msdumo

I have a late 80s Raleigh Mountain bike with 26in wheels with cup and cone bottom bracket with square cranks.
The cone on the axles are pitted and need to be replaced. The ball bearings look healthy and the cups are ok.
The crank axle has a 5S H8 stamped onto it. I would like to convert this to a cartridge type BB or else just replace the axle.
The question is what info do I need to select the right cartridge or axle?
I no I need the length of the axle to keep the crank distance the same.

HillRider

Measure your current spindle from end to end. If it uses crank fixing bolts, measure the overall length. If it uses nuts, measure from the bottoms of the threaded ends. A cartridge matching that overall length should be about right. Both the cup and cone axle or the cartridge may be asymmetric so just the length may not be a perfect choice.

Kimmo 

There's a good chance you won't be able to make the cranks sit exactly where they should be with any available cartridge BB, but you should be able to get close enough.

Bill Kapaun

The spindle should have a code on it such as 3-P, 3-S.....
One can then look up the offsets.

msdumo

Is the spindle what I call the crank axle. I'm a newbie
The axle has "5S H-8" stamped on it. Does that help?

Kimmo 

Synonym for axle.

Bill Kapaun

The "5" series is for Italian BB's.

Iride01 

My Raleigh Competition GS is BSA threaded with a 68 mm shell width. It's 10 years older than your bike and I can use most any modern crank in it that has a BSA threaded BB. Though your bike isn't a road bike, I'd be surprised if you can't find a modern crank for yours too with either cartridge or external cups as mine are.

What exact model is your bike? Search for a catalog of Raleigh bikes for the year of your bike and you might find the bb type in the specs. If it's BSA threaded you are off to a good start.

dedhed

YOu're going to want to know the type threading you have in your BB shell as well as the shell width. AS you pulled out the spindle already did you pay attention to which end is which?
They are not always symmetrical and one side may be longer than the other.


See more here.
https://www.sheldonbrown.com/bbsize.html

and here.
https://www.yellowjersey.org/photosf...st/spindle.pdf

msdumo

It's a mid 80s Raleigh portage mountain bike. I tried to look up but all I get is the road bike. Can't find any info on bike?

msdumo

It is asymmetrical. There is a line stamped on the spindle to indicate the gear side.

Iride01 

As I understood the OP they are wanting to switch to cartridge type bb. I'm not sure I understand why several others seem to be concerned about spindle offset and other stuff that only seems relevant for if they were keeping a cup and cone spindle. Am I missing something?

Kimmo 

The cranks are married to that spindle length and offset. Change either and the cranks aren't in the same place.

Iride01 

Portage is a touring bike isn't it? Not a mountain bike. If it is a touring bike, then that to me means you likely have a 1.37" x 24 tpi english threaded (BSA) bb shell and probably just 68 mm wide. But you can measure that width and know for sure. I was starting to worry though as I remembered after my first post a lot of mountain bikes then were one piece cranks.

https://www.parktool.com/blog/repair...nd-terminology

If you want to put a cartridge bb in it, you'll need to know the current length of your spindle end to end. I'd also bet it is JIS tapered. But if you want to get a modern two piece crank, I'm sure that would fit too and you can have external cups to get a wider bearing spacing.

Iride01 

yeah, I guess y'all are right, it will make a difference. That's why I bypassed cartridge BB's and went straight to two piece cranks when I was done with cup and cone.

The_Joe

You could also try to swing by a local bike co-op if there are any in your area that are open through the pandemic. They likely have a bucket load of orphan spindles.

msdumo

The bike (Raleigh Portage) has steel frame, 26 x 2" in wheels, 5 spd freewheel, mountain bike riser bars, no fenders and cantelever brakes.
Can't remember when I bought it but thinking 1985-87. So it is not a road bike and I'm not sure what would make it a touring bike.

