Just returned from a four-day trip to the TX hill country around Fredericksburg, which worked out well. It seems that with as many miles and years I've ridden, I still pick up new problems and questions, and this trip was no exception. This time I ran into questions about belt tension and tire-pressure gauges.

First problem: Belt tension

The night before departing I checked my belt tension, which seemed a bit loose for my tastes, about 9/16" deflection using the HD gauge. I had checked it about a month earlier after changing the rear tire, setting to 7/16", but I don't recall if the bike was warm or cold at the time. For that check before the trip the garage was cool, so I tightened it up to about 7/16", and the next day about 100 miles down the road reached down to do a feel test, which revealed a very tight belt with little deflection. This worried me for the whole trip and after returning did the following checks. Keep in mind that although I have an SG, I have 12½" shocks, so the spec on tension should fall somewhere between and SG and an EG with 13" shocks:

HD spec (2007):
FLHX/FLHRS: 1/4 - 5/16"
Other FLH: 3/8 - 7/16"

Arrival (hot): 3/16"
After 3 hrs.: 5/16"
Next AM: 3/8"

The next day I adjusted and checked as follows:

Adj. cold to 9/16"
Outside (85°) after wash, no run: 3/8" (tightened 3/16" with no running but in warmer ambient conditions!)
After 15-mile ride: 5/16"
Next morning, cold: 9/16"

The service manual gives no conditions in the spec except that checks should be made with no rider and "no luggage." I assume "no luggage" means nothing in the saddlebags, but I checked with bags offand no tour pak attached. It also says the bike can be either on the kickstand or on a jack, and all my checks were made on the kickstand. A Google search reveals a few tutorials that say to check when the bike is at ambient temperature, but as many others don't specify. The manual says nothing about temperature, checking with bike cold or hot.

My point here is that when you check it makes a big difference. If you set an SG at 1/4" when cold, that belt is going to be tight as a banjo string after a hot ride. I think where I have it now is an acceptable tension, where it moves to 5/16" when warm (80° ambient). But what will happen this summer when temps climb to 95°? I'll be watching it, and may adjust it even looser at that time. Maybe none of this matters and the belt, sprockets, bearings, etc. can handle a wide range of tensions. I do worry most about the IDS bearing, which is under more strain with a tight belt.

Next problem: Tire-pressure gauges

On the trip, one guy thought his front tire (21" on a WG) looked low, so we checked it with my HD pencil gauge, showing 27 lbs. Another guy pulled his gauge out and it showed 31 lbs. Two more gauges showed 29 and 27 lbs. This is a 4-lb. variance between four gauges, only two agreeing, which is unacceptable. How do we know which is right?! How can they be checked against a calibrated gauge? I visited a Wal-Mart in Fredericksburg, TX and they had five different gauges available--pencil, dial, and digital--none of which showing an accuracy specification! So how do we know?

 

I'll be interested in hearing the responses about belt tension - I have noticed the same things you described.

As to the tire pressure gauges, the pencil type that rely on friction to register psi are notoriously inaccurate and quite variable from gauge to gauge. I went with a battery powered digital gauge (available from just about any auto parts store) and I now claim that it is 100% totally accurate and if anybody else's gauge measures something different, they must be wrong!

 

I haveprofessional dial gauges (About $40 each). I don'tbang them around andstore themthemin a box in my closet (along with other calibrated/delicate tools).I use them when I'm at home,so far the readingshave always beenalways identical.
Ikeep a cheap gauge ineach vehicle and I check them against the professional gauges every time I check tire pressure.
When I have a gauge that reads more than 3-4 PSI off, I replace it.
From my experience the dial type and digital gauges seem to be more accurate than the pencil type (especially the cheap ones).

Also it is best to use a gauge where the correct pressure is mid-scale. Don't use a 100 PSI Max gauge to check for 15 PSI or a
40 PSI Max gauge to check for 38 PSI.

 

Seems fair enough! The thing with pressure gauges is to use the same one and regard it as a comparison aid, rather than an absolute guide. For example when the weather is cold the pressures will go down, and the gauge will tell you they need, say, two pounds to put them back up to 'spec'. When the tyres are hot, after a long run, the pressures may be higher than when 'cold'.

A pencil gauge is reliable enough for most users, certainly me! I don't trust filling station air lines and use my pencil gauge to check afterwards.

My Buell not only has no means of adjusting belt tension, it actually has a roller to introduce tension. I suggest belt tension will change with local temperature, and especially when the bike is hot after a long run.

Like tyre pressures, check belt tension when the bike is 'cold' before a run. If it is different when the bike or weather gets hot, but was right when cold, leave well alone! Too much information is not always a good thing.

 

I agree,sometimes too much info is a bad thing.I never worried about my oil temp.untill I put a oil temp.gague in my dash.

 

I'll either buy a pro gauge or borrow one to compare my pencil gauges with. Both my pencil gauges show the same PSI.

As for belt tension, perhaps I'm making too much out of it, as I suggested in the first post. If temperature was a big deal HD would surely specify it in the manual. That said, I'm erring on the loose side by adjusting out of spec (loose) when cold, letting it stretch to the specified tension when hot. I feel better about it being a bit loose than tight.

 

My head hurts after reading this.......were ya able to enjoy ANY of the ride?????[]

 

Not to tight not to loose feel it with your finger to check it and ride it for 75,000



Ride on !!!

 

How often does the Service Manual or the Owner's Manual specify to check belt tension. I never checked the belt tension on my FLHS, and it still runs great (although I did replace the belt after 12 years because we were taking a long road trip). If these bikes need daily monitoring of belt tension, I'll sell my UC and buy an LT or Goldwing.

 

Can't help you with the belt tension issues. On the tire pressure gauges, you might want to give these a read:

www.mcnews.com/mcn/technical/tiregauges1.pdf
www.mcnews.com/mcn/technical/tiregauges2.pdf
www.mcnews.com/mcn/technical/tiregauges3.pdf

I don't know why they split them up in individual files but I think it's a fairly comprehensive comparison.

Good luck & Ride Safe,
Steve R.