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Dahon Jetstream P8 2007 - Front derailleur conversion.

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Dahon Jetstream P8 2007 - Front derailleur conversion.

Old 12-12-19, 11:03 AM
  #26  
tomtomtom123
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Yes, it appears about 5 to 8mm too high. Normally the FD cage should only be between 1 to 2 mm above the chainring teeth.

How did you solve the problem with the braze on part being flat instead of curved on the front surface, and not being able to mount the normal FD nut with the SRAM chain catcher?

I found this similar adapter on Aliexpress, but with more material cut out. And still with a flat surface on the front. Well, I guess if the surface is wide enough, the chain catcher could still work, but it would rotate too easily.
https://www.aliexpress.com/item/10000022927644.html

Last edited by tomtomtom123; 12-12-19 at 11:32 AM.
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Old 12-12-19, 11:47 AM
  #27  
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No it is fine; itís 1.5 mm clear from the longer chainring radius. The chainrings are power q rotors that are supposed to smooth the low torque.
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Old 01-31-20, 09:45 AM
  #28  
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So I ordered the newer and cheaper litepro braze on adapter for $12. It seems to fit the thicker aluminum seat tube, but I couldn't test it because I didn't want to remove my existing adapter. I could only wrap on half of the clamp. If I get a chance in the future to remove my existing adapter, then I'll test the new one again to see if it will really fit.

The tilt angle of the new adapter is almost the same as the older P adapter. I still think it should tilt 1-3 degrees forward, at least for smaller chainrings from 44T. Perhaps if you were using larger chainrings like 50T or more, then the angle is ok.

The flat front face of the braze on part means that you probably won't use the curved mounting nut that derailleurs some with. You would simply mount the bolt plus washer directly onto the flat front face of the braze on. It means that the derailleur will always be perpendicular to the braze on, which might or might not be a good thing depending on how you are adjusting the swing of the derailleur. You could rotate the clamp to adjust the swing.

At least the FD can fit the braze on, and the cage doesn't seem to hit the clamp anywhere. On the old P adapter, the FD would not fit on the braze on because of clearance problems, and the cage would hit the clamp, which required some shaving.

One problem is that the vertical part of the adapter with the actual braze-on is only held in with a single bolt, so it could possibly twist itself loose, and on my copy, the tiny tab on the bottom that's supposed to be the "anti-twist" stop has such a huge gap to the surface that the tab is supposed to press against, so the vertical part would have to twist almost 5-10 degrees until it hits the stop. I would probably have to glue some shims to it if I want to keep it more parallel to the clamp.

If I had the chance to redo my FD adapter, I would still 3D print another vertical part for the new clamp, for better ease of adjustment and positioning. But at least the new model might solve some of the problems that the old adapter had, although it introduces 2 new problems with the "twisting" with the single bolt, and the flat bolt face.
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Old 02-03-20, 01:57 AM
  #29  
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This is a more "universal design". In my limited experience, the adaptor needs to be able to be fitted upside down as I did (put the braze peg on the other side) whish you can do wit this new design however, the cable stop is still an issue. ideally, the cable stop would be linked to the peg so that it is totally universal.

I'd about 100kms with my setup of mountain biking in the mud, giving through fords and it works well. if I can be bothered, I'll take it apart to improve the look of the adaptor, machine the excess out and paint it...
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Old 02-03-20, 07:56 AM
  #30  
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Originally Posted by Fentuz View Post
In my limited experience, the adaptor needs to be able to be fitted upside down as I did (put the braze peg on the other side) whish you can do wit this new design however, the cable stop is still an issue. ideally, the cable stop would be linked to the peg so that it is totally universal.
On Brompton I am using the adapter for Birdy, with the band above the derailleur, i.e. effectively inverted relative to other offerings, see below. However this one is expensive. I had to use an asymmetric shim under the derailleur mounting bolt to get the angle right. As far as inverting other mounts is concerned, I tried it but with no success. In another thread tomtomtom123 showed a 3D printed hanger portion of the adapter - this obviously opens up a multitude of opportunities.


