all gears, to avoid chain and sprocket wear. it claims that the chain will not get hung up inbetween gears, allows "under power" shifts, and allows you to downshift by pedaling backward while standing still. sounds neat.
I want one, but have never seen one, and if I did I would hang it on the garage wall and throw worn out campy stuff at it to relieve stress. I already do that with every positron I find. proves nothing, but its pretty pointless and therefore better than tv. but you should probably ride it and tell us about it. jason
| Ebay item # 190156005124 is either the bike under discussion or one just like it. There are a couple of pictures of the gear changer. Interesting and, it appears, unsuccessful idea. I wonder if it was the first attempt at such a mechanism; most current bike features can be found in the ancient Sears catalogs.|
| I have instruction manual for the tokheim model 505 bike transmission, also a few[new] of the transmissions. The manual gives assembly instrutions. keith|
| I'd like to share my recent (and ultimately successful) experience with freeing a frozen handlebar stem.|
The problem was the removal of an alloy handlebar stem (AVA) from a 1960 Schwinn Continental. I was able to raise the stem bolt and free the wedge, but was then unable to rotate the stem relative to the fork steerer tube, even after daily application of penetrating solvent for a week's time (to both the upper and lower stem/steerer tube access points). I quickly realized that I would damage the [surprisingly slender] fork blades if I attempted to use much leverage while attempting to rotate the stem and free it from the fork steerer tube.
My next step was to search the Oldroads archives. One post suggested clamping the fork crown in a wood vise with the fork still mounted on the rest of the frame. I attempted this (using some steel handlebars clamped in the stem for leverage), but was still not able to free the stem. I decided to pause the attempt and contemplate my options.
After remembering an Oldroads post that described how a stuck seatpost could removed with vertical hacksaw cuts administered from inside the seatpost, I decided on a surgical approach that would sacrifice the stem (but save the fork).
I completely removed the wedge bolt, then made a horizontal cut through the stem to completely remove the stem extension while leaving a two-inch "stub" of the stem exposed above the steerer tube. I was then able to unscrew the upper headset bearing assembly and remove the fork from the frame.
I then clamped the fork (at the crown) in vertical position in a wood vise. Using a round file, I enlarged the inside hollow area of the stem so that I could insert a hacksaw blade inside. I then cut a slot along the entire long axis of the stem, monitoring carefully to avoid any change in sound and feel of the sawing (the objective being to cut completely through the alloy wall of the stem but to avoid cutting into the surrounding steel fork steerer tube!)
After the cut was made, I used a large pipe wrench and attached it to the exposed stub of the stem. I positioned it so that when force was applied with the wrench, the stem would be slightly crushed into the space of the slot. After the deformation was accomplished, the stem immediately began to turn and I was able to ease the stem out of the steerer tube.
Hope this helps others who might be faced with removing badly-stuck handlebar stems (assuming you are willing to sacrifice the stem).
| Thanks for posting, Lenny, and congratulations on owning one of the most collectible Schwinn bicycles ever made. I am glad you were able to salvage that fork!|
| Hi John,|
You're welcome...hope it helps others. I certainly have appreciated your long-time and always informative contributions to this great discussion group.
I most likely won't complete the overhaul of this bike until spring. It's in pretty good condition considering its age and has most of the original components (except for one replacement pedal, alloy handlebars in place of the original steel, and will of course, it will now feature a replacement stem). I'll post my impressions of its riding qualities when I get it all back together. It's quite a bit lighter in weight and contruction compared to Schwinn Continentals from the 1970s (the fork blades, fork steerer tube, and wheel rims are of much thinner steel contruction compared to later versions). The frame tubes may possibly be thinner or of narrow diameter as well, though I have not yet measured them against later versions (don't have any later Contis on hand at the moment).
My current favorite rider is a 1973 Schwinn Super Sport (Sunset Orange) that I recently rebuilt. It's a very comfortable ride and gets up hills just fine (if you're not in a hurry). I also really like the durability, bearing quality, and gleaming chrome beauty of its one-piece crank!
| Hey, I did that recently, too. Seems like September is the official "pie-cut your frozen stem" month. |
I had the same problem with a Trek 770 frame that was just too nice to destroy. After exhaustive research on the web and trying every method recommended by Lennard Zinn (including saturating the whole darned thing with PB Blaster), I was left with no other option but sacrificing the stem (a Cinelli too, sob) and attempting the "pie cut" hacksaw blade method. I was aided by a neat little tool I had from Stanley that holds a single hacksaw blade like a straight-saw. It made the process a lot easier and saved me from a few blistered fingers.
