Reducing HTA on Yama Jama 20"?- Mtbr.com
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  1. #1
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    Reducing HTA on Yama Jama 20"?

    Just got the Yama Jama 20" for my kid. I'm thinking of reducing the HTA using an Angleset to improve downhill performance.

    Anyone having experience of slacking the HTA on that bike or similar? Any drawbacks? BB getting too low? Could EC instead of ZS at bottom be a remedy to that (something like https://www.workscomponents.co.uk/20...ube-89-p.asp)?

  2. #2
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    To me it looks like the Yama Jama has an integrated headset. Iím pretty sure my sons Spawn Savage has the same. I donít think there is an angleset for integrated headsets since the angle adjustment for all the ones Iíve seen comes from the headset cups not the bearings.

    I have a Works 1.5 degree on a GF Rumblefish and have never had any issues. Itís a well made headset.
    The Good Times are Killing me

  3. #3
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    Quote Originally Posted by wallander View Post
    Just got the Yama Jama 20" for my kid. I'm thinking of reducing the HTA using an Angleset to improve downhill performance.

    Anyone having experience of slacking the HTA on that bike or similar? Any drawbacks? BB getting too low? Could EC instead of ZS at bottom be a remedy to that (something like https://www.workscomponents.co.uk/20...ube-89-p.asp)?
    I think this is a fantastic idea. 66d HTA would be much better all around (its a hardtail so even 64 or 65d would be great as undersag and downhill/braking it drops REALLY fast to be pretty steep unlike a FS).

    I would like to do this as well, tho I do worry about our BB height. The bikes are already so low to the ground. -2d of HTA would drop the BB approx 3.1 mm. Not massive drop I guess.

    As a side note, if you want improved downhill performance, definitely service the fork and shave down the yellow travel spacer. I don't know why its in there and if it has to be there...but it eats up approx 15mm of travel. This also doesn't allow the air to fully compress and ramp up so we always end up bottoming out even with decent air pressure. When we shaved it down a lot (maybe 5mm left) the ramp up was more noticable (watching the travel bands) and we didn't bottom out as much. Moar travel!

    I did a service video on how to do this. Well it was actually Brian at Lil Shredder (helped design the fork) and did me a huge favor and serviced it while I watch and grabbed some video (there is very little documentation on the fork). Sorry for the poor edit lol.

    https://www.youtube.com/watch?v=-t_TI_ABY7A

  4. #4
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    Quote Originally Posted by ÷tzi View Post
    To me it looks like the Yama Jama has an integrated headset. Iím pretty sure my sons Spawn Savage has the same. I donít think there is an angleset for integrated headsets since the angle adjustment for all the ones Iíve seen comes from the headset cups not the bearings.

    I have a Works 1.5 degree on a GF Rumblefish and have never had any issues. Itís a well made headset.
    Ah dang...

  5. #5
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    What's the max tire clearance on the fork?

    Wouldn't any tire with a higher volume than the stock 20x2.2 Maxtion raise the front end up slightly and decrease HTA?

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    Quote Originally Posted by TimTucker View Post
    What's the max tire clearance on the fork?

    Wouldn't any tire with a higher volume than the stock 20x2.2 Maxtion raise the front end up slightly and decrease HTA?
    Good idea! I'll check clearance. But, at 20" there are not many options. The originally mounted, Brood Maxtion, is one of the best at that size, and it's "only" 431 grams. I really want to keep rotating weight low. Did you have any specific tire in mind?

  7. #7
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    Quote Originally Posted by svinyard View Post
    As a side note, if you want improved downhill performance, definitely service the fork and shave down the yellow travel spacer. I don't know why its in there and if it has to be there...but it eats up approx 15mm of travel. This also doesn't allow the air to fully compress and ramp up so we always end up bottoming out even with decent air pressure. When we shaved it down a lot (maybe 5mm left) the ramp up was more noticable (watching the travel bands) and we didn't bottom out as much. Moar travel!

