Shimano freehub body internals

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fastpedaller
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Re: Shimano freehub body internals

Post by fastpedaller »

kylecycler wrote: 17 Apr 2021, 7:14pm
TheBomber wrote: 16 Apr 2021, 8:57pm Freehub tool came from eBay. I also made one originally and it worked for the first freehub but subsequent ones were too tight - my home made one didn’t have a bolt through the hub to hold it in place so it had a tendency to slip. The eBay ones are Chinese made but seem to be absolutely fine for the job and it was delivered much faster than the 2 weeks predicted.
I'd echo that - same experience - arrived so soon it was as if it was from the UK (although I don't know how or if the pandemic will affect shipping now), and it's a quality tool. Pebble did a nice job on the 11/16th socket but for all the tool costs it's well worth getting one.
One thing I've learnt in the last couple of years is to scroll down the Ebay page to see if there is any additional info - sometimes the address is in China, but there is a UK vat number (which can be checked online). meaning (from my experience) the goods are in UK. The other thing is to see if 24 hour delivery is an option (at extra cost, so I don't use it) indicating good in UK (or ISS delivery service :lol: )
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kylecycler
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Re: Shimano freehub body internals

Post by kylecycler »

fastpedaller wrote: 17 Apr 2021, 10:36pm
kylecycler wrote: 17 Apr 2021, 7:14pm
TheBomber wrote: 16 Apr 2021, 8:57pm Freehub tool came from eBay. I also made one originally and it worked for the first freehub but subsequent ones were too tight - my home made one didn’t have a bolt through the hub to hold it in place so it had a tendency to slip. The eBay ones are Chinese made but seem to be absolutely fine for the job and it was delivered much faster than the 2 weeks predicted.
I'd echo that - same experience - arrived so soon it was as if it was from the UK (although I don't know how or if the pandemic will affect shipping now), and it's a quality tool. Pebble did a nice job on the 11/16th socket but for all the tool costs it's well worth getting one.
One thing I've learnt in the last couple of years is to scroll down the Ebay page to see if there is any additional info - sometimes the address is in China, but there is a UK vat number (which can be checked online). meaning (from my experience) the goods are in UK. The other thing is to see if 24 hour delivery is an option (at extra cost, so I don't use it) indicating good in UK (or ISS delivery service :lol: )
That's a neat trick. I could trace back my Ebay order - it was about three years ago, although I've never got around to using the tool yet - and see if that applies. Especially just now, with shipping being affected by the pandemic, it would be worth doing what you've described, particularly if ordering Chinese goods. Some of their other tools are excellent as well.
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531colin
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Re: Shimano freehub body internals

Post by 531colin »

TheBomber wrote: 17 Apr 2021, 8:44pm
You can't mean 4 pawls in a hub body?
Yes, that is what I mean. I can’t seem to find a photo at the moment but obviously they are smaller than the ones in Pebble’s picture above. Each pair have their own spring squeezing on an ‘ear’ that is either on the inner or outer side of the freehub body. The idea is they give you faster pick up of the ratchet as the required rotation is halved. This is only an issue when trying to restart on a steep off road climb with clipless pedals and low gears. The problem is real but I’m not convinced the freehub modification really solved it.

Given what you say, and rjb’s comment, I may investigate the ball bearing situation. They are just spare wheels now though, since I brought the XTR ones back into service by building them onto some nice 700c rims.................
I can't avoid that nagging thought that there must be an easier way to get a faster pick-up....or at least a way that doesn't involve making the stressed components smaller. (If you think its tricky on clipless, try getting into toeclips and straps!)
We have got great fat axles, through axles, cassette bearings for everything to run on (with tiny balls) 1 by drivetrains pushing the size of the top sprocket down.......
Going back to screw-on blocks, I think the actual freewheel was bigger, because the block body was stepped diameter....big sprockets had a big hole in the middle, small sprockets a smaller hole, and the top sprocket or two overhung the end of the freewheel.
As a penniless schoolboy, I used to dis-assemble blocks to remove them.....removers were expensive and unreliable. You couldn't actually see the things working even when you re-assembled them, so maybe I'm wrong and they had both pawls engaged? But for whatever reason, Shimano seem to use 2 offset pawls both engaged, and it obviously works for them. If they used 2 pawls, but only one engaged they could straightaway halve the pick-up lost motion; which suggests to me that they think the pawls aren't strong enough to do that.
jb
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Re: Shimano freehub body internals

Post by jb »

People should ride with a pre-NIG AW three speed for a while then they'd think pick up was pretty damed instant in Shimanos freed hubs. :lol:
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TheBomber
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Re: Shimano freehub body internals

Post by TheBomber »

I can't avoid that nagging thought that there must be an easier way to get a faster pick-up....or at least a way that doesn't involve making the stressed components smaller. (If you think its tricky on clipless, try getting into toeclips and straps!)
You may well be right - the tricky restart described remained tricky with the new wonder freehub. As for toe clips - you don’t see many of them being used off road any more. All in all, perfecting your ‘stamp and go’ cleat engagement technique was the best solution.

