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Hope Pro II 150x12 48pt - a little mod

Udi

RM Chief Ornithologist: “I Brake for Birds”
Mar 14, 2005
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Did this a while ago and been riding it for a couple months, thought I'd share.

Always liked the price / weight / strength ratio of the Pro II's but thought the stock 24pt engagement was particularly slow, even though it doesn't make a big difference to most riding. Decided since I've run them for years on two pawls anyway that it would be fun to bring the other two back in, except modified for offset 2+2 engagement and 48 in total.

 

Sandwich

Pig my fish!
Staff member
May 23, 2002
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01776
Looks like two longs pawls and two short ones. Neat mod. What was the reasoning for dropping two in the first place?

damn those parts are clean...
 

Udi

RM Chief Ornithologist: “I Brake for Birds”
Mar 14, 2005
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Sandwich - Yep, two shorter pawls. The reasoning behind dropping two in the first place was to make it a bit quieter and kill a bit of drag, but this is more fun. I played with the spring tension a little bit to reduce volume/drag while still pushing all pawls into their seats firmly, so it's not too bad even though it's louder than with just two.

92SE-R - I've run them (had three of the rear hubs) for nearly 6 years on two pawls, so while technically you would halve the load capacity, it seems to be well within the strength limits of the hub (at least for my 180lbs with gear and whatever force I can generate personally). I can notice the faster pickup, obviously the dead zone is now halved so it's a reasonable difference.

Racebike/juanbeegas - Two (shorter) pawls now engage offset to the regular two, so engagement points are doubled. The load is on two pawls at a time, similar to a 72pt hadley.
 

Udi

RM Chief Ornithologist: “I Brake for Birds”
Mar 14, 2005
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I used a sharp axe and a lot of faith.

I'll take some vernier measurements of the shortened pawls next time I have the hub open if that helps, but basically you have to get two things right: 1) the timing, i.e. the short pawl has to engage exactly between two clicks of the standard pawls and 2) the contact angle with the track, this changes slightly from stock as the short pawls engage at a greater angle of rotation. I just trimmed one on a bench grinder a little at a time, testing until it was perfect, and then made a second one identically shaped.
 

bismojo

Monkey
May 5, 2009
271
38
Very nice mod and tidy as ussual, udi :)

I always liked my hope singlespeed hub (48pt of engagement) and wonder about retrofit the pawl mech into 150mm proII hub body..

Maybe the SS hub uses alternating pair of pawls as well?
 

EVIL JN

Monkey
Jul 24, 2009
487
23
as long as we are talking poe, those supertar 120 points (same as halo supa drive hub) i had one halo and I9 and it does not feel as if they equal engagement speed. It feels like the halo as a lag in the engagement, it seems the teeth are engageing but then it takes a little more angle for it to become a solid engagement. Kind of feels like false marketing that they are supposed to engage as fast as my I9.

Anybody that knows the mechanincs behind them that can explain the apparent difference?
 

norbar

Turbo Monkey
Jun 7, 2007
9,614
368
Warsaw :/
as long as we are talking poe, those supertar 120 points (same as halo supa drive hub) i had one halo and I9 and it does not feel as if they equal engagement speed. It feels like the halo as a lag in the engagement, it seems the teeth are engageing but then it takes a little more angle for it to become a solid engagement. Kind of feels like false marketing that they are supposed to engage as fast as my I9.

Anybody that knows the mechanincs behind them that can explain the apparent difference?
Aren't they less pawls, more teeth?
 

Sandwich

Pig my fish!
Staff member
May 23, 2002
16,123
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01776
The halo mega point hubs have three pawls with three teeth each. I looked into it when I was doing my trailbike. I think the idea is that with one pawl you can get three different engagement points, so with 60 teeth on the hub you get "180" or something like that, but some of them overlap. Not sure exactly how many teeth are on the hub, I suppose 40 would make more sense, but I've read that most people say they don't actually have 120 points of engagement.

Edit, I r dum:
http://forums.mtbr.com/4880549-post34.html
http://forums.mtbr.com/5023624-post48.html

If you don't have an mtbr login, then tough luck sister. It's actually a "wedge pawl" system, and it uses lots of TINY teeth, instead of three teeth per pawl like I9. My bad.
 
Last edited:

Salami

Turbo Monkey
Jul 17, 2003
1,621
1
Waxhaw, NC
I used a sharp axe and a lot of faith.

I'll take some vernier measurements of the shortened pawls next time I have the hub open if that helps, but basically you have to get two things right: 1) the timing, i.e. the short pawl has to engage exactly between two clicks of the standard pawls and 2) the contact angle with the track, this changes slightly from stock as the short pawls engage at a greater angle of rotation. I just trimmed one on a bench grinder a little at a time, testing until it was perfect, and then made a second one identically shaped.
This has me thinking now.


Can the guts of the Hope single speed hub be easily swapped into a regular Pro2? It sound like the hub is similar to what you did.

http://www.hopetech.com/page.aspx?itemID=SPG242
 

Udi

RM Chief Ornithologist: “I Brake for Birds”
Mar 14, 2005
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Salami / bismojo -
I'm pretty sure that wouldn't work - the offset in hubs is generally done with the pawl seat (i.e. the seat that the pawl slots into is machined in a slightly different location), so you'd most likely find that the pawls themselves would all be the same size even though they engaged at an offset. If that's the case, using the pawls from the SS hub would achieve nothing. Perhaps someone could open their SS hub and confirm whether that's correct.

