Author Topic: BXT-MTB-097 build  (Read 4174 times)

dpenev

BXT-MTB-097 build
« on: August 25, 2021, 11:02:38 AM »
Hi Guys,

I am new to MTB builds so I would like to ask for advice.
I have selected components all from Aliexpress.
Rough budget $2000. I don't want to extend the budget more.

As I am very new probably I have some incompatibility
or probably some of the components are not with good price/performance ratio.
Probably for some of you it will be trivial to browse my selection and give me some advices.
Thank you in advance!

BXT Frame - boost
https://www.aliexpress.com/item/32959328821.html?spm=a2g0o.cart.0.0.17813c00p4f8IV&mp=1

SHIMANO DEORE XT M8100 Groupset
https://www.aliexpress.com/item/4000033930438.html?spm=a2g0o.cart.0.0.529e3c00fJEend&mp=1

4 piston Brakes
https://www.aliexpress.com/item/1005002687526980.html?spm=a2g0o.productlist.0.0.5c677aa9YezzWF&algo_pvid=62998392-7804-4aa2-b104-dd2815172a8c&aem_p4p_detail=202108250846175924491506129230039648168&algo_exp_id=62998392-7804-4aa2-b104-dd2815172a8c-0

wheelset
https://www.aliexpress.com/item/32960412111.html?spm=a2g0o.cart.0.0.73ac3c00z6dCp5&mp=1
Seller said he will put 12speed compatible rear hub

34mm x 140mm fork
https://www.aliexpress.com/item/1005002186413314.html?spm=a2g0o.cart.0.0.17813c00p4f8IV&mp=1
   
Shock
https://www.aliexpress.com/item/1005001717967875.html?spm=a2g0o.cart.0.0.17813c00p4f8IV&mp=1

Seat Post
https://www.aliexpress.com/item/32800919087.html?spm=a2g0o.cart.0.0.17813c00p4f8IV&mp=1

Saddle
https://www.aliexpress.com/item/32850242307.html?spm=a2g0o.cart.0.0.17813c00p4f8IV&mp=1

Did I forgot something?

Thanks once again.
Dimitar



zilcho

Re: BXT-MTB-097 build
« Reply #1 on: August 25, 2021, 11:20:35 AM »
That groupset is using a SunRace 12 speed cassette that is compatible with standard HG freehubs so you don't need a special 12 speed hub on the wheels.

140mm of travel on the fork is really going to throw off the geometry and handing of that frame.  It is pretty standard cross country oriented geo that is a little dated compared to some, but you could probably get away with a 120mm.  It was meant for a 100mm fork though.

dpenev

Re: BXT-MTB-097 build
« Reply #2 on: August 25, 2021, 03:33:23 PM »
Hi zilcho,

Thank you for the comment!

>That groupset is using a SunRace 12 speed cassette that is compatible with standard HG freehubs so you don't need a special 12 speed hub on the wheels.
Strange the DAIRSBIKE Store person told me that I will need Novatek NT-d462 rear hub if I want 12speed cassette

For the frame where the fork will be they specify L=500mm
For that fork they specify 555mm. Minus 30% sag means 513mm
So my front of the bike will be probably around 10mm higher
Do you believe this is an issue?
BTW this is not 140mm actual stroke fork, 140mm is the exposed length.
I am not sure how much will be the actual travel.

What do you guys think about the brakes.
A friend of mine told me that 160mm front and rear disks may be too small?

Thanks     
« Last Edit: August 25, 2021, 03:35:18 PM by dpenev »

zilcho

Re: BXT-MTB-097 build
« Reply #3 on: August 25, 2021, 03:49:24 PM »
From the description on the 007 page "SunRace CSMZ90 Cassette Sprocket 11-51T
(Compatible with :9/10/11 speed HUB.)"
Also, straight from SunRace: https://www.sunrace.com/en/products/detail/csmz90
So wheels should be good as is.

I'm not an expert on geometry and fork lengths, just familiar with certain frame designs and their intended use case.  This frame is meant as a 100/100 XC bike, but if the total length isn't that much different maybe it would be fine?  Still seems odd to have that much difference in travel between the front and rear.

For brakes, 160/160 is usually seen on racey XC builds, but a lot even come with a 180 front now.  I'm running 180/160 on my FM936.

sync1

Re: BXT-MTB-097 build
« Reply #4 on: August 25, 2021, 03:54:38 PM »
Thats a XC 100/100 frame. You should use a 100mm travel fork.
My advices:
1 - Save on transmission (try to get an used 11 speed group)
2 - Save on wheels (try to get an used arch mk3 wheelset)
3 - Spend on a good fork, shock and tyres.

