Bent frame!

[Wheelnut]

I have an A65 which appears to be slightly twisted at the steering head. With the rear wheel vertical, the front wheel heels slightly to the right. The variance top to bottom is about 14mm at the rim.

Forks, swinging arm, and the main part of the frame check out okay with my crude assessment using spirit levels and string lines, but suspicion lies with the steering head, which does have evidence of having had a knock just below the steering head at some point in its life. There's just a small mark on the frame, but it's there.

At very low speed the bike feels as if it wants to turn right. At higher speed, riding hands off the bars, the rider has to shift his weight well over to the right in order to keep the bike going straight.

Obviously, I need to get the frame geometry checked and corrected.

Any recommendations as to where I could get this done? I've heard good reports of Maidstone Motoliner and Abba, but they are both in the south east. That's a long way from the Northumberland border where I live! There must surely be somewhere in the northeast where I can get my frame jigged and corrected, but I've drawn a blank so far.

I guess the alternative is to try to source a good replacement A65 frame. Anyone got one going spare?

[TTJOHN]

When I last checked Maidstone for a quote on checking and straightening a bent frame it was £200 but that was a few years ago, I'm not sure what they would want now but I dare say that it would be better than buying a second hand frame that could be worse than your original one, plus you would have all the rigmaroll of having to change it on the log book.

TJohn

[BEEZABRYAN]

Buy a frame with unknown provenance or send your frame to Motoliner.
The costs including carriage may well be about the same.
 I know what I'd do and it is not source a frame.

[Wheelnut]

I might well end up going to Maidstone Motoliner but it's a 730 mile round trip to deliver the bike then another 730 mile round trip to collect it. That's a big spend on fuel and on trailer hire. Abba in Essex is a bit closer, but still a heck of a long way.

That's why I would really like to find someone further north with a Motoliner frame jig and the expertise to use it.

Unfortunately, you can't just post off the frame because they would need the engine, swinging arm and rear wheel installed.

I agree that fitting a replacement frame of unknown heritage is not the way to go.

[Stubaker58]

Would they be able to do the work while you waited if you arranged things beforehand?  It worked for me getting my barrel rebored and that was only an hours journey each way!

[DAVE BRADY]

Hi,

Saddleworth Classic Motorcycles or Seastar Superbikes. Google them for details.
Some A65s had the front wheel slightly off vertical to get the front and rear wheel in line on the ground. What year is your A65 and what front brake does it have?  Do your wheels sit in line when a straight edge is used across the rims/tyres about 3" above the ground?
There was a thread about this topic a while ago.

Dave.

[redmelons]

https://www.motoliner.com/motorcycle-frame-straightening/modern-and-scooters.php

"Most bikes need to come to us as a rolling chassis with the engine fitted. Call us to discuss how we require your model of bike to be prepared.
If you are in any doubt at all or would just like to chat this through please just phone us on 01622 790 705 and we will be pleased to help."

"Steel Frame Straightening: From £250.00 exc VAT"

https://www.motoliner.com/motorcycle-collection-delivery.php

"By using our trusted partner we are able to offer a bike collection service if you are unable to transport your bike to us.
Just give us a call on what we require to be taken off the bike prior to transport and then call the number below to arrange delivery.
Call Tony
07765 665 988"

[Wheelnut]

Thanks for the replies. I've looked at Seastar but that's still a 6 hour drive each way, and Saddleworth don't do frame straightening any more. However, I've been told about a dealer in North Yorkshire (John Warrington Motorcycles) that has a Motoliner jig, and that's only 100 miles south, so I'll give them a call to find out if they can help.

[Wheelnut]

As for getting the wheels in line, I've checked and that's not a problem. Also, the rear wheel seems to be dead in line with the spine of the frame. I would send pics showing the string lines but can't seem to upload them.

With the rear wheel dead upright, the front wheel is at a slight angle, so effectively leaning to the right. That would explain the tendency to turn right.

I have also found that the front wheel is laced slightly to the left of centre (about 4.5mm), so there is a 9mm difference in the gap between the rim and each fork leg. I can't see this making much difference to the way the bike handles, but the front wheel's inclination to the right is concerning. This would point to a misaligned frame at the steering head. 

The bike is a US spec 1965 Spitfire Hornet with a single-sided front brake.

[JulianS]

It may not be the frame?

Sometime during the 1966 season the forks were modified so that the spindle was slightly out of horizontal, causing the front wheel to lean out of verticle, all about handling problems in the US with the camber, according to the most excellent book by Peter Crawfords "Thunderbolts and Lightnings" Volume 1 the road bikes, pages 128 and 129. (Published by Wideline) In theory the point of contact between tyres and road remained in line.

https://www.wideline.co.uk/

See below service bulletin.

The stamped "A" mentioned in the bulletin can be very faint but can just be seen between the bolt holes in the second image below.

[Wheelnut]

Reckon you could be on to something there JulianS.

Although I could find no sign of an 'A' on the fork leg bracket, I have just placed a digital box level on the flat part underneath the top yoke and adjusted the forks so that the level reads zero degrees, then moved the level to the fork spindle and it shows about 0.8 degrees, effectively leaning the front wheel so that it would have a natural tendency to turn right! Hopefully that is the issue rather than the frame itself.

Hard to comprehend that this is what the factory did, but it would account for the symptoms I have experienced.

I also have an A10 based Tribsa (which handles impeccably) and I think the A10 forks are probably interchangeable with the A65. They certainly look the same. If I do a fork swop I'll know for sure if the problem lies with the US-spec A65 forks or with the frame.

Just checked the details of my A65 Spitfire Hornet. The frame is actually a Lightning (despatched to US West Coast October 1965),  paired with Hornet running gear and Hornet engine (despatched to US West Coast January 1966). It's something of a BSA soup. That said, the Hornet and Lightning frames were identical for the 1966 model year as far as I can tell.

[Wheelnut]

On reflection, the Yanks drive on the right, so wouldn't the US spec forks have the fork spindle inclined so as to have a tendency to turn left to counteract the camber? My bike has the fork spindle inclined to have a tendency to turn right!

The plot thickens, but the forks might well be the issue on my bike.

Here's my machine, now fitted with Spitfire alloy tank as the original Hornet tank was sadly destroyed by modern ethanol fuel, despite having an epoxy liner.

[John Dynostar]

Wheelnut
we are in North Yorkshire if thats near enough for you .
motorliner jig
http://www.jwmotorcycles.co.uk/
John Warrington Motorcycles.
01653 698 258
john@jwmotorcycles.co.uk
can't do anything till the new year though  :'(

and if I don't answer the phone its because I am busy sorry

[Pete Gill]

On reflection, the Yanks drive on the right, so wouldn't the US spec forks have the fork spindle inclined so as to have a tendency to turn left to counteract the camber? My bike has the fork spindle inclined to have a tendency to turn right!

The plot thickens, but the forks might well be the issue on my bike.

Here's my machine, now fitted with Spitfire alloy tank as the original Hornet tank was sadly destroyed by modern ethanol fuel, despite having an epoxy liner.

I suppose it is possible if you have a mismatched combination of fork legs ( early/late ) that it could interfere with front wheel tracking.

[John Dynostar]

front wheel laced 4.5mm offset
1 degree camber on front wheel .

mmm