In their defence I never had a problem with the smaller pawls breaking - but could doubling the number have increased the wear rate on the ratchet when freewheeling, leading to my issue from page 1 of this thread?

A couple of pictures from the freehub Brucey recommended to ‘rest in pieces’:
34BBB897-73BE-4DEA-8F9D-E55FC2A7D987.jpeg
0004024A-011B-4CA6-AC12-7B80DA0E6F7B.jpeg
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531colin
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Re: Shimano freehub body internals

Post by 531colin »

TheBomber wrote: 19 Apr 2021, 6:04pm In their defence I never had a problem with the smaller pawls breaking - but could doubling the number have increased the wear rate on the ratchet when freewheeling, leading to my issue from page 1 of this thread?
I think (as Brucey said) the wrong material is the most likely answer.
Pebble
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Re: Shimano freehub body internals

Post by Pebble »

kylecycler wrote: 17 Apr 2021, 11:42pm
fastpedaller wrote: 17 Apr 2021, 10:36pm
kylecycler wrote: 17 Apr 2021, 7:14pm

I'd echo that - same experience - arrived so soon it was as if it was from the UK (although I don't know how or if the pandemic will affect shipping now), and it's a quality tool. Pebble did a nice job on the 11/16th socket but for all the tool costs it's well worth getting one.
One thing I've learnt in the last couple of years is to scroll down the Ebay page to see if there is any additional info - sometimes the address is in China, but there is a UK vat number (which can be checked online). meaning (from my experience) the goods are in UK. The other thing is to see if 24 hour delivery is an option (at extra cost, so I don't use it) indicating good in UK (or ISS delivery service :lol: )
That's a neat trick. I could trace back my Ebay order - it was about three years ago, although I've never got around to using the tool yet - and see if that applies. Especially just now, with shipping being affected by the pandemic, it would be worth doing what you've described, particularly if ordering Chinese goods. Some of their other tools are excellent as well.
The packaging when it arrives is a big giveaway of where it originated. Stuff is coming from China very quickly at the moment as flights are not busy and as such the planes have plenty spare capacity, goods are leaving the same day they arrive at the airport, in more normal times it could linger at the airport for weeks

I bought something recently, it would have been about £7 in a UK shop, it was £2.99 with free postage from mainline china, it took 4 days! The packaging was Chinese. No wonder Trump wanted to stop this unfair heavily gov subsidised service.
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kylecycler
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Re: Shimano freehub body internals

Post by kylecycler »

Pebble wrote: 19 Apr 2021, 11:52pmThe packaging when it arrives is a big giveaway of where it originated. Stuff is coming from China very quickly at the moment as flights are not busy and as such the planes have plenty spare capacity, goods are leaving the same day they arrive at the airport, in more normal times it could linger at the airport for weeks

I bought something recently, it would have been about £7 in a UK shop, it was £2.99 with free postage from mainline china, it took 4 days! The packaging was Chinese. No wonder Trump wanted to stop this unfair heavily gov subsidised service.
That's good to know, I thought it was the other way around just now - I thought it was like the slow boat from China! I've got a few things I was going to order from China but what I thought would be the long shipping times (or even more expensive shipping, which might be wrong too) was putting me off.
fastpedaller
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Re: Shimano freehub body internals

Post by fastpedaller »

Beware of added import duties though!
Last edited by fastpedaller on 20 Apr 2021, 11:16pm, edited 1 time in total.
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kylecycler
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Re: Shimano freehub body internals

Post by kylecycler »

fastpedaller wrote: 20 Apr 2021, 3:58pm Beware off added import duties though!
Well, there is that too, right enough. It's a bit of an unknowable, I think. I believe you can order some stuff with customs duties 'pre-paid', or whatever, but I suppose it's something you have to factor in. Maybe a bit of a lucky bag, even.

Only time I've had to pay customs duties, although I've hardly ever ordered stuff from abroad so far, was a NOS Raleigh 26tpi headset for my Carlton Ten from Yellow Jersey in Wisconsin, USA (the BB is 24tpi, the steerer 26tpi, typical at the time for that frameset, apparently).