    I did a service video on how to do this. Well it was actually Brian at Lil Shredder (helped design the fork) and did me a huge favor and serviced it while I watch and grabbed some video (there is very little documentation on the fork). Sorry for the poor edit lol.

    https://www.youtube.com/watch?v=-t_TI_ABY7A
    That's some tip! Thanks for the video, I'll probably get back with some questions.

  8. #8
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    Quote Originally Posted by ÷tzi View Post
    To me it looks like the Yama Jama has an integrated headset. Iím pretty sure my sons Spawn Savage has the same. I donít think there is an angleset for integrated headsets since the angle adjustment for all the ones Iíve seen comes from the headset cups not the bearings.
    Thanks! I'm not so familiar with headsets, I've only swapped worn bearings on my bikes. But, I took it apart last night and to me it looks like this is a press fit type, there is a bottom and top cup. Referring to this figure it would be the "integral" type: https://www.merlincycles.com/blog/wp...7/hopesets.jpg (I found this nice little guide on headsets: https://www.merlincycles.com/blog/bu...bike-headsets/)

    If I got that right, next step would be to remove the cups and measure the inner diameter.

    See pictures below:
    Reducing HTA on Yama Jama 20"?-img_3082.jpgReducing HTA on Yama Jama 20"?-img_3078.jpgReducing HTA on Yama Jama 20"?-img_3079.jpgReducing HTA on Yama Jama 20"?-img_3080.jpg

  9. #9
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    You are correct, sorry for the bad info.

    Good luck with search, let us know what you turn up.
    The Good Times are Killing me

  10. #10
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    Quote Originally Posted by wallander View Post
    Thanks! I'm not so familiar with headsets, I've only swapped worn bearings on my bikes. But, I took it apart last night and to me it looks like this is a press fit type, there is a bottom and top cup. Referring to this figure it would be the "integral" type: https://www.merlincycles.com/blog/wp...7/hopesets.jpg (I found this nice little guide on headsets: https://www.merlincycles.com/blog/bu...bike-headsets/)

    If I got that right, next step would be to remove the cups and measure the inner diameter.

    See pictures below:
    Click image for larger version. 

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    This looks like a 44mm head tube if the the headset cups fit in the frame. It is a 1 1/8 straight fork, right?

    If so, you are in luck with an Angleset. Anglesets work by using the offset cup in the upper head tube. What you need is a EC44 cup up top and the ZS44 cup below. Cane Creek makes kits in a 1.0 degree option or a .5 and 1.0 degree kit. Hit them up, they are super helpful.

  11. #11
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    superstar do a -2 degree slackeriser headset

  12. #12
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    Quote Originally Posted by wallander View Post
    Quote Originally Posted by svinyard View Post
    As a side note, if you want improved downhill performance, definitely service the fork and shave down the yellow travel spacer. I don't know why its in there and if it has to be there...but it eats up approx 15mm of travel. This also doesn't allow the air to fully compress and ramp up so we always end up bottoming out even with decent air pressure. When we shaved it down a lot (maybe 5mm left) the ramp up was more noticable (watching the travel bands) and we didn't bottom out as much. Moar travel!

    I did a service video on how to do this. Well it was actually Brian at Lil Shredder (helped design the fork) and did me a huge favor and serviced it while I watch and grabbed some video (there is very little documentation on the fork). Sorry for the poor edit lol.

    https://www.youtube.com/watch?v=-t_TI_ABY7A
    That's some tip! Thanks for the video, I'll probably get back with some questions.
    @svinyard I finally got around to increase travel. BUT, there was no yellow travel spacer/bumper in our fork (and yes, I checked that it wasn't sticking in the legs ) . See the pictures below! I'll continue with the idea of reducing HTA with an angleset/slackeriser headset.

    I also noticed that there was no oil in the lowers (I have only experience from Fox and Rockshox forks where oil is used). However, it seems like there is space for a foam ring below the dust wiper seal and the attachment bolts seems to be sealed with o-rings. Maybe oil could be used instead of grease then to reduce stiction even further? Did Brian mention anything about why they chose a design with grease instead of oil in the lowers? To reduce need for maintenance?

    Reducing HTA on Yama Jama 20"?-img_3270.jpg
    Reducing HTA on Yama Jama 20"?-img_3272.jpg

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