Just one more question. How do you measure the shell length? Is that measured on the frame with all BB parts removed?
The spindle had "5S H-8" stamped on it. Someone suggested that the 5 series spindles have a 70 mm shell.

dedhed

Just one more question. How do you measure the shell length? Is that measured on the frame with all BB parts removed?

It is the width of the frame where the BB goes in. You don't necessarily need to remove the BB. Standard widths of threaded shells are 68mm, 70mm, 73mm

dedhed

It is most likely BSA threaded but as the OP quotes "Mt. Bike" it may be a 73mm shell width.
As most cartridge BB are symmetrical, they will require a longer spindle than just measuring the existing asymmetrical spindle due to the offset in it.

JohnDThompson 

A 5S spindle is intended for a 70mm shell with a 37.5mm drive side offset.

Most 70mm cartridges are designed for Italian thread shells, but you say this is off a Raleigh, so Italian thread is unlikely. I'd try an English thread cartridge with the same overall spindle length and drive side offset. Be prepared to exchange it if it doesn't work.

Moe Zhoost

My understanding of the difference between an axle and a spindle is that, although they do the same relative thing, axles are a shaft around which something turns and spindles are shafts which turn within something.

To respond to the OP: The 5S spindles are designed for 70mm BB shell width. They are asymmetric with about a 3mm offset towards the drive side. I believe they should be JIS taper so it may be easy to move to a cartridge BB, but there may be some difference in how deep or shallow the crank arms fit. Whenever I do a conversion like this, I first measure the original chainline at the crank for reference before taking things apart. Then I fit a cartridge BB of known spindle length, remount the DS crank, and measure the chainline again. Then I apply any positive/negative difference from the reference number to the length of the test cartridge to arrive at the proper size replacement.

I don't think you will be far off if you order a cartridge BB 2-3 mm longer than your current spindle length, but you won't know until you try. Just make sure the cartridge matches your shell width.

Bill Kapaun

Are there ANY thread size markings on the face of the cups themselves such as 1.37X 24tpi?
Often the DS cup is marked.

Iride01 

So what do you want to do? Now that you've found out a little more? And so have I.

If you are replacing your BB because it is worn, what about your chainrings? If they are ready or nearing time to replace, then a new crankset and bb might be just as inexpensive as a new bb and rings, depending on what you get.

A new crankset opens the possibility of more choices and options. I'd go with a two piece crank and external cups over a cartridge. Two piece cranks eliminate the issue of spindle offset that had me confused here earlier. The issues that necessitated a spindle offset don't apply in two piece cranks. That's one reason I like them.

If you've got the spindle out, take the threaded cups to a bike shop or co-op and someone there should be able to tell you if they are 1.37 x 24 tpi Enlish. Was the drive side left threaded? That's another tick mark for it being BSA. I'd think it unlikely anything Raleigh in mid eighties will be italian threaded. But I'd be happy for you to prove me wrong. I learn when it's done.

If it's BSA, then all you have to know is the bb shell width if you want a two piece crank. I think its the same for an ISIS or Octalink cartridge and crankset. You only need to know the bb shell dimensions and you are good to go searching. For square taper, you apparently have to know the offset.

So you saw how to measure the bb shell, what is it?

msdumo

Great answer. You educated an engineer and I now know the difference between a shaft and a spindle.

I measured shell length at 70 mm and the length of spindle at 127.7 mm. You are right on with 3 mm offset between right and left.
I was worried I might have Italian threads (26 tpi) but took the right handed bb end from my Norco and it threaded on OK. So I have English thread.
Just have to find a BB cartridge that might work.

msdumo

Measured everything. Have 70 mm shell, spindle length is 127.7mm and offset is 3mm.
I have a Raleigh Grandprix that was made in Italy. No idea on this my Raleigh Portage. So took end of my Norco and threaded onto Portage to confirm 24 TPI.
Bike is not worth spending money on a 2 piece crank. I like it for trails and gravel roads.
I have a Hybrid Norco Malahat and my Raleigh Grandprix for everything else.