Which is better? 20/21 or 19/20 rims? Cross 3 or cross 4 spokes lacing? pattern??

[Albervin]

I will always go for 21" front. More choice of rubber, especially the lovely Avon RoadRider. With Brampton forks they give more stable riding over bumps and holes, better braking and comfort. They may have a slightly greater gyro effect which is good for straight line but small roundabouts require more effort, however with the better rubber I use counter steer for those with utmost confidence. Almost impossible to find good 20" rear rubber so I stick to standard with RoadRider tyres. It is most important that you use the correct tyre pressures with modern tyres so it is 28psi front and 30-32 psi rear. Even higher if two up with luggage. I do find rear tyre life is quite limited (original suspension set-up) but the pluses far outweigh the costs. No way would I ever choose 19" front, way too small, too high a load on too small a footprint for touring. When my Shadow comes home the first thing I will do is fit a 21" front wheel. I may even buy a set of AVO dampers whilst in the UK as I have heard nothing but positive about them. Of course this is all from an Australian perspective and may differ in other countries.

 

[Marcus Bowden]

Have just built another three wheels,two 21" rims a 2.15 (WM3) & a 2.50 (WM4) Avon's higher limit for fronts, an 18" x 3.00 (WM5) rear, never fitted thess sizes before, fitting Avon Trailrider tyres , with communications with Central Wheel Components.
A few comments I didn't really understand, bedding in spokes !! and other things ?

LETTERS
Richard my handsome,
First wheel 21 x 2.15 spot as always.

Second wheel 21 x 2.50 spokes a tad on long side but have eight that are too long and thread bound

Third wheel 18 x 3.00 all spokes too short as more than one “D” (spoke dia) is protruding beyond the nipple. Also would it be better to have a “cross three” lace up as the outside spokes are having to be sprung inwards to fit nipple and binding on spoke flange also head of spoke on first spoke crossed. See first photo. Smaller diameter rims creating this problem.
Not sure of the advantages or disadvantages other than a x 4 is stronger as opposing spoke is in a straight line nearly !

SPOKES IN 21” RIM 9”5/8” or 245mm REQUIRE 8 at 238mm or 9”3/8”

SPOKES IN 18” RIM 7”7/8” or 200mm REQUIRE SET 205 mm or 8”1/16” OR 3 cross pattern please what ever the professionals think.
I would love a chat with one of your experienced builders if at all possible.
Look forward to hearing from phone 01503 262 175, or e-mail but need a call for card details,
Marcus.

Marcus

I have forwarded this to Richard to look into on Monday when he returns from his holiday.

A couple of points from the information that you have given and the pictures - with the 21 x 2.50 wheel - assuming this is now tensioned and trued correctly - it is not uncommon for odd spokes to come up long and need grinding off - this is more common with old wheels but we even see it with brand new wheels where you might get 1 wheel in a batch of 10 where using the exact same components the spokes will come up long and need grinding, so i would say that you are over egging the price trying to just replacing the odd spoke with shorter ones.

For the 18” wheel - from the photos you have not bedded the spokes into the hub correctly which will immediately increase the length, also there should not be an offset on a Vincent so not sure why you are looking to move it over 3/8”, but almost certainly the rim will not be drilled for an offset. If you do not bed the spokes correctly then they will come loose very quickly and lead to a collapsed wheel.

We are happy to make any length of spoke that you want and charge you accordingly if you wish to ignore all of the above.

Kind regards
Warren

 

[Albervin]

Marcus, if you are using a standard 40 hole rim then THREE CROSS will not work. They look like serious sized spoke too; are they double butted? They do not look like they are so some
close contact there.

 

[Spqreddie]

Dear All,
this is Eddie, I've posted a few months back a first thread to get some advice on how to rebuilt my 1948 Rapide (http://www.vincentownersclub.co.uk/showthread.php?5439-The-best-set-up-Tips-on-how-to-rebuild-an-un-matching-Rapide-All-input-welcome!&highlight=), I'm aiming at a rideable bike, a bike I whish to use as much as possible not a garage queen,
I'm planning on some improvements to the engine (carburetors, cams etc.. see other thread) and I’m starting now to collect parts for the cycle part rebuild.

I would like to get some advice on the wheel size, I was so far thinking about a classic set up with normal 19 rear and 20 front wheel, but lately I was considering why not 20/21 a la lightning?? I'm not planning to race with this bike, it going to be mostly used for fast touring as meant by the constructors,
but I like the big skinny wheel stile, do you think slow speed handling will be really affected? Top speed only slightly improved? Any tips?