Sure enough, some careful sawing, taking care not to cut the steerer tube, resulted in a 100% successful effort. The remains of the stem came out looking like they'd been salvaged from the Titanic. By the way, Jobst Brandt, legendary author of "The Bicycle Wheel" book recommends this as the only fail-proof method. Moral of the story: make sure your stems are well (and frequently) greased.
| I think I might have found another way to do it. On my own bike, the stem was installed as far as down it would go. This meant that, when I unscrew the headset nuts, they quickly start butting up against the stem overhang. Unscrew some more and they start pushing the stem out millimetre by millimetre... |
The top nut will eventually come off the thread so turn your attention to the lower one. This will butt up against the top nut - unscrew some more and you'll push the stem out another couple of cm or so until the lower nut too reaches the top of the thread.
It takes quite a bit of force to keep things moving. You'll probably need a longish headset spanner with a decent bit of leverage. I managed to snap a cheaper tool so went out and bought a good one.
Before you do this, it might be a good idea to unscrew the the quill bolt 6-8 turns or so and then whack it (carefully!) with a hammer to knock the quill end down, in case it's stuck.
I think I managed to pull the stem half an inch or an inch in this way before I ran out of thread. Oddly enough it still wouldn't come free by twisting the bars. Jammed tight as ever. I'd expected the layer of corrosion to give way in a sudden "snap!" after which the stem would once again be pliable but it looks like it's going to fight every inch of the way.
At this point I could just grease my bearings - that's all I really wanted to do - screw everything back down, and ride off with a slightly higher stem. If you're in the same boat be careful: if the stem tapers or is shaped it could be damaged by the headset bolt being forced up into the metal and possibly this could lead to a stress fracture later. I once had a set of bars break on me and it wasn't pretty. Think you can ride with one hand? I thought so too.
If you really have to remove the stem it should in principle be possible just to screw it out bit by bit but you'd need to figure out some way to keep packing spacers in. In theory it would go like this:
1. Unscrew the lower headset nut up until it's at the end of thread. The stem should have been pushed out a little bit.
2. Screw the nut back down again.
3. Insert a spacer under the stem so that, when you unscrew the headset nut again, it pushes the stem out another little bit.
Washers or spare headset bolts might be used as spacers. Obviously you can't get them onto the fork with the stem in the way but maybe you could try cutting them in half and then break out the superglue, gluing each to the one above. Or something. They'd have to be attached firmly enough not to pop out once the headset nut starts winding back up, piling on the pressure. Perhaps some kind of clamp would do it?
As I say, I haven't getting the stem out completely in this way but I think it could work and it might be a whole lot easier than drilling/cutting out the stem.
| Hi all, I picked up a Miyata 'Three Ten' S/N 0G74566 recently and have got myself thoroughly confused about wheels and tires.|
It came with a 27x1 Araya rim on the rear, built on a Suzue cup'n'cone hub. The front however was an Ambrosio Extra Elite 19 on a Shimano hub - no obvious sizing info on it (and tire to far gone to tell) but I think it's a 700C.
Assuming the rear to be original I picked up an almost matching 27in Araya/Suzue wheel locally. I fitted a pair of Conti Ultra Gatorskin 27 x 1-1/4 but when I went to fit them they do not clear (well the rear BARELY clears and the front rubs hard on the fork crown - sidewall clearance is OK it is just the overall tire height).
So - is this a 700C bike? Or is the Conti 27 x 1-1/4 a tall tire? Everything I have read on the early-80s Miyatas lists 27 x 1-1/4 as the original size. Would I have better luck with a 27x1 (unfortunately nothing available locally in that size to try)?
Thanks in advance.
| Hi! |
It´s funny but true: 27" wheels are bigger in diameter (630mm) than 28"(622mm)also called 700C. This confusion is caused by different ways of measuring tires in Britain and continental Europe. You won´t find 27x1 tires. I believe there is only one size of 27" tires.
See this: http://sheldonbrown.com/tyre-sizing.html
| Thanks, I am aware they are different sizes - I am confused about which is correct for this frame.|
27 x 1-1/4, 27 x 1-1/8 and even 27 x 7/8 are all 'available' sizes according to sheldonbrown / harris
| FWIW, I had a three-ten and had 700c wheels. It might be different for other years.|
Watch for cracks on the top tube where the internal cable routing enters and exits.
| ...and the ambrosio elite is a wonderful rim.|
| Sometimes you can use either 27" or 700C wheels - just depending on the tires you mount on them. On some frames built more for 700C wheels - sometimes a 27" rim with a low-profile tire will work just fine......but mounting a taller profile tire - and it won't even fit - it rubs the fork crown.|
| 700 x 28C is the original tire size for a Miyata 310 of that vintage. The OEM wheels were Ukai 20A rims laced to Shimano Z-series hubs.|
| Thanks! that's exactly the info I was looking for.|
Makes sense too because the brakes are Z-series (BR-Z57 calipers + BL-Z326 levers) - the rest is 105 'Golden Arrow'
| Thanks, T-Mar. I believe most 1980s and even late 1970s road bikes came with 700C rims, even in the U.S., where 27" wheels were standard through the 1960s and into the mid-1970s.|
| There's usually a bit more clearance at the rear brake bridge than the fork. You can often get away with using a 27" wheel in back when a smaller 700C wheel was original. Check the wheel sizing info from a cyclocomputer and you can get an idea of the relative sizes of different rims and fatness of tire, since the overall circumference is what matters to the computer.|
(BTW, don't call 700C 28", since the so-called 28" size is even bigger at ISO 635. I know; many Europeans do call 'em that.)
