Britbike forum

Classic British SparesKlempf British PartsBaxter CycleBritBike Sponsor SteadfastCyclesThe Bonneville ShopLowbrow CustomsSRM EngineeringGirling Classic MotorcycleLucas Classic MotorcycleHepolite PistonsIndustrial tec supply

Upgrade your membership: Premium Membership Gold Membership


New Sponsor post
Cyber Monday Sale - 10% off at The Bonneville Shop
by The Bonneville Shop - 11/29/21 5:34 pm
New FAQ post
How to find my own threads?
by reverb - 11/20/21 3:55 pm
Manuals on DVD - Buy 4 for 3
All 4 DVD Manual
Member Spotlight
Tridentman
Tridentman
New Jersey USA
Posts: 5,789
Joined: February 2008
ShoutChat
Comment Guidelines: Do post respectful and insightful comments. Don't flame, hate, spam.
Top Posters(30 Days)
NickL 80
Rohan 73
Top Likes Received (30 Days)
Newest Members
old ion limey, muzz750, Motorcycles and Art, SteveDee, Gus_Carrero
11,924 Registered Users
Who's Online Now
2 members (MaaseyRacer, mxman1), 27 guests, and 20 robots.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Joined: Oct 2009
Posts: 226
M
machico Offline OP
Britbike forum member
OP Offline
Britbike forum member
M
Joined: Oct 2009
Posts: 226
Just wondering if somebody knows the differences of the steering head bearings between rigid models and swing arm models.

I am planning to fit the yokes for pre unit swing arm models (nacelle model) to the rigid frame. I tried to fit the steering bottom cup for 1955 to the rigid frame but it doesn't fit because the frame side is bigger than the cup. According the factory parts manual, the parts number for the bottom cup is all H111 from 1950 to 1959 so the cup should be fit. I am kind of confused why this happens.

I thought the yokes for swing arm model are able to fits to the rigid frame but.....is it possible?

Do you guys have any advises?

Btw, I also would like to know the differences of the yokes from 1950 to 1959. According to the parts manuals, H695 is from 1950 to 1954. H942 is from 1955 to 1957. H1229 is from 1958 to 1959. They all look kinda same but what's the differences?

Thanks,
macico

Last edited by macico; 11/07/10 8:53 am.
Triumphs on eBay
Joined: Aug 2001
Posts: 7,413
Likes: 122
Britbike forum member
Offline
Britbike forum member
Joined: Aug 2001
Posts: 7,413
Likes: 122
Differences that readily come to mind are the earlier 1950-1954 had 5/16" pinch bolt holes, '55-'57 3/8" pinch bolts and the 1958-1959 models have a slot in th steering stem for a fork lock on the right side of the steering head. These changes are probably the major factor for the part number change.

As for the H111 bottom cup, it should fit your rigid frame too, unless it's a 3T frame. What year is the frame and what model ? Also,the 3T used different cups - XS10 with 22 3/16" bearings.

The top steering cup, 5T,6T,T100 & TR5(H437)fits into the top of the steering head/neck and requires the use of 3/16" ball bearings x 22.


Last edited by Jon W. Whitley; 11/07/10 12:14 pm. Reason: Post was jacked up

Jon W.


1957 6T Thunderbird 650
1968 T100R Daytona 500
1971 TR6R Tiger 650
1970 BSA A65F 650
1955 Tiger 100 - Project
1971 BSA A65 650 - Project
1972 Norton Commando 750 "Combat"


"Every time I listen to AC/DC, so do my neighbors"

Joined: Oct 2009
Posts: 226
M
machico Offline OP
Britbike forum member
OP Offline
Britbike forum member
M
Joined: Oct 2009
Posts: 226
Originally Posted by Jon W. Whitley
What year is the frame and what model ?


I am not sure what year the frame is because I bought the only front section. The prefix on the frame is "TF" so I think the model is 5T, 6T or T100. The seat tube doesn't have the split lug so I think my frame is before 1951. what else should I check to determine the year? If the frame number is original, the number is TF 21337. Do you know what year it is?

As for the bearing cup and the yokes, Thanks so much for the details. I really appreciate it.

Thanks,
macico

Joined: Aug 2001
Posts: 7,413
Likes: 122
Britbike forum member
Offline
Britbike forum member
Joined: Aug 2001
Posts: 7,413
Likes: 122
I don't have all my stuff to check the numbers, but TF is 1949 or earlier 5T, T100 & TR5. My '47 starts with TF or to be accurate T.F. Looks like your frame is a 1948.

My guess is that you probably have the wrong bearing cup/race.


Jon W.


1957 6T Thunderbird 650
1968 T100R Daytona 500
1971 TR6R Tiger 650
1970 BSA A65F 650
1955 Tiger 100 - Project
1971 BSA A65 650 - Project
1972 Norton Commando 750 "Combat"


"Every time I listen to AC/DC, so do my neighbors"

Joined: Oct 2009
Posts: 226
M
machico Offline OP
Britbike forum member
OP Offline
Britbike forum member
M
Joined: Oct 2009
Posts: 226
Originally Posted by Jon W. Whitley
TF is 1949 or earlier 5T, T100 & TR5. My '47 starts with TF or to be accurate T.F. Looks like your frame is a 1948.