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Old 06-26-20, 02:19 PM
  #31  
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Originally Posted by tomtomtom123 View Post
One problem is that the vertical part of the adapter with the actual braze-on is only held in with a single bolt, so it could possibly twist itself loose, and on my copy, the tiny tab on the bottom that's supposed to be the "anti-twist" stop has such a huge gap to the surface that the tab is supposed to press against, so the vertical part would have to twist almost 5-10 degrees until it hits the stop. I would probably have to glue some shims to it if I want to keep it more parallel to the clamp.

If I had the chance to redo my FD adapter, I would still 3D print another vertical part for the new clamp, for better ease of adjustment and positioning. But at least the new model might solve some of the problems that the old adapter had, although it introduces 2 new problems with the "twisting" with the single bolt, and the flat bolt face.
Uh, I just tried this new Litepro on Brompton and the finger of the adapter, secured with just one bolt, rotates uncontrollably under the forces common for derailleur operation. Yes, maybe one could stabilize it with some shim, but then the shim might slip out or something. I am retreating from that route and going back to my adapter for Birdy there. The latter worked fine, but I was curious whether I could pull the derailleur in by 1 mm or so by swapping the adapters Another problem was with the derailleur's spring getting in the way of shift cable. As background info, I have there a double derailleur working as triple. I was working around that area so it was a good opportunity to try.
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Old 06-26-20, 02:39 PM
  #32  
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I did order the cheap one with the single bolt because it was just $10. I did not install it, but the braze on part twists around and doesn't stay perpendicular. They should have used 2 bolts or milled an insert or used better tolerances to keep it from twisting. But I would still 3d print my own braze on part and only need the clamp. So $10 for this new version vs $30 for the old version is better for my purposes. Although the trapezoid shape of the old one made it more forgiving for 3d printing tolerances. The new one with a slot would make it more difficult to prevent slipping, you'd probably just rely on 2 bolts to keep the printed part in place.

As for a shim, maybe folding it over so a part of it also goes into the slot may prevent it from getting lost.
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Old 06-26-20, 04:02 PM
  #33  
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Originally Posted by tomtomtom123 View Post
As for a shim, maybe folding it over so a part of it also goes into the slot may prevent it from getting lost.
Yeah, I already made the first washer with a lip as a ship and it limited the rotations, but it was too thin, so I will try a thicker sheet. Nonetheless a better design with 2 bolts would have been obviously better, with a longer leverage arm for holding back the rotations.
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Old 06-28-20, 03:40 PM
  #34  
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Originally Posted by tomtomtom123 View Post
One problem is that the vertical part of the adapter with the actual braze-on is only held in with a single bolt, so it could possibly twist itself loose, and on my copy, the tiny tab on the bottom that's supposed to be the "anti-twist" stop has such a huge gap to the surface that the tab is supposed to press against, so the vertical part would have to twist almost 5-10 degrees until it hits the stop. I would probably have to glue some shims to it if I want to keep it more parallel to the clamp.
The tiny tab along the bottom of the finger is so thin, that the twisting forces can shear it off. One photo below shows the outside of fingers bottom with the bends signifying the start of the shearing off for the tabs. Manufacturing variations appear to yield tabs of different thickness, so I am using an old silver finger with a thicker tab in combination with the newer slimmer band that leaves more room for the derailleur. My L washer, placed where the arrow is, fills the gap between the finger's tab and clamp, preventing rotation, trying to fix the design's flaws.



Fingers w/different tab thickness + washer


The thinner tab has progressed more towards getting sheared off.


L-washer in place.
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Old 06-29-20, 01:20 PM
  #35  
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I'm late to the party as usual.

Fentuz, there is a Litepro FD adapter that is made for the JP8 frame. I thought this would have been brought up somewhere in the thread but I didn't see it mentioned.
I haven't used it, but it might be worth checking out. As you can see, it puts the FD quite a bit back.


