29er MXUS XF07 wheel build, good idea, bad idea?

Scorpio

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Apr 13, 2020
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Portugal Algarve (temporary)
Hi folks just adding some background as I've been using a 29 MTB with 36v Yose kit (upgraded to KT) for a couple of years now and like it a lot
It's on semi slick tyres from Curio, rear motor is from a 26" wheel - relaced into a 29" rim, original Yose conroller has been upgraded to KT (I'd say this is an essential mod for Yose kit!).
Most routes are B roads or gravel tracks which it suits well, steering is good but I guess the larger wheels would be slower on the turns than 26" for any serious MTB routes.
I'm over 6ft so the XXL frame and 29 wheels are a better size for me, ride is smoother, torque from the motor is reduced due to the larger rims but it still runs happily at a decent speed.
I's a shame EVERY route from my house has at least a couple of short steep climbs where the motor bogs down badly - not enough to stall it but it's obviously running well below it's "happy" speed.

The first layout was with the battery on the rear rack, handling was fine but it was very tail heavy with the battery and motor all at the back wheel, the battery is now mounted on the frame and the bike feels a lot more balanced when you lift it.

Possible (but low priority) upgrades for the future involve moving to 48V and looking for a motor with more torque, ideally also wound for higher speeds..
 
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Ghost1951

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Jun 2, 2024
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Aye sounds about right, 54.XV fully green lit. Balancing sounds complex, can it be done with the standard charger? If there is any removing cells etc I am out.
What is the voltage on the output of the battery when the charging ends?
 
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PC2017

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Sep 19, 2017
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moving to 48V
Hi bud, still temporarily in the sun? Mine will be on 48v, do you think front hub would make much difference? The YOSE front had a good top speed on 48V (kt) the MXUS has a little more torque at set off. I think I will go with the 29er from the feedback from this thread, I feel more positive in my thinking, tbf I was anticipating a barrage of naysayers. The motor simulator says top speed unlimited would be 20mph that's enough for anyone imo.

Did you do the motor transplant yourself I can not remember?

voltage on the output of the battery when the charging ends?
54.4V -I can not setup this battery as I changed out the xt90 on the controller for an xt60 in anticipation of the Woosh 48v. I currently use the 36v on a stealth controller from Dillenger but it will only take the 36V, I wouldn't consider risking it for a voltage check either if that blows I am bike-less and when I do use the bus[once a year] I end up with "bus" germs and is ill for a month... At a push I could get an XT60 to XT90 converter as the battery rack passthrough is still XT90, I won't be using this rack mount with the new battery.
 

Scorpio

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Apr 13, 2020
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Portugal Algarve (temporary)
@PC2017 yep I'm still temporarily in the sun - and hoping the move can be made permanent ;)

The only front motor bikes I've used were older 36v 250W Ladies / Dutch shopping bikes fitted with very basic controllers, no risk of them behaving oddly due to very soft & slow power delivery. A newer / stronger front hub system might feel different..

Check the motor ratings, it's a while since i looked but Yose fronts were 250W, Yose rears were 350W.
I did the re-rimming myself using a hub from a Yose 26" wheel, new rear rim to match the original front (a good match and bargain price from Bankrupt Bike Bits), "Spokes by Ryan" for the obvious ...
Working out the spoke length and doing the actual lacing were the main bits. I fed everything into a spoke calculator then shared the results on here for a comments before I ordered anything. The work wasn't difficult but it took time. It's done and I'm happy but I think it's slightly off-center (the spokes are at their limit of adjustment so it's as good as it can be) - make sure you arrange a couple of hours with no distractions of phone calls...
I loosely built the wheel in an evening (using bike upside down in the lounge as a jig to hold the wheel) then did the truing & spoke tensioning in daylight the next day. I took 1/2 day total, next time would be a lot quicker.
 

Az.

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Apr 27, 2022
2,044
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Plymouth
Start converting bike by checking if battery will fit in triangle. 29" bikes have generally smaller triangles than 27.5" and 26". On this bike


I had to unclip brake cable from under crossbar. It gave me extra 2 or 3mm. Otherwise I wouldn't be able to remove battery.
 
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PC2017

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Sep 19, 2017
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yes the yose is 250w but I think its torque & rpm that matter here. The MXUS is 250w. I would say it would be efficiency that's going to be my main issue at set off.

As for the wheel build, I will leave that in the hands of an ebay seller. If they do a good job I will inform the gen pop here with a little kudos post & vice versa . From the messages they seem able and willing, they provide the spokes and the rim + building labour, its up there in costs however with import duties and VAT, not to mention tru-ing at the LBS, aliexpress is ruled out, saving average of £150. I haven't looked elsewhere as this MXUS motor I have is only a year old but the wheel its losing grip on reality, with lose nipples.

Glad to hear you are well & I hope you do get the nod for a more permanent footing in the sun!
 
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Peter.Bridge

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Apr 19, 2023
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yes the yose is 250w but I think its torque & rpm that matter here. The MXUS is 250w. I would say it would be efficiency that's going to be my main issue at set off.

As for the wheel build, I will leave that in the hands of an ebay seller. If they do a good job I will inform the gen pop here with a little kudos post & vice versa . From the messages they seem able and willing, they provide the spokes and the rim + building labour, its up there in costs however with import duties and VAT, not to mention tru-ing at the LBS, aliexpress is ruled out, saving average of £150. I haven't looked elsewhere as this MXUS motor I have is only a year old but the wheel its losing grip on reality, with lose nipples.

Glad to hear you are well & I hope you do get the nod for a more permanent footing in the sun!
I am interested, I have had a couple of wheels from top like kit, they cost an extra £25 over the bare motor and the shipping was about an extra £40. The wheels seemed fine. I was thinking this was probably cheaper than building one here
 

PC2017

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Sep 19, 2017
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Scunthorpe
Otherwise I wouldn't be able to remove battery.
I do have the battery dimensions, I have yet to see the "free" frame, but I will heed your wisdom. Life is seriously getting in my way of starting this project, so everything is going on a storyboard, I will whittle the list down, all suggestions are noted and things are fluid and open to interpretation and change.

I was thinking this was probably cheaper than building one here
As mentioned I haven't even looked beyond aliexpress, the added VAT monster and precarious customs charges is what focused my thinking on recycling my motor and supporting UK business in the process, whether there is any savings is another thing + if I did get a new motor wheel from "China" then I would have to sell my wheel, which is in need of minor repair, alongside the hassle of strangers, trust in my fellow forumite, for here would be the sale route. It gets too much for one old(ish) dude struggling with life issues.
 
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saneagle

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Oct 10, 2010
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I do have the battery dimensions, I have yet to see the "free" frame, but I will heed your wisdom. Life is seriously getting in my way of starting this project, so everything is going on a storyboard, I will whittle the list down, all suggestions are noted and things are fluid and open to interpretation and change.


As mentioned I haven't even looked beyond aliexpress, the added VAT monster and precarious customs charges is what focused my thinking on recycling my motor and supporting UK business in the process, whether there is any savings is another thing + if I did get a new motor wheel from "China" then I would have to sell my wheel, which is in need of minor repair, alongside the hassle of strangers, trust in my fellow forumite, for here would be the sale route. It gets too much for one old(ish) dude struggling with life issues.
If you want to build a bike to meet your needs, it's better to do it properly with the stuff you need, not just use what's on hand or what's cheap unless you're really pressed for funds.
 

PC2017

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Sep 19, 2017
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with the stuff you need
Indeed, I do like the minimal look. I had a quick look at "28"/"700" wheels on YOSE, I haven't looked into the sizing however these sizes don't make much sense to me, when I assumed 29er would be 29". Also there is no front in black unless I go 500w and for sure I know the MXUS rpm, 250w, etc, not to mention the quality.
 

sjpt

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Jun 8, 2018
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Winchester
Tyre sizing is nuts. It used to be confusing for various historic reasons with different conventions in different countries. (eg a 26x1 1/4" is different than a 26x1.25", and a 27" is bigger than a 28")
They then nearly go it sensible with ISO sizing. But marketing departments didn't like the sensible sizings because it made it more difficult to persuade people to do unnecessary 'upgrades'. It's much easier to sell to a confused customer.

It is the bead diameter that is most critical and must be correct for matching rim and tyre. The width of the rim should be in the right ballpark for the width of the tyre but the exact width is not critical. The ISO sizing gives these values.

You will see all 700c and 29" and most 28" have a 622mm bead diameter.

 
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