Also, which is the best spokes lacing pattern? cross 3 or cross 4? I’ve heard both were used at the factory, right? I guess cross 4 might be stronger even if using longer spokes.

Thanks!
Eddie

Hi All,
i saw this thread coming up again, and given i started i tought i could report on my progress,
here a few pictures of my wheels coming togheter.

I had the rims specially made here in Italy by a rim factory. Not by "Borrani" (i am not even sure if they still prduce in italy or not), but another one.

They do not normally produce them but thye had the right valanced alloy bar to made them to my specs. I wanted 21 in front and 20 at the rear but not in the standard WM1 and WM2 but had them made WM2 in fron and WM3 at the rear so the wheels are:

- Safety bedded alloy racing type rims a la "Borrani Record"

- 21 WM2 in front on a 250mm Fontana 4 leading shoes brake hub

- 20 WM 3 for the rear with regular Vincent brakes on a 10 holes hub

- 3,5 mm regular spokes (no sainless steel), front and rear

Rims widht is, as said, a bit larger than original, but hopefully a bit more tyre surface will allow for for better braking (given also i am using a bigger brake!), hopefully without affecting too much handling.

I have bought an Avon Speed Master for the front an Avon SM for the rear.. a bit squared but the only tyre available in 20...
I have spoken with an Avon engineer and he explained me that the ribbed speed master is actually desinged for a WM2 widht rim (but ok on a WM1 and to WM3), and the SM for a WM3 rim (but Ok from WM2 to WM4).

The wheel bulider told me that he laced them "in seconda" in front and "in terza" at the back, i guess this should mean "cross four at the rear" and "cross three" at the front. He said he couldnt aceive better given the angle of the large fontana brake.

 

[Spqreddie]

 

[Spqreddie]

Dear All,

This week end I have mounted the tyres on the wheels, and an issue I haven’t considered has come out!

With the 21in 3.00 Avon Speedmaster in front, and the 20in 3.50 Avon Safety Mileage Original at the rear (the only currently available tyre in 20in), the rear Wheel is taller than the front one due to the overall larger diameter of the tyre despite being one size smaller (20 VS 21)…..!

I will share pictures soon, but for the Avon website which I am looking at now this is what they state for the two tyres diameters:

· Avon Speedmaster MKII 21in 3.00 overall diameter: 691mm

· Avon Safety Mileage Original 20 inches overall diameter: 698 mm

On paper by reading the technical specifications, the difference seems only 7mm, but ‘live’ seems much more. I will post actual dimension and pictures as soon as I can.

Would this affect the handling?

I have seen Gunga Din pictures with both set ups (larger and smaller front tyre), may be at the time as well due to tyres availability?

In these two pictures, by roughly ‘measuring ‘ the tyre by counting the ‘pixels ‘ of the pictures with Paint, the wheels seems bigger at the rear in the B/W outside factory photo.


Thanks!

Eddie

 

[davidd]

Edmondo,

I don't think you will notice anything. The performance of wheel size and tires is very subjective. Many of the combinations mentioned that are said to be quick and precise seemed slow and ponderous to me. All to say that there are many combinations that have been tried and not many that have proved troublesome. You should select the one you think you will like.

I don't see that you will encounter a major problem having the front smaller. It happens on many combinations.

David

 

[Spqreddie]

Thank you David for your reassurance,
I will still try to report the actual sizes for general knowledge of the group and hopefully report soon on the handling!! when the bike will be completed....

 

[Spqreddie]

Edmondo,

I don't think you will notice anything. The performance of wheel size and tires is very subjective. Many of the combinations mentioned that are said to be quick and precise seemed slow and ponderous to me. All to say that there are many combinations that have been tried and not many that have proved troublesome. You should select the one you think you will like.

I don't see that you will encounter a major problem having the front smaller. It happens on many combinations.

David

I was thinking indeed, that this might happen as well with other wheel size/combinations.
For instance it might happen with the 19 3.50 rear and front 20 3.00? or in general with one size difference in rims or even with same size rims when the rear tyre is larger? (ie 3,50 vs 3,00)?
Thanks!

 

[A_HRD]

I'm definitely with David on this one. In any case, in my experience, the rear tyre will wear-down remarkably quickly and will soon become the same dia or smaller than the front tyre! . I'm planning the same rim selection on one of my projects and have no qualms about it whatsoever.

Peter B