My guess is that you probably have the wrong bearing cup/race.


Really? Do you mean that the 1948 cup is different from the cup which is after 1950? How is your '47? I only have the parts books after 1950 so... I can't check the differences...

Joined: Aug 2001
Posts: 7,413
Likes: 122
Britbike forum member
Offline
Britbike forum member
Joined: Aug 2001
Posts: 7,413
Likes: 122
No, I mean that if you ordered that bearing cup, you may have been sent the wrong cup.

H111 is good for 1946 on up twins except the 3T.It may fit twins from earlier years, but I will have to verify that later.

Maybe a crazy question, but is the old race ( bearing cup ) possibly still in your frame ?


Jon W.


1957 6T Thunderbird 650
1968 T100R Daytona 500
1971 TR6R Tiger 650
1970 BSA A65F 650
1955 Tiger 100 - Project
1971 BSA A65 650 - Project
1972 Norton Commando 750 "Combat"


"Every time I listen to AC/DC, so do my neighbors"

Joined: Oct 2009
Posts: 226
M
machico Offline OP
Britbike forum member
OP Offline
Britbike forum member
M
Joined: Oct 2009
Posts: 226
Originally Posted by Jon W. Whitley

you may have been sent the wrong cup


I compared the '55 old cup with the '55 new one. I think the cup is right. The Both O.D is same.


Originally Posted by Jon W. Whitley

Maybe a crazy question, but is the old race ( bearing cup ) possibly still in your frame ?


No. the old one is not in there.

The O.D of the cup is about 23.20mm and the I.D of the cup housing of the frame is about 23.30-23.95mm. So the bearing cup is too loose to fit. I am not sure but it seems that the cup housing may be damaged? The housing looks good though.
Is this problem possibly happened??

Joined: Aug 2001
Posts: 7,413
Likes: 122
Britbike forum member
Offline
Britbike forum member
Joined: Aug 2001
Posts: 7,413
Likes: 122
That's a good question, but I can't answer this one for you at the moment as I'm a little far from home right now. Maybe one of the other members can compare measurements for you and help you figure this out.

I would imagine metal could be removed from that area and a slightly larger bearing cup installed for use with another manufacturers front end.




Originally Posted by macico

Is this problem possibly happened??


Jon W.


1957 6T Thunderbird 650
1968 T100R Daytona 500
1971 TR6R Tiger 650
1970 BSA A65F 650
1955 Tiger 100 - Project
1971 BSA A65 650 - Project
1972 Norton Commando 750 "Combat"


"Every time I listen to AC/DC, so do my neighbors"

Joined: Mar 2005
Posts: 10,730
Likes: 113
J
Britbike forum member
Offline
Britbike forum member
J
Joined: Mar 2005
Posts: 10,730
Likes: 113
The O.D. of the bottom cup (H411 also know as 97-0111) is 2.0938" or 53.182mm.

Where does the 23.20 dimension come from?

Joined: Oct 2009
Posts: 226
M
machico Offline OP
Britbike forum member
OP Offline
Britbike forum member
M
Joined: Oct 2009
Posts: 226
Originally Posted by Jon W. Whitley

I would imagine metal could be removed from that area and a slightly larger bearing cup installed for use with another manufacturers front end.



I agree. Somebody might machine the frame in the past.

I have to do something about this anyway.
Thank you so much Jon. I appreciate your advices.

Macico

Joined: Oct 2009
Posts: 226
M
machico Offline OP
Britbike forum member
OP Offline
Britbike forum member
M
Joined: Oct 2009
Posts: 226
Originally Posted by John Healy
The O.D. of the bottom cup (H411 also know as 97-0111) is 2.0938" or 53.182mm.

Where does the 23.20 dimension come from?


I'm sorry about my mistake! The dimension of the O.D. is not 23.20mm but 53.20mm. The I.D.is also wrong. It's not 23.30-23.95mm but 53.30-53.95mm. Sorry about that. Thanks for pointing out.

Joined: Sep 2005
Posts: 1,566
Likes: 14
G
Britbike forum member
Offline
Britbike forum member
G
Joined: Sep 2005
Posts: 1,566
Likes: 14
If it helps at all ...

I have a 1955 5T s/a and a 1948 5T rigid. The headrace cups are the same for both.

G.


https://www.amazon.com/gp/product/B074C7CZYL?ref_=dbs_r_series&storeType=ebooks

Good judgment comes from experience, but the most memorable experiences tend to come from bad judgment!



Joined: Oct 2009
Posts: 226
M
machico Offline OP
Britbike forum member
OP Offline
Britbike forum member
M
Joined: Oct 2009
Posts: 226
Originally Posted by Graham Ham

I have a 1955 5T s/a and a 1948 5T rigid. The headrace cups are the same for both.

G.


Graham, Thank you so much for the information. it helps.
I think something is wrong with my frame cry


Moderated by  John Healy 

Link Copied to Clipboard
Job CycleBritish Cycle SupplyMorries PlaceKlempf British PartsPodtronicVintage MagazineBSA Unit SinglesBritBike SponsorBritish Tools & FastenersBritBike SponsorBritBike Sponsor






© 1996-2021 britbike.com
Powered by UBB.threads™ PHP Forum Software 7.7.5