R1250RT rear end alignement

General discussion of the BMW R1200RT/R1250RT
Post Reply
GadgetGuy
Posts: 3
Joined: Fri Feb 16, 2024 6:49 pm
Bike Model and Year: R1250RT
United States of America

R1250RT rear end alignement

Post by GadgetGuy »

Greetings!
I recently bought a 2023 R1250RT. By now I clocked little over 1000 miles in city traffic. Could not be happier!!!
As the times spent together accumulates, some questions about design and functionality emerge and so far answered with the help of Internet searches. All, but one!

Question:
If you stand behind the bike and look at the mud guard over the rear wheel, you will notice that the whole rear end is off to the right. Why?

I searched the internet and the only answer I found: BMW designed it this way. I received the same answer from BMW Service Department in local dealership. I hope that some one could share some insight knowledge regarding such an unusual alignment by design.
R1250RT frame misalignement.jpg
R1250RT frame misalignement.jpg (343.3 KiB) Viewed 457 times
Our Gee
Posts: 770
Joined: Sun Nov 08, 2015 7:43 am
Location: North Yorkshire UK
Bike Model and Year: R1200RT 2011
Been liked: 24 times
Great Britain

Re: R1250RT rear end alignement

Post by Our Gee »

Well spotted Sir !
Just had a quick look at my 2011 Twin Cam RT which appears to be the same. Must say I have never noticed this before. Now we need someone to explain the reason for this slightly odd arrangement. Over to you David.
User avatar
EasyRider
Subscriber
Posts: 596
Joined: Tue Nov 21, 2023 7:27 am
Location: South Wales
Bike Model and Year: 2019 R1250RT LE
Has liked: 88 times
Been liked: 162 times
Wales

Re: R1250RT rear end alignement

Post by EasyRider »

The first thing i would check is front and rear wheel alignment.

Edit.
Just been and looked at my 2019 1250RT and going by eye it looks lined up ok.


Edit. photo added.
A1.jpg
A1.jpg (170.69 KiB) Viewed 400 times
Dont Ride Faster, Than Your Angel Can Fly. :thumb:
User avatar
EasyRider
Subscriber
Posts: 596
Joined: Tue Nov 21, 2023 7:27 am
Location: South Wales
Bike Model and Year: 2019 R1250RT LE
Has liked: 88 times
Been liked: 162 times
Wales

Re: R1250RT rear end alignement

Post by EasyRider »

I just had a look though Autotrader and the 5 ads with photos i found with the bike on its main stand, all look to be off centre like GadgetGuy bike.

I must have a friday afternoon bike :lol:
Dont Ride Faster, Than Your Angel Can Fly. :thumb:
User avatar
Doctor T
Posts: 1670
Joined: Tue Dec 21, 2021 10:21 pm
Location: west sussex
Bike Model and Year: 2007 R1200RT SE
Has liked: 909 times
Been liked: 239 times
Great Britain

Re: R1250RT rear end alignement

Post by Doctor T »

That's the way they are designed. If you lay a straight line on the floor you will find the wheels are true.
Trust me I am a retired Doctor and lecturer at Oxford University of Structural and Mechanical/Electrical engineering.
GadgetGuy
Posts: 3
Joined: Fri Feb 16, 2024 6:49 pm
Bike Model and Year: R1250RT
United States of America

Re: R1250RT rear end alignement

Post by GadgetGuy »

I appreciate replies reconfirming my statement in the opening posting. I also understand that it appears to have something to do with design.
However, I would still like to find out:
Why is the whole rear end is off to the right?
Panman40
Posts: 336
Joined: Tue Mar 22, 2022 8:46 pm
Has liked: 267 times
Been liked: 36 times
Great Britain

Re: R1250RT rear end alignement

Post by Panman40 »

Sadly I cannot answer your question but it was one of the first things I noticed on my 2019 1250. I try not to look now as I do have some ocd !. I tried realigning the mudguard a little but then it doesn’t look right with the panniers.
I really can’t think of any reason for this :?:
User avatar
EasyRider
Subscriber
Posts: 596
Joined: Tue Nov 21, 2023 7:27 am
Location: South Wales
Bike Model and Year: 2019 R1250RT LE
Has liked: 88 times
Been liked: 162 times
Wales

Re: R1250RT rear end alignement

Post by EasyRider »

This is strange, as my 1250RT looks fine from the rear end.
As you can see from the photo i added, it all lines up.
You can see the photo was taken square on.
I would not of known about this if it was not for this thread.
Dont Ride Faster, Than Your Angel Can Fly. :thumb:
Panman40
Posts: 336
Joined: Tue Mar 22, 2022 8:46 pm
Has liked: 267 times
Been liked: 36 times
Great Britain

Re: R1250RT rear end alignement

Post by Panman40 »

EasyRider wrote: Tue Feb 20, 2024 7:37 am This is strange, as my 1250RT looks fine from the rear end.
As you can see from the photo i added, it all lines up.
You can see the photo was taken square on.
I would not of known about this if it was not for this thread.
Unless it’s my eyes yours doesn’t line up perfectly either 🤔 although without your added line I wouldn’t notice.
User avatar
60Aviator
Posts: 54
Joined: Sun Mar 28, 2021 10:17 pm
Bike Model and Year: 2017 GSA & 2021 R1250RT
Has liked: 8 times
Been liked: 11 times
United States of America

Re: R1250RT rear end alignement

Post by 60Aviator »

This was brought up years ago on one of the forums and if I remember correctly it has to do with how the engine is mounted in the frame. If you look even the ends of the jugs are not equidistant from the centerline. No issue, as designed.
“I’d rather go down the river with seven studs than with a hundred poopheads” Charlie Beckwith
User avatar
Doctor T
Posts: 1670
Joined: Tue Dec 21, 2021 10:21 pm
Location: west sussex
Bike Model and Year: 2007 R1200RT SE
Has liked: 909 times
Been liked: 239 times
Great Britain

Re: R1250RT rear end alignement

Post by Doctor T »

Take a look at 1200/1250 GS, RS ect they are all the same. I think the design is like that to keep the shaft in a straight line. Other makers with shaft drive design their shaft at an off set line. It all depends where the gearbox output is mounted
Trust me I am a retired Doctor and lecturer at Oxford University of Structural and Mechanical/Electrical engineering.
GadgetGuy
Posts: 3
Joined: Fri Feb 16, 2024 6:49 pm
Bike Model and Year: R1250RT
United States of America

Re: R1250RT rear end alignement

Post by GadgetGuy »

Thank you everyone for the input.
We are getting deeper in to the topic, which is: Why is the whole rear end is off to the right?

Perhaps the following lines of thought could direct us to the answer:

First Line of Thought.
1. Is there procedure in BMW Shop service manual regarding front to rear wheel alignment?
2. If there is, does it have anything to do with attaching the frame to the motor?

If the answer to both questions "Yes", that may explain the whole rear end is off to the right.

Second Line of Thought
1. Is there mentioning in BMW Shop service manual of any spacers between the rear wheel and the hub, allowing adjustment of the front to rear wheel alignment?

Since the "rear end is off to the right" appears in earlier models, referring to earlier models BMW Shop service manual may be applicable.
Post Reply