Didn't cost a lot by itself but with shipping and import duties it probably cost at least twice as much, but it was worth it. I've only got the frame and fork - the rest got thrown out years ago (don't ask!) - but it means a lot to me for sentimental reasons.
zenitb
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Re: Shimano freehub body internals

Post by zenitb »

531colin wrote: 19 Apr 2021, 10:29am I can't avoid that nagging thought that there must be an easier way to get a faster pick-up....or at least a way that doesn't involve making the stressed components smaller. (If you think its tricky on clipless, try getting into toeclips and straps!)
Well Colin - in the mountain bike word there is .. in recent times getting a faster pick-up became an obsession with the manufacturers .. and we have seen "click wars" with vendors jousting with one another for maximum "clickage" !!!

I have a Novatec 642 rear hub (also sold as the Nukeproof Horizon) and that has 42 teeth in the hub - with 6 pawls.

The "clever" bit is that only 3 of the pawls engage at once since 3 of the pawls are offset by the other 3 pawls by a 1/2 tooth spacing... giving 42 x 2 = 84 clicks per revolution and a drive pickup of 360/84 = 4.2 degrees before a pedal stroke engages.

When the hub does engage the drive is going through half (i.e. three) of the six pawls. Each pawl is scalloped so it contacts two teeth .. presumably to make it stronger - meaning although only three pawls are engaged at a time they are engaging six teeth in the hub.
Three pawls engaged at any one time.. contacting six teeth
Three pawls engaged at any one time.. contacting six teeth
This needs a huge hub shell of course to accommodate all the gubbins ..
My Novatec 642 hub showing pawls and teeth
My Novatec 642 hub showing pawls and teeth
My Novatec 642 hub showing hub width
My Novatec 642 hub showing hub width

Apparantly Novatec have now released an even more monstrous hub similar to this one but with two stacked sets of pawls accommodated by an even bigger bulge in the hub ..
Stacked !!!
Stacked !!!
...this is for e-bikes from the looks of it where the drive forces are going to be stronger. I wonder how much of this e-bike stuff would be useful for tandems...?

I plan to build my hub into a 29er wheel and I predict it is going to buzz like a swarm of angry wasps due to the 84 clicks per revolution - will just have to keep pedaling.. !!! Time will tell whether this is any more reliable than Shimano's traditional freehub ..
ClappedOut
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Re: Shimano freehub body internals

Post by ClappedOut »

Marine grease
ClappedOut
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Re: Shimano freehub body internals

Post by ClappedOut »

Marine grease my plan for things that get wet unavoidably with poor seals
Pebble
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Re: Shimano freehub body internals

Post by Pebble »

zenitb wrote: 20 Apr 2021, 10:50pm
Well Colin - in the mountain bike word there is .. in recent times getting a faster pick-up became an obsession with the manufacturers .. and we have seen "click wars" with vendors jousting with one another for maximum "clickage" !!!

I have a Novatec 642 rear hub (also sold as the Nukeproof Horizon) and that has 42 teeth in the hub - with 6 pawls.
What is the diameter of the teeth (lowest point to lowest point) ? looks a lot bigger than the standard shimano one,
zenitb
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Re: Shimano freehub body internals

Post by zenitb »

Pebble wrote: 21 Apr 2021, 12:04am
zenitb wrote: 20 Apr 2021, 10:50pm
Well Colin - in the mountain bike word there is .. in recent times getting a faster pick-up became an obsession with the manufacturers .. and we have seen "click wars" with vendors jousting with one another for maximum "clickage" !!!

I have a Novatec 642 rear hub (also sold as the Nukeproof Horizon) and that has 42 teeth in the hub - with 6 pawls.
What is the diameter of the teeth (lowest point to lowest point) ? looks a lot bigger than the standard shimano one,
Pebble it measures 45mm ... yes you would never cram all those teeth into a Shimano HyperGlide cassette body .. Shimano are moving away from HG cassettes/teeth/pawls though and using some sort of ratchet system in their Scylence Micro Spine hubs ...

[EDITED: to show correct location of ratchets]
Shimano Scylence ratchets ..
Shimano Scylence ratchets ..
Scylence teeth ..
Scylence teeth ..
..I am guessing these will eventually take over from HG ? And I am also guessing "Scylence" means it doesn't buzz !!!

RIP freehub pawls ?
Last edited by zenitb on 21 Apr 2021, 3:55pm, edited 2 times in total.
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