| Harv, the only 105 should be the derailleurs/shifters. To cut costs Miyata downgrqaded the brakes and hubs (Shimano Z), headset (Tange), pedals and crankest (SR). From what I can see it is a 1986 model. The color, components and serial number all corroborate the year. I even bet it has a silver head tube. |
John, I think that statement is a little broad. Many entry level models used 27" wheels through the mid 1980s. For instance Miyata did not introduce 700C on the 310, a lower-midrange model, until 1986. Some true entry level models like the 110 and 112 still had 27" as of 1990. And if we look at Peugeot, the entry level Monaco and Marseille were still using 27" wheelsets in 1988.
David, there are at least four different 28" tire/rim sizes with distinct bead seat diameters. One of them has a 622mm bead seat diameter, the same as 700C. Back during the 1970s boom, many racers used them for training wheels so that they did not have to reset the brake pads when switching from their race tubulars, They were commonly known as 28 x 1-5/8 x 1-3/8.
| Thanks T-Mar, you are spot on - I shouldn't have said "the rest": pedals are SR SP-153; crankset SR 'Signature' 170mm with 52-42 chainrings; bars Sakae CT. I am having trouble finding clips to fit the pedals so for now I've swapped on a pair of 600's. |
The head tube is kind of flat white with a 'Miyata' sticker rather than an actual badge - see pic. Haven't positively ID'd the stem/headset or BB yet.
I put on a new chain today and swapped a take-off Challenge Gara that I had lying around onto the front (700C) with the Kenda gumwall 27x1-1/4 off the intended 'replacement' front wheel onto the rear. She rides and shifts really nicely and will be a great replacement commuter for the low-end Dawes 12sp ('Sterling') that I brought over and promptly got stolen (before I had even re-taped the bars...)
I was originally planning on making her my 1st single-speed project but the Golden Arrow is so pretty that I'm going to keep it. The Ambrosio runs super true and I will be on the look-out for a rear to match it!
So all-in-all not too expensive a lesson - I only paid $15 for the 'new' 27in wheel and I got a usable tire for the rear that will tide me over until I find a suitable 700C replacement wheel... at which point I will have a nice pair of Araya 27in alloys to find a project for :)
| I, too, have a pair of SR SP-153 pedals. Do you have any info on these pedals such as who makes them, quality, year made, etc.? This is forum thread is the only result I found when googling the pedals.|
| does anyone have info/history for marzano bicyles? i cant seem to find any info anywhere. here links to to bikes that are/were on ebay:|
all comments or infi is appreciated.
| Never heard of them but I find it very interesting how dissimilar those two examples are. No one element of construction apart from maybe the rear track ends, are identical on these two bikes. Maybe ones a fake?|
| the larger of the 2 appears to be 15 or 20 years older then the red and yellow one. i purchased the red and yellow frame and it arrived yesterday. its a nice looking frame. feels like the tubing might be spx. i havent had a chance to remove the headset and bb yet.|
thanks for the comment, ed.
| I grabbed a Motobicane Mirage frame out of the scrap metal pile. This had 27 inch wheels. I had herd that French frames had wide spaced frames. I put a pair of 700 x 38 wheels on it and it fit. This included Raleigh sprite fenders! I use a modern hybrid bicycle for my primary ride. I hope to use this as a second bicycle and depending how this feels and rides, it may replace the modern one. I would rather ride an old French Bicycle. I have to find good brakes for this that clear the tires. Keep an eye out for old 70s French 29er Bicycles! Ed|
| Mafac racers...original equipment, cheap, efficient stoppers that should reach.|
| Thank you, I will try to find them. I remember seeing those or some other center pull brakes on French bicycles. The bicycle is looking stranger. I found the forks to be damaged at the top of the steerer. But fortunately I had a set of Peugeot forks that were just right. I now have a white bicycle with blue forks and white Raleigh fenders. I have used oval chain rings on other bicycles and this one got a triple SR 165 crank set with gold KKT pedals. Amazing what fun recycling can be. Ed |
| Keep "recycling," Ed! Centerpull calipers are an under-appreciated solution to the problem of providing effective braking across high-profile, wide tires. Weinmanns or Universals should work fine, as well, but Mafacs would be correct for a 1960s or early 1970s French bike. (By the late 1970s Peugeot seems to have converted from Mafac to Peugeot-labeled Weinmanns, at least on some models.)|
| Yes I found a pair of Mafac Racers! A1 cool look and with some new modern pads I think this will provide stopping power. I am using nice Weinmann levers for a north road style handlebar. I was able to install a sealed bottom bracket into the old cups! I knocked off the cups on the sealed bracket and it went right in! It needs some tuning but a comfortable ride. Ed|