1950 Triumph WL springer mount

[LarsL]

Hey Guys.
New member here. Thanks for the aproval!

I have a 50 thunderbird and thinkin about mounting a vintage WL springer.
What do i need? The WL and triumph shares the same 7/8 stem. So new bearings?

Shoot!

Best
Lars

[Sky]

Yup measure the od and Id, then to head to your local bearing house.

[TriNortchopz]

You got both front ends there? What are the lengths of the necks, and more importantly, the locations for the bearing fits on the neck and the location of the upper threaded portion. Don't want threads inside the bearing inner race.

Below is some info for the bearing sizes on the Triumph, some research for upgrading to tapered roller bearings and some parts info for the springer that may be helpful.

But ya, just swap bearings; the '50 6T Thunderbird (first year of 650) neck bearing bore OD should be as listed, 53mm, then measure bearing fits on your springer neck to get cones that fit the neck.

Triumph Steering (ball) Bearing Set (Cups and Cones).

Fits Triumph motorcycle T90, T100 (1967-74), Pre-unit twins 1950-1962, Unit 650cc Twins 1963-70, T150 1969-74
Top & bottom outer race OD: (2+3/32") 53mm
Top & bottom outer race ID: (1+1/8") 29mm
Top & bottom inner race OD: (1+7/8") 47mm
Top & bottom inner race ID: (1+1/16") 27mm
OEM: 40-4074, 40-5027, 97-0111, 97-1018, 97-0439, H0111, H1018, H0439

https://www.feked.com/triumph-steering-bearing-set-5ta-t100.html

There is a tapered roller kit, but states it does not fit the rigid frame pre-unit 650s;
"This is a new taper roller steering head bearing conversion kit to fit the Triumph pre-unit models from 1955-1962 (with the swinging arm frame not rigid frame),"
yet it fits the T150 1969-74* listed above in the ball bearing, and adds this detail:
"*When fitting to a T150 from model year 1971-1974 please note that you will need to remove the bearing adaptor (97-4145) from your old top cone and fit it to the new top bearing."

https://www.thunderbirdspares.com/steering-head-taper-roller-kittriumph-650-1955-70-500-1967-73-t150-1969-74-747-p.asp

A bit more info here for the pre-unit:
Thread: Steering head bearing problem for pre unit models
"Just wondering if somebody knows the differences of the steering head bearings between rigid models and swing arm models.

http://www.britbike.com/forums/ubbthreads.php?ubb=showflat&Number=341836

Springer Front Forks & Parts
Springer Rebuilding Parts for your Flathead 45 Cubic Inch Solo & Servi-Cars

http://www.45restoration.com/Departments/Springer-HandlebarsForks/Springer-Front-Forks-and-Parts.aspx

[LarsL]

Thanks guys.
Seems that its hard to get bearings for the 50 bird. So need to make something else fit.

[TriNortchopz]

Thanks guys.
Seems that its hard to get bearings for the 50 bird. So need to make something else fit.

Not really that hard. Already know the bore in the neck to fit the bearing cup is 53mm, and there is a tapered roller bearing set with cones and cups that have a 53mm OD^^^^, so we know it exists...so just need to find a tapered roller cup that has a 53mm OD...

oh, look, this bearing set, although it has an ID too large for your 7/8" neck the cup has a 53mm OD and is 11.5mm wide:

Metric Tapered Roller Bearings
SKF JL26749F710
32mm*53mm*14.5mm

http://www.55bearings.com/SKF-JL26749F710-JL26749F710-SKF-284265.html

and in UK:

https://simplybearings.co.uk/shop/p14798/SKF-JL26749F710-Metric-Single-Row-Taper-Roller-Bearing-32x53x14.5mm/product_info.html?backstep=1

a bearing cone from Timken TS series that has a 7/8" ID will drop into that 53mm OD cup...

Another option is to get a tapered roller bearing set that has the ID you want (7/8", and get one with a cup OD too small and sleeve it to fit the 53mm neck bore
on page 37 here, there is a 7/8 x 50.005mm OD, so the sleeve would have a wall thickness of 1.5mm = 0.060".

https://www.bearingsandindustrialsupply.com/pdf/koyo-tapered-roller-bearings.pdf

Or,just call a bearing supplier...they will get what you want with a 53mm cup and a 7/8" cone. Done. I was on the phone for about 5 hours, researched online catalogs for about 5 days to find bearings to fit one small bore in a Invader rear wheel for a Harley on my rigid Triumph frame...

[LarsL]

I also could sleeve the fork stem. To make it 1 inch.

[LarsL]

Found a tapered roller bearing set on evilbay for 50 preunits with telescopic forks. So thats sorted. Then make a 1/8 sleeve on the fork stem.

[TriNortchopz]

Good stuff. Let us know how it works out.