Not sure if anyone can help but I'm looking for some detailed information about the assembly of the front wheel. I had both wheels rebuilt during covid so it's taken a while to refit them. When I mount the front wheel and tighten the axle, the whole assembly binds up and the wheel doesn't run free. It's almost as though the brake shoes are hitting the rear of the drum and binding on it. It almost looks as if I'm missing a spacer somewhere but I can' find accurate parts lists or drawings. All the ones I can find seem to be generic, non specific (to mine anyway) and don't help. Has anyone got experience of the model and could help? Much appreciated.
BMW R23/3(1954) Front wheel issues
- Thread starter Mark8303
- Start date
Hi Mark, why not get in touch with the National motorcycle Museum in Birmingham.
The guys that maintain and restore their bikes have a wealth of technical information and I think it is quite an approachable organisation. Someone there might be more than happy to help you.
The guys that maintain and restore their bikes have a wealth of technical information and I think it is quite an approachable organisation. Someone there might be more than happy to help you.
If it's a 1954, I assume you have an R25/3, the final rendition with tele forks, before the R26 Earles fork 250 model arrived in 1956.
If so, then this diagram may help ........ https://www.realoem.com/bmw/enUS/showparts?id=0T13-EUR-03-1954-T25-BMW-R25_3&diagId=34_0906
If so, then this diagram may help ........ https://www.realoem.com/bmw/enUS/showparts?id=0T13-EUR-03-1954-T25-BMW-R25_3&diagId=34_0906
SteveHop
Registered user
I wouldn't bother getting in touch with any wheelbuilders as from my experiance they don't understand how the BMW wheel bearing setup works.
If you take one of the inner races out you should find two spacers , a large on and a small one sometimes refered to the wedding ring.
When you tighten up the axle the only thing that stops you forcing the outer races into the inner races and binding up are the spacers.
So if the combined size of the spacers are to big then the wheel has play , if the size is to small then the bearings binds up.
Adjustments are made buy altering the size of the small spacer (item 17 above ), untill there is a slight preload on the bearing , but not to much.
There is quite a bit of info on the internet but i would take it apart to figure out how the system works yourself.
I bought a bike a few years back that had rebuile wheels from a reputabel wheelbuilder and the rear nearly siezed up , i discovered that they had not fitted the small spacer and the bearing was overloaded .
If you take one of the inner races out you should find two spacers , a large on and a small one sometimes refered to the wedding ring.
When you tighten up the axle the only thing that stops you forcing the outer races into the inner races and binding up are the spacers.
So if the combined size of the spacers are to big then the wheel has play , if the size is to small then the bearings binds up.
Adjustments are made buy altering the size of the small spacer (item 17 above ), untill there is a slight preload on the bearing , but not to much.
There is quite a bit of info on the internet but i would take it apart to figure out how the system works yourself.
I bought a bike a few years back that had rebuile wheels from a reputabel wheelbuilder and the rear nearly siezed up , i discovered that they had not fitted the small spacer and the bearing was overloaded .
SteveHop
Registered user
Sorry should beite 33 not item 17
Thanks for the info, it makes sense from what I can see. We discovered yesterday (after looking at a photo from when I collected the bike in 2017) that the reputable wheel builder has laced the rear wheel hub as a front and the front as a rear! It's partly my fault as I have had them back from him for ages and only just got around to test fitting. I was a bit suspicious when they were sent back with differing diameter rims as I had thought when I removed them for the rebuild they were the same (and the manual I found for the R25/2 states both are 19"). When I took them to Beaulieu for tyres they fairly assumed that the larger should be the rear and fitted tyres accordingly. Now I am stuck with either getting new tyres and living with the incorrect rim sizes or have to do a second wheel rebuild and swap the tyres!
I can't seem to find a manual specific to the 1954 R25/3 but suspect the bike has also had 'make overs' in the past as the original front rim was aluminium and the rear was steel. Upon sanding down the rusty battery tray I also discovered green paint under the black (I think they only came in 2 colours) which makes me wonder if it's been re-painted at least once.B.T.W. Would anyone recommend the idea of going with odd rim diameters? Or would that be a big no, no. My wheel woes continue as I couldn't find the rear axle so ordered a new one from Germany and it arrived yesterday afternoon. It's about 0.2mm to big (diameter) so now I have to find someone with a lathe to turn it down to fit. And, I've only just started tackling the perished wiring! Oh the joy of trying to save older rare bikes, ho hum.
This suggests 18'' rear, 19'' front, both on 3.25 tyres........ https://www.motorcyclespecs.co.za/model/bmw/bmw-r25-3.html
The 25/2 was, as you say, on 19'' F&R, but this changed when the /3 arrived.
As to colours, IIRC they came in cream but most were black for public consumption, but I think some German police bikes were green.
The 25/2 was, as you say, on 19'' F&R, but this changed when the /3 arrived.
As to colours, IIRC they came in cream but most were black for public consumption, but I think some German police bikes were green.
Tried to reply to the above just as the site closed out for update! Thanks for all of the input.
The bike is black but only the tank has the pin stripe. I think at least the battery tray and mudguards have been repainted. I haven't rubbed through the outer coat on the guards to see if they are hiding any green.
The latest rear wheel fitting problem turns out to be the new axle. I took it to a good engineering company in Aldershot and they think that the shaft was manufactured correctly but then plated, making it slightly over sized. They will have it turned down or a new one (in stainless) made by tomorrow, I'll update. Having now got a move out date (our house has been sold s.t.c. since December!) of 2nd June, I am on a deadline to get it at least rolling so that I can move it to its new temporary home.
The bike is black but only the tank has the pin stripe. I think at least the battery tray and mudguards have been repainted. I haven't rubbed through the outer coat on the guards to see if they are hiding any green.
The latest rear wheel fitting problem turns out to be the new axle. I took it to a good engineering company in Aldershot and they think that the shaft was manufactured correctly but then plated, making it slightly over sized. They will have it turned down or a new one (in stainless) made by tomorrow, I'll update. Having now got a move out date (our house has been sold s.t.c. since December!) of 2nd June, I am on a deadline to get it at least rolling so that I can move it to its new temporary home.
Similar threads
