Author Topic: Stumpjumper clone  (Read 46881 times)

Goodzilla

Re: Stumpjumper clone
« Reply #135 on: July 13, 2021, 05:09:47 PM »
Here it is I’m almost finished with the build a little Setup on the suspension and bleed the frontbrake left over.
It ended having 13,85 kg and I don‘t went with that super lightest parts like my nx parts I had left from another bike and some other parts  ;D

Sometimes i left everthing in downstairs and went to bed before I throw everthing away
« Last Edit: July 13, 2021, 05:14:04 PM by Goodzilla »

Mikey12345

Re: Stumpjumper clone
« Reply #136 on: July 14, 2021, 01:37:23 AM »
Can anyone confirm a rear 210x55 shock will result in 150mm of rear travel? Thinking of scrapping my AM831 build as it is taking a little longer than I'd like to ship the frame, and all of the parts except the BB will transfer over to this frame.

Guyzer73

Re: Stumpjumper clone
« Reply #137 on: July 15, 2021, 11:34:49 PM »
So couple of photos of the finished build per say...

Things still to be done are:

1. Cut down the front rear shock bolt.
2. Remove bushes from rear shock so flip chip fits.

In both cases thanks @swuw2331

Other all good, rides well but will take some getting used to coming from a 26er... especially the slower but more nervous steering resulting from the bigger front wheel and shorter stem.




Goodzilla

Re: Stumpjumper clone
« Reply #138 on: July 16, 2021, 09:02:02 AM »
So here is my finished product

Thrill21

Re: Stumpjumper clone
« Reply #139 on: August 09, 2021, 06:51:41 PM »
Anyone having issues with the front shock mount bolt? Mine snapped right where it threads in to the frame  :-\

While browsing around I stumbled across this;

https://geracycles.com/2020-SPECIALIZED-STUMPJUMPER-EVO-CARBON-29-FRAMESET-ssecf29

Pretty sweet deal for a carbon frame and shock, Making me think of ditching current as ASWT are not warrantying the part...


RobertRinAustin

Re: Stumpjumper clone
« Reply #140 on: August 09, 2021, 09:29:31 PM »
Anyone having issues with the front shock mount bolt? Mine snapped right where it threads in to the frame  :-\

While browsing around I stumbled across this;

https://geracycles.com/2020-SPECIALIZED-STUMPJUMPER-EVO-CARBON-29-FRAMESET-ssecf29

Pretty sweet deal for a carbon frame and shock, Making me think of ditching current as ASWT are not warrantying the part...
You won't get anything from Gera. They're fraudsters

paracord

Re: Stumpjumper clone
« Reply #141 on: August 10, 2021, 12:50:47 AM »
I just bought a wheelset from OBMbicycle.com and anyone confirm they are not a fraud site?

Can we continue here about that store. I noticed that some of you bought from them.
http://chinertown.com/index.php/topic,3354.0.html

Goodzilla

Re: Stumpjumper clone
« Reply #142 on: August 10, 2021, 02:40:32 AM »
So I’ve finished the build a few weeks ago, suspension is set up and I’ve made a few runs with it. For my poor legs I took a 30tooth chainring it climbs very well. Me and my friends doing only 1k hm tours and riding the rough trails down it works great but it was a hard way to fix everthing ;).
I took the original specialized bearing kit and bolt hardware but I had to build me some spacers to get out the play of the rear triangle. That was only an issue with the specialized hardware. For the headset I bought also a higher quality one and took one 2,1 mm Spacer to fix the gap on the upper bearing and cap. I don‘t recommend building this one without mechanical background there are lots of small problems coming up here and there. But if you master them you’ll become a cool bike working well

Thrill21

Re: Stumpjumper clone
« Reply #143 on: August 10, 2021, 05:08:46 AM »
You won't get anything from Gera. They're fraudsters

Thank you - I had suspicions...

miles

Re: Stumpjumper clone
« Reply #144 on: August 26, 2021, 05:39:20 AM »
I created an account just to post here. For anybody that gets one of these, some advice;

By the time you're done you've likely gone more than half way to the cost of the genuine frame. I regret my purchase and don't think I'll ever be "happy" with the bike.

If you really want to there are some things you *need* to do before riding it, I snapped several linkage pins before working this out.
Basically, the frame is a good copy externally. It's nowhere near as stiff though, that's the main problem. It hates side loads.

Any sideways deflection on the back end is transferred to the top shock mount, this results in failures of the top pin. Even after taking some precautions against this, more paint is missing from that area of the frame every time I use it. I doubt it has long left.
This issue is exaggerated by using a specializerd "flip chip" as lower mounting hardware, as it removes the slight pivot a bushing provides.

1) Replace the bearings that come with the frame, they have loads of play. I used some loctite on the outer race as the fit is quite loose.
2) Don't use the flip chip, instead install a needle bearing in the lower eyelet (enduro, get the narrowest one they sell, I had to grind it down a bit). This doesn't help with the flex but protects the top mount a bit.

These changes go some way to mitigating the problem but there's still too much flex in my opinion. I suppose you might get away with it if you're on the lighter side.

Other things;

1) Definitely install the specialized chainstay protector and some kind of downtube protector. The downtube is really thin.
2) Use jagwire foam internal routing tubes.
3) Replace the seat clamp (wolf tooth, mentioned previously). The stock one touches the tire.
4) Cover the gap between the bottom bracket and chainstays where the pivot is. Rocks get into the gap and dirt gets into the bottom bracket. Flex tape works.
5) Take care with dropper post insertion. Don't fully "bottom out" the post in the frame. When you feel it stop, pull back a bit. If you bottom the post out, the actuation mechanism is touching (or close to touching) the pivot that goes through the seat tube. It can interfer with the actuator and if the post slips can cause damage. Make sure the clamp is good and tight.

I've got quite a few hours on the bike now and I have to say, every time I ride it I end up stopping at least once because it "doesn't feel right". Like the back wheel is loose, or a crank arm, headset. There's just so much flex.
I do like the geo. The large seat tube size is really good, all frames should do this. Very little play in the dropper.

In summary, I wish I'd got the genuine frame. With all the extra bits, the many hours of work involved, the cost isn't far off.

deucelee

Re: Stumpjumper clone
« Reply #145 on: August 28, 2021, 06:42:44 AM »
miles,

Sorry to hear of your troubles.  hopefully the AM831 doesn't have much of your side flexing issues :(

I wonder if your 'other things' also apply to other chinese carbon bike frames? will have to keep them in mind...

Thrill21

Re: Stumpjumper clone
« Reply #146 on: August 29, 2021, 11:21:51 AM »
miles,

Sorry to hear of your troubles.  hopefully the AM831 doesn't have much of your side flexing issues :(

I wonder if your 'other things' also apply to other chinese carbon bike frames? will have to keep them in mind...

The rear triangle is carbon, the flex is because if this - anything you buy from china that is carbon will have a carbon triangle.

chetosmachine

Re: Stumpjumper clone
« Reply #147 on: August 29, 2021, 06:44:24 PM »
The rear triangle is carbon, the flex is because if this - anything you buy from china that is carbon will have a carbon triangle.
uh.........no. Aluminum rear triangles also flex.

emu26

Re: Stumpjumper clone
« Reply #148 on: August 29, 2021, 10:04:32 PM »
uh.........no. Aluminum rear triangles also flex.

This.

Unwanted sideways (lateral) flex in the rear triangle of a carbon frame is down to either poor pivot design, poor workmanship or poor layup design. Some are designed to have vertical flex, think "flex stays" but that is different.

Castolian

Re: Stumpjumper clone
« Reply #149 on: August 30, 2021, 03:26:41 AM »
Hi Everyone,

Just ordered this frame for my first own bike build,

I can't seem to find it on the specs list on Ali Express nor on the posts in this thread, perhaps I am just missing it, but has someone perhaps have the maximum seat post insertion length measured?

Thanks in advance.

Edit : So Airwolf responded to my message an notified me the maximum insertion length is 17-18cm, but if anyone else has the actual measurement it would be very helpfull.
« Last Edit: September 01, 2021, 03:45:36 AM by Castolian »