rear wheel corroded

peter chapman

Finding my (electric) wheels
Aug 16, 2015
18
1
49
hello fellow ebikers,

i noticed on my way home today that the bike just didn't feel right, on closer inspection i noticed that my rear wheel had rotten out and i can pull some of the spokes out of the rim. Could someone give me some advice on re rimming and e bike wheel, how is the best way, should i use new spokes are there any pitfalls i need to know about before i attempt this. The bike concerned is a cyclotricity stealth 1000w the front wheel is unmarked, i suspect that the green slime that i used to prevent puctures has contributed to the corrosion. Im a fairly competent diy bike mechanic. Any advice would be appreciated.
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
20,091
8,212
60
West Sx RH
If you have never attempted a wheel build before then it is not so straight forward and takes a bit of practice, after a two or three goes you can get a reasonable job.
Ideally a truing stand is easier to use for trueing or you can it in the rear drops outs with the bike up turned.
Start from scratch buy a new rim and check the ERD (effective rim distance), then using a spoke calc input all the info to get the spoke length's.

For spokes I use Spim strong 14g butted spokes with a 13g J bend.
Use this seller on ebay for spokes .
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
20,091
8,212
60
West Sx RH
Patience is needed I tend to have the T.V on when I work but witht he sound low and work in the living room, I use a home made truing stand.
A couple of utube 's to watch in wheel lacing.



Which method are you going yo use to true the wheel/rim ?
For cross pattern just adjust the number of spokes you cross and follow the above examples.
 

Sturmey

Esteemed Pedelecer
Jan 26, 2018
541
307
67
Ireland
Hi. I wore down the rear rim on a Pendleton (V brakes) after about 7000 mile of some hilly cycling and had to replace rim. In my case, the front wheel had an identical rim (13g spoke) to the worn rear hub rim and was in good condition, so I used this rim to replace worn rim and stuck a spare ordinary wheel on front. To change over rim, I taped replacement rim to worn rim and changed over spokes one by one.
I have a particular way of trueing wheels that works for me. I leave the spokes on non drive side very loose and coarsely tighten spokes on drive side. I use a vernier calipers and improvised wire gauge to make sure all spokes are even. Surprisingly the wheel was not be too far out. I then mount wheel on upturned bike and start to tighten and true drive and non drive side. Some more spoke tightening is necessary to get the wheel right, keeping an eye on the rim for side to side movement ( tighten brakes and use as guide), also checking wheel is circular and the wheel is central in frame (offset/dish). Also check spokes for even tension.
Its important not to accidently damage the julet motor connector pins so I would recommend wrapping plug in cardboard and taping if this is necessary.
I have another wheel to do this winter and have found a replacement rim thats the same ERD (or height of 25mm) so I plan to re-use the 13g spokes on the drive side and put the lighter 14 g on the non drive side. This has worked very well for me before.

PS. Incidently, I notice (in my case anyhow) that the front wheel hubs rims are much more reliable and not subject to the same wear or spoke problems as the rear hubs.
 
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Nealh

Esteemed Pedelecer
Aug 7, 2014
20,091
8,212
60
West Sx RH
Rear wheels esp cassette hubs have a fair dish on them so as Sturmey says get the right side tightened so the rim is central between the stays, then you can tighten left side to pinch tight before toing and froing from side to side where patience is needed some times only adjusting a few spokes (this part I find very relaxing and therapeutic ).
Once I have a point on the rim that is central between the stays I temp mark it with tippex, then I wrap a cable tie around the stay on the rhs and cut the tail off so it touches the rim wall at the tippex mark. The tie then becomes the point to where I will true the rim to as I slowly rotate the rim to check for adjustment.
If a gap appears between tie and rim then the opposing sides nipple/s need undoing and the rhs nipple/s tightened, if the opposite happens and the tie is moved the rhs will need loosening and the opposing side tighten to move the rim over.
With adjustment for course truing I use 1/2 - 1 turn, for fine tuning it can be as fine as 1/16 turn up to a 1/4 turn. Once you have the wheel trued pluck the spokes on one side for tension, any that give a dull tone need tightening to give a similar tone and any that sound to tight (a much higher tone need loosening too match), then do the other side. From time to time the wheel will need checking for true. so as not to lose my place of where I'm at I use a bit of masking tape on a spoke, if a break is needed.
Or for about £15 you can get a tensiometer gauge, not all spokes will have the exact same tension but usually they are within 20%.
You might be lucky and the rim may true up quickly say 30 - 40 mins work, other times it might be a couple of hours. It you get nowhere fast leave it and go back the next day, slacken of nipples and have another go. Practice almost makes perfect so may take a few goes.
 
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