Litepro JP8 FD adapter

Originally Posted by tomtomtom123 View Post
On this blog, some comments said that the clamps were different, but one person who tried both wrote that the K fit on his 41mm seat tube. You could have a look:
https://handsonbike.blogspot.com/201...-16-front.html
I can confirm the Litepro K adapters work fine on 41mm seat tubes. I have had them on 3 bikes. I currently have one on a Mariner frame.

I had the same problem of not being able to get the FD close enough to the frame even with a K adapter. I'll have to check out the Yaw FD.

I also bought one of the cheapo adapters, but it is the older, unrefined, generic model. I never even mounted it because it puts the FD much too far out from the seat tube.
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Old 06-29-20, 01:54 PM
  #36  
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I am happy with the sram yaw fd. no problems so far, and haven't had to readjust it since installing it last year. No need to worry about trim. I was worried that setting my high limit screw below the high trim of my Shimano trigger shifter so that both high index and high trim are at exactly the same physical position would put too much tension on the cable, but it doesn't seem to be a problem so far. I only had to widen the outside cage plate as described previously or on my other thread, by pulling the front of the cage until the unscrewed tail became around 3mm wider and then inserting a few washers before reattaching the screw at the tail.
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Old 06-29-20, 09:46 PM
  #37  
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While it might not be the choice for the present situation, there is a new adapter entering the market, with an adjustable mounting angle:

https://www.aliexpress.com/item/32638769122.html

https://gineyea.en.alibaba.com/produ...ding_bike.html'

Adjustability may make it harder to stay in position, but more options for projects is usually good .


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Old 06-30-20, 01:08 AM
  #38  
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Originally Posted by tomtomtom123 View Post
I did order the cheap one with the single bolt because it was just $10. I did not install it, but the braze on part twists around and doesn't stay perpendicular. They should have used 2 bolts or milled an insert or used better tolerances to keep it from twisting.
Mine is mine, no twist at all. That said, as I had to turn the base around (and cut a groove), I had to add a plate onto which I put a brake cable adjuster to hold the cable housing. This plates is mounted on the baze on post bolt and a 2nd one goes right behind which is probably adding some constraint.

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Old 06-30-20, 02:01 AM
  #39  
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Originally Posted by Hinge View Post
I'm late to the party as usual.

Fentuz, there is a Litepro FD adapter that is made for the JP8 frame. I thought this would have been brought up somewhere in the thread but I didn't see it mentioned.
I haven't used it, but it might be worth checking out. As you can see, it puts the FD quite a bit back.

.
I didn't know about this one, it was not on ebay These litepro are "expensive" £30 vs the £5 for the other one. As I knew I was going to cut, reshape, I didn't want to order the expensive litepro, wait for 1 month and then bodge it...

The spare litepro initially bought went on the helios... and, I love it...
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Old 06-30-20, 12:54 PM
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Originally Posted by 2_i View Post
...there is a new adapter entering the market, with an adjustable mounting angle:
That adapter has a lot going for it.
I seriously considered it for my last build but I ultimately opted for a Litepro K series adapter because 1. the Gineyea doesn't have a cable/housing stop and more importantly 2. it isn't offered in RED!!!!
But I agree, it does offer more mounting options.
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Old 06-30-20, 12:57 PM
  #41  
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[QUOTE=Fentuz;21561108 These litepro are "expensive" £30 vs the £5 for the other one.[/QUOTE]

Agreed, they are expensive. The JP8 mount even more so. As long as your current solution is working out, that's what matters most.
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Old 06-30-20, 01:09 PM
  #42  
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Originally Posted by Hinge View Post
That adapter has a lot going for it.
I seriously considered it for my last build but I ultimately opted for a Litepro K series adapter because 1. the Gineyea doesn't have a cable/housing stop and more importantly 2. it isn't offered in RED!!!!
But I agree, it does offer more mounting options.
Looking on their website and elsewhere suggest that Gineyea could be the manufacturer behind the Microshift brand. With this, the quality might be good. I put out an order for the sake of exploration.
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