The SS hub also uses a narrower freehub body so transferring the whole freehub to a regular hub isn't really an option either, and to me personally would take the point out of running the Pro II anyway (as a stainless hub shell brings the weight into the same range as faster engaging and heavier hubs such as Hadley).
 

w00dy

In heaven there is no beer
Jun 18, 2004
3,412
28
that's why we drink it here
Careful with your timing, guys. Regular engagement with only one pawl can snap an axle. If it works right it's a neat mod. Had to have taken some patience to get it right.
 

Udi

RM Chief Ornithologist: “I Brake for Birds”
Mar 14, 2005
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I don't think axles snapping were due to freehub engagement (although I agree that one pawl at a time is a bad idea for many reasons on this hub), it's because the original internal axle was very thin and relied heavily on the frame's 12mm axle for support - which is why frames with 12mm maxles snapped hub axles very easily. The new Pro II Evo hubs have been updated with a significantly thicker internal axle and I've had no problems with mine.

I do agree it's important to get the timing (and contact angle) right though because any failure of the freehub mechanism could result in injury. Hopefully this goes without saying.
 

csermonet

Monkey
Mar 5, 2010
940
122
Cool mod. My mate just got a Pro 2 Evo rear hub laced up, its brand new so I don't know how wise or willing he will be to do this. I however just picked up some Hadley's and he liked the quicker engagement. Is this something that could be done on his Pro 2 Evo? Can he just buy some extra pawls and we can try our hand at it? I have a bench grinder at my house that I use quite often, and some vernier calipers that we could use to make sure the measurements are precise. Worst case scenario he will have a back up set of stock length pawls to make it all right again.
 

Udi

RM Chief Ornithologist: “I Brake for Birds”
Mar 14, 2005
4,748
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The freehub pictured (and my whole hub) is an Evo, there's no difference in the actual freehub mechanism between them, The Evo just uses a thicker axle and different bores and bearings in the freehub to deal with the new axle.

By all means try it out, I don't have time to open and measure my work but it's been running great. Just enlarge the photo and use that as a guide, but test often as you get closer to those dimensions so you don't overdo it. The contact angle of the pawl is just as important as the overall shape (see post 15).

As you said, worst case you just replace the pawls. Just keep in mind that if you do a bad job and it slips, you could risk damage to the track/freehub and injury, but given a picture to follow it'd be hard to mess it up that bad I'd hope.
 

csermonet

Monkey
Mar 5, 2010
940
122
The freehub pictured (and my whole hub) is an Evo, there's no difference in the actual freehub mechanism between them, The Evo just uses a thicker axle and different bores and bearings in the freehub to deal with the new axle.

By all means try it out, I don't have time to open and measure my work but it's been running great. Just enlarge the photo and use that as a guide, but test often as you get closer to those dimensions so you don't overdo it. The contact angle of the pawl is just as important as the overall shape (see post 15).

As you said, worst case you just replace the pawls. Just keep in mind that if you do a bad job and it slips, you could risk damage to the track/freehub and injury, but given a picture to follow it'd be hard to mess it up that bad I'd hope.
Thanks for the tips, and yes that was what my question was about. Figured he could get a $4 bag of pawls, which includes 4. Gives us two chances to get it right. I presume check and double check the timing and angle before you assemble for a test ride, as you don't want it to fail and cause damage/injury
 

bansheefr

Monkey
Dec 27, 2004
337
0
Haggardly modded my hub the other night with a dremel, vise and some patience. Took a lot of trial and error. The offset looks and sounds about right to me and the two modified pawls appear to engage at the same time. I had to bend the spring out a little more on the shortened pawls to get solid engagement i felt comfortable with. Time will tell if it holds up (I know it's not perfect). Initial reaction, it is much louder and has way better engagement.



 

Udi

RM Chief Ornithologist: “I Brake for Birds”
Mar 14, 2005
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860
A useful test is to compare the two modified pawls side by side to get them identical, and to slowly hand test the hub with only those two pawls installed (i.e. the two stock pawls removed) to make sure those are not engaging offset from each other.
 

HardtailHack

used an iron once
Jan 20, 2009
2,347
238
Just out of curiosity are these things case hardened and and if so will the rest chip off after a while if you cut them?
 

Udi

RM Chief Ornithologist: “I Brake for Birds”
Mar 14, 2005
4,748
860
I presume you mean coated if you're asking about chipping, but the answer is there is none, or anything of the sort. The pawls themselves are fairly crude, obviously some variety of hardened steel that is the same all the way through. The contact surfaces usually end up polished as a result of sliding and engaging anyway.
 

Verskis

Monkey
May 14, 2010
458
8
Tampere, Finland
I presume you mean coated if you're asking about chipping, but the answer is there is none, or anything of the sort. The pawls themselves are fairly crude, obviously some variety of hardened steel that is the same all the way through. The contact surfaces usually end up polished as a result of sliding and engaging anyway.
Case hardened means that only the surface is hardened, not all the way through. If you cut off pieces of case hardened parts, the new surface is not hardened and could wear much faster (or pieces could chip off) than the original hardened surface.
I don't know what is the case with the Hope pawls, they are so small that they are probably hardened all the way through?
 

Udi

RM Chief Ornithologist: “I Brake for Birds”
Mar 14, 2005
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As I said I'm pretty sure they're the same all the way through.
 

werkinit

Chimp
Feb 19, 2014
5
0
I was told the amount taken off the pawl is one half the length of one of the hub shell engagement teeth. The flat edge not the angled part:) Can anyone verify this?