acedeuce802

Re: BXT-MTB-097 build
« Reply #5 on: August 25, 2021, 03:58:21 PM »
Strange the DAIRSBIKE Store person told me that I will need Novatek NT-d462 rear hub if I want 12speed cassette   
There's certainly a lot of confusion when it comes to freehubs.  The number of gears doesn't matter, the specific cassette does.  The older and more typical freehub (Shimano HG) works for all cassettes that use a freehub (so not old 7 speed freewheel cassettes) that use an 11t small cog.  So all 8/9/10 speed, and 11/12 speed cassettes that use an 11t small cog.  This includes SRAM NX 11 and 12 speed, and aftermarket cassettes like Sunrace.  The SRAM XD driver is used for SRAM 11/12 speed cassettes that use a 10t small cog, and aftermarket cassettes like E13.  The Shimano Microspline is used for Shimano HG+ cassettes, which is all of their 12 speeds.  The HG+ has a new updated tooth profile that's beneficial, so if your budget can accommodate, then it'd be worth finding a Shimano 12 speed cassette and Microspline freehub.  Not the end of the world if you stick with that groupset with Sunrace cassette and use an HG freehub.

For the frame where the fork will be they specify L=500mm
For that fork they specify 555mm. Minus 30% sag means 513mm
So my front of the bike will be probably around 10mm higher
Do you believe this is an issue?

Geo charts list extended A2C.  So the fork you specified is 55mm longer than desired.  That is too tall, will compromise geometry, and can have catastrophic results with the frame.  I would personally try to find a used fork from a name brand, those generic forks just don't have quality damping, similar to a low end Suntour. 

What do you guys think about the brakes.
A friend of mine told me that 160mm front and rear disks may be too small?

Thanks     
I use 160mm front and rear on my XC bike.  For my longer travel bike and aggressive hardtail, I prefer 200mm front and 180mm rear.  It's all preference.  It's not much weight gain to use larger rotors, so if you are going to be doing big downhills then it's worth it for the heat capacity.

dpenev

Re: BXT-MTB-097 build
« Reply #6 on: August 25, 2021, 04:51:12 PM »
Quote
Quote
Quote from: dpenev on Today at 03:33:23 PM
For the frame where the fork will be they specify L=500mm
For that fork they specify 555mm. Minus 30% sag means 513mm
So my front of the bike will be probably around 10mm higher
Do you believe this is an issue?
Geo charts list extended A2C.  So the fork you specified is 55mm longer than desired.  That is too tall, will compromise geometry, and can have catastrophic results with the frame.  I would personally try to find a used fork from a name brand, those generic forks just don't have quality damping, similar to a low end Suntour.
OK I see. I have found another possible fork candidate :)   
https://www.aliexpress.com/item/4001059235217.html?spm=a2g0o.productlist.0.0.1c135eb6UOMsh7&algo_pvid=f0f423be-cfc5-4223-af5b-79a7353abd3e&algo_exp_id=f0f423be-cfc5-4223-af5b-79a7353abd3e-2
On this site https://hayesbicycle.com/products/markhor?variant=32139633524781 for MARKHOR they say "Axle to Crown:  490-530mm  (27.5+/29")"
It is 80mm-120mm travel Internally adjustable
Is this going to be better?
« Last Edit: August 25, 2021, 04:53:25 PM by dpenev »

acedeuce802

Re: BXT-MTB-097 build
« Reply #7 on: August 25, 2021, 09:17:53 PM »
Yes, the Markhor is a good match for the bike and is a very good fork for the price

dpenev

Re: BXT-MTB-097 build
« Reply #8 on: August 26, 2021, 03:25:19 AM »
As for the wheelset:
The Aliexpress shop has suggested I go with https://www.aliexpress.com/item/1005001946012899.html with the Shimano groupset above.
Probably he does not know the difference between the Sunrace and Shimano HG+

In this respect two doubts
The new  wheelset is 25mm inner asymmetric rim , the old I have selected is 29mm symmetric rim .
I tend to think bigger carbon rim should be stronger.
From the other side the asymmetrical rim seems to distribute the weight better.
Do you think the suggested wheelset is better?

the suggested  wheelset uses koozer XM390 boost
https://www.koozer.net/219.html I see they goes in 3 different bodies  Shimano 11S, SRAM XD and microspline
What I am unclear if those bodies are replaceable or this is an option in the hub partnumber?   


emu26

Re: BXT-MTB-097 build
« Reply #10 on: August 26, 2021, 04:57:26 PM »
depenev, wider is better for bigger size tyres. If you want to run 2.4's then 29 is better than 25 IMO.  Can't comment on strength because I haven't used either of those rims but strength isn't just a factor of rim width.

Another user here tried to order Dair wheels and they never showed up. From memory they claimed it was a postage error. Search Dair wheels on the site and you should be able to find it.

Can't comment on the hub selection, sorry.

FlaMtnBkr

Re: BXT-MTB-097 build
« Reply #11 on: August 30, 2021, 02:37:02 AM »
Does everything have to come from aliexpress? Where are you located? Are you open to alternative suggestions?

I think you can probably do better for around $2k if other stores and options were available.