1936 Excelsior 250 Model F7 Pathfinder

[Ronb]

Can anyone tel me the number of teeth there should be on the rear sprocket of this model to aid restoration

Thanks Ronb
 

[R]

Can't help directly, hopefully someone with this model will respond.

But there are other methods to help.
What does the parts list say - sprocket sizes are sometimes listed as 42t say.
Parts lists reprints are available from a few sources, you have one ?

What size is the gearbox sprocket (teeth count) (and chain size) ?
The gear ratios in top gear have to add up to about 5:1 or 6:1 say, especially if you have the specs for your machine from a road test or brochure.

What does the back wheel /sprocket mount look like, a lot of manufacturers used common parts from a limited number of suppliers, and another make or model could easily have used the same setup.

Hopethishelps.

[R]

P.S. Looks like someone enquired about this model here a few years back.
http://www.classicmotorcycleforum.com/index.php?topic=3749.0

Could be worth seeing if they can be contacted.

[33d6]

Another lucky Excelsior owner!! Hi Ron, I don't know how many teeth are on the rear sprocket but I do know that D is the 1934 identifier for Excelsior.
Excelsior started alphabetical identification of each years range in 1931 with an A prefix on all frame numbers followed by the actual model number so as your description of your bike shows, the frame identification consists of a letter, a number, and then the actual frame production number.
So. we have an A frame prefix for 1931, B for 1932, C for 1933, D for 1934 and so on.
The above makes for very simple identification of any Excelsior from 1931 up to Herr Hitler stopping play. As you can see, by this system, if you frame number reads D7/**** I think your bike is a 1934 model.
How about a photo? Always like to see photos of Excelsiors, unfinished, incomplete, before restoration, who cares. I like Excelsiors.
Cheers,

[chaterlea25]

Hi Ronb
I suggest you contact,   http://www.sprocketsunlimited.com/Index.html

They have all the old chain and sprocket application books and may be able to help
Really nice people to deal with and great service 

HTH
John

[Ronb]

Thanks to all of you who have viewed or responded so far. With regard to the responses received:
- Despite refering to as a D7 it is actually a F7 1936 Pathfinder (the F denoting the 1936 model year as pointed out) 
- Unfortunately I cannot locate parts book and have been looking for several years although do have Sales brochure for 1934 and "Hints and Tips" book for 1933/34 neither of
  which show the number of teeth on rear wheel sprocket
- The National Motorcycle Museum (GB) did have a 1934,  250 Norseman (wet sump) pre fire but I dont know whether this survived and I believe this had 19 inch wheels as compared to the Pathfinders 18 inch so the gearing may be different.
- More than happy to post (on Website) or send photos on completion of restoration but neeed to get the wheels sorted and back on first.
- Some useful advice on sprocket suppliers and how to calculate sprocket size if all else fails

Keep your comments and advice coming

Thanks

Ron B

 

[R]

Bruce Main Smith shows both a 1936 Sales Brochure,
 and 1936 Instruction book with illustrated parts list.

http://www.brucemainsmith.com
select 'e' then 'excelsior' all years search - under photocopy sets.

1154 / HERMES/164
1155

Sometimes pot luck if it actually contains what you want, so Good Luck.

[Ronb]

Tried the Bruce Main Smith route (great idea!).
Unfortunately the document referred  to had a massive amount of detail, including sprocket sizes, but does not cover the F7 and other cooking models being focussses on  sports and manxman models. Currently waiting for the VMCC Library to respond to see if they can help.   

The search goes on .......... 

RonB

[Ronb]

Sorted .....albeit via a complex route:
- Found an old article in Classic Motorcycle featuring a 1934 model then at the National Motorcycle museum.
- The article referred to a road test of the 1935 Model featured in Motocycling  in Feb 1935
- Contacted the VMCC library and Pat Davy very kindly looked at the article which quoted the gear ratios as they often did in
  the 30's and sent them in an Email.
- From this and by knowing the number of teeth on the other sprockets in the drive train (engine, clutch and gearbox drive)
  I can calculate how many teeth should be on the rear wheel sprocket using a standard formula.

Result !

Now to place the order for the sprocket and get the bike back on its wheels once the new chrome rims and spokes arrive!
Thanks to all who contributed.

We are not just vintage bike "nuts" we also need a touch of the Sherlock Holmes to restore bikes.

Ronb