Dahon Espresso Crank Guard/shield/protector?

[Julian Cox]

Hello people

Just registered as we have 2 Dahon Espresso folding bikes we've been using for a year now but one has a slight problem and a missing part.

Ok the problem on one is when pedalling under power there's a very slight clunk on each revolution. I recall this kind of clunk on bikes when I was a kid, I recall it was something to do with a cotter pin, there doesn't seem to be a visible type pin on the Dahon's crank, anyone know how I get rid of this wee clunk.

Other slight problem is the what I think is a guard for the main crank that fits under the pedal hub, this was loose and on inspection one of the Allen head bolts were missing, so I removed the unit as I couldn't find any similar bolt to replace it in standard metric thread. Does anyone know the thread used to fit these guards.

I have found the Dahon parts supplier from this site, but they don't seem to list this guard, or I just can't find it.

 

[mrandmrspoves]

Hello people

Just registered as we have 2 Dahon Espresso folding bikes iv'e been using for a year now but one has a slight problem and a missing part.

Ok the problem on one is when pedalling under power there's a very slight clunk on each revolution. I recall this kind of clunk on bikes when I was a kid, I recall it was something to do with a cotter pin, there doesn't seem to be a visible type pin on the Dahon's crank, anyone know how I get rid of this wee clunk.

Other slight problem is the what I think is a guard for the main crank that fits under the pedal hub, this was loose and on inspection one of the Allen head bolts were missing, so I removed the unit as I couldn't find any similar bolt to replace it in standard metric thread. Does anyone know the thread used to fit these guards.

I have found the Dahon parts supplier from this site, but they don't seem to list this guard, or I just can't find it.

Problem 1: Hard to guess exact cause so try the following...hold both pedals and try rocking them side to side. If there is lateral play check to see if the crank spindle is moving - if it is moving, bottom bracket needs attention. Next check the chain by spinning pedals backwards - look for stiff links as they pass over the gear sprocket on the rear wheel. While doing this also check that the padals are revolving freely and neither spindle is bent.
Problem 2: no idea about thread sizes but almost everything is metric nowadays....a photo may help and soon enough a Dahon expert will appear and correct my assumption about metric threading....

 

[Julian Cox]

Problem 1: Hard to guess exact cause so try the following...hold both pedals and try rocking them side to side. If there is lateral play check to see if the crank spindle is moving - if it is moving, bottom bracket needs attention. Next check the chain by spinning pedals backwards - look for stiff links as they pass over the gear sprocket on the rear wheel. While doing this also check that the padals are revolving freely and neither spindle is bent.
Problem 2: no idea about thread sizes but almost everything is metric nowadays....a photo may help and soon enough a Dahon expert will appear and correct my assumption about metric threading....

Hi there, thanks for that I'll do as you suggest.

 

[RecordAceFromNew]

The easiest and most effective way to check the bottom bracket is to slip the chain off the chainset (letting it rest on the frame's bottom bracket shell) and then spin the crank arm (not the pedal) while applying some pressure. Any play or roughness will become apparent (without being masked by the rattly chain). If not that check pedals by similarly spinning the pedals on stationary crank arm.

If I have a chance I can look up the stand/protector bolt size for you later today.

ps Both bolts under the bb and the chainstay are M5

 

[Julian Cox]

The easiest and most effective way to check the bottom bracket is to slip the chain off the chainset (letting it rest on the frame's bottom bracket shell) and then spin the crank arm (not the pedal) while applying some pressure. Any play or roughness will become apparent (without being masked by the rattly chain). If not that check pedals by similarly spinning the pedals on stationary crank arm.

If I have a chance I can look up the stand/protector bolt size for you later today.

ps Both bolts under the bb and the chainstay are M5

That's great thanks again I'll do as suggested.

 

[Julian Cox]

Great news, the clunk is gone. There was some play in the crank area when flexing the pedals side to side. I couldn't remove the crank arm even though releasing the Allen bolts was easy. I noted the large threaded ring on the crank hub was loose and the inner threaded section was to. I managed to tighten using a largish nail punch, a bit crude but did the job without doing any damage, the outer ring had segments and was easy to tighten and lock tight with a large screwdriver head and tap tight with small mallett.

By the way,where can I get the proper tools for doing this, are they Dahon specific? and any particular name for them?

I also checked the other Dahon Espresso and that ring was also loose, but not quite as much so wasn't clunking but would have done soon, so that one is tightened also.

I'll check out the M5 thread when I get hold of a bolt with M5 thread.

Thanks again, mrandmrspoves and RecordAceFromNew

 

[RecordAceFromNew]

By the way,where can I get the proper tools for doing this, are they Dahon specific? and any particular name for them?

If your bb is like this then this is an excellent guide for what to do to adjust it. Your existing tools are fine.

However if you are to replace it I would not recommend replacing like for like, but to get a UN5x for 68mm shell of the same spindle length - they are maintenance free and superior in quality to the original bb. The guide for chainset removal including tool requirement is here.

 

[Julian Cox]

If your bb is like this then this is an excellent guide for what to do to adjust it. Your existing tools are fine.

However if you are to replace it I would not recommend replacing like for like, but to get a UN5x for 68mm shell of the same spindle length - they are maintenance free and superior in quality to the original bb. The guide for chainset removal including tool requirement is here.

That's some great info cheers, the part you've shown is the same. I've road tested since tightening and it's fine. I'll certainly take your advice should a replacement ever be needed though.

One more question, anyone know the spoke key size needed for the Espresso, one wheel has a slight wobble, I remember straightening wheels as a kid so confident I can do it. Would one of these suffice http://www.ebay.co.uk/itm/Silver-6-...sure_Cycling_BikeLocks_SR&hash=item338ca13df8

 

[RecordAceFromNew]

I remember straightening wheels as a kid so confident I can do it. Would one of these suffice http://www.ebay.co.uk/itm/Silver-6-...sure_Cycling_BikeLocks_SR&hash=item338ca13df8

It probably would but I would not recommend them. Try getting one that can grip the nipple snuggly on all 4